PSCAD Code Generator

RAPID PROTOTYPING OF
CONTROL SYSTEMS FROM
ELECTROMAGNETIC
TRANSIENT SIMULATOR
PROGRAM
By:
Dexter M. T. J. Williams, Esa Nummijoki,
Aniruddha M. Gole and Erwin Dirks
University Of Manitoba
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NSERC Industrial Research Chair in Power Systems Simulation
Content
• Introduction
• Background
• PSCAD Code Generator (PSCADCG)
• Example System
• Validation Testing
• Conclusion
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INTRODUCTION
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Introduction
• Software based design in power systems
– Grown in popularity with computer processing
power
- Electromagnetic Transient (EMT) simulation
models the network in the greatest detail
- Application: Flexible Alternating Current
Transmission System (FACTS), High Voltage
Direct Current (HVDC)
- Exhaustive simulations are done to confirm the
controls operate in an appropriate manner
- However the control model must still be
transferred into a useable control code for infield use
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Introduction
• Solution to Problem
– Automatic code
generation from
simulation control
elements
• PSCAD Code
Generator
(PSCADCG)
• MATLAB’s Real-time
Workshop
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BACKGROUND
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Background
Library
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Workspace
Background
• PSCAD/EMTDC power system simulator
– 2 main types of Library components:
– Electrical
» passive electrical components, power electronic
components, machines, transformers, application
specific components (EX: HVDC, FACTS)
– Control
» arithmetic operations, logical operations, filters,
application specific controls and more
– Problem: To convert the control model to a
real-world real-time implementation
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Background
• To allow for prototyping of the controls
the PSCAD Code Generator
(PSCADCG) is used
– PSCADCG reads the graphic model and
develops embedded software compatible
code from the model
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PSCAD CODE GENERATOR
(PSCADCG)
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PSCADCG
• The PSCADCG contains 3 main parts involved in the rapid prototyping
process
– Network generation
– C function generation
– C interface generation
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PSCADCG: Network Generation
• Network generation
– Generates a virtual
network describing
the interconnection of
the control elements
of the design
• Reads project and
library files to
generate and
equivalent virtual
network of the
systems controls
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PSCADCG:C Function Generation
• C function generation
– Generates the code that describes the control operations modeled
• Sequential orders all elements into a queue based on order of operation
• Elements are sequentially de-queued and the code for each element is sequentially
generated
• Then the code is formatted and used to generate the header and C file
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PSCADCG: C Interface Generator
• C interface
Generator
– Interfaces the C
function to the
hardware platform
• A hardware platform
must first be selected
• The program reads
the virtual header file
and generates header,
configuration and
main loop C files
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PSCADCG: C Interface Generator
• C interface
Generator
– Main program
• Configuring all
parameters
• Infinite loop
– Reads the A/D
converter values
and runs
– Runs the C function
generated by the C
function generator
– Outputs the values
to the ports
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EXAMPLE SYSTEM
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Example System
• Step Down converter
– Reduces voltage from input to output using pulse width modulation
– Parameters
• • • • EPEC 2011
Input = 10 Volts
Output = 5 Volts
Voltage Ripple = 0.2%
Current Ripple = 2.0%
Example System: Controls
• Step Down converter
– Control
• Pulse Width Modulation
• Negative feedback
• Proportional-Integral (PI) controller for error reduction
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Example System:PSCAD Simulation
• Step Down converter
– Control system
– Optimized controls
• Controls must be
converted to a real
time controller
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Real-time Control Implementation
• Cerebot 32MX4
development board
– PIC32MX460F512L
microprocessor
• • • • 80 MHz
32-bit memory.
PWM
digital and analog I/O
(Input and outputs)
– 8 peripheral ports
• • • • open collector driver
A/D
D/A converters
Etc.
– Programmed with C using
the MPLAB development
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VALIDATION TESTING
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Validation Testing
• 5 volt output test
– Calculated: 5.00
– Simulated: 5.00
• Blue signal represents the
PWM signal (Top)
• Green signal represents PI
control signal (Top)
• Blue signal represents the
output voltages (Bottom)
• Green signal represents
the input voltages
(Bottom)
– Hardware: 5.10
• Blue signal represents the
PWM signal
• Green signal represents
the input voltages
• Orange signal represents
the output voltages
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Validation Testing
• 9.90 volt output test
– Calculated: 9.90
– Simulated: 9.90
• Blue signal represents the
PWM signal (Top)
• Green signal represents PI
control signal (Top)
• Blue signal represents the
output voltages (Bottom)
• Green signal represents
the input voltages
(Bottom)
– Hardware: 9.53
• Blue signal represents the
PWM signal
• Green signal represents
the input voltages
• Orange signal represents
the output voltages
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Validation Testing
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Duty
Cycle
(%)
Calc.
(V)
PSCAD
(V)
Actual
Hardware
(V)
1
50
5.00
5.00
5.10
Error
PSCAD
VS
Hardware
(%)
1.00
2
99
9.90
9.90
9.53
3.70
CONCLUSION
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Conclusion
• PSCADCG capable of:
– generating control systems for a PSCAD system
– generating most any control system generated by PSCAD
• PSCADCG can possibly reduce cost and expedite the
development of controls
• Proof of Concept was demonstrated using a simple stepdown controller
– It is equally applicable to design arbitrary Power System
Controllers
– Larger scale / power systems may require additional hardware
for isolation, etc.
• Additional code may be needed to interface with these devices
• Future work
– Support for multiple page modules
– Support for FPGA platforms
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QUESTIONS
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