Presentation at OPAL-RT RT15 User Group event in Berkeley on May 13-14, 2015

1. © Fraunhofer IWES
Slide -1- Ron Brandl Project: DEAstabil
Multi-Terminal Power Hardware-in-the-Loop
Test-Bench for Power System Stability
Analyses Focused on Distributed Generation
RT15
Berkeley, CA | 13 - 14 June, 2015
Authors: Ron Brandl, Fraunhofer IWES
Dominik Geibel, Fraunhofer IWES

2. © Fraunhofer IWES
Slide -2- Ron Brandl, Project: DEAstabil
Multi-Terminal PHIL Test Bench for Power
System Stability Analyses
Content
1. Introduction
2. Power System Stability (PSS)
3. Simulation Environment
4. Hardware Environment
5. Power Hardware-in-the-Loop (PHIL) Simulation
6. Conclusion

3. © Fraunhofer IWES
Slide -3- Ron Brandl Project: DEAstabil
1. Introduction
Motivation
 Large increase in inverter-coupled generating units
 In Germany over 50% of power generation is from PV and wind at certain times
Change of future network
 Loss of spinning reserves
 Decentralization of power production
 Future mix of power plant park will
be inverter-dominated
 Power system stability (PSS)
has to be assured
Transformation to inverter-dominated networks
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Conventional Production > 100MW Wind Solar
18th April 2013 in Germany

4. © Fraunhofer IWES
Slide -4- Ron Brandl Project: DEAstabil
2. Power System Stability
Conventional PSS
 Focused on rotating generators
 Rotor angle stability
 Frequency stability
 Voltage stability
 Reconsideration of conventional
stability assessment Source: Definition and Classification of Power System Stability, IEEE/CIGRE Joint
Task Force, P. Kundur et. al.
Definition of Stability

5. © Fraunhofer IWES
Slide -5- Ron Brandl Project: DEAstabil
2. Power System Stability
Factors for network imbalance
 Failure/blackout of
 central power plants
 large loads
 transmission line
 HVDC terminals
 Switching operations on transmission network
 Weather influence
 Change of active coupling points of the interconnection to boundary networks
Scenarios for different PSS disturbances

6. © Fraunhofer IWES
Slide -6- Ron Brandl Project: DEAstabil
2. Power System Stability

7. © Fraunhofer IWES
Slide -7- Ron Brandl Project: DEAstabil
3. Simulation Environment
Intention of new simulation
platform
 Holistic simulation of transmission
and distribution network for stability
studies
 Include dynamics of decentralized
generators in the distribution
network
 Ability to conduct real-time
simulations, esp. PHIL simulations
 Evaluation of the future needs of
the power system, with increasing
inverter-based generation, on a
scientific basis
Motivation

8. © Fraunhofer IWES
Slide -8- Ron Brandl Project: DEAstabil
3. Simulation Environment
German interconnection network
 Holistic stability analyses required
 >> 100.000 nodes and machines from
high voltage down to low voltage level
Handling
 Aggregated models of distribution
networks with dynamic behaviors
 Development of models ≤ 110 kV
which are scalable and containing the
influence of distribution generators
 Verification of network models based
on available data of real network
disturbance
Dynamic Model of Distribution Networks

9. © Fraunhofer IWES
Slide -9- Ron Brandl Project: DEAstabil
3. Simulation Environment
Benefits/Summary
Advantage
 Use of self-made simulation models
 Access to calculation equations and simulation routine
Challenges
 Development of a holistic interconnection network simulation
 Real-time capability and compatibility with real-time products
 Parallel simulation on different cores is necessary, due to high numbers of nodes
General Benefits
 Flexibility  total access for developer possible
 Scalability  Level of detail user defined
 Expansion to new research fields

10. © Fraunhofer IWES
Slide -10- Ron Brandl Project: DEAstabil
4. Hardware Environment
Laboratory Test bench
Power Hardware-in-the-Loop test bench
 Development, construction and operation
of PHIL test Bench
 Demonstration of the contribution of
distributed generators (DER) to power
system stability in a laboratory environment
 Verification of the influence of power-
stabilizing control method from inverter-
based generators by coupling real-time
simulations with larger transmission and
distribution networks

11. © Fraunhofer IWES
Slide -11- Ron Brandl Project: DEAstabil
4. Hardware Environment
Laboratory (under preparation)
 Systec Laboratory, Fraunhofer IWES
 Power Hardware-in-the-Loop test bench
 Ametek, Power amplifier, 3x 3phase 90 kVA (single/parallel operation)
 Scienlab, DC-source (battery emulator), 290 kW
 TriPhase, DC-DC-AC inverter, 2x 15 kVA

12. © Fraunhofer IWES
Slide -12- Ron Brandl Project: DEAstabil
5. Power Hardware-in-the-Loop Simulation
Benefits/Summary
Intention of Power Hardware-in-the-Loop simulation
 Integration of „black box“ devices for stability support (e.g. converters)
 Level of detail increased due to use of the real hardware in comparison to software
models
 All effects of the hardware can be monitored

13. © Fraunhofer IWES
Slide -13- Ron Brandl Project: DEAstabil
5. Power Hardware-in-the-Loop Simulation
Network Simulation Scheme
German interconnection
network
 Transmission level
 2.000 nodes
 1.000 machine
 Distribution level
 Aggregated models
 4.500 active nodes
 4.000 machines
 Connection point HUT
 Current feedback circuit

14. © Fraunhofer IWES
Slide -14- Ron Brandl Project: DEAstabil
5. Power Hardware-in-the-Loop Simulation
Simulation platform
Controlled execution
 Higher-ranked phasor simulation
 Transmission network simulation
 Adaption/Integration of self-made
models
 Classified aggregated distribution
network
 Distributed generator
 Wind park
 Photovoltaic system
 CHPs
 HVDC link
 …

15. © Fraunhofer IWES
Slide -15- Ron Brandl Project: DEAstabil
6. Conclusion
Summary
Summary
 Reconsideration of power system stability
 Focusing of inverter-dominated generators in future
 Creating of holistic network simulation for stability analyses
 Scenarios of conventional PSS
 Research of new/upcoming PSS
 Power Hardware-in-the-Loop
 Laboratory Test – “Black Box” or self-programmed inverter testing
Outlook
 Network simulation for stability studies
 Development of new control strategies for DER
 Advanced test platform for DER

16. © Fraunhofer IWES
Slide -16- Ron Brandl Project: DEAstabil
Thanks for your attention
Ron Brandl
Fraunhofer Intitute of Wind Energy and Energy System Technologies
Koenigstor 59
34119 Kassel/Germany
Ron.Brandl@iwes.fraunhofer.de
Acknowledgement
We acknowledge the support of our work by the
German Ministry for the Environment, Nature and
Nuclear Safety and the Projekträger Jülich within
the project “DEA-Stabil: Beitrag der Windenergie
und Photovoltaik im Verteilungsnetz zur Stabilität
des deutschen Verbundnetzes” (FKZ 0325585).