基于电动机热模型的微机反时限保护方法研究

用微分方程建立导体发热的连续模型,全面反映了导体温升随电流变化的过程.根据该模型得到的过流保护反时限动作特性曲线,为了解决反时限特性曲线中的对数运算转换为微处理器能够处理的运算的问题,对其进行了探讨,并提出了解决方法,通过仿真表明完全可以在实际的微机保护装置中应用,具有较高的实际应用价值.

Study on inverse-time protection method based on thermal model of induction motor

In this paper, the establishment of differential equations of the continuous thermal model, conductor temperature changes with the current process has been fully reflected. The model is adopted to produce the inverse time overcurrent characteristic curves. In order to solve the problem of the inverse-time characteristic curve of exponential calculation into a microprocessor capable, this paper discusses it and puts forward solutions. The simulation shows it can be used in the actual application of microprocessor-based protection devices. It has a higher value of the practical application.