International Symposium on
Industrial Electronics
ISTANBUL
Authors: Vahid Jalili-Marandi, Jean Belanger, Fabio Jose Ayres
Presenter: Simon Abourida
Simon.abourida@opal-rt.com
Real-Time Digital
Simulator
Real-Time
Phasor-Domain
Model
Electric Power System
Motivation: To model the impact of DC systems (VSC)
and their controllers in the phasor-domain simulation
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 Design, and analysis of power system stability and
performance
 Test a variety of difficult operating scenarios on the real
power grid: faults, load rejection, and islanded operation
 Testing components (control, monitoring, protection, etc)
hardware in a closed-loop with the simulator
 Sample Applications:






Closed-Loop testing of devices
Protective relay testing
Phasor Measurement Units and Wide Area Monitoring
Solar and Wind Farm integration Testing
FACTS Control-in-the-loop testing (HIL, Power HIL)
…
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 Hardware-In-the-Loop (HIL):
 Test and validate new components before installing them in the field
 Create realistic set-up to test and prototype the final application of a
new component
 The design iteration is slow at this point
 Model-In-the-Loop (MIL)
 One level before HIL simulation
 Model of new component is developed and connected to the
simulation tool
 The development iterations are fast
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Economic Effect
Frequency
Fluctuation
Power
Fluctuation
Shaft Torsional
Resonance
Harmonics
Surge
1 day
1h
1 min
1s
10 s
1s
100 ms
10 ms
1ms
100 µs
100 ns
Main Focus of RT Simulators
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Electromagnetic & Electromechanical Phenomena
Temporary Overvoltage
Transient Overvoltage
Resonance & Ferroresonnace
Instantaneous Values
RMS Values
1 day
1h
Steady State
Electromechanical Oscillation
Load Flow
Short Circuit
Harmonics
Transient Stability
Modal Analysis
Voltage Stability
1 min
1s
10 s
1s
100 ms
10 ms
1 ms
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
100 µs
100 ns
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Grid Size
(Number
of 3-Phase
Buses)
Wide Area
Transient
Stability
PSS/e
ETAP
DigSilent
Electromagnetic
Transient (EMT)
PSCAD
EMTP
SPS
Ultra-fast
Transients
SPICE
SABER
SIMPLORER
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Number of
3-Phases
Buses
Wide Area
Transient Stability
20,000
ePHASORsim
Real-Time Transient
Stability Simulator
10,000
Electromagnetic
Transient (EMT)
2,000
HYPERsim
1,000
Large Scale Power System
Based on Nodal Algorithm with Single Line Diagram
500
100
10
Ultra-fast
Transients
eMEGAsim
Power System & Power Electronics Simulation
Based on MATLAB/Simulink and SimPowerSystems
eFPGAsim
Power Electronics Simulation on FPGA
0
1s
10 ms
50 µs
10 µs
1µs
100 ns
10 ns
(1 Hz)
(100 Hz)
(20 KHz)
(100 KHz)
(1 MHz)
(10 MHz)
(100 MHz)
Model Sampling Period (sec.) | Frequency (Hz)
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 Detailed EMT models - eMEGAsim:
 For design and validation of control and protection systems
 To analyze interaction of new power electronic systems with conventional
protection and control systems
 To validate average/phasor type models used in distributed generation
 Phasor type models - ePHASORsim:
 Testing of wide area control and protection schemes
 Voltage and VAR control and automated restoration technique require the
simulation of large-scale systems
 Such simulation is out of reach for the powerful EMT parallel simulators
 Real-time Phasor-Type simulators for operator training
 Hybrid Simulations
 Mixed-mode (EMT-Phasor) simulators will be more and more needed
1. EMT simulation
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Real-time transient stability simulator
• Large-scale power systems
• Transmission, distribution and generation
Phasor domain solution
• Nominal frequency
• Positive sequence (balanced systems)
• 3-phase (unbalanced systems)
• Time-step in the range of few milliseconds
Machines,
Controllers,
Dynamics
+
Network side
algebraic
equations
 x  f ( x, V , t )

0  g ( x, V , t )
 x(t )  x
0
 0
Discretization of
differential equations
Solving linear algebraic
equations
Explicit Euler
LU Factorization
x : vector of state variables
V and I are the vectors of bus voltages and currents
Y is the nodal admittance matrix of the network
In ePHASORsim:
• Power system components inject current via an
external source into an individual bus of the power system
• The current flow can be positive-sequence-balanced, or three-phase-unbalanced.
This injection is directly added to the vector I(x,V) in (2)
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 Solver built as a MATLAB/Simulink S-function + library of coded models
 The network description (components, parameters,…) are defined in Excel
 Convenient for large networks (20,000 bus)
 Operation Commands can be sent to solver directly or via Distributed
Network Protocol (DNP3):






Apply faults on buses, with variable fault location
In-service/Out-of-service commands for loads, C banks, transmission lines, …
Adjust tap position, reference for controllers
Change load profile
Open and reclose breakers
Etc.
 Data Import: the tool offers importing from PSS/e load flow cases (*.raw)
and dynamic data files (*.dyr) for a list of components
 open to add import from other third party simulation package
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 Using the “Current injection” for a VSC
With this formulation, the user can develop DC-side components and their required
control scheme, and then the unit can be placed in a closed-loop system where the AC
grid is modeled in ePHASORsim.
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 Static Synchronous Compensator (STATCOM)
 Shunt-connected device used to regulate the voltage of an AC bus
 It consists of three parts: DC source, voltage-source-converter (VSC),
and controller
 Simple Photovoltaic cell (PV)
 A simplified model as a voltage and radiation-dependent current
source
 The PV is modeled as a current source in parallel with a capacitor
 Details of the PV equation related to diode’s voltage-current
characteristics are ignored
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 Shunt-connected device used to regulate the voltage of an AC bus
 It consists of three parts: DC source, voltage-source-converter (VSC), and controller
The steady state and dynamic response of the simulation are compared with the
Phasor mode simulation of SimPowerSystems toolbox.
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Voltage at Bus 2
Err < 0.4 %
Err < 2 %
Bus 1
Bus 2
Bus 3
Vref: initially set to 1 p.u., and
subsequently lowered at t = 0.5 s to
0.97 p.u., raised at t = 0.7 s to 1.03 p.u.,
and changed back to 1 p.u. at t = 1 s.
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
At t = 1.4 s a threephase-to-ground fault
happens at Bus 1 for a
duration of 50 ms.
16
Current flow in
transmission line at Bus 1
Bus 1
Bus 2
Bus 3
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 A simplified model as a voltage and radiation-dependent current source
 The PV is modeled as a current source in parallel with a capacitor
 Details of the PV equation related to diode’s voltage-current characteristics are ignored
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Voltage at Bus 2
Relative error < 1%
Increase of solar radiation with a step
function characteristic at t = 0.5 s
No Voltage Regulator included
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 Application of ePHASORsim to perform MIL simulation
 How to integrate power system components with VSC (such
as STATCOM and PV) with the rest of the power system
 Test and tune the controllers
 Useful for large-scale system and wide area control
Future Work:
 Parallel processing and high-performance programming
techniques (100,000 buses)
 Add more built-in components to the library
 Add more third party network format
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 A single platform that handles the RT simulation of:
 Transient stability (time step = 5 - 10 ms) - Phasors
 Electromagnetic transients (time step = 20 – 50 us) - Instantaneous
 Ultra-Fast transients (time step < 1 us) – Instantaneous (VSC, MMC)
 Works with:
 Single line diagram modeling, or
 Simulink / SimPowerSystems modeling
 Applications:






Closed-Loop testing of Physical devices
Protective relay testing
Phasor Measurement Units and Wide Area Monitoring
Solar and Wind Farm integration Testing
FACTS Control-in-the-loop testing (HIL, Power HIL)
…
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Host PC
Ethernet
RT Simulator
PC-Based Architecture
PCI-Express bus
MultiCore
Model
RT Comm.
Board
PCI Express
Adapter
CPU
MultiCore
Model
Shared
Memory
CPU
FPGA
…
Carrier Board
D/A
A/D
DO
DI
CAN,
IEC61850
…
Physical Device
under test
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 Software-in-the-loop (all digitally simulated)
 Hardware-in-the-loop
Projects
 Real-Time Simulation of Phasor Measurement Unit
 Emulation of an Over-Current Relay
 Model Developed in SimPowerSystems (MATLAB/Simulink)
 Real-Time Simulation on OPAL-RT Simulator
 Validated with actual relay (SEL-487E) in HIL setup and comparison
with Stand Alone Testing System
 Power System Communication (Station & Process Bus
Implementation)- Real-Time HIL Setup [Opal-RT + ABB-RED 670]
 PMU in HIL setup with development of graphical monitoring
interface
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