正弦和重复方波电压下变频电机绝缘局部放电特性对比  

Comparison of PD Characteristics for Inverter-fed Motor Insulation Under Inusoidal and Repetitive Square Wave Voltage Conditions

作　　者：王鹏[1] 周婉亚 王科镜 李金泉[1] 周群[1] 雷勇[1] 

机构地区：[1]四川大学电气信息学院,成都610065

出　　处：《高电压技术》2016年第12期3895-3900,共6页High Voltage Engineering

基　　金：国家自然科学基金(51407121)~~

摘　　要：为对比研究正弦和重复脉冲电压下变频电机绝缘的局部放电特性,基于超高频测试技术搭建了两种电压条件下电机绝缘的局部放电测试平台。利用该平台,分别在正弦及200 ns上升时间的重复脉冲电压下,对低压变频电机漆包绝缘单点放电模型进行了局部放电测试,对比分析了正弦和重复脉冲电压下的局部放电单个脉冲的时频幅值、相位分布及频域能量分布、多个脉冲的统计谱图等特性,研究结果发现:对于相同峰峰值和频率的重复方波和正弦电压,重复方波电压下变频电机绝缘局部放电幅值及耐电晕寿命分别约为正弦电压下的10倍及1/3,且相位、时频域统计特性存在明显差异,在基于国际电工委员会标准对变频电机绝缘系统进行评估时,必须依据重复方波脉冲对放电特性及耐电晕寿命影响规律,重新考虑局部放电测试及耐电晕系统的设计。The partial discharge （PD） test system is set up based on ultra-high frequency technologies in order to study PD characteristics for inverter-fed motor insulation under both sinusoidal and repetitive square wave voltage conditions. Re- sorting to the system, we performed PD tests on single discharge models made up of enameled wires used in low-voltage inverter-fed motor insulation under sinusoidal and repetitive square wave voltage with 200 ns rise times. Moreover, we analyzed single PD pulse magnitude, phase distribution in time domain, energy distribution in frequency domain, and the statistical PD patterns. Conclusions can be drawn that repetitive square wave and sinusoidal voltages having same peak-to-peak voltage and frequency can produce PD with significantly different magnitude, phase, and energy distribution as well as endurance lifetime. The PD magnitude and insulation endurance under repetitive square wave voltages are around 10 times and 1./3 times of those at sinusoidal voltages. Therefore, when performing insulation evaluation on in- verter-fed motors according to standards released by International Electrotechnical Commission, PD and endurance test system should be considered carefully on the basis of the influence of repetitive square wave voltage parameters on PD and endurance characteristics.

关 键 词：变频电机 绝缘老化 绝缘材料 局部放电 方波电压 耐电晕 

分 类 号：TM344.6[电气工程—电机]