Electrical drives and control

MSRSAS - Postgraduate Engineering and Management Programme - PEMP

Electrical drives and control

ASSIGNMENT

Module Code MMD511

Module Name Electrical drives and controls

Course M.Sc [Engg] in Machinery design

Department Mechanical & Manufacturing Engineering.

Name of the Student Prabhakar.P

Reg. No BAB0911001

Batch Full-Time 2011.

Module Leader Prof. Ramdas chandrashekar

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M.S.Ramaiah School of Advanced Studies

Postgraduate Engineering and Management Programmes(PEMP)

#470-P Peenya Industrial Area, 4th Phase, Peenya, Bengaluru-560 058

<Assignment Title>

ii

Declaration Sheet Student Name Prabhakar.P

Reg. No BAB0911001

Course M.Sc [Engg] in Machinery design Batch Full-Time 2011.

Batch FT11

Module Code MMD511

Module Title Electrical drives and controls

Module Date 11/06/2012 to 07/07/2012

Module Leader Prof. Ramdas Chandrashekar.

Extension requests:

Extensions can only be granted by the Head of the Department in consultation with the module leader.

Extensions granted by any other person will not be accepted and hence the assignment will incur a penalty.

Extensions MUST be requested by using the ‘Extension Request Form’, which is available with the ARO.

A copy of the extension approval must be attached to the assignment submitted.

Penalty for late submission

Unless you have submitted proof of mitigating circumstances or have been granted an extension, the

penalties for a late submission of an assignment shall be as follows:

• Up to one week late: Penalty of 5 marks

• One-Two weeks late: Penalty of 10 marks

• More than Two weeks late: Fail - 0% recorded (F)

All late assignments: must be submitted to Academic Records Office (ARO). It is your responsibility to

ensure that the receipt of a late assignment is recorded in the ARO. If an extension was agreed, the

authorization should be submitted to ARO during the submission of assignment.

To ensure assignment reports are written concisely, the length should be restricted to a limit

indicated in the assignment problem statement. Assignment reports greater than this length may

incur a penalty of one grade (5 marks). Each delegate is required to retain a copy of the

assignment report.

Declaration

The assignment submitted herewith is a result of my own investigations and that I have conformed to the

guidelines against plagiarism as laid out in the PEMP Student Handbook. All sections of the text and

results, which have been obtained from other sources, are fully referenced. I understand that cheating and

plagiarism constitute a breach of University regulations and will be dealt with accordingly.

Signature of the student Date

Submission date stamp

(by ARO)

Signature of the Module Leader and date Signature of Head of the Department and date



iii

Abstract

____________________________________________________________________________

In Part-A the debate is on the variable frequency drive and flux vector drive for

controlling AC motors is presented by understand the various aspects involved such as

considering accuracy, complexity, response, manufacturability, reliability and cost etc. With proper

justification and case study the debate is supported.

In Part-B assignment is based on the video provided by the module leader, were by

understanding the cup filling automation processes video and the assignment is presented in which

various electrical elements – motors, drives, PLC’s, mechanisms are implemented with proper

justification. This part has four sub parts were first the sequence involved in cup filling processes is

explained and by selecting the various elements of the automation machine the possible

mathematical equations are derived. The various motors and used in the machine is compared in

next part and suggestion for improvement in velocity and torque is explained. In the final part the

five requirements of the control system is identified and system description diagram and control

block diagrams are generated.

The Part-C is based on the understanding of the Part- B for the same cup filling automation

processes the is extended in this part were this part has four sub parts in the first sub part the flow

chart is shown with logic after identifying the five control task in the machine. In the next sub part a

PLC ladder diagram is generated with proper assumption and is explained. And in the next sub part

various modes of controlling the motors used in the automation processes is presented in the last

sub part the servo valve and the servo motor is compared and their area of applications were

presented.

<Assignment Title>

iv

Contents

____________________________________________________________________________

Contents

Declaration Sheet ......................................................................................................................... ii

Abstract ....................................................................................................................................... iii

Contents ........................................................................................................................................iv

List of Tables ................................................................................................................................vi

List of Figures ............................................................................................................................ vii

List of Symbols ............................................................................................................................ix

Nomenclature ............................................................................................................................ x

1.0 Introduction: ........................................................................................................................ 1

1.1 Stance taken for the debate: ................................................................................................. 1

1.2 Variable frequency drive: .................................................................................................... 1

1.3 Flux vector control drives: .................................................................................................. 1

1.4Comparison of flux vector with VFD drives: ....................................................................... 2

1.4.1 Advantages of flex vector over VFD: .............................................................................. 2

1.4.2 Vibration and noise comparison: ...................................................................................... 2

1.4.3 Efficiency comparison: ..................................................................................................... 3

1.4.4 Efficiency at the full power/torque: .................................................................................. 3

1.5 Case study: .......................................................................................................................... 3

1.5.1 Results after installing flux vector: .................................................................................. 4

1.6 Conclusion: .......................................................................................................................... 4

2.0 Introduction: ........................................................................................................................ 5

2.1 Analyzing the requirement of cup filling automation: ........................................................ 5

2.2 The fundamental mathematical equations for the system: .................................................. 6

2.2.1 Mathematical equation for the conveyor for transferring cups: ....................................... 6

2.2.2 Mathematical equation for the gear box connected to AC motor: ................................... 9

2.2.3 Mathematical equation for the thermal heaters for sealing of cups: .............................. 11



v

2.3 Comparison of various motors drives used in automation processes: ............................... 12

2.3.1 Velocity profile improvement suggestions: ................................................................... 14

2.4 The various control system used in cup filling automation: ............................................. 16

2.4.1Stepper motor control system: ......................................................................................... 16

2.4.2 Encoder control system: ................................................................................................. 17

2.4.3 Pneumatic solenoid valves control system: .................................................................... 17

2.4.4 Variable frequency drive control system: ...................................................................... 18

2.4.5 Sensor control system: .................................................................................................... 19

2.4 (B) System description diagram: ....................................................................................... 19

3.1 Introduction: ...................................................................................................................... 21

3.2 PLC ladder logic for cup filling automation: .................................................................... 23

3.2.1The assumptions made for cup filling automation: ......................................................... 24

3.2.2 Explanation of PLC circuit: ............................................................................................ 25

3.3 Control of motors in the artifact: ....................................................................................... 29

3.3.1 The control system used for stepper motor is: ............................................................... 29

3.3.2Justification for using encoder with stepper motor: ........................................................ 30

3.3.3 The control system used for AC motor is: ..................................................................... 31

3.3.4 Justification for using VFD with AC motor: .................................................................. 32

3.4 Servo valve operated control and servo motor operated control: ...................................... 33

3.4.1 Servo valves: .................................................................................................................. 33

3.4.2 Servo motor: ................................................................................................................... 36

4.0 Learning outcome: ............................................................................................................. 38

References ............................................................................................................................... 39



vi

List of Tables

____________________________________________________________________________

Table No. Title of the table Pg.No.

Table 1. 1 Showing cost & energy savings ...................................................................................4

Table 2. 1 Various motors used in automation processes ...........................................................12



vii

List of Figures

____________________________________________________________________________

Figure No. Title of the figure Pg.No

Fig 1. 1 Graph showing comparison of VFD and Flux drives ..................................................... 3

Fig 1. 2 Flux drives installed on motor ......................................................................................... 4

Fig 2. 1Production processes flow chart ....................................................................................... 5

Fig 2. 2 Conveyor ......................................................................................................................... 7

Fig 2. 3 Angular displacement ...................................................................................................... 8

Fig 2. 4 Gear box connected to motor .......................................................................................... 9

Fig 2. 5 Electric band heaters ..................................................................................................... 11

Fig 2. 6 Unipolor drive ............................................................................................................... 13

Fig 2. 7 VFD drive ...................................................................................................................... 13

Fig 2. 8 Velocity profile ............................................................................................................. 14

Fig 2. 9 Velocity profile of the Stepper motor ........................................................................... 15

Fig 2. 10 modified velocity profile by RMS .............................................................................. 15

Fig 2. 11Suggested modified velocity profile of the Stepper motor .......................................... 16

Fig 2. 12 Stepper motor block diagram ...................................................................................... 16

Fig 2. 13 Encoder block diagram ............................................................................................... 17

Fig 2. 14 Pneumatic cylinder control block diagram ................................................................. 18

Fig 2. 15 VFD block diagram ..................................................................................................... 18

Fig 2. 16 Sensor block diagram .................................................................................................. 19

Fig 2. 17 System description block diagram .............................................................................. 20

Fig 3. 1 PLC ladder diagram ...................................................................................................... 23

Fig 3. 2 Assumed grouped operation in processes ..................................................................... 24

Fig 3. 3 Block-1 in PLC Ladder Circuit ..................................................................................... 25

Fig 3. 4 Block- in PLC Ladder Circuit ....................................................................................... 26

Fig 3. 5 Block-3 in PLC Ladder Circuit .................................................................................... 27




Fig 3. 9 Encoder ......................................................................................................................... 30



viii

Fig 3. 10 Cup unloading conveyor ............................................................................................. 31

Fig 3. 11 Block diagram of VFD ................................................................................................ 31

Fig 3. 12 VFD with AC motor .................................................................................................... 32

Fig 3. 13 Torque Vs Speed curve ............................................................................................... 33

Fig 3. 14 Servo valve .................................................................................................................. 34

Fig 3. 15 Cut section of servo valve ........................................................................................... 35

Fig 3. 16 Servo valve block diagram .......................................................................................... 35

Fig 3. 17 Servo motor ................................................................................................................. 36

Fig 3. 18 Pulse input to servo motor ........................................................................................... 37

Fig 3. 19 Block diagram of servo motor ..................................................................................... 37



ix

List of Symbols ____________________________________________________________________________

Symbol Description Units

ω Angular acceleration m/s2

g Acceleration due to gravity - 9.81 m/s2

a

ө

Angular velocity

Angle

m/s

deg

F Force N

ɽ Torque N-m

MFL Moment at the Load N-m

MFC

K

m

d

l

f

�

Moment at the cylinder

Bulk modulus

Mass

Diameter

Length

Frequency

Frictional co efficient

N-m

N/m2

kg

m

m

Hz



x

Nomenclature

Acronyms

AC Alternative current.

DC Direct current.

VFD Variable frequency drive.

PID Proportional integral derivative.

PLC Programmable logic control.

PMC Programmable motion control.

PWM Pulse width modulation.

CSI Current source inverter.

VSI Voltage source inverter.


1

PART-A

CHAPTER 1

1.0 Introduction:

An AC electric motor is electromechanical device which is widely used in various

applications to convert electrical energy into mechanical energy. At the initial stages the motors are

designed to run at fixed speed and later on the drives are developed to run the motor by frequency

of power grid. The drives are used to control the motors during the operation like VFD and flux

vector drives etc, in order to effective use of the motor. As the VFD is the earlier invention which is

widely used as a drive for AC motor and in this debate it should be analysed that the recent

invention of flux vector drive can completely rule out the earlier VFD.

1.1 Stance taken for the debate:

In this debate the stance taken is the “The variable frequency drive can be completely

phased out of usage in AC motor control applications with the advent of flux Vector control

drives.” As the flux vector drives has the more advantage than the variable frequency drive it can

rule out VFD which is been explained below.

1.2 Variable frequency drive:

The primary functions of a variable frequency drive are to convert electrical power to the

usable form for controlling speed, torque and direction of rotation of AC motor. All variable

frequency drives control the speed of an AC induction motor by varying the motor supplied voltage

and frequency of power. There are three major designs are available in VFD based on the function

which are pulse width modulation (PWM), current source inverter (CSI), and voltage source

inverter (VSI). The comparison and the working principle of the various designs are:

1.3 Flux vector control drives:

An alternating current flux vector drive is a device that is used to control the motor. The AC flux

vector drives differ from other drive types by the control of motor speed, as well as the motor

torque or rotational force. The working of the flex vector is as the electrical current enters the AC

motor it magnetizes the motor components and generates the drive speed. When the motor begins to

rotate, a closed loop system notifies the flux vector drive microprocessor of the motor position and

speed through electronic components. The constant communication between the AC motor and the

drive microprocessor makes to control the speed and torque of the drive. Flux vector drives have

the same power section as all PWM drives, but use a sophisticated closed loop control from the



2

motor to the drive microprocessor. The motor rotor position and speed is monitored through the

resolver or digital encoder to determine and control the motor actual speed, torque, and power.

1.4Comparison of flux vector with VFD drives:

Variable Frequency drives adjust the output speed of a motor by varying the frequency of and the

voltage supplied to the motor. This method of speed control has a number of drawbacks it wastes

energy by creating harmonics it must be shielded for harmonic interference it requires costly

installation procedures it doesn’t work well in harsh or humid environments and it is inherently an

unreliable system due to its complex nature. The flux Drive is a simple mechanical device that

saves energy is easy to install and is very reliable.

1.4.1 Advantages of flex vector over VFD: The Variable Frequency Drives are also the energy saving devices but their installation and

operation is not always practical or cost effective. This is due to the inherent problems in their

reliability, complex electronic components, and a need for extensive infrastructure and highly

trained personnel to program and service these devices. The other major problem with the VFD

technology is the electronic harmonics generated by the drive which requires an additional

equipment to be installed and maintained. The simple and reliable Flux Drive has wide applications

providing the energy savings of speed control without the problems often associated with VFD. In

these installations, system complexity is reduced and vibration is eliminated and harmonic

distortion problems are also eliminated. In addition the Flux Drive technology makes adjustable

speed control available to markets previously resistant to using VFD.

The other advantages of Flux Drives over VFD are:

• Flux vector drives can be used to any type of voltage motor without high cost as in VFD.

• In flux vector drives no special filters and reactors required as used in VFD

• In flux vector drive no inverters are required as used in VFD.

• Flux vector Operates with Zero harmonic interference and no power quality issues.

• In there is no motor noise is generated as created by harmonic power sources in VFD.

• The VFD drives required bypass starters which is not required in flux vector drive.

1.4.2 Vibration and noise comparison: The Flux Drive does not introduce Harmonics that are created by electronic VFD drives. As

a result of the harmonics, the VFD creates audible noise and vibration in the motor. The harmonics

are always present and as a result the motor powered by a VFD needs to be upgraded to Inverter

duty rated in order to run without failing. Even with this upgrade the noise and vibration remains



3

and can also cause stray shaft currents that will still destroy motor bearings. But these problems are

eliminated using the flux vector drive.

1.4.3 Efficiency comparison:

An example showing the Flux Drive performance to a throttling valve and a VFD is shown below

in the Fig 1.1. Note that both the Flux Drive and the VFD provide substantial energy savings over

the Throttling Valve line but operate with powers above the pure the Affinity curve. This is because

of practical conditions that take into account the complete pumping system including the

efficiencies of the Motor, Flux Drive or VFD Pump, and the pump system curves

Fig 1. 1 Graph showing comparison of VFD and Flux drives

1.4.4 Efficiency at the full power/torque: During full power/torque operation of the Flux Drive and Coupling are designed to operate

with only 1.5% slip (at 98.5% efficiency) and will produce no noticeable heat on the Induction

Rotor. This highly efficient power transfer is inverse to electronic VFD, where their losses and heat

generation are a maximum at full power operations. This condition requires the VFD to provide

maximum cooling at the highest power levels and results in substantial energy losses that are

documented to be between 5 – 7%. In many VFD installations, climate controlled rooms are also

required at a cost of additional space and power.

1.5 Case study: The case study is about Pierce and Kitsap County YMCA facilities in Washington State has

worked on the power savings and cost savings by implementing the vector control drives in their

processes and in their web blog the quotes are “Mel Korum Family YMCA Installs Flux Drive

Adjustable Speed Drives—Energy Savings Qualified for 70% Energy Grant from Puget Sound

Energy” The two motor pumps i) main spool pump of 15 hp runs at the 1750rpm and the other

pump ii) Spa-hydro pump which run at constant speed with corresponding flow rate of 520GPM

with the energy consumption of 10.2kw is used for their process. An analysis determined that the



4

flow rate could be reduced by 50% (260 GPM) for 23hrs a day and then increased to full speed for

the hour needed to complete the backwash cycle. The solution arrived was It was calculated that

energy savings could also be realized by reducing the pump speed and eliminating the use of the

throttle valve to reduce the flow by the affinity laws of centrifugal pump. To slow down the pumps

flux vector drive is installed for both the pumps. After installing the overall energy saving, vibration

and noise levels on the two motor and pump applications were notably reduced.

1.5.1 Results after installing flux vector: The Main spool pump rpm is reduced to 866rpm to obtain the same flow rate of 260Gpm

with the energy consumed dropping from approximately 10.2 kW to 2.2 kW for a savings of 8 kW.

This is a documented 78 percent energy reduction or a savings of $4,555 / year.

After installing flux drive in the spa-hydro pump the throttle valve was opened 100% and

the pump speed was reduced to 957 RPM for a flow rate of 160 GPM. Energy consumption went

from 5 kW to 2.2 kWh for a savings of 2.8 kWh.

Fig 1. 2 Flux drives installed on motor

Table 1. 1 Showing cost & energy savings

1.6 Conclusion: From the above case study it can be identified that the level of energy savings by installing

the flux vector drives the improvements and the advantages in the flux vector drives which will be

eliminating the VFD may not be immediately but in future.



5

PART-B

CHAPTER 2

________________________________________________________________________________

2.0 Introduction:

The Part-B assignment is based on the video provided by the module leader. The video is on

the automation of “Cup filling operation” were the various different operation is performed in the

various stages in sequence such as i) Cup loading ii) Cup rinsing iii) Cup filling iv) Al foil placing

and cup sealing and v) Unloading of filled and packed cups. In this automation processes various

mechanical and electrical drives and control systems are used with the available data in the video

and by making the suitable assumption for the unknown data the assignment is to be presented.

In general the production process flow is shown in Fig2.1 the cup filling automation processes

comes under the special purpose machine (SPM) in which the below shown considerations are to be

made.

Fig 2. 1Production processes flow chart

2.1 Analyzing the requirement of cup filling automation:

• The movement of cups from the one stage to the other stage is by the automation were the

chain and sprocket type conveyor driven by stepper motor is used on which a plate with

holes is fixed which holds the cup and carries the cup to various stages in the processes were



6

the cycle time for each stage is assumed as 3 second which means for every 3 second the

plate with the cup will be moved forward or indexed to one stage.

• In each stage 6 cups are loaded on the plate with holes fixed on the conveyor were the cups

are held by the collet and when a pneumatic cylinder extends a plate from the cylinder

extends from the cylinder expands the collet and the collet releases the cup into the holes

drilled in the plate.

• Then the cup rinsing takes place were the cups are exposed to the atmosphere were the cups

are allowed to pass through the chain conveyor by plates holding the cups for few stages

ideally so as the cups are rinsed or cleaned by air supplied on the cups the conveyor is

driven by the stepper motor.

• After rinsing the cup filling takes place at a time 6 cups loaded in a row is filled and using

the capacitance sensor the level of filling is signaled, were the cycle time for the filling

operation is assumed as 3 second.

• After filling Aluminum foil is picked and placed by pneumatic cylinder on all 6 cups.

• These foils are sealed to the cups by the heaters were a pneumatic cylinder is used to bring

the heater in contact with the cups while extending and when the cylinder retracts the cups

in the next row gets indexed and will be ready for sealing and the processes continues.

• In the next stage by using the pneumatic cylinders the cups are lifted by the grip arm of the

cylinder when the cylinder extends and by the other horizontal cylinder the cups are placed

on the unloading conveyor.

• The unloading conveyor unloads the filled cup continuously so that the new cups can be

loaded on the unloading conveyor which is driven by AC induction motor with VFD.

These are the various requirements and the steps involved in the automation of the cup filling

processes.

2.2 The fundamental mathematical equations for the system:

The mathematical equations are the fundamental working principles of the different

operations is derived into the mathematical form to obtain the data such as inertia, momentum,

acceleration and torque etc by using these data as the guide line the various components of the

assembly can be selected such as motor sizing etc.

2.2.1 Mathematical equation for the conveyor for transferring cups:

The conveyor is the system which is used in cup filling automation to carry the cups to the

various stages by indexing the cups to stage by stage to complete the processes in this operation the



7

chain and sprocket mechanism driven by the stepper motor is used and the cycle time for the each

indexed cycle is assumed as 3 second the mathematical derivation for the conveyor is shown in the

Fig 2.2 below.

Fig 2. 2 Conveyor

Were,

JM = stepper motor used to drive the conveyor.

Ffr = Co-efficient of friction.

Fp = Push or pull force.

Fg = force due to gravity.

Jp = Mass moment of inertia of pulley 1, 2 & 3.

The circumference of the pulley (CP):

The circumference of the pulley is the pulley length around the pulley which can be calculated by:

C�:� = πxD�:�m

Similarly:

C�: = πxD�: m

C�:� = πxD�:� m

Were,

Dp = Pitch diameter of pulley 1, 2 & 3.

Angular displacement (ӨM) of the motor shaft can be defined as a point or line has been rotated in

a specified sense about its axis. S shown in the Fig 2.3 below the point “ti” is the initial position

when the shaft is rotated at the velocity “ω” the angular displacement “tf” can be expressed as

Ө = ti + ∆t were ∆t is the distance traveled.



8

Fig 2. 3 Angular displacement

For the conveyor motor the angular displacement can be expressed as

ө =��

��:�

Were,

XL = distance travelled by the load.

CP = Circumference of the motor.

Angular velocity of the motor (ωM)

The rate of change of angular displacement of the conveyor pulley is called angular velocity of

motor as the motor is keyed to the same shaft of the pulley which can be expressed as linear

velocity of load to circumference of pulley.

ω =��

��:�

Were, VL = Linear velocity of the load.

Angular acceleration of the motor (aM)

The rate of change of angular velocity of the motor shaft is called angular acceleration of the motor

which in the conveyor can be expressed as angular velocity of motor to the time taken.

aM =

��

�

Were, t = time

Moment of inertia of the load (JL):

The moment of inertia is related to the rotation of the motor shaft it is the measure of the motor

resistance to any change in its state of rotation.

JL = (WL +WB) /g x (DP /2)2

Were, WL = weight of the load.

WB = width of the conveyor belt.

DP = Pitch diameter of pulley.

Therefore the total moment of inertia is



9

JTotal=JM +JP1 + JP2(DP1 /DP2)2+JP3(DP1 /DP3)

2 + JL /e

To find the motor power to drive the conveyor:

The power (P) is

P = T X ωM

Were,

T = torque of the motor

ωM = angular velocity of the motor

In case of mathematical equation of the conveyor:

Total torque = torque in acceleration + torque in running

Torque due to Acceleration

Ta = JTotal X aM

Constant Torque during running

TC = ��

� X

��

Therefore power (P) for the conveyor is:

P = (Ta + Tc) X ��

��:�

2.2.2 Mathematical equation for the gear box connected to AC motor:

The gear box is connected to the AC motor which is connected to the cup unloading

conveyor the gear box is placed between the conveyor and the AC motor in order to reduce the

speed and increase the torque as the high torque is required to move the conveyor assembly.

Fig 2. 4 Gear box connected to motor

In the gear box the velocity ratio can be found by

N�

N=D

D�=T�

T



10

N� = InputRPMtogearbox.

N = OutputRPMfromgearbox.

D� = PCDofdrivinggear.

D = PCDofdrivengear.

T� = Numberofteethindrivinggear.

T = Numberofteethindrivengear.

In this case the velocity ratio (Nr) for the cup unloading gear box can be expressed as

N� =Inputspeed

Outputspeed

Angular displacement of the motor (ӨM) input to the gear box:

ӨM = Nr X ӨL

Were, Nr = velocity ratio of gear box

and ӨL = Distance travelled by the output shaft of the gear box.

The Angular velocity of the motor (ωM) can be expressed as:

ωM = Nr X ωL

Were, ωL = angular velocity of output shaft from the motor.

The total moment of inertia of the assembly can be calculated by adding the moment of

inertia of motor + moment of inertia of the gearbox + moment of inertia of the load which can be

expressed as:

J:;�<== JM + Jr + >�

�

Were, JM = Moment of inertia of motor.

Jr = Moment of inertia of the gearbox.

JL = Moment of inertia of the load.

e = efficiency of the mechanism.



11

2.2.3 Mathematical equation for the thermal heaters for sealing of cups:

Fig 2. 5 Electric band heaters

In the cup filling automation processes after filling of cups the aluminum foil is placed on

the cups and sealing operation is carried out by the thermal heaters. To derive the mathematical

equation for this operation considering a thermal heater with the temperature “T” kept in contact

with the cups which has to be sealed which has the temperature “TL” and if the thermal resistance to

heat flow from heater to the cups is “R” then

Therefore net rate of heat flow (q) is:

q = T − TA

R

The thermal capacitance “C” of the cups to be sealed can be expressed as:

q1 – q2 = CB:�

B�

As there are net flow of heat from the heater to the cups q1= q and q2 = 0 and therefore

q = CdTA

dt

Substituting “q” in net rate of heat flow (q) equation:

CdTA

dt=T − TA

R

Rearranging the equation:

RCdTA

dt+TA = T

This equation a first order differential equation describes how temperature gradually raises in the

cups from the heater with the temperature “T”.



12

2.3 Comparison of various motors drives used in automation processes:

In the automation processes two different types of motors are identified i) A stepper motor

is used to operate the conveyor which carries the cups to various station in the cup filling

automation processes. ii) Induction AC motor is used to operate the cup unloading conveyor which

unloads the finished cups at the end of the processes.

Motors used in automation Processes

Criteria Stepper motor Induction AC motor

Positioning Step-accurate positioning without

external linear encoder (open loop)

No control of position by the

motor

Speed The speed is proportional to the

input frequency

Multiple pole motors are

available for multiple speeds. It

has two sets of windings one at

low speed and one for high speed

Holding position

The high stiffness enables the rotor

to remain in its holding position

without requiring a brake.

Low stiff cannot be held in a

position requires a break

Torque High torque even at lower speeds

It has no or little starting torque

an external device is used for

initial start of the motor

Acceleration Excellent acceleration Moderate acceleration compared

to stepper motor

Drives LR drive, unipolar drive and

chopper drive VFD and Flux vector drives

Table 2. 1 Various motors used in automation processes

Unipolar drive for stepper motor:

A unipolar drive is used in the automation processes for driving the stepper motor, the

stepper motor moves one step when the direction of current flow in the field coil changes, reversing

the magnetic field of the stator poles. In unipolar two Separate field Coils and are Charge over

Switch are used. The unipolar circuit needs only one changeover switch which requires a double

bifilar winding. This means that at a specific bulk factor the wire is thinner and the resistance is



13

much higher the drive circuit appears to be simpler when implemented with discrete devices.a

unipolar drive is shown in Fig 2.6.

Fig 2. 6 Unipolor drive

VFD drives for Induction AC motor:

The primary functions of a variable frequency AC drive are to convert electrical power to

the usable form for controlling speed, torque and direction of rotation of AC motor. The AC electric

motor used in a VFD system is usually a three-phase induction motor which has three main sub-

systems: AC motor, main drive controller assembly, and drive operator interface. Motors that are

designed for fixed-speed operation are often used such as in cup filling automation processes.

Elevated voltage stresses imposed on induction motors that are supplied by the VFD drive. The

VFD drives are shown in the Fig 2.7.

Fig 2. 7 VFD drive



14

2.3.1 Velocity profile improvement suggestions:

In the velocity verses time profile usually the motor takes trapezoidal moves were the

velocity ramps up linearly to a final velocity “V” over time “Ta” then the velocity ramps down

linearly from “V” to zero over time “Td” as shown in the Fig 2.8.

If the overall move time is “T” then the total distance travelled “D” by a motor in a cycle will be:

D = Da + Dv + Dd

Da = distance traveled during accelerating velocity.

Dv = distance traveled during constant velocity.

Dd = distance traveled during decelerating velocity.

Fig 2. 8 Velocity profile

As in the cup filling automation processes the cycle time is assumed to be 3 seconds as the

conveyor is indexed by every 3 seconds. As above the velocity profile has 3 components

accelerating velocity, constant velocity and decelerating velocity it is not possible for the stepper

motor to take the trapezoidal velocity profile as shown above in Fig2.9. Instead it will take the

velocity profile as shown below in Fig 2.10 for the maximum velocity Vmax, were there is no

constant velocity only the accelerating and the decelerating velocity will be available as the cycle

time is 3 second.



15

Fig 2. 9 Velocity profile of the Stepper motor

The improvement in the velocity profile can be done by finding the RMS (root mean square) which

is calculated instead of normal average of velocity profile as the motor losses are mostly

proportional to I2-R losses. The most important conclusion from this formula is the square root of

the cycle time. Instead of triangular the profile can be modified as the equaling profile for the

triangular profile which is trapezoidal profile which is just above the “average” line.

Fig 2. 10 modified velocity profile by RMS

The most disadvantage of the trapezoidal profile is it will be resulting in the “jerk” as the velocity

changer linearly in the during acceleration and the deceleration to avoid these jerk the trapezoidal

profile can be modified into S- curve moves as shown in the Fig 2.11.



16

Fig 2. 11Suggested modified velocity profile of the Stepper motor

2.4 The various control system used in cup filling automation:

The various control systems are used in the cup filling automation which are useful in

managing, commanding, directing or regulating the behavior of other devices in the cup filling

automation machine. The 5 different control systems used in the machine are:

i) Stepper motor drive – It is used to control the stepper motor.

ii) Encoder – To provide the positional feed back to the stepper motor.

iii) Solenoid controller – the solenoid control is used to the solenoid valves used for controlling the

motion of the pneumatic cylinders.

iv)Variable frequency drive

v) Sensor

2.4.1Stepper motor control system: A control system is required when a motor is used for an application that requires

continuous position or velocity as in the cup filling automation processes the chain and sprocket

conveyor has to be indexed and continually positioned at the various station of the operation. The

control system block diagram of stepper motor is shown in Fig 2.12.

Fig 2. 12 Stepper motor block diagram



17

In this the input command to the HMI is given through the HMI (Human/Machine

interface). From HMI the command goes to the controller, were the controller is the combination of

PLC, indexer and pulse generator which generates the signals as per the input command to the

driver and the driver drives the Stepper motor.

2.4.2 Encoder control system:

The encoder is the feedback device based on the feedback of the encoder the accurate

positioning of the motor is controlled. In this automation processes stepper motor is used were the

stepper motor is open loop system as there is no feedback is there in stepper motor. The encoder is

used to control the position of stepper motor.

Fig 2. 13 Encoder block diagram

The control block diagram of encoder shows from the user interface the input command goes to

PMC (Programmable motion controller) from there it goes to interface hardware then to motor

controller/ amplifier to motor based on the motor position the encoder gives the position feedback

to interface hardware which in turn generate pulse and send to motor controller and the motor

controller corrects the position of the motor.

2.4.3 Pneumatic solenoid valves control system:

Pneumatic cylinders are used for picking and placing of aluminum foils on the cups in the

automation process, to actuate these cylinders DCV (Direction control valves) are used which is

used to control the flow of the fluid to the cylinders. The valves are operated by means of electrical

signals to the solenoids, the control block diagram of solenoid is shown in Fig 2.14.



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Fig 2. 14 Pneumatic cylinder control block diagram

In the solenoid control system the input is transferred from user interface to gripper script unit and

goes to micro controller generate the electrical pulse and sends to the transistors from the transistors

the required voltage is sent to the solenoid valves the operates the cylinder (gripper arm) the

cylinder extends and when the operation is carried the cylinder gets contact with limit switches

sends signals to the microcontroller and from there to transistors and transistor operate the solenoid

and retract the cylinder.

2.4.4 Variable frequency drive control system:

Variable frequency drive control system is used to control the motion of the AC motor used

for controlling the motion of cups unloading conveyor. The control block diagram is as shown in

the Fig 2.15.

Fig 2. 15 VFD block diagram

The 3phase AC current is supplied to diode bridge rectifier were it is converted in to DC from there

goes to DC filter and the inverter converts back to AC current and based on the speed reference by

the user voltage and frequency control sends signal to the inverter and the inverter supplies AC

current to the motor.



19

2.4.5 Sensor control system:

The sensors are used for the feedback in order to ensure various operations are performed at

various stations in a sequence the control block diagram of sensors are shown in Fig 2.16.

Fig 2. 16 Sensor block diagram

The sensor senses the source and sends the analog signals to the comparator unit the comparator

unit does the logic and sends the binary data to microcontroller and the microcontroller signals the

motor driver and driver drives the motor.

2.4 (B) System description diagram:

In system description diagram the various processes of the whole system is shown in the Fig

2.17 were the various stations of the process such as cup transferring unit, cup filling unit,

aluminum foil placing unit, cup sealing unit and the cup unloading unit is shown. Were the various

electrical drives and the control units incorporated in the construction of the cup filling automation

machine is shown.



20

Fig 2. 17 System description block diagram



PART-C

CHAPTER 3

________________________________________________________________________________

3.1 Introduction: In the cup filling automation PLC has to perform the following tasks as shown in the flow

chart below in the Fig 3.1 were it has to control the automation by starting and stopping the

operation in a proper sequence and has to allow the timings for the completion of the operations and

has to take the logical decision which can also be called as artificial intelligence were the required

actions to be carried if there is error in the process.



Note: in this cup filling automation processes cup rinsing takes place were the cups are loaded in

the conveyor and filling doesn’t takes place immediately after cup loading but it is allowed to pass

through the air blower were the cups are cleaned and dried during which the cups are allowed to

travel ideally many stages then the cups are filled and the further processes are carried out.



23

3.2 PLC ladder logic for cup filling automation:

Fig 3. 1 PLC ladder diagram



24

3.2.1The assumptions made for cup filling automation:

• The cycle time taken for each operation is 3 seconds.

• The circuit is designed not for the first initial processes were the operation will be carried

out one after the other such as cup loading followed by cup filling followed by foil placing

etc, but the circuit is designed at the stage of full pledge process is started were the many of

the operations in the processes will be carried out at a time for example while cup loading

processes is carried in one station at the same time in other station cup sealing processes is

taking place for this stage of processes the PLC circuit is been designed.

Fig 3. 2 Assumed grouped operation in processes

• In the above shown figure the number indicated with 1 are grouped together and the number

indicated with 2 are grouped together which means at the same cycle time the grouped

operations are carried out at various stations simultaneously.

• The operations grouped at 1 are:

i) Cup loading

ii) Cup filling

iii) Placing of AL foil.

iv) Sealing

v) Lifting of cups

These operations are assumed to be carried out simultaneously but at different stages in the

cup filling automation machine.



25

• The operations grouped at 2 are:

i) Indexing

ii) Picking of top cover

iii) Placing of finished cups on unloading conveyor.

These operations are assumed to be carried out simultaneously but at different stages in the

cup filling automation machine.

• When the light “Y0” glows it is assumed that cup loading process is carried out.

• When the light “Y1” glows it is assumed that the nozzle opens and cup filling process is

carried out.

• When the light “Y2” glows it is assumed that indexing of cups by the conveyor is taking

place.

• When the light “Y3” glows it is assumed that the AL foil is picked by the pneumatic

cylinders.

• When the light “Y4” glows it is assumed that the AL foil is placed on the filled cups by

pneumatic cylinders.

• When the light “Y6” glows it is assumed that Al foils are sealed with the cups using thermal

heaters.

• When the light “Y7” glows it is assumed that sealed cups are lifted by the pneumatic

cylinders.

• When the light “Y8” glows it is assumed that the sealed cups are placed on the unloading

conveyor.

• The process is assumed to be continues cycle and to stop the machine a push button “X2” is

pressed.

3.2.2 Explanation of PLC circuit:

Fig 3. 3 Block-1 in PLC Ladder Circuit

The push button “X0” is pressed to start the internal relay “M0” as push button is used the

“M0” is latched as shown above in circuit. Were the logic for the block is shown below:



26

X0 M0

0 0

1 1

Were “0” indicates OFF and “1” indicates ON as “X0” is push button until the “X0” is pressed the

internal relay “M0” is on and when “X0” is released “M0” will be off, even after releasing of “X0”

to keep “M0” in on condition the “M0” is latched.

Fig 3. 4 Block- in PLC Ladder Circuit

When the internal relay “M0” is on and as well as the another internal relay “M1” is on the

assumed various grouped processes are performed at various station of the machine as the bulbs

“Y0,Y1,Y4,Y8&Y6” glows at this time for 3 seconds which indicates in the same 3 seconds of the

cycle time the various operations like Cup loading, Cup filling, Placing of AL foil, Sealing, &

Lifting of cups are carried out at the different stations of the machine the logic for the block shown

above is:

M0 M1 Y0 Y1 Y4 Y8 Y6

0 0 0 0 0 0 0

0 1 0 0 0 0 0

1 0 0 0 0 0 0

1 1 1 1 1 1 1



27

Were “0” indicates OFF and “1” indicates ON from the table it can be noticed that when both the

internal relay”M0 & M1” is ON the all the operations will be carried out and if any one of the

internal relay is in OFF condition all the operations will be stopped from this it can be noticed that

since all the bulbs are branched if operation takes place all 5 process will be carried out and if not

all 5 process will be stopped there is no possibilities of starting any 2 or 3 processes or stopping 2

or 3 process in this circuit.


When the internal relay “M0” is ON and the various grouped processes are performed at various

station of the machine as the bulbs “Y2, Y3 &Y7” glows at this time for 3 seconds which indicates

in the same 3 seconds of the cycle time the various operations like Indexing, Picking of top cover

and Placing of finished cups on unloading conveyor are carried out at the different stations of the

machine the logic for the block is shown above:

M0 Y0 Y1 Y4 Y8 Y6 Y2 Y3 Y7

0 0 0 0 0 0 0 0 0

1 0 0 0 0 0 1 1 1

1 1 1 1 1 1 0 0 0

In the table “0” indicates OFF and “1” indicates ON from the table it can be noticed that the internal

relay “M0” is OFF and also the grouped operations “Y0,Y1,Y4,Y8&Y6” is also OFF in this

condition all the grouped operations of “Y2, Y3 &Y7” will be also OFF and when the internal

relay “M0” is ON and the grouped operations “Y0,Y1,Y4,Y8&Y6” is OFF in this condition the

bulb “Y2, Y3 &Y7” will glow which indicates the various operations like Indexing, Picking of top

cover and Placing of finished cups on unloading conveyor are carried out at the different stations.



28

The other condition is the internal relay “M0” is ON and “Y0, Y1, Y4, Y8 &Y6” is also ON in this

condition “Y2, Y3 &Y7” bulbs will not glow which indicates these operations are not performed.


In the block the condition is the internal relay “M0” is used to trigger the timer “T1” in which the

timer is set to 3 seconds (0.01s X 300). In which after 3 seconds the other internal relay “M1” will

be “ON” this internal relay “M1” is used to control the other block shown below in the Fig() the

logic for this block is:

M0 M1

0 0

1

(3 seconds) 1

When the internal relay “M0” is OFF the internal relay “M1” is also OFF and when the internal

relay “M0” is ON for 3 second the internal relay “M1” will be ON.


In the next block the condition is the internal relay “M1” is used to trigger the timer “T2” in which

the timer is set to 3 seconds (0.01s X 300). In which after 3 seconds the other internal relay “M2”

will be “ON” this internal relay “M2” is used to control the other block shown in the Fig 3.4 the

logic for this block is:

M1 M2

0 0

1

(3 seconds) 1

When the internal relay “M1” is OFF the internal relay “M2” is also OFF and when the internal

relay “M1” is ON for 3 second the internal relay “M2” will be ON.



29


In the next block of the ladder diagram the condition is the internal relay “M2” is used to reset the

timer “T1” and also used to latch the circuit shown in the Fig 3.6 which in turn makes the process to

be carried out continuously. The logic for this block is shown below:

M2 T1

(Timer reset)

0 0

1 1

When the internal relay “M2” is OFF the timer “T1” will not reset and when the internal relay

“M2” is ON the timer “T1” will get reset.

3.3 Control of motors in the artifact:

The various motors identified in the automation processes of cup filling are:

i) Stepper motor with encoder – for controlling the motion of chain conveyor for moving cups to

various stations.

ii) AC motor with VFD- for controlling the motion of cup unloading conveyor in the processes.

3.3.1 The control system used for stepper motor is:

To control the stepper motor in the automation processes an optical rotary encoder is used to

converts the rotary motion into a sequence of digital pulses. The pulses are counted to convert

position measurement. The absolute encoder provides the exact rotational position of the shaft in terms of

digital pulses which is required in the cup filling automation processes as the accurate indexing of cups from

station to station is required. The optical encoder consists of a disc with a number of accurately etched

equidistant lines or slots along the periphery. The encoder disc is attached to the shaft of the stepper motor

which drives the cup indexing unit. The disc is placed between a light source and a light-measuring

device. When the disc rotates the lines are interrupted and the light-measuring device counts the number of

times the light is interrupted. By a careful counting and necessary calculations it is possible to know

the position traversed by the shaft.



30

Fig 3. 9 Encoder

3.3.2Justification for using encoder with stepper motor:

The cup indexing unit should have very accurate positioning at various stages so that

various processes takes place for example the cups has to be positioned exactly below the nozzle so

as the liquid exactly fill the cups a slight mis positioning of cups results in stoppage of processes to

control the Stepper motor for accurate positioning encoders are used for controlling the stepper

motor.

MSRSAS - Postgraduate Engineering and Managem


3.3.3 The control system used for AC motor is:

Fig 3.

The Ac motor is used for the conveyor which is used to unload the cups

all the processes is been completed. To control this AC motor a Variable frequency drive is used t

functions of a variable speed AC drive, is to convert

speed, torque and direction of rotation of AC motor

The purpose of VFD to control AC motor is:

i. Energy savings- as the motor has to ramp up and ramp down continuously for unloading of cups

ii. Better process control and regulation

iii. Speeding up or slowing down a machine

iv. Inherent power-factor correction

v. Emergency bypass capability

vi. Protection from overload currents

vii. Safe Acceleration.

Fig 3.

Postgraduate Engineering and Management Programme - PEMP

The control system used for AC motor is:

Fig 3. 10 Cup unloading conveyor

motor is used for the conveyor which is used to unload the cups as shown in the Fig(). A

all the processes is been completed. To control this AC motor a Variable frequency drive is used t

functions of a variable speed AC drive, is to convert electrical power to the usable form for controlling

speed, torque and direction of rotation of AC motor

The purpose of VFD to control AC motor is:

as the motor has to ramp up and ramp down continuously for unloading of cups

ss control and regulation – helps in maintaining the cycle time in the processes.

Speeding up or slowing down a machine.

factor correction.

bypass capability.

Protection from overload currents.

Fig 3. 11 Block diagram of VFD

as shown in the Fig(). After

all the processes is been completed. To control this AC motor a Variable frequency drive is used the primary

electrical power to the usable form for controlling

as the motor has to ramp up and ramp down continuously for unloading of cups.

helps in maintaining the cycle time in the processes.



32

In VFD the following conversion takes place when the 3 phase power is supplied to the

motor through the VFD. In the first converter stage the supplied power is converted to a higher

adjustable DC voltage. In the inverter stage, the power transistors in the rectified DC are switched

off and on. This produces a voltage waveform at the frequency which the motor requires. In the

control system, the voltage waveform receives information from the motor-driven system and will

adjust the output voltage to the selected value. The Fig 3.12. Shows the VFD connected to AC

electric motor.

Fig 3. 12 VFD with AC motor

3.3.4 Justification for using VFD with AC motor:

The motion of the cup loading conveyor is too fast the motor has to rotate in clockwise and

anti clockwise continuously the function of the motor will be as the four-quadrant diagram can

represent mode of operation of variable speed drive. In the first quadrant the speed and torque can

be represented positive or forward direction. This is consistent with a motor driving a load taking

power from the mains. Similarly in third quadrant both speed and torque are in negative or reverse

MSRSAS - Postgraduate Engineering and Managem


direction. The Fig 3.13 shows the function of AC motor in various sta

in the automation processes.

Fig 3.

Which in turn driving a load and a

speed and torque are in mutually opposed

rotation, giving a braking effect. As per the conservation of the energy

energy of the load is being converted into electrical energy. The motor is behaving as a generator

and the system as a whole is delivering power

order to better processes control and regulation of the cycle time.

3.4 Servo valve operated control

3.4.1 Servo valves:

Servo valves are electro hydraulic valves or EHSV (Electro hydraulic servo valves) which can

transform analog or digital signal into a step less hydraulic output.

accurate control of position, velocity, pressure and force

valve includes valve design with brushing spool assembly the movement of the spool in the valve is

controlled by the servo which is attached to the valve

valve controls the direction of fluid flow to the cylinder.

electric pulses are sent to the coils by the servo the valve changes its position so that the cylinder

will be actuated.

Postgraduate Engineering and Management Programme - PEMP

shows the function of AC motor in various stages during unloading of cups

Fig 3. 13 Torque Vs Speed curve

driving a load and again taking power. In second quadrants and fourth quadrant

opposed directions that are the torque of the motor is opposing its

g a braking effect. As per the conservation of the energy mechanical and kinetic


delivering power. Thus a VFD is required to control the AC motor in

order to better processes control and regulation of the cycle time.

control and servo motor operated control:

o valves are electro hydraulic valves or EHSV (Electro hydraulic servo valves) which can

transform analog or digital signal into a step less hydraulic output. Servo valves provide the

accurate control of position, velocity, pressure and force in the hydraulic system. The term servo


controlled by the servo which is attached to the valve and based on the movement of the spool the

fluid flow to the cylinder. The servo valves have coils when the


ges during unloading of cups

second quadrants and fourth quadrant the

the torque of the motor is opposing its

mechanical and kinetic


Thus a VFD is required to control the AC motor in

control:

o valves are electro hydraulic valves or EHSV (Electro hydraulic servo valves) which can

Servo valves provide the

lic system. The term servo


and based on the movement of the spool the

The servo valves have coils when the




34

The components of the servo valves are:

• Torque motor

• Two stages of hydraulic regulation.

were, the torque motor consist of coils, upper and lower pieces, armature and two magnets. The

torque motor converts input signal from a valve driver or valve controller into a physical movement

for the armature which inturn moves the spool.

Fig 3. 14 Servo valve

Principle of operation of servo valve:

The electromagnetic first stage produces a torque which may be assumed proportional to current

and the flapper generates pressure that are applied to each end of the spool. The feedback wire

which is coupled to the spool and the flapper creates the feedback. With a current applied the

flapper rapidly returns to its central position within the spool displaced such that the wire feedback

torque balances the electromagnetic torque as shown in the Fig 3.15. As the flapper in the valve tilts

to an angle due the supply of current in the armature the spool displaces in the valve and allows the

fluid to flow through the valve and when by the supply of current makes the armature to be vertical

without any tilt of angle the flapper becomes vertical and does not allow the fluid to flow.



Fig 3. 15 Cut section of servo valve

The block diagram of the servo valve control system shown in the Fig 3.16.

Fig 3. 16 Servo valve block diagram



36

When the current is supplied to the torque motor it sends to the torque summation unit which tilts the

armature or flapper to the angle as per the supplied voltage of current which inturn moves the spool. From

the spool the feedback wire is connected to the to the torque summation unit which in turn as per the flow

requirement increases or decreases the angle of tilt of the flopper so as the spool will be displaced for the

required flow. This is the closed loop system as it functions based on the feedback.

3.4.2 Servo motor: The servomotor is the motor which is controlled by the servo mechanism usually the

servomechanism controlled motor is called servo motor. But all servo mechanism needs not to have

the motors and therefore the servo can be identified as a separate unit. The servo motor can provide

precise motor output generally with the used of the microcontroller the servo motors are controlled.

The servo mechanism present in the servo motor provider precise position control of the motor. The

servo motors operate on the principle of negative feedback were the input given to the motor is

verified by the feedback devices such as transducers at the output shaft of the motor. The difference

between the input and the actual output is called error and this is amplified and corrected as the

input value will be equal to the actual output based on the feed back in the servo motor.

Fig 3. 17 Servo motor

Working principle of servo motor:

Servo motors are controlled by sending them a pulse of variable width. The control wire is used to

send this pulse the various types of pulse send to the motor is minimum pulse, a maximum pulse,

and a repetition rate. Given the rotation constraints of the servo, neutral is defined to be the position

where the servo has exactly the same amount of potential rotation in the clockwise direction as it



37

does in the counter clockwise direction. The pulse supplied to the servo motor is shown in the

Fig3.18.

Fig 3. 18 Pulse input to servo motor

The rotation of the motor shaft is determined by the duration of the pulse supplied to the motor.

Three basic types of servo motors are used in modern servo systems: ac servo motors, based on

induction motor designs; dc servo motors, based on dc motor designs; and ac brushless servo

motors, based on synchronous motor designs. The block diagram of servo motor is shown in

Fig3.19.

Fig 3. 19 Block diagram of servo motor

In servo motor from digital controller the input goes to the amplifier which generate the pulses and

run the servo motor the encoder or resolver connected to the motor gives back the feedback of the

position to the digital controller and velocity feedback to servo amplifier based on the feedback the

amplifier generates the pulses and runs the motor to correct the error.



38

4.0 Learning outcome:

In the module electrical drives and control different electro mechanical system and its

application, principle of automation , analyzing a drive system , electrical motors and various types

of electrical motors like AC motors, DC motors, stepper motor, servo motor and their working

principle and their applications was learned. Feedback devices like encoder and its types and its

application piezoelectric effect and application of strain gauge was learned. Sensors and various

types of sensors like inductive, capacitance, photo electric sensors and their applications and

programmable motion controller control of position, velocity and torque was learned interpolation

and its types and PLC, PLC architecture, PLC programming language and its function was learned.

Servo motor sizing and the aspects to consider while motor selection was learned CNC key

technology FANUC controller, Siemens CNC SENUMERIK, okuma THINC and Mitsubishi CNC

controller differences was learned. Micro controller and micro processer difference and PIC and

ARM micro controller and their differences were learned.

In lab session using FATAC and Allenbradly PLC kit using micro logics 500 and winpro

loader software various practical problems are solved.

Benefits derived by solving this assignment:

• Able to identify the technology involved in VFD and flux vector drive and their suitable

applications.

• Able to design a PLC circuit for the given processes by visualizing the video provided of

cup filling automation.

• Able to select various drives and motors for the automation processes.

• Able to generate system description diagram and control block diagram of the given

automation processes.

• Able to identify the difference and application of servo valves and servo motors.

Whether assignment was able to assess module learning outcomes or not?

Yes, the assignment was able to asses the module outcome which has covered all the topics

covered in the module.



39

References ________________________________________________________________________________

[1] Carrier Corporation Syracuse, New York “variable frequency drive”

http://www.docs.hvacpartners.com/groups/public/documents/marketing/wp_varfreqdrive.pdf

Retrieved on 16/03/2012.

[2] Flux Drive Inc. “Mel Korum Family YMCA CASE STUDY”

http://www.fluxdrive.com/docs/flux_drive_ymca_case_study.pdf Retrieved on 13/07/2012.

[3] Ramin Monajemy, “Control Strategies and Parameter Compensation for Permanent Magnet Synchronous Motor Drives”

http://vtechworks.lib.vt.edu/bitstream/handle/10919/11247/MASTER.pdf?sequence=1

Retrieved on 17/03 /2012.

[4] Bobby Martinez, P.E, “All Electric Motor Drives for LNG Plants”

http://lnglicensing.conocophillips.com/EN /documents/GastechElectricMotorPaper.pdf


[5] Rockwell automation, “Technical Application Notes”

http://http://www.rockwellautomation.com/solutions/get/RA-AP012A-EN-P_CLX.pdf


[6] Moog servo valve, “Moog servo valve repair and service”

http://www.blow-moulding-controls.com/_valverepairservicing.html


[6] G. W. Younkin, (2007) “Industrial Servo Control Systems - Fundamentals and Applications” –

2nd edition, Taylor and Francis,

[7] W.Bolton, (2002) “mechatronics” 2nd edition pearson education publishing.

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Electrical drives and control