Power Electronics to Improve the Performance of Modern Power Systems

Case Studies on Multi-Terminal HVDC Transmission Systems and Truck-Mounted Transformers

a report on subtask 1-1

Armin Teymouri

Wind

• Generator types• Power electronics

Trends of wind turbine sizes and rating of power electronics :

Degrees of freedom in designing wind turbines:[1]

• Speed control systems • Aerodynamic power limits 2

A. DFIG with Partial-Scale Power Converter

B. A/SG with Full-Scale Power Converter

WindPopular Topologies

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Grid integration performance comparison

Wind

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Technology Challenges for Power Electronics in Wind Turbine SystemsA. Levelized Cost of Energy

Protection and islanding operation of wind power systems

D. Future Technologies for Wind Power Integration

Wind

C. Reliability

B. Grid Integration Features

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[2]

[1]

Reasons for PV inverter cost reduction over the years:

• Increase in inverter rated power,

• Reduction of component costs as a result of higher numberof components,

• Reduced production time due to automation,

• Functionality integration of inverter doing several tasks byone component.

SolarPV electricity cost1991 2014120 cents/kWh 14 cents/kWh

qReasons: 1. Increased efficiency and reduced system losses - 41 cents/kWh2. Developments in power electronic sytems- 30 cents/kWh

material cost of 3 consecutive generations of PV inverters

year

6[3]

Concepts for the distributed power electronics in PV systems:

Solar

The use of string or modular PE topologies decreases the effects of module mismatch or partial shading. 7

[4]

q Benefits of PV Power Electronics

DC-DC converters can mitigate

SolarA. Decreased Lost Power C. Improved Safety-Arcing

B. Cracked Cell Impact Mitigation D. Enabling Creative Designs

q Challenges of PV Power ElectronicsA. Reliability B. Interoperability C. Cost D. Parasitic Losses

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• Based on magnetic core and Aluminum windings• Oil based/dry cooling• Fixed voltage/current/power ratio and low frequency

SSTClassical transformer basics

Performance characteristics overview.

MV-SST (a) weight breakdown (b) cost breakdown.9

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q degrees of freedom in selecting SST topologies

A. Partitioning of the AC/AC power conversion

SSTSST Topologies

B. Partial or full phase modularity

C. Partitioning of medium voltage

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Examplesthermosmeasurements,supposedsemiconductorssome

SSTChallengesA. Availability and selection of power semiconductors

C. Protection

vibration acoustic noise

Perfect choice for low noise SST design

• Nano-crystalline material (power density and efficiency)

• Ferrite

• Semiconductor failure (V/I limiter)• Error in control systems• Error in measurements• Insulation breakdown

• Co-based amorphous alloy

B. Noise emissions

SST faults

• Fe-based amorphous alloy

D. Need for multi-disciplinary education

E. Limited university MV-power electronics

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Mechanical circuit breaker flaws

• Not being able to affect the peak current.

grid

SSCB• Limited short circuit current rating.

• Limited number of high current clearances.

SSCB advantages

• Higher speed

• Involvement in power quality issues

SSCB problems

• Higher voltage drop

• Higher power dissipation

• Non-zero off-state leakage current• Need for heat sink and EMI protection

q Selected topologies

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• Power electronics can provide a controllableinterface between the ESS, DER, and the grid,making the deliverable power comply with the gridcodes and utility schemes.

Storage

• Major industrial solutions available:

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Driving technology trends towards the application of power electronics

1. Wide Band Gap Semiconductors (WBG)2. Multi-level Converters

WBG Devices

Si-based technologies • Max. temperature allowed: 200 °C• Max. voltage allowed: 6.5 kV

• By some expert accounts, we have less than a decade left to extract additionalperformance before silicon capability is at its theoretical maximum.

Front-running solution: SiC & GaNSiC/GaN Features: • Better conduction and switching properties

• Smaller, faster, and more efficient than Si• Greater durability • Good commercial availability

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WBG DevicesEfficiency changes by replacing Si with SiC or GaN• DC-to-DC conversion efficiency from 85% to 95%• AC-to-DC conversion efficiency from 85% to 90%• DC-to-AC conversion efficiency from 96% to 99%

Summary of Si, SiC, and GaN properties

Challenges

• Design optimization• Reliability• Exploiting full material quality

Si, SiC, GaN, and diamond physical properties

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WBG DevicesqWide Band Gap Impacts on Medium Voltage Power Delivery System

q Wide Band Gap Impacts on Renewable Energy Systems and Clean Transportation

qWide Band Gap Impacts on High Voltage Power Delivery System

SiC has shown a 40-100X increase in the ratio of V*f for high voltage devices

POL: point of load converter

Considering data centers and ITequipment consume a substantial amount of energy (about 15%

of the worldwide electricity) and is rapidly growing, such apower delivery architecture is critical for a sustainable society.

• Application in SST:

• No current commercial application.• Potential applications in HVDC.

• PV, wind, electric vehicles, and motor drives• Current voltage level: 1200-6500 V• Currently developed devices are based on SiC. 16

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Driving technology trends towards the application of power electronics

1.Wide Band Gap Semiconductors (WBG)2.Multi-level Converters

Multi-level Converters

qMulti-level converter classification:Applications

1. Energy and power systems2. Production3. Transportation

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[1] F. Blaabjerg, K. Ma, “Future on Power Electronics for Wind Turbine Systems,” IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS, VOL. 1, NO. 3,SEPTEMBER 2013 139[2] “Levelized cost of new generation resources in the annual energy outlook 2013,” U.S. Dept. Energy, U.S. Energy Information Administration (EIA), Washington, DC, USA, 2013,[Online]. Avaiable: http://www.eia.gov/[3] J. Friebe, M. Meinhardt, “Future Challenges of Power Electronics for PV-Inverter,” PCIM Europe 2015, 19 – 21 May 2015, Nuremberg, Germany.[4] T. Kaur, “Solar PV Integration in Smart Grid – Issues and Challenges,” International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering, Vol.4, Issue 7, July 2015[5] S. Kurtx, C. Deline, J. Wohlgemuth, “Opportunities and Challenges for Power Electronics in PV Modules,” National Center for Photovoltaics, ARPA E Workshop, February 8, 2011,Arlington, VA.[6] “Power Transformers Market - Global Industry Analysis, Size, Share, Growth, Trends and Forecast, 2013 –2019,” Transparency Market Research, November 2, 2013,http://www.prweb.com/releases/2013/11/prweb11294070.htm (accessed December 12, 2013)[7] ] J. W. Kolar and G. Ortiz, “Solid-State-Transformers: Key Components of Future Traction and Smart Grid Systems,” in Proc. of the International Power Electronics Conf. (IPEC),May 2014.[8] C. Meyer, S. Schroder, R. De Doncker, “Solid-State Circuit Breakers and Current Limiters for Medium-Voltage Systems Having Distributed Power Systems,”IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 19, NO. 5, SEPTEMBER 2004 1333.[9] US Department of Energy, Global energy storage database. [Online] Available: http://www.energystorageexchange.org/ Access on: Aug. 25, 2016.[10] J. Millan, A. Perez, “A Survey of Wide Bandgap Power Semiconductor Devices,” IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 29, NO. 5, MAY 2014.[11] P. Gammon, “Silicon and the wide bandgap semiconductors, shaping the future power electronic market,” 14 International Conference on Ultimate Integration of Silicon, 2013.[12] A. Huang, “Wide bandgap power devices and their impacts on power delivery systems,” 2016 IEEE International Electron Devices Meeting, 2016.[13] J. Rodri, S. Kouro, I. Leo, et. Al, “Multilevel Converters: An Enabling Technology for High-Power Applications Multilevel converters generate voltage and current waveforms ofimproved quality, that can be used to power drives for trains and other vehicles, and many other applications”. Proceedings of IEEE, Vol. 97, No. 16, 2009.

References