一种磁轴承开关功放的半周期控制方法

A Half-Cycle Control Algorithm for Switching Power Amplifier in Magnetic Bearing

针对传统数字单周期控制算法存在一个周期内无法精确控制实际电流的问题,提出一种新型的半周期控制方法。该方法每半个周期进行一次电流控制并用泰勒级数减小传统方法中用极限计算占空比所造成的误差,分别推导了双极性、单极性调制方法下的半周期占空比数学模型,并构建了用于磁轴承开关功放的半周期控制系统。与传统单周期控制方法的仿真结果比较表明:半周期控制的电流纹波和谐波含量比单周期控制小,电流的动态响应速度比单周期控制快,且磁轴承悬浮位移性能优于单周期控制。

The traditional digital one-cycle control algorithm could not accurately control the actual current in one cycle.To address this problem,a new half-cycle control algorithm was proposed.This method performed current control every half cycle and used Taylor series to reduce the error caused by the limit calculation of the duty cycle in the traditional method.The mathematical models of the duty of half-cycleunder bipolar and unipolar modulation methods were deduced respectively,and the half-cycle control system for magnetic bearing switching power amplifier was constructed to test this method.Compared with the traditional one-cycle control method,the simulation results had demonstrated that the current ripple and harmonic content of half-cycle control was smaller than that of one-cycle control,the dynamic response speed of current was faster than that of one-cycle control,and the magnetic bearing suspension displacement performance was better than single-cycle control.