复合结构永磁同步电机多点测温系统

Multi-point temperature measurement system for compound-structure permanent-magnet synchronous machine

针对复合结构永磁同步电机温升实验中测量点多、传感器引线空间有限、电磁干扰严重等问题,研究了基于二线制PT100的测温系统。为减小引线电阻及电路元件参数误差的影响,提出了基于线性测量电路的线性误差校准方法;在短时间采样窗内温度信号近似直流的条件下,分析了电磁干扰对测量的影响,对比了非同步采样条件下传统矩形窗与四项Blackman-Harris窗对干扰信号在直流位置能量泄露的抑制效果,提出了加窗平均值滤波方法。实验证明测温方法能有效降低抑制电磁干扰,实现电机温度多点实时测量。

To solve the problems of multipoint measurement,limited sensor wiring space and severe electromagnetic interference in thermal test of compound-structure permanent-magnet synchronous machine,the 2-wire PT100 based temperature measurement system is investigated.A linear sensor circuit and corresponding error calibration method were proposed to minimize the influence of wire resistance and circuit component error.The electromagnetic interference was analyzed within short sampling period when the temperature signal can be considered as DC component.The attenuation performance of interference leakage was compared between rectangle window and 4-term Blackman-Harris window when asynchronous sampling occurred,and a windowed average filtering method was proposed to improve system accuracy and stability.Experiments were carried out and the proposed method showed efficient tolerance to electromagnetic interference for the real-time temperature measurement of electric machines.