摘要
火力发电厂重要辅机采用变频调速,对电动机差动保护产生了重大影响。分析了应用高压变频器后电动机差动保护的装设范围,研究了变频器输出侧频率宽范围变化对常规相量差动保护的影响。同时,针对变频运行时电动机主保护缺失问题,提出采用采样值差动保护作为变频电动机主保护的解决方案。通过适当地选择S值,采样值差动保护对电流互感器(TA)饱和的影响具有一定的抵御能力,在工程实际中具有良好的应用前景。
It makes great impacts to the traditional motor differential protection when the high-voltage converter is applied in important auxiliary generators of coal-fired power plants.This paper analyzes the installation scope of motor differential protection after applying high-voltage converter and studies the influences on traditional motor differential protection due to the converter side frequency fluctuation of a wide range.Sampling value differential protection can be adopted as main protection for motor when it works in frequency-conversion mode.Sampling value differential protection can guard against TA saturation by selecting appropriate value of S,and it has a well application value in engineering.
出处
《江苏电机工程》
2011年第1期62-65,共4页
Jiangsu Electrical Engineering
关键词
电动机保护
高压变频器
采样值差动保护
motor protection
high-voltage frequency converter
sampling value based differential protection
