New single-bias all-optical ETO configuration for a 15 kV-100A SiC thyristor eliminating the turn-on leakage current

Abstract

In this paper a new single-bias optically-triggered (OT) emitter-turn-off (ETO) configuration for a 15kV-100A SiC thyristor, used in the next generation high-voltage highfrequency and high-power-density applications is outlined. Optical turn-off and turn-on of the OT ETO is achieved using an auxiliary optically-triggered power transistor (OTPT) in the anode path of the SiC thyristor. Leakage current during the turn-on transition of OT ETO is caused by the undesired activation of the turn-off path of the gate of the thyristor. This undesired activation is due to parasitic inductances and high di/dt in the commutation path, resulting in additional switching loss and electro-magnetic noise. In contrast to other works, the proposed method removes the leakage current enhancing the switching performance, reducing the switching loss and EMI. The other feature of the proposed work is using a single highvoltage bias eliminating the need for low-voltage (LV) control bias and devices in conventional methods. The system reliability is increased via using optical link to turn the SiC thyristor on and off, precluding the susceptibility to external noise. The proposed method and the OTPT are respectively verified through simulation and experimental results.

Direct-Triggering LTT With Monolithic Structure

“…However, most LTTs are each composed of two parts, one of which is of low power and the other is of high power, and the two parts are triggered oneby-one in a cascade manner: only after the low-power part is optically triggered ON, is the high-power part electrically triggered into ON state [17][18][19][20][21]. Such cascade triggering inherently deteriorates the turn-on process as a whole [22][23][24][25][26].…”