Center für Flexible Elektrische Netze FENEU Directorate General for EnergyRound Table – Hybrid Grids
BrusselsMay 2018
Energy System Transition and DC Hybrid Power
Systems
Prof. Dr. ir. Dr. h.c. Rik W. De DonckerDirector Forschungscampus FEN, Director ISEA & E.ON ERC | PGS, RWTH Aachen University
The Energy System Transition and DC Hybrid Power Systems
Introduction• RWTH CAMPUS Cluster Sustainable Energy• Distributed Generation & Sector coupling• Research CAMPUS Flexible Electrical Networks
MVDC and LVDC hybrid distribution gridsIntegration of RES and E-mobility in the Urban Environment
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RWTH CAMPUS Cluster Sustainable EnergyFEN Research CAMPUS to drive innovation with industry partners
CWD
CMP E.ON ERC
FEN CARL ISEAELab
E3D
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Concepts for a CO2-neutral Energy Supply System
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Research groups at RWTH Aachen University for the Energy Transition
CWDKESS
ISEA
ELAB
CMP
FEN
e3D
E.ON ERC
Kopernikus
Grids
ENSURE
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BMBF Forschungscampus „Flexible Electrical Networks”Partners of FEN Research Campus*
Status: January 2017
BMBF FEN Research Campus
* Member of CIGRE C6.31 MVDC Feasibility Study and DKE LVDC Std. Committee
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FEN Flagship ProjectP4 Medium-voltage (5 kV) CAMPUS grid
MVDC and LVDC hybrid distribution grids
• Underlay distribution grid• Renewable and decentralized power sources
• Cellular distribution grid structures
• Hybrid distribution grids
• Intelligent DC substations key enabling technology for power routing• Medium voltage grids
• Low-voltage DC transformers
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Distributed REN InstallationBalancing by meshed, regional medium-voltage distribution grids
Munich
Berlin
Hamburg
Bremen
Underlay distribution gridIs interesting business proposition from DSO perspective
Area for
100% windArea for
100% PV
Cologne
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DC-Grids are less prone to instabilities and are more flexible to control via intelligent sub-stations than AC grids
Power flow in DC grids depend
only on voltage
DC current follows voltage
and path of lowest resistance
Power flow in AC grids is controlled by
voltage and phase
Reactive currentNo-load
Active current
Unwanted Power Flow
Reactive Currents
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Classical Distribution Grids are radialIntegration of decentralized supplies. renewables, storage and e-Mobility is difficult
MV MV
LVLVLVLV
HV
25% 25% 25% 25%
50% 50%
=~3~
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Classical Distribution Grids are radial and massively oversizedIntegration of decentralized supplies. renewables, storage and e-Mobility is difficult
HV
25% 25% 25%
100 %
25% 25% 25%
MV MV
LVLVLVLV
25%
=~3~
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Hybrid Approach to Maximize Capacity of Distribution Grids Integration of e-Mobility, PV, Wind, Storage … by MVDC-Backbone
3~= =
3~= =
MVDC
MVDC
3xFCS
HV
==
==
==
==
==
==
==
3xFCS
==
25%
25%
25%
100% 100%
25%50 %50 %
MV MV
MVDC
LVLVLVLV
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Medium-Voltage High-Power DC-DC ConverterDual-Active Bridge as a universal PEBB
P = 7 MW, VDC = 5 kV ±10 % Three-Phase Dual-Active Bridge (DAB) High efficiency (99%) Medium-frequency ac-link Modular approach- PEBB Scalable in power and voltage Buck-Boost operation, short circuit proof
R. Lenke, „A Contribution to the Design of Isolated DC-DC Converters for Utility Applications“, Diss. RWTH Aachen University, E.ON ERC, 2012
N. Soltau, „High-power medium-voltage DC-DC converters : design, control and demonstration”, Diss., RWTH Aachen University, E.ON ERC, 2017
DAB uses ABB IGCT Stacks
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R. Lenke, „A Contribution to the Design of Isolated DC-DC Converters for Utility Applications“, Diss. RWTH Aachen University, E.ON ERC, 2012
N. Soltau, „High-power medium-voltage DC-DC converters : design, control and demonstration”, Diss., RWTH Aachen University, E.ON ERC, 2017
DAB uses ABB IGCT Stacks
P = 7 MW, VDC = 5 kV ±10 % Three-Phase Dual-Active Bridge (DAB) High efficiency (99%) Medium-frequency ac-link Modular approach- PEBB Scalable in power and voltage Buck-Boost operation, short circuit proof
Medium-Voltage High-Power DC-DC ConverterDual-Active Bridge as a universal PEBB
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Multiport DC-DC Converters as Power Router
Fully bidirectional power flow between different loads/grids, i.e., no intermediate (high voltage) stage is required to exchange power between loads/grids of different or equal voltage levels
Solid state fault protection
Low component count (each load/grid requires only one power electronic port)
Arbitrary number of loads/grids can be operated in island mode
Highly efficient and flexible way for interconnecting dc grids/loads
Using multi-port dc-dc converter
identical
power
stages
Using separate dc-dc converters
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150 kW Multiport DC/DC Converter
Coupling of MV to LV DC grids 150 kW SiC MOSFETs Sophisticated dynamic control for
stable operation
10 kV SiC MOSFETs and drivers of the
medium-voltage port
Opportunity for fast charging service in cities with DC distributionCharging for fast charging with public transportation grids
Opportunities for infrastructure cost and energy savings, efficiency improvements in building and industry sector
Integration of RES and E-mobility in the Urban Environment
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Modern Electric Vehicle Drive TrainModular and fast charging ready!
• Demonstrator 280 kW
2x 115 kW ASM
1x 50 kW PMSM
2 LiIon batteries
144 V and 216 V
38,4 kWh
• Audi Q6 e-tron quattro 370 kW (three motors)
Max. speed 210 km/h
95 kWh LiIon
DC charging with 150 kW
500 km driving range
e performance developed at RWTH - predecessor of the Audi Q6 Production at AUDI, Brussels
Audi e-tron Quelle: Audi
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DC (co-) infrastructure to allow grid integration of fast-charging stations using already existing AC infrastructure
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Fast-Charging InfrastructureDual Use of Railway and Light Rail Infrastructure
• Low utilization of large capacity railway infrastructure (12%)• Existing capacities can be used for fast charging• Railway and light-rail grids are available in cities Light rail typically 750 Vdc
Belgium, Spain, Italy, Russia use 3000 Vdc
France, NL use 1500 Vdc
Source: Müller-Hellmann
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Fast-Charging Infrastructure linked to light-rail
• Research project „BOB“ (Solingen) Double use of Trolley bus infrastructure Catenary power used for charging of
on-board batteries during operation Possible electrification of lines without
catenary Integration of renewable energies Services for feeding ac grid
• 4 GW (750 Vdc) installed capacity in German cities alone (VDV) Average use is 12% Each day about 85 GWh is available to charge EV 1.4 million EVs with 60 kWh battery 420 million km range (@20 kWh/100 km)
Source: Uni Wuppertal
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DC-grid and energy management in a DC quarterLower infrastructure cost, higher efficiency and bi-directional
MVDC
+/- 380 V
LVDCAC
DC converter
+/- 5 kV
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Commercial DC Building and Factories
• Building infrastructure with DC HVAC with heatpumps Heat/cold storage Lighting ICT Elevators/escalators E-mobility parking lots (dual use of
batteries) Local generation and storage
• AC-branch for legacy devices
• Local hybrid AC/DC substation
BAT
AC
DC
DC
DC
LVACLVDC
AC
DC
DC
DC
Clipart: Openclipart.org
Source: Forschungscampus FEN MVDC
M=
Center für Flexible Elektrische Netze FENEU Directorate General for EnergyRound Table – Hybrid Grids
BrusselsMay 2018
Power electronics for Medium-Voltage Distribution Grids
Prof. Dr. ir. Dr. h.c. Rik W. De DonckerDirector Forschungscampus FEN, Director ISEA & E.ON ERC | PGS, RWTH Aachen University
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DC Collector Grid Configurations for Large PV Parks
AC configuration DC configuration 1DC configuration 2
H. A. B. Siddique, S. M. Ali and R. W. De Doncker, "DC collector grid
configurations for large photovoltaic parks," 2013 15th European Conference on
Power Electronics and Applications (EPE), Lille, 2013, pp. 1-10, doi:
10.1109/EPE.2013.6631799
H. A. B. Siddique and R. W. De Doncker, "Evaluation of DC Collector-Grid
Configurations for Large Photovoltaic Parks," in IEEE Transactions on Power
Delivery, vol. 33, no. 1, pp. 311-320, Feb. 2018, doi:
10.1109/TPWRD.2017.2702018
