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PEBB-based Power Electronic Systems to
Support MVDC Studies
Herbert L. Ginn III, Mississippi State University
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Multifunctional Power Electronic Converters
One research focus area at MSU has been flexible management of energy flow throughout
distribution systems by means of multi-functional power electronic converter systems.
Consideration of parallel operation and system
level control issues of multiple power electronic
converters
S
T
u
iRc iSc iTc
Lc
ic
Lc Lc
iR
iS
iT
i
Bi-directional
Voltage
Source
Converter
C
Interface with System
Level Control
Reference Signal
Generation
DSP
uRS uTR
uST
Current Controller
Modulator
Protection Logic
CPLD
•
R
Data Acquisition &
Signal Processing
Efforts in this direction have included:
• Investigation and development of PEBB based multi-functional
converters by development of appropriate application level
control architectures
• Development of lower level control functions to cope with
shipboard power system concerns such as distorted voltages,
high frequency variability, and EMI.
Gate Driver Circuits
Controller Power
Supply
PEBB Hardware Section, Sensors and
Section of PEBB Level Control
Parallel converters
Test-bed for
experimental validation
PEBB-based
converter
Digital
controller
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Systems of Multifunctional Power Electronic
Converters
A current research focus area at MSU and USC is development of control methods that
enable the coordinated operation of distributed systems of multi-functional power
electronic converters.
•
This work leverages the multi-functional converter research conducted during the past two
years at MSU as well as the research on mobile agents conducted at USC.
Some near term efforts of USC and MSU building on
these capabilities that can support MVDC
include:
•
Development of a HIL interface for the MSU
PEBB controller
•
Further develop the MSU PEBB controller
software so that it can be used as a real-time
target for C code realizations of control
algorithms generated using VTB Pro
•
Combine the VTB based dynamic reprogramming of the power modules and
hardware-in-the-loop interface for the MSU
controller in order to provide a test-bed for
MVDC technologies
PEBB and Load Test-bed at MSU.
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MSU PEBB Controller
ic
Lc L c L c
Bi-directional
Voltage
Source
Converter
C
u
i
•
Interface with System
Level Control
Reference Signal
Generation
Application Level
Control
DSP
iRc iSc iTc
iR
iS
iT
Current Controller
Converter Level
Control
Modulator
Protection Logic
CPLD
uRS
uST
S
T
uTR
Data Acquisition &
Signal Processing
R
PEBB Hardware
Level Control
Gate Driver Circuits
Controller Power
Supply
PEBB Hardware Section, Sensors and
Section of PEBB Level Control
PLANNED ENHANCEMENTS:
• Addition of a HIL interface to
the reference signal
generator
• VTB based code generation
for fast control prototyping
•
Ethernet communications
capability and dual
processor design are
features of the new MSU
controller board
The new controller
interfaces with the AMSC
PM-1000 at the hardware
control level
Fixed Point DSP: Implementation
of PLL, Reference Signal
Generator, Current Controller,
modulator
Hardware TCP/IP Stack
CPLD: fault protection logic
Floating Point DSP:
Implementation of Higher
Level Control Functions
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Phase I:CAPS PHIL experimental setup
4.16 kV
utility bus
with AMSC PEBBs
DC Voltage
reference from
RTDS
• The HIL enabled PEBBs will be
used to form a DC zone at the
100kW level in the CAPS test bed
DC Current
feedback to
RTDS
0-1.15 kV experimental DC bus
AMSC PEBB
Based DC Zone
Bidirectional
DC/DC
Bidirectional
DC/AC
Simulation Based
Commands
0-4.16 / 8.2 kV experimental
bus
0-480 V experimental bus, 1.5 MVA
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Present Experimental Setup
for Agent Validation
Converter 1
Converter 2
Load Bank
Mini-dc link
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Phase II: HIL Experimental Setup
with Active Rectifiers
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Other Proposed MVDC Activities at MSU
Power Systems Group:
1.
Develop methodology for optimal power management based on steady state
power flow models of DC system and controllers
2.
Develop a method to implement simultaneous inter area de-coupling and local
area oscillation damping in MVDC systems
3.
Develop DC system fault detection and protection schemes
High Voltage Group:
1.
Cable testing with DC waveforms
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Brief Description of The Proposed Activities
Optimal Power Management
Objective:
To develop methods for optimal power management in MVDC systems.
Motivation:
• Voltage source converters (VSCs) offer advantage in MVDC applications,
with ease of parallel operation on DC side.
• VSCs can operate in voltage regulation mode or in power dispatch mode.
• Optimal settings of converters ensure desired power management and also
avoid excessive voltage build up under failure of one of the converters.
Approach:
• Use of steady state power flow models of MVDC system
• Optimal power flow methodology for the power management.
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System Stability and Control
Objective:
Develop a method for simultaneous inter area decoupling and local area damping
in MVDC system and evolve control strategies to avoid excessive or low voltage
build up under disturbances.
Motivation:
•VSCs have two control degrees of freedom. Supplementary controllers need to
be designed for inter area decoupling and local area damping.
•In addition, the converter controls have to be properly designed to avoid any
excessive or low voltage build up under disturbances
Approach:
•Develop dynamic model of MVDC system.
•Carry out transient and small signal stability studies.
•Design of controllers to damp out oscillations.
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MVDC System Protection
Objective:
To develop fault detection and protection schemes.
Motivation:
• Detection of fault in MVDC system is relatively difficult.
• COTS protective devices not available.
• Proper protection schemes need to be developed to make the MVDC
system reliable, dependable, and secure.
Approach:
• Employing advance level converters.
• System modeling and transient simulation.
• Optimal control strategy of converters for protection under fault.
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Background Work Already Carried Out
1. MVDC system modeling employing 12-pulse converter rectifiers with static
resistive load
2. MVDC protection study (in terms of fault propagation and system level
impact)
a) Impact of different converter configurations
b) Impact of different converter control modes
c) Impact of change in controller and system parameters
3. Ring bus MVDC system stability
4. Power quality issues including harmonics.
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