长线变频系统反射波过电压振荡的解决方案

Solution Proposal of Overvoltage Vibration of Reflection Wave of Long Cable Variable Frequency System

变频器与电缆长距离连接的应用已很普遍,但这种连接导致电动机绝缘受损已越来越受到关注。从理论上分析了长距离电缆线路波反射的机理,通过采用Saber仿真软件建立仿真模型,得出基于长线数学模型变频调速系统的等效电路图,为不同场合变频应用系统消除高次谐波反射过电压振荡与抗干扰设计提供了参考依据。以变频器与电动机间电缆的长度问题为切入点,寻求一种电缆与变频器、电动机之间的合理匹配,提出了变频系统动力电缆选型要考虑的因素,给出了变频器载波频率与变频电缆导线截面校正系数与变频电缆温度校正系数,以及使用普通电力电缆时,通过加装电抗器的方法,可增加变频器与负载电动机的最大距离。

At present, the connection of frequency converter and long cable is used commonly in coal mine. But this kind of connection leads to insulation of electromotor damaged, which becomes more and more focus. The mechanism of long cable line wave reflection is theoretical analyzed. And the simulation model is adopted through Saber simulation software and gains the equivalent circuit diagram of frequency speed drive system based on long- term methematical model, which provides reference basis for frequency application system eliminates high-order harmonic reflection voltage oscilation and anti-jamming design in different occasions. As an entry point to the length of the cable between inverter and motor, to seek a reasonable match between a cable and the inverter motor. Proposes the factors need to consider the frequency system motor cable selection. Gives the coefficient of frequency carrior and frequency cable wire cross-section correction factor and correction coefficient of cable temperature, as well as the common ordinary power cable, through installation of reactor, which can increase the maximum long distance of frequency and loading motor.