大中型城镇排水泵站电动机无功补偿设计

Design of Reactive Power Compensation for Electric Motors in Large and Medium sized Urban Drainage Pumping Stations

在大中型城镇排水泵站中,大量安装使用高压异步电动机,其功率因数一般均较低,且可能长期运行在轻载工况,此时功率因数更低,需要进行无功功率补偿,以满足当地电网公司的考核和节能要求。该文结合某大型城区排水泵站,对高压异步电动机无功补偿方案设计、无功补偿容量计算及无功补偿装置实际输出无功容量计算进行论述,针对按电动机额定值进行无功补偿,在轻载或低负载率时补偿效果差的问题,提出采用EXCEL绘图功能中多项式曲线拟合法,对电动机负载率、电动机母线电压在一定范围内变化时,无功补偿前、后功率因数曲线及无功补偿装置实际输出无功容量曲线进行模拟计算,分析补偿效果,方法简单实用。

In large and medium-sized urban drainage pumping stations,a large number of high-voltage asynchronous motors are installed and used.Their power factor is generally low,and they may operate under light load conditions for a long time.At this time,the power factor is lower,and reactive power compensation is required to meet the assessment and energy-saving requirements of local power grid companies.This article discusses the design of reactive power compensation schemes for high-voltage asynchronous motors,the calculation of reactive power compensation capacity,and the actual output reactive power capacity calculation of reactive power compensation devices,based on a large urban drainage pump station.In response to the problem of poor compensation effect when reactive power compensation is carried out according to the rated value of the motor at light or low load rates,a polynomial curve fitting method in the Excel drawing function is proposed to simulate and calculate the power factor curves before and after reactive power compensation and the actual output reactive capacity curve of the reactive power compensation device when the motor load rate and motor bus voltage change within a certain range.The compensation effect is analyzed,and the method is simple and practical.