Electromagnetic Disturbance Characteristics and Influence Factors of PETT Oscillation in High-Voltage IGBT Devices

Plasma extraction transit time (PETT) oscillation occurs when insulated gate bipolar transistor (IGBT) devices turn
off
, whose frequency can reach hundreds of MHz. This high-frequency oscillation can induce electromagnetic interference problems and may exceed relevant IEC limits for electromagnetic emission. As one of the electromagnetic disturbance sources from internal IGBT, the PETT oscillation has not attracted much attention in the electromagnetic compatibility (EMC) problems of application and development of high-voltage IGBT devices yet. In this article, the detailed characteristics of PETT oscillation, i.e., oscillation frequency, duration time, and oscillation peak, in high-voltage IGBT devices are systematically investigated by experiments. From the results, oscillation frequency increases with the increase of reverse voltage, whereas decreases with the increase of the temperature. Then, more complex dependencies of the PETT oscillation characteristics on IGBT's commutation conditions are presented. It is shown that its characteristics vary greatly under different reverse voltage, forward current, and temperature. The hazard of PETT oscillation to electronic components is discussed as well. PETT oscillation occurs during the turn-
on
process, which is first reported. Based on the experiment results, the EMC test related to PETT oscillation is suggested to be performed under different commutation conditions.