Effect of Negative Gate Voltage on the Turn-off Performance of Si-IGBT Device

Abstract

In this study, the impact of negative gate voltage (V_G(off)) on the turn-off performance of Si-IGBT device is investigated. In general, the switching energies of the IGBT devices are given at specific V_G(off) =-15V. When estimating the power dissipation of the inverter system at different V_G(off), a correction factor of the switching energies from the given values is required. Although it is known that the value of V_G(off) affects the turn-off switching characteristic, it has not been investigated in detail. Hence, it is difficult to theoretically estimate the correction factor for the turn-off energy (E_off) for different V_G(off) and gate resistance (R_G). The effect of V_GE(off) on the behavior of collector-emitter voltage (V_CE) during the turn-off operation of the IGBT is investigated. The estimation method of E_off at different V_G(off) and R_G is derived from the investigation and theoretical formula confirmed by the experimental results. Then, a novel procedure to estimate the E_off correction factor under different gate drive conditions is proposed.