Group 8
Anthony McCorvey
Ronnie LalchanChris Beck
George Thompson
ProblemThe power companies are
converting the old mechanical meters to Smart meters. Wireless Communication Accurate Readings KWH every hour Power Factor Connect/Disconnect
No jobs for meter readers Hiring untrained contractors Cheaper
Looking for a cost efficient method to train contractors
GoalsTo design a product that the power companies can use
for their renovationsCost efficientSafeUser FriendlyTest and Train
Design Requirements Hardware
Meter CansPotential TransformersVariable TransformerToggle Switches/RelaysFusesControl Box
Thinking about the Design
PhasePhase
ConfigurationConfigurationPhase to Phase to GroundGround
Phase 1 to Phase 1 to Phase 2Phase 2
Phase 2 to Phase 2 to Phase 3Phase 3
and and
Phase 3 to Phase 3 to Phase 1Phase 1
*Power *Power leg to leg to
GroundGround
Single PhaseSingle Phase
DeltaDelta120 Volts120 Volts 240 Volts240 Volts 240 Volts240 Volts
Three PhaseThree Phase
DeltaDelta120 Volts120 Volts 240 Volts240 Volts 240 Volts240 Volts
208 208 VoltsVolts
Single PhaseSingle Phase
WyeWye120 Volts120 Volts 208 Volts208 Volts
Three PhaseThree Phase
WyeWye120 Volts120 Volts 208 Volts208 Volts 208 Volts208 Volts
2 Phase Configurations Delta Wye
Single Phase Three Phase How can we convert single phase to
three phase? Rotary motors etc Too expensive Defeats our goal
“Trick the Voltage” That’s when Simulator was added to
the name
Meter Cans(2) Three Phase Meter Cans
2 Wire Delta Junction Meter3 Wire Delta3 Wire WyeLED Lights
(3) Single Phase Meter Cans(3) Single Phase Meter Cans 2 Wire Delta2 Wire Delta 3 Wire Delta3 Wire Delta 3Wire Wye3Wire WyeLED Lights (Safety Precautions)LED Lights (Safety Precautions)
Potential Transformers6 total potential transformers3 Step-down PT’s “Configuration”
115:50 (Phase to Phase - Delta) and (Phase to Ground – Delta and Wye)
115:80 (Stinger leg Delta)115:42 (Phase to Phase – Wye)
3 Step-Up PT’s “Multiplier”3 Step-Up PT’s “Multiplier”2.4:12.4:1
Step-Up PT Schematic
Secondary
Primary
Secondary
Primary
Secondary
Primary
11550
11580
11542
S3 S3
Variable Transformer
S3
Voltage CalculationsPhase to Ground for Wye and Delta (115:50)
50 x 2.4 = 120 VoltsPower leg to Ground (Delta) (115:80)
80 x 2.4 = 192 VoltsSpecific to needsFound a solution
Phase to Phase for Wye to DeltaSubtractive PolarityDelta
50 x 2.4 = 120 volts Different terminals 120 <0 – 120 <180 = 240 Volts
Wye (115:42) 42 x 2.4 = 100.8 Volts 100.8 <0 – 100.8 <180 = 201.6 Volts
Control BoxVariable Transformer4 Fuses
(1) 5 Amps (3) 2 Amps
ON/OFF switch Safety Precautions
5 toggle switches for selection of configuration 3PDT
Delta Single Delta Single PhasePhase
Switch 1Switch 1 Switch 2Switch 2 Switch 3Switch 3 Switch 4Switch 4 Switch 5Switch 5
Phase 1&2 to Phase 1&2 to GroundGround
UpUp UpUp UpUp UpUp DownDown
Phase 1 to Phase 1 to Phase 2Phase 2
UpUp UpUp UpUp UpUp DownDown
Delta Three Delta Three Phase Phase
Phase 1&2 to Phase 1&2 to GroundGround
UpUp UpUp UpUp UpUp DownDown
Power Leg to Power Leg to GroundGround
UpUp UpUp UpUp UpUp UpUp
Phase 1 to Phase 1 to Phase 2Phase 2
UpUp UpUp UpUp UpUp DownDown
Phase 1 to Phase 1 to Power LegPower Leg
UpUp UpUp UpUp DownDown DownDown
Phase 2 to Phase 2 to Power LegPower Leg
Up Up UpUp UpUp Down Down DownDown
Delta Switching Sequence
Wye Switching SequenceWyeWye
Single PhaseSingle Phase
Switch 1Switch 1 Switch 2Switch 2 Switch 3Switch 3 Switch 4Switch 4 Switch 5Switch 5
Phase 1&2 Phase 1&2 to Groundto Ground
UpUp Down Down Up Up Down Down DownDown
Phase 1 to Phase 1 to Phase 2Phase 2
Down Down DownDown DownDown UpUp DownDown
Wye Three Wye Three PhasePhase
Phase 1,2,&3 Phase 1,2,&3 to Groundto Ground
UpUp DownDown UpUp DownDown DownDown
Phase 1 to Phase 1 to Phase 2Phase 2
DownDown DownDown DownDown UpUp DownDown
Phase 1 to Phase 1 to Phase 3Phase 3
DownDown DownDown DownDown DownDown DownDown
Phase 2 to Phase 2 to Phase 3Phase 3
DownDown DownDown DownDown DownDown DownDown
Phase Converter Simulator Hardware 1
• Mechanically changes configurations• Allows microcontroller to control
switching• A lower voltage device can now
control the voltages of the meter cans
• Eliminates need for the user to know list of combinations
Relays
• -
• Type Impedance Input voltage
Voltage Required to operate
Current Required
Triple pole double throw (3PDT)
120 Ω 6 – 240 VAC 8 - 14V Min of .2 A
Schematic of Relay Connection
Testing
1.Tested relays by realizing the schematic
2.For the microcontroller, we applied a steady voltage.
3.Connected to relays to microcontroller.
4.Replaced switched with relays.
First attempt:•Diode parallel with relay• Purpose:• Protect circuit from feedback
current when relay switched• Diode shorted out the
transistors• Solution:• Remove diode
Second attempt:•1K resistor• Limited current to
microcontroller• Too much impedance on
breadboard•Switch to 100 ohms• Blew transistors 2n2222• 2n2222 didn’t have a high
enough rating• Solution:
•Changed transistor to TIP120
Building
Software Objective
Create a Interface to compliment the Training Simulation
To allow the user to interact with the system.To give a visual reference to the user of his
or her actionsControl Relays for Configuration PurposesApprove or Decline Users Certification
Software ComponentsMicrocontroller Voltmeter CircuitLCD Screen 2 line X 20 characters
LCD System Flow Chart
Push Button Voltmete
rCircuit
Switches to Switching Relays
Microcontroller changes configurations
Eliminates need for the user to know switch combination
Configurations can switch when required or prompted automatically
LCD/system Code
Voltmeter Circuit(Feedback) Input Voltage (120-240)
| Probes
| Transformer
| Full Wave Rectifier w/ Capacitor | Voltage Divider | A/D converter(microcontroller)
Problems….
A/D Converter-5(A/D) Voltage +5(A/D)
115V-.284V(53) 120V 125V-.385V(77)
203V-1.85V(379) 208V 213V-1.87V(385)
235V-1.88V(388) 240V 245V-1.91V(397)
PCB2 Layer PCB.10” TracesGround PlaneUsing PCB ExpressSchematicPCB Board
Schematic
PCB Board
Microcontroller Vs. FPGA
PIC16F876A ATmega168 FPGA Basys
ATmega168
Features ATmega168 I/0 Pins 23Memory Type FLASH Program Memory (KB)
16
EEPROM (Bytes) 512SRAM (KB) 1Operating Voltage 5.5 Volts
PIC16F876A
Features PIC16F876A I/0 Pins 22Memory Type FLASH Program Memory (KB)
14
EEPROM (Bytes) 256SRAM (KB) 0.359Operating Voltage 5.5 Volts
FPGA Basys
Features FPGA Basys I/0 Pins 24Memory Type FLASHProgram Memory (KB)
72
EEPROM (Bytes) -SRAM (KB) 72Operating Voltage 3.3 Volts
Microcontroller Vs. FPGAFeatures ATmega168 PIC16F876A FPGA Basys
I/0 Pins 23 22 24
Memory Type FLASH FLASH FLASH
Program Memory (KB) 16 14 72
EEPROM (Bytes) 512 256 -
SRAM (KB) 1 0.359 72
Operating Voltage 5.5 Volts 5.5 Volts 3.3 Volts
•ATmega168
BudgetPart Development Immediate Cost PrototypeSwitches $10 $10 $10
Fuses $10 $10 $10
Enclosure $30 $30 $30
Three Phase Meter Box $140 $140 $140
Single Phase Meter Box $75 $75 $75
Potential Transformer $60 $60 $60
Wiring $0 $30 $30
Microcontroller $60 $60 $60
Interface $60 $60 $60
Volt Meter $30 $30 $30
A/D converter $40 $40 $40
Variable Transformer $0 $100 $100
User Interface $50 $50 $50
Keyboard $0 $30 $30
Total: $565.00 $725.00 $725.00
Budget Analysis
Budget
Current Cost $550Development Budget $565Prototype Budget $725
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