基于热网络的异步电机过载保护模型及数字算法

以试验样机为例,依据电机内部不同的发热源将电机分作五部分,即定子铁心和机壳、定子槽绕组、定子绕组端部、转子导条和转子铁心,分别应用集总参数法建立了五阶的热网络分布模型.在保证模型精度的前提下,利用零极点对消法对五阶热模型进行了降阶简化,从而得到了反应电机温升主要特性、精度高、计算简单的低阶热网络模型.对低阶热模型进行离散化,得到了适用于智能电机过载保护继电器的数字算法.

Overload Protection Model of Asynchronous Motor Basing on Thermal Network and Digital Algorithm

According to the different heat sources within the motor,the motor can be divided to five parts,namely,the stator core,the stator slot winding,rotor bar and rotor core.then the lumped parameter method was respectively used to them to establish an five-order thermal network model of asynchronous motor.With ensuring the accuracy of the thermal models,the full-order thermal models could be systematically reduced via pole-zero cancellation.As a result,a low-order thermal network models,which had nearly the majo...