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

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 high-frequency 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 high-voltage 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.