一种用于电机铁芯磁性能测试的恒流源

A constant-current power supply inverter applied to a test system for the magnetic performance of the core

针对电机铁芯磁性能测试中保持磁场强度H的波形为正弦形的问题,设计了一种基于数字信号处理器(DSP)全数字实时控制的逆变恒流源。分析了正弦波逆变电源斩波和逆变控制的一般方法和特点,控制系统前级采用同步Buck电路对母线电压斩波,斩波输出电压经过PI闭环控制实现了其在突加、突减负载时的稳定性。控制系统后级通过对电感电流的PID闭环控制和单极性正弦脉宽调制(SPWM)方式,实现瞬时跟踪给定的交流恒流源控制。实验结果表明逆变恒流源具有很好的静、动态性能和稳定性,输出信号谐波含量少,负载适应能力强,很好地实现了系统设计的要求。

Aiming at testing the magnetic performance of the core,a digital signal processor（DSP）-based constant-current power supply in-verter was designed.First,normal methods and common features were analyzed to control buck converter and power supply inverter.The bus voltage of the system was reduced by synchronous Buck converter,whose output voltage was kept constant by PI controller when the load changed suddenly.Then the induction current of the power supply inverter was controlled by PID controller,whose output was modulated by unipolar sine pulse width modulation（SPWM）.The experiment results show that the system has good static,dynamic performance and stabil-ity,which satisfies the design requirement.