A Partial Discharge Study of Medium-Voltage Motor Winding Insulation Under Two-Level Voltage Pulses With High Dv/Dt

IEEE Open Journal of Power Electronics

Rui Liu¹  Boxue Hu¹  Jin Wang¹  Zhuo Wei¹  Julia Zhang¹  Haoyang You¹  Han Xiong¹  Pengyu Fu¹  Risha Na¹ 

[1] Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, USA;

关键词: Silicon carbide (SiC);    pulse width modulation (PWM);    electric machines;    variable speed drives;    partial discharge;    high-voltage techniques;   

DOI  :  10.1109/OJPEL.2021.3069780

来源: DOAJ

【 摘 要 】

Medium-voltage (e.g., 10 kV rated) silicon carbide (SiC) devices have great potentials in medium-voltage variable speed drives. But their high switching dv/dt can increase the voltage stress on motor windings and cause partial discharges. This paper presents a partial discharge study of a medium-voltage form-wound winding under two-level square-wave voltage pulses. A 10 kV SiC device-based test platform is built to generate voltage pulses with high dv/dt. A three-step test approach is proposed and employed to systematically investigate the effects of various voltage parameters on partial discharges. These include voltage rise/fall time, voltage pulse width, pulse repetitive rate, duty ratio, voltage polarity, fundamental frequency, and modulation index. Partial discharge inception voltages (PDIVs) and repetitive partial discharge inception voltages (RPDIVs) of the sample are measured with varied voltage parameters. Test results show that voltage rise/fall time is a major affecting factor which reduces PDIVs of the winding sample by 6.5% when it decreases from 800 ns to 100 ns. Based on test results, a hypothetical partial discharge mechanism is presented to explain the effects of fast voltage rise/fall edges. An empirical equation is also derived to estimate PDIVs of a winding sample under various voltage rise/fall time and pulse width conditions.

【 授权许可】

Unknown