高压电机直接启动时电压降的计算方法及比较

Calculation Methods and Comparison of Voltage Drop in Direct Starting of High Voltage Motor

随着经济的飞速发展,大容量高压电机设备越来越频繁出现在工业企业的生产过程中。高压电机直接启动属于冲击负荷的一种,它会对电能质量产生较严重的影响。因此,大容量冲击负荷在接入系统前要经过严格校核。目前工程上常采用《工业与民用配电设计手册》第六章中所给出的计算方法进行校核,也有一种估算法,但通常都只是对用户变电站的母线电压降进行计算,而对系统变电站的电压降关心较少。本文首先介绍两种电压降的计算方法,然后定性分析了预接无功负荷时对电压降的影响,最后提出了对系统变电站电压降校核较恰当的计算方法。

With the rapid development of economy,the high-voltage motor equipment with large capacity appears more and more frequently in the production process of industrial enterprises.The direct starting of high voltage motor is a kind of impact load,which will have a serious impact on power quality.Therefore,the large capacity impact load should be strictly checked before it is connected to the system.At present,the calculation method given in Chapter 6 of"Industrial and Civil Power Distribution Design Manual"is often used for checking.There is also an estimation method,but usually only the bus voltage drop of user substation is calculated,and the voltage drop of system substation is less concerned.This paper first introduces two calculation methods of voltage drop,then qualitatively analyzes the influence of pre-connected reactive load on voltage drop,and finally puts forward a more appropriate calculation method for the voltage drop check of system substation.