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Dr. Sudip K. Mazumder, Professor and Director of the Laboratory for Energy and Switching-Electronics Systems has developed an Optically-Switched Very-High-Voltage SiC Single-Bias High-Frequency Thyristor for Energy-Efficient and Economic Massive Grid Penetration of Renewables and Energy Storage.


The success of grid penetrations of carbon-neutral renewables (e.g. PVs, wind), energy storage, and power-quality conditioners (e.g. FACTS, SVCs) are critical to nation’s energy security and energy-surety needs. A key to that success is the realization of reliable, compact, cost-effective, and efficient power-electronic interfaces enabled by high-voltage (HV) and high-frequency (HF) power semiconductor devices (PDSs). Presently, the HV devices market is Si based (e.g. IGCTs, IGBTs, GTOs) which are fast reaching their performance limits due to Si’s low band gap, low critical electric field, and low thermal conductivity. There is thus an immense business and scientific and technological opportunity to address that emerging need.

Wide-bandgap (WBG) and high-thermal-conductivity based HV SiC devices have the potential to address that need and yield devices with smaller footprint and lower switching and conduction losses. Initial success was obtained with SiC based HV DMOSFETs. However, it is now being realized that for distribution/sub-transmission level operation, even higher voltage bipolar active devices are required to overcome the limitations of majority-carrier DMOSFETs. Two options are opening up: one based on SiC IGBTs while the other is based on SiC thyristors. MOS-controlled IGBTS have simple charge-controlled gate structure and can switch fast. However, compared to the thyristors, IGBTs’ short-circuit-current capability is limited. Further, thyristors yield lower on-state drop and can yield very HV (VHV) as well as very high current capabilities. The implications of the latter for the next generation energy grid and power systems are profound. For instance, VHV SiC devices can eliminate plurality of multi-ton 60-Hz transformers to enable direct grid interface of solar, wind, and energy-storage power converters, thereby yielding significant reduction in size, weight, cost, loss, and thermal requirements of the energy-conversion systems.

However, conventional thyristors typically have slow turn-off commutation, which limit their operating switching frequency. This bottleneck has been addressed in leading integrated electrical thyristors such as ETO, IGCT, and MTO. However, this is achieved using plurality of low-voltage (LV) biases, which add to the complexity of the thyristor gate drive.

This project will develop world's first patented all-optical, single-bias (i.e. only the power bias), and fully- controllable very-low-conduction-loss SiC-based 15-40 kV and 0.1-5 kA Integrated Thyristor. ArialMT">It improves upon core all-electrical multi-bias thyristors (IGCT/ETO/MTO) by incorporating direct photonic activation of the Integrated Thyristor. This yields the following advantages:

Electrical isolation between Integrated-Thyristor-based HV power stage and LV control stage;

Enhanced reliability due to a single power bias and no need for LV bias(es);

Rapid switching capability unlike Si based HV thyristors;

Elimination of electrical gate drivers;

Very low optical power requirement for device excitation;

Reduced device on-state and switching losses;

Reduced device and drive complexities;

Modular device voltage and current scalabilities;

Mitigation of drive-device-interconnect parasitic noise;

Immunity against electromagnetic interference;

Reduced switching delay due to direct photogeneration;

Higher device and system reliability;

High thermal conductivity.

More on Professor Mazumder.

Topic revision: r2 - 2013-08-14 - 15:20:58 - Main.tmatthes
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