Real-Time Simulation of Distribution Grids with high Penetration of Renewables and Distributed Generation

1. © Fraunhofer IWES, Paris, 26.06.2013,
Real-Time Simulation
of Distribution Grids
Paul Kaufmann
Dr. J.-Chr. Toebermann

2. © Fraunhofer IWES, Paris, 26.06.2013,
Real-Time Simulation of Distribution
Grids with high Penetration of
Renewables and Distributed Generation
Dr. J.-C. Toebermann, D. Geibel, M. Hau, R. Brandl,
P. Kaufmann, C. Ma, Prof. Dr. M. Braun, Dr. T. Degner
Dr. J.-Chr. Toebermann

3. © Fraunhofer IWES, Paris, 26.06.2013, 3
The Fraunhofer-Gesellschaft in Germany
Fraunhofer-Gesellschaft, the largest
organization for applied research in
Europe
undertakes applied research of direct
utility to private and public enterprise and
of wide benefit to society.
• 80 research units, including
60 Fraunhofer Institutes
• 20, 000 staff
• € 1.8 billion annual research budget
Research centers and representative offices
in Europe, USA, Asia and in the Middle
East.
Dr. J.-Chr. Toebermann

4. © Fraunhofer IWES, Paris, 26.06.2013, 4
Fraunhofer IWES:
Institute for Wind Energy and Energy System Technology
Research spectrum:
 Wind energy from material development to grid connection
 Energy system technology for all renewables
Foundation: 2009
Staff: approx. 500
Annual budget: approx. 30 million euros
Directors: Prof. Dr. Andreas Reuter, Prof. Dr. Clemens Hoffmann
Formerly:
 Fraunhofer-Center für Windenergie und Meerestechnik CWMT in Bremerhaven
 Institut für Solare Energieversorgungstechnik ISET in Kassel
Dr. J.-Chr. Toebermann

5. © Fraunhofer IWES, Paris, 26.06.2013, 5
Fraunhofer IWES:
Business Fields
 Environmental analysis for wind
and ocean energy
 Control and integration of
decentralized converters
 Energy and grid management
 Energy supply structures and
systems analysis
Dr. J.-Chr. Toebermann

6. © Fraunhofer IWES, Paris, 26.06.2013, 6
Renewable and Distributed Generation in Germany
Share of Renewable Energies in Power Supply
 Today: 23%
 2020: 35%
 2030: 50%
 2050: 80%
Renewable Energies in Distribution Grids
 45 GW capacity in LV and MV grids
 Reverse power flows -
example LV grid “Sonderbuch”
 Max. load: 130 KWp
 Max. feed-in: 1,200 KWp
 Estimation of 42.5 billion Euros for
distribution grid reinforcement up to 2030
Sources: J. Appen, M. Braun, T. Stetz, K. Diwold, D. Geibel,
“Time in the Sun”, IEEE Power & Energy Mag., vol.11,
pp.55-64, March 2013
Dr. J.-Chr. Toebermann

7. © Fraunhofer IWES, Paris, 26.06.2013, 7
Project 1: Holistic Smart Distribution Grid Simulation
 minimize charging costs
 improve integration of renewables
 reduce network extension costs
 challenge: What are the behavioral and electric interdependencies and
the dynamics within a distribution network?
 intelligent generators and loads exhibit
complex behaviors
 depend on local and global events and
decisions
 follow different and sometimes
contradicting goals
 example: charging of electric vehicles
Dr. J.-Chr. Toebermann

8. © Fraunhofer IWES, Paris, 26.06.2013, 8
Project 1: Holistic Smart Distribution Grid Simulation
Example: Integration of Electric Vehicles
 our vision: a system for HIL simulation and testing of
 system operation control strategies
 power HIL simulation of electric vehicles
Dr. J.-Chr. Toebermann
Funded by
BMU, 0325402

9. © Fraunhofer IWES, Paris, 26.06.2013, 9
Project 2: Test Bench for System Stability based on
Distributed Generation
Factors of influence of network stability
 Balance between production and
consumption
 Coming inverter-dominated areas
 Balance more complex
 Compensation of system
stability necessary
Overview of stability issues
Ron Brandl, Dominik Geibel

10. © Fraunhofer IWES, Paris, 26.06.2013, 10
Overview of stability issues 2
 Classic network stability
 Prospective power plant
change
 New system stability necessary
 Rotor angle stability
 Frequency stability
 Voltage stability
 Compensation of conventional
power plants stabilities
regulation effect
 require new stability
functionalities of DER
Project 2: Test Bench for System Stability based on
Distributed Generation
Ron Brandl, Dominik Geibel
Source: Definition and Classification of Power System Stability,
IEEE/CIGRE Joint Task Force on Stability Terms and Definitions, IEEE
Transactions on Power Systems, Prabha Kundur et. al.

11. © Fraunhofer IWES, Paris, 26.06.2013, 11
State-of-the-art Network
Simulator
Advanced PHiL Test Bench
Interaction
between simulator
and Device under
Testing (DUT)
No feedback from device Feedback by current
measurement as input for U/f
calculation at network
connection point
Voltage and
frequency curves
- Fixed before test run
- Independent from DUT
Depends on interaction
between simulated network
and DUT
Characteristics of
network
connection point
- Emulated by physical
resistance
- Network impedance is fixed
- Simulated
- Adopted due to network
behaviour
Power system
capability
- Less complexity
- No interaction between
different functionalities
- Entire transmission/distribution
networks
- Influence of complex
functionalities
Comparison between state-of-the-art and PHIL-Test-Benches
Project 2: Test Bench for System Stability based on
Distributed Generation
Ron Brandl, Dominik Geibel

12. © Fraunhofer IWES, Paris, 26.06.2013, 12
Simulation Model for Stability Analyses
 Transmission/Distribution networks
 Prospective change of inverter dominated areas
 3phase EMT model for PHIL simulation
 >2500 nodes in transmission level and >100.000 nodes in distribution level
Project 2: Test Bench for System Stability based on
Distributed Generation
Ron Brandl, Dominik Geibel

13. © Fraunhofer IWES, Paris, 26.06.2013, 13
 Transmission/Distribution networks
 Prospective change of inverter dominated areas
 3phase EMT model for PHIL simulation
 >2500 nodes in transmission level and >100.000 nodes in distribution level
 Development of
distribution network
equivalent
Simulation Model for Stability Analyses 2
Project 2: Test Bench for System Stability based on
Distributed Generation
Ron Brandl, Dominik Geibel

14. © Fraunhofer IWES, Paris, 26.06.2013, 14
Multi –Purpose Test Bench for Stability Research
 Real-Time Simulation
 Transmission/Distribution level
 EMT signal output of defined
network buses
 Network fault
 Generation unit
 Up to 300kVA
 Up to three units
 Rotation and static
 DER
 Self-controllable
 Stability support
Acknowledgments
We acknowledge the support of
our work by the German Ministry
of Environment, Nature and
Nuclear Safety and the
Projekträger Jülich in the frame
of the project “DEA-Stabil”
(FKZ 0325585A).
Only the authors are responsible
for the content of the
publication.
Project 2: Test Bench for System Stability based on
Distributed Generation
Ron Brandl, Dominik Geibel

15. © Fraunhofer IWES, Paris, 26.06.2013, 15
Project 3: Test Benches for Controllers of Wind Turbines /
Wind Parks
HIL-Simulation and control for grid integration of Wind Energy
1. Wind park controller
 Participation in grid voltage support (reactive power at PCC)
 Active power control at PCC
2. Control on wind turbine level
 Actuator of wind park controller (active / reactive power)
 Fault-Ride-Through
 Synthetic inertia, i.e. replicating the natural inertia in the grid
General aim: grid-friendly behavior = stable control system, avoid oscillations
Melanie Hau, Park Control and Real-Time Simulators

16. © Fraunhofer IWES, Paris, 26.06.2013, 16
Development of Wind Park Controllers:
1. Software-in-the-loop (Basis: detailed model of the wind park / grid)
 model insecurities (parameters, communication dead-times)
 Software-only (hardware-related issues ignored, e.g. signal exchange)
2. Commissioning and testing in real wind parks
 Testing for few, non-critical operating points
 Environmental conditions (wind, grid) not reproducible
 High costs
 Additional hardware-in-the-loop testing prior to commissioning
 Hardware controller and communication system connected to a real-
time simulator of the wind park and superior grid
 Systematic testing: reproducible, safe & cost-effective hardware testing
Project 3: Test Benches for Controllers of Wind Turbines /
Wind Parks
Melanie Hau, Park Control and Real-Time Simulators

17. © Fraunhofer IWES, Paris, 26.06.2013, 17
 Basis: model library in Matlab/ Simulink
 Flexible with respect to real-time environment platform
 Embedded into automatic test processing environment
Project 3: Test Benches for Controllers of Wind Turbines /
Wind Parks
 Funded by
Melanie Hau, Park Control and Real-Time Simulators

18. © Fraunhofer IWES, Paris, 26.06.2013, 18
Summary
 Growth of wind and solar energy as well as rising E-Mobility usage will
increasingly challenge grid assets, operation, and control
 Real-time Hardware-in-the-loop simulation is essential for understanding
the interdependencies and stability of "smart" inverters and system
operation strategies and providing stability to the electric grid
 The challenge of integrating "smart" grid components is urgent in
Germany demanding for quick technical and regulatory solutions
Thank you very much for your attention
Contact: Paul Kaufmann / Dr. J.-Chr. Toebermann
paul.kaufmann@iwes.fraunhofer.de
Fraunhofer IWES
Koenigstor 59
34119 Kassel / Germany
Dr. J.-Chr. Toebermann

19. © Fraunhofer IWES, Paris, 26.06.2013, 19
Research Objectives and Real-Time Simulation
Primary objective of our research is to find solutions which
 are based on distributed power plants interfaced with an inverter
 lead to reduced / acceptable operational and investment cost
 ensure the current high quality standard in power supply
Application examples based on real-time simulation
 Simulation of distribution grid system operation
 Simulation of system stability based on distributed generation
 Simulation of grid connection of wind turbines and wind parks
Dr. J.-Chr. Toebermann