© 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

© 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

© 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

0

10000

20000

30000

40000

50000

60000

70000

80000

0:0

01:0

02:0

03:0

04:0

05:0

06:0

07:0

08:0

09:0

010

:00

11

:00

12

:00

13

:00

14

:00

15

:00

16

:00

17

:00

18

:00

19

:00

20

:00

21

:00

22

:00

23

:00

Pro

du

cti

on

in

MW

Conventional Production > 100MW Wind Solar

18th April 2013 in Germany

© 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

© 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

© Fraunhofer IWES

Slide -6- Ron Brandl Project: DEAstabil

2. Power System Stability

© 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

© 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

© 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

© 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

© 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

© 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

© 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

© 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

…

© 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

© 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).