变频器中电动机过载保护的算法及其实现

在分析传统的电动机反时限过载保护局限性的基础上,根据电动机的一阶热模型方程,文章提出了一种应用于变频器的新型电动机过载保护算法,详细介绍了该算法中参数的整定和修正方法,并给出了算法流程。仿真结果表明,该电动机过载保护算法体现了电动机过载过程中电动机本体发热和散热的物理过程,使得传统算法难以解决的过载波动、断续过载等问题得到了较好的解决。

An Algorithm of Overload Protection of Motor in Converter and Its Implementation

On the basis of analyzing limitation of traditional overload protection of inverse time lag of motor,the paper put forward a new algorithm of overload protection of motor used in converter according to first order equation of thermal model of motor.It introduced methods of parameters settling and(amending) in the algorithm in details and gave flow of the algorithm.The simulation result showed that the(algorithm) reflected physical process of heat generation and heat emission of motor in overload process of motor,and preferably solved the problems such as overload fluctuation and intermittent overload that was not solved by traditional algorithm.