Research on the Oscillation Mechanism of Insulated-Gate Bipolar Transistor in Short-Circuit Test

The oscillation of gate $V_{GE}$, collector-emitter VCE and short circuit current is caused in the process of parallel short circuit desaturation from the start to the short circuit pulse of IGBT module. In this paper, the oscillation mechanism of parallel devices $V_{CE}$, VGE and Isc is analyzed based on the resonant circuit composed of nonlinear capacitance and loop inductor in IGBT short-circuit depletion region. Secondly, the short-circuit test platform of IGBT module is set up to analyze the short-circuit test results of single and parallel modules. The results show that the chip carrier concentration and loop parasitic inductance are the main problems causing IGBT parallel oscillation. Finally, the front and back processing conditions of the power device are optimized to solve the oscillation problem of the IGBT device.

I. Introduction

Insulate-Gate Bipolar Transistors(IGBT) are widely used in industrial frequency conversion, traffic traction, energy storage and other fields [1]–[2]. With the increase in the proportion of wind, solar, and storage power generation in global power generation, the power of energy storage converter units is getting higher and higher [3]. As the core component of energy storage converters, IGBT also have increasing requirements for their robustness. As one of the type tests of IGBT, the short-circuit test is susceptible to the influence of gate resistance , bus voltage , parasitic inductance and parasitic capacitance of the device during the test process, resulting in the gate voltage V GE, set-emitter voltage V_CE and short-circuit current oscillation in the short-circuit desaturation process, and in serious cases, the IGBT module explodes and fails.