A Novel Local Voltage Sensing Mode for High Voltage IGBT Sensor

Yang Yang,Zhaoji Li,Zehong Li,Yule Lin,Yishang Zhao,Luping Li,Xiao Zeng,Pengfei Jia,Jiali Wan

doi:10.1109/tpel.2021.3114175

Abstract

Collector-emitter voltage ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V ce ) detection of insulated gate bipolar transistors (IGBTs) is important for safety-critical and mission-critical power applications. The conventional voltage sensing method is characterized by the detection range from 0 V to the rated voltage in the application ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V r ), which is limited by the contradiction between the dynamic range of the signal and the ADC resolution in high voltage situations. This letter proposes a novel local voltage sensing (LVS) mode, in which the detection range is from <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V st to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V r , where <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V st is a controllable starting point for the sensed voltage. Based on the LVS mode, a novel controllable voltage sensor structure is given, which can provide a sensing signal that is a scaled version of the large <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V ce when <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V ce ≥ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V st . <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V st can be controlled by applying a negative voltage to a control electrode gate ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V G2 ). An analytical model is derived to understand the mechanism of the sensor and simplify the design. The effects of internal and external parameters on the sensing characteristics are simulated using Medici & TS4. Furthermore, the sensor is incorporated into a prototype 1200-V IGBT. The test results show that, under the condition of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V G2 = 0 V or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V G2 = −1 V, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V st and nonlinear error are 622 V and 3.9% or 708 V and 3.4%, respectively, and the experimental data agree with the analytical model results. Finally, an application of dc-bus voltage monitoring using the LVS mode is presented.

Full Text