Learn about Model-In-the-Loop real-time simulation, by OPAL-RT

1. International Symposium on
Industrial Electronics
ISTANBUL
Authors: Vahid Jalili-Marandi, Jean Belanger, Fabio Jose Ayres
Presenter: Simon Abourida
Simon.abourida@opal-rt.com

2. 2
Electric Power System
Real-Time Digital
Simulator
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
Real-Time
Phasor-Domain
Model
Motivation: To model the impact of DC systems (VSC)
and their controllers in the phasor-domain simulation

3.  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)
 …
3ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

4.  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
4ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

5. 5
10 s 1 s 100 ms 10 ms 1ms 100 µs 100 ns1 min 1 s1 day 1 h
Economic Effect
Frequency
Fluctuation
Power
Fluctuation
Shaft Torsional
Resonance
Harmonics
Surge
Main Focus of RT Simulators
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

6. 6
I n s t a n t a n e o u s V a l u e s
R M S V a l u e s
Steady State Electromechanical Oscillation
Transient Overvoltage
Temporary Overvoltage
Resonance & Ferroresonnace
Electromagnetic & Electromechanical Phenomena
Load Flow
Short Circuit
Harmonics
Transient Stability
Modal Analysis
Voltage Stability
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
10 s 1 s 100 ms 10 ms 1 ms 100 µs 100 ns1 min 1 s1 day 1 h

7. 7
Wide Area
Transient
Stability
Ultra-fast
Transients
Electromagnetic
Transient (EMT)
Grid Size
(Number
of 3-Phase
Buses)
PSS/e
ETAP
DigSilent
PSCAD
EMTP
SPS SPICE
SABER
SIMPLORER
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

8. ePHASORsim
Real-Time Transient
Stability Simulator
HYPERsim
Large Scale Power System
Based on Nodal Algorithm with Single Line Diagram
eFPGAsim
Power Electronics Simulation on FPGA
10,000
2,000
1,000
500
100
10
0
20,000
1 s
(1 Hz)
10 ms
(100 Hz)
50 µs
(20 KHz)
10 µs
(100 KHz)
1µs
(1 MHz)
100 ns
(10 MHz)
10 ns
(100 MHz)
Model Sampling Period (sec.) | Frequency (Hz)
Number of
3-Phases
Buses
eMEGAsim
Power System & Power Electronics Simulation
Based on MATLAB/Simulink and SimPowerSystems
8
Wide Area
Transient Stability
Ultra-fast
Transients
Electromagnetic
Transient (EMT)
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

9.  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
9
1. EMT simulation
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

10. 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
11ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
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)








00 )(
),,(0
),,(
xtx
tVxg
tVxfx
Machines,
Controllers,
Dynamics
Network side
algebraic
equations
+
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

11.  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
12ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

12.  Using the “Current injection” for a VSC
13ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
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.

13.  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
14ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

14. 15ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
The steady state and dynamic response of the simulation are compared with the
Phasor mode simulation of SimPowerSystems toolbox.
 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

15. Voltage at Bus 2
16ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
Bus 2 Bus 3Bus 1
At t = 1.4 s a three-
phase-to-ground fault
happens at Bus 1 for a
duration of 50 ms.
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.
Err < 0.4 %
Err < 2 %

16. 17ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
Current flow in
transmission line at Bus 1
Bus 2 Bus 3Bus 1

17. 18ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
 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

18. 19ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain
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

19.  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
20ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

20.  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)
 …
21ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

21. 22
Host PC
RT Simulator
PC-Based Architecture
Physical Device
under test
…
FPGA
Carrier Board
D/A A/D
CAN,
IEC61850
…DO DI
RT Comm.
Board
Ethernet
CPU
PCI Express
Adapter
Shared
Memory CPU
Multi-
Core
Multi-
Core
PCI-Express bus
Model Model
ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain

22.  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
23ISIE 2014 - Model-In-the-Loop Real-Time Simulation in Phasor Domain