Modul RL 2012

PRACTICUM MODULE

ELECTRIC CIRCUIT

HIGH VOLTAGE AND ELECTRICAL MEASUREMENT

LABORATORY

ELECTRIC ENGINEERING DEPARTMENT

ENGINEERING FACULTY UNIVERSITY OF INDONESIA

DEPOK

2012

Electrical Circuit Experiment 2012

High Voltage and Electrical Measurement Laboratory 1

EXPERIMENT I

ELECTRICITY BASIC, LINEARITY

MESH AND NODE ANALYSIS

I. PURPOSE

1. Practitioner can define electrity, current, and voltage

2. Practitioner can investigate a linear circuit

3. Practitioner can use Mesh and Node analysis in solving electrical circuit problem

4. Practitioner can simplify the solution equation of voltage and current in electrical

circuit

II. BASIC THEORY

II.1 Linearity

Linear circuit can be formed from independent source, linear independent source and

linear element. The value of voltage applied in some linear electrity circuit will be

proportional with the value of the the circuit’s current.

II.2 Mesh Analysis

In using mesh analysis, first we must note some things :

1. The active element being used is voltage source

2. The passive element being used is impedance

3. Using Ohm’s law and the seccond kirchoff’s law

4. Used to determine the value of current in closed loop circuit

5. Making voltage equation



How to get a Mesh Equation :

1. Determine the value of every element and source

2. Make a mesh current ( clockwise/counter-clokwise ) on every mesh

3. If the circuit have only voltage source, use kirchoff’s voltage law on every mesh

4. If the circuit have current source, for a while, change the circuit with the current

source become open circuit. With those determined value of current, use the the

second kirchoff’s law for every mesh or super mesh in this circuit.

II.3 Node Analysis

In using Node analysis, first we must note some things:

1. The active element being used is current source

2. The passive element being used is impedance

3. Using Ohm’s law and the first kirchoff’s law

4. Used to determine the value of voltage in closed loop circuit

5. Making current equation

How to get a node equation :

1. Determine the value of every element and source

2. Pick one node as a reference. Write node voltage on every node which the value

measured against reference .

3. If the circuit have only current source, use the first kircoff’s law on every non-

reference node

4. If the circuit have voltage source, for a while change the with the voltage source

become short circuit. Using the voltage node to the determied reference node, use

the first kirchoff’s law on every node or super node in this changed circuit

III. EQUIPMENT

1. DC Current Source = 1 unit

2. DC Voltmeter = 3 units

3. Amperemeter = 2 units

4. Resistance

o 10 ohms = 1 unit



o 12 ohms = 1 unit

o 100 ohms = 1 unit

o 160 ohms = 1 unit

o 880 ohm = 1 unit

5. Connecting wires

IV. EXPERIMENT’S CIRCUIT

V. PROCEDURE

V.1 Mesh Analysis

1. Make a circuit like the circuit shown above

2. Record the voltage value of V1, V2, V3 and the current value of A1, A2 for the

value of every current source

V.2 Node Analysis

1. Make a circuit like the circuit shown above

2. Take off the 880 Ohms resistance from the circuit

3. Record the voltage value of V1, V2, V3 and the current value of A1, A2 for the

value of every current source

VI. QUESTION AND ASSIGNMENT

VI.1 Linearity

1. Plot a chart V(t) vs I(t) based on the experiment using milimeter block



VI.1 Mesh Analysis

1. Determine the value of I1 and I2 using mesh analysis for every change of voltage

measured on V1

2. Find the measurement’s error for every change of voltage measured on V1 and

determine the average error

3. Plot a chart of V1 against V2, V3, A1, A2, and write down the equation of the chart

VI.2 Node Analysis

1. Determine the value of V1, V2, and V3 using mesh analysis for every change of

current source’s value

2. Find the measurement’s error for every change of current source’s value and

determine the average error

3. Plot a chart of the value of current source against V1, V2, V3, A1, A2, and write

down the equation of the chart



EXPERIMENT II

SUPERPOSITION, THEVENIN AND NORTON ANALYSIS

I. PURPOSE

1. Determine the value of voltage in an electrical circuit if there’s more than one voltage

source

2. Verify the Thevenin and Norton Theorem in an electrical circuit

3. Simplify the equation of voltage and current from an electrical circuit

II. BASIC THEORY

II.1 Superposition

In every linear circuit which contain some sources, the value of current or voltage passing

through every resistance or source can be measured by doing an algebra addition from

every voltage or current which is produced from every independent source working on

itselves, with every other independent source changed. Short circuit for voltage source

and open circuit for current source.

II.2. Thevenin Theorem

NA NB

i(t)

Image 1

NA : Circuit contain active and passive element

NB : Circuit contain only passive element



Current i(t) flows from NA to NB

1. Apply a voltage source V(t) which the magnitude will make there will be no current flows

from NA to NB

NA NB

V(t)+ - 1

1'

Image 2

.

2. i(t) = 0 means NA and Nb can be broken of on terminal 1 – 1’

3. The voltage equation on 1 – 1’in open circuit condition :

-V1-1’ + V(t) = 0

V(t) = V1-1’

4. V1-1’ is the voltage of the open circuit

5. Measure V(t) = V1-1’

6. Reverse the polarity of V(t) and erase every current and volage source on NA

7. Then from NA to NB current i(t) flows as before

II.3. Norton Theorem

1. Apply current source as shown as image 3 which the magnitude ig is the same as i(t) and

there won’t be current flows to NB

NA NBigi(t)

1

1'

Image 3

2. This means i(t) = ig. Circuit is being shorted on port 1-1’. NA and NB can be taken off at 1-

1’.



NA NBi(t)

1

1'

image 4

3. Measure the short circuit’s current ig

4. Reverse the polarity of ig and erase every active element on NA

5. Then current i(t) will flow from NA to NB as before

igNA NBi(t)

1

1'

image 5

III. EQUIPMENT

1. DC Voltage Source

2. DC Voltmeter = 3 units

3. Amperemeter = 2 units

4. Connecting Wires

5. Resistance

o 880 ohms = 3 units

o 40 ohms = 1 unit



IV. CIRCUIT EXPERIMENT

IV.1. Thevenin Theorem

Image 6

IV.2. Norton Theorem

Vs

R1 R2

R3 A1 RL

A2

1

2

2

S1

Image 7



V. PROCEDURE

V.1. Thevenin Theorem

1. Make a circuit as shown as image 6

2. Apply S1 at position 1 then close S2. Record the voltage of Va and the close loop current

IL. Repeat for every different voltage source value

3. Drop the voltage source magnitude to 0

4. Open S2 then apply voltmeter as shown as Voc on image 6. Record Voc and repeat for

every voltage source value the same as point 2

5. Drop the voltage source magnitude to 0

6. Apply S1 at position then apply voltmeter as shown as VTH on image 6. Record current IL

and repeat for every voltage source value the same as point 2

V.2. Norton Theorem

1. Make a circuit as shown as image 7

2. Apply S1 at position 1. record Vs and load current IL (A2) close loop. Repeat for differen

value of Vs

3. Close S2. Measure the short circuit current Isc (A1) with Vs the same as point 2.

4. Turn power supply at 0 magnitude. Open S2 and move S1 on position 2. Set the power

supply at the current supply. Reverse the polarity of the amperemeter A1 and record the

load current IL (A2) for the same current (A1) at point 4.


VI.1. Thevenin Theorem

1. Is the load current at point V.1.2 dan V.1.6 has the same value ? Explain !

2. In condition still the same circuit, does IL in point V.1.6 can be made two times IL in point

V.1.2 ? jelaskan!



3. Compare the measurement Voc with the real calculation ? determine the percent error!

4. Give your conclusion!

VI.2. Norton Theorem

1. Does the load current IL in V.2.2 dan V.2.4 has the same value ? Explain!

2. Does the load current IL on experiment norton and thevenin has the same value for the same

Voltage source ? Explain!

3. Compare the measurement Isc with the real calculation !

4. Fing RTH from the experiment result and compare it with RTH real calculation result! Count

the percent error !

5. Plot a chart for Voc vs Isc on the same voltage source !

6. Give your conclusion!



EXPERIMENT III

TWO PORT NETWORK

I. PURPOSE

1. Determine the impedance and admitance parameter from a two port network

2. Using the parameter to simplify and systematize network analysis with two linear node

II. BASIC THEORY

Two port network is generally portrayed as the image below :

+

--

Ia

Ic

Ib Id

V1 V2

+

Image 3.1

The analysis of a two port network is based on the connection between voltage and current at

the network’s terminal to get the network’s parameter.

Two port network parameter distinguished:

a. Admitance parameter (Y)

b. Impedance parameter (Z)

c. Hybrid parameter (h)

d. Transmission parameter (ABCD)

e. Inverse-Transmission parameter

f. Inverse-Hybrid parameter (g)



Admitance parameter obtained by writing the current equation of the network

1 11 1 12 2

2 21 1 22 2

1 11 12 1

2 21 22 2

Y

Y Y

I Y V Y V

I Y V Y V

I Y V

I V

Impedance parameter obtained by writing the voltage equation of the network

1 11 1 12 2

2 21 1 22 2

1 11 12 1

2 21 22 2

Z

Z Z

V Z I Z I

V Z I Z I

V Z I

V I

III. EQUIPMENT

a. Power Supply

b. DC Amperemeter ( 2 units )

c. DC Voltmeter ( 2 units )

d. Resistor

e. Connecting wires




IV. 1 Admitance parameter

Image 4.2

IV.2 Impedance parameter

Image 4.3



V. EXPERIMENT’S PROCEDURE

V.1 Admitance Parameter

1. Make a circuit as shown on image 4.2

2. connect point B with R, and point S with P

3. Give voltage source on V1 and reverse the polarity of A2.

4. Turn on the Power Supply. Record I1’s and I2’s current for every inclining value of V1

5. Turn off the power supply

6. Connect point A with R and S with Q

7. Give voltage source on V2 and reverse the polarity of A1 and A2.

8. Turn on the Power Supply. Record I1’s and I2’s current for every inclining value of V2


V.2 Impedance parameter

1. Make a circuit as shown on image 4.3

2. Give voltage source on V1

3. Turn on the Power Supply.

4. Record V1’s and V2’s voltage for every inclining value of I1


6. Give voltage source on V2

7. Turn on the Power Supply.

8. Record V1’s and V2’s voltage for every inclining value of I1


I. QUESTION AND ASSIGNMENT

1. Define two port network !

2. Explain why two port analysis is important in electrical circuit analysis !

3. Make a hybrid, inverse hybrid, transmission, and inverse transmission from the

experiment !



EXPERIMENT IV

AC NETWORK

I. PURPOSE

1. Analysing the difference of AC and DC

2. Analysing AC network

3. Analysing the character of active and passive element on AC network

4. Complete the equation of current and voltage from a circuit that has AC source

5. Practitioners can aplly the laplace equation on an electrical circuit with ac source

II. BASIC THEORY

1. Alternating Current ( AC )

Scientifically, the definition of alternating current is a current that changes its value

as time changes. Generally an AC chart is drawn as a sinusoidal graphic :



2. Inductor

An inductor (also choke, coil, or reactor) is a passive two-terminal electrical

component that stores energy in its magnetic field. Any conductor has inductance. An

inductor is typically made of a wire or other conductor wound into a coil, to increase the

magnetic field.When the current flowing through an inductor changes, a time-varying

magnetic field is created inside the coil, and a voltage is induced, according to Faraday’s

law of electromagnetic induction, which by Lenz's law opposes the change in current

that created it.

3. Capacitor

A capacitor (originally known as condenser) is a passive two-terminal electrical

component used to store energy in an electric field. The forms of practical capacitors

vary widely, but all contain at least two electrical conductors separated by a dielectric

(insulator); for example, one common construction consists of metal foils separated by a

thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in

many common electrical devices. When there is a potential difference (voltage) across

the conductors, a static electric field develops across the dielectric, causing positive

charge to collect on one plate and negative charge on the other plate. Energy is stored in

the electrostatic field. An ideal capacitor is characterized by a single constant value,

capacitance, measured in farads. This is the ratio of the electric charge on each

conductor to the potential difference between them.

III. EQUIPMENT

1. AC Power Supply

2. Variable Capacitor

3. Variable Inductor

4. Resistor ( 1000 ohms ) = 2 units

5. Connecting Wires

6. AC Voltmeter




V. PROCEDURE

1. Make a circuit as shown on image above

2. Record the voltage measured on voltmeter

3. Repeat point 2 with different value of voltage source, inductance, and capacitance


1) What happen if capacitor and inductor used in network that uses DC source ?

Explain ! ( Theoritically )

2) Find the function of time from the circuit using the second order analysis!



EXPERIMENT V

THREE PHASE NETWORK

A. Delta Network

I. PURPOSE

1. Describe the network that is essential for delta three phase load network

2. Differentiate between symmetric load and asymmetric load.

3. Determine the value of current in assymetric delta three phase load network.

II. BASIC THEORY

On electrical system, it generally uses three phase network on power transmission and

distribution. Three phase network is chosen because the economical value and the electrical

system optimization. Three phase network can be a delta network or wye network.

In delta network, all three impedance at the load is series connected. The three phase

network is connected each one with node between two resistors.

IS

IL

R2R1

R3

L3

L2

L1

Image 1

If the value of all three resistance is the same, then it is called the symmetric load.if not, then

it is called asymmetric load.



III. EXPERIMENT’S EQUIPMENT:

1. Universal Power Supply/ Function Generator LM4501

2. Basic Unit SO4201-2C

3. Three Phase Circuits SO4201-6P

4. Connector SO5124-8F

5. Connector SO5126-6T

6. Connector SO5126-2W

7. Connector SO5126-7B

IV. EXPERIMENT’S NETWORK

IMAGE 2



V. EXPERIMENT:

VOLTAGE AND CURRENT MEASUREMENT IN DELTA NETWORK

- Experiment A

Image 3

1. Make a circuit with R1 = R2 = R3 = 402 ohms (symmetric).

2. Measure the line current IL on the three phase network and the phase currrent Iph on the

three phase resistor using multimeter

3. Compare the line current with the phase current.

- Experiment B

1. Move the R1 resistor to simulate disturbance. Measure the line current. Then move the R2

resistor and measure the line current

2. Continuing from point 1. Make R1 short circuit and measure the line current.



- Experiment C

image 4

1. Make the circuit network asymmetric by connecting 680 ohms to R2 and 1200 ohms to

R3, both in parallel

2. Measure the line current and phase current

B. WYE NETWORk

I. PURPOSE

1. Assemble and count parameter-parameter on wye network

2. Describe the network that is essential for delta three phase load network

3. Differentiate between symmetric load and asymmetric load.

4. Determine the value of compensation current on ‘neutral-line’.

II. BASIC THEORY

In Wye network, the ends of every resistance from each phase is connected in one point

where there’s a neutral line connected. And the other end of each phase from the load is

connected to a line which current flows out or in (L1,L2,L3).



Image 5

On three phase load, each of every front ends given notations U1, V1, and W1. While the

other ends given notations U2, V2, and W2 (standard identification). Therefore, practically,

for wye network, the connection can be ilustrated as the picture below :

Image 6

If the value of all three resistance is the same, then it is called the symmetric load.if not, then

it is called asymmetric load.



III. EXPERIMENT:

VOLTAGE AND CURRENT MEASUREMENT IN WYE NETWORK

- Experiment 1

a. Make a circuit like the image below, with R1 = R2 = R3 = 232 ohms (symmetric).

Image 7

b. Using multimeter, measure the line current Il on each phase and neutral current, In.

c. Using multimeter, measure the voltage current on each phase and each line.

d. Using oscilloscope, measure the voltage of Ul, U2, and U3 and image it to the diagram

- Experiment 2

a. Make a circuit like the picture below, connect a 1200 ohms resistor to R3 in parallel and

680 ohms resistor to R1 in parallel

Image 8



b. Measure the current of each phase, neutal line current, line voltage, and each phase

voltage.

IV. QUESTION AND ASSIGNMENT:

A. Delta Network

1. Explain the connection between line current and phase current, and between line voltage

and phase voltage ! ( on symmetric load )

2. What are the consequences if one phase released from the circuit ?

3. What are the consequences if two phase released from the circuit?

4. What are the consequences if one line released from the circuit?

B. Wye Network

1. Explain the connection between line current and phase current, and between line voltage

and phase voltage ! ( on symmetric load )

2. What happen if on asmmetric load wye network the neutral line is released ?

3. Draw a phase vector diagram when the neutral line is released from the circuit!



Reference

- Johnson, David E. Electric Circuit Analysis.1997. Prentice Hall

- Ramdhani, Mohammad. RANGKAIAN LISTRIK. 2008. Penerbit Erlangga

- and other book

High Voltage and Electrical Measurement Laboratory

Electrical Engineering Department

Enginggering Faculty University of Indonesia

2012

Documents

Modul RL 2012