误差自校正混合脉宽调制策略

Error Self-Correction Mixed Pulse Width Modulation Strategy

针对基于传统空间矢量脉宽调制方法的单电流传感器相电流重构存在不可观测区域,且无法实现零点漂移校正问题,提出一种误差自校正混合脉宽调制方法,通过在不可观测区域各载波周期插入两个互补有效电压空间矢量代替零电压矢量,为电流传感器提供可靠的采样窗口,消除了电流不可观测区域。同时,通过对互补有效电压矢量进行动态电流双采样,实现电流零点漂移量的自检测和自校正。实验工况下所提方法重构相电流误差小于3.57%,相电流总谐波畸变率低于4.02%,可为控制系统提供可靠的重构相电流。

The phase current reconstruction of a single current sensor based on the traditional space vector pulse width modulation method has an unobservable area and cannot realize the zero-point drift correction.Therefore,an error self-correcting mixed pulse width modulation method is proposed.Two complementary effective voltage space vectors are inserted in each carrier cycle of the unobservable area to replace the zero-voltage vector,which provides a reliable sampling window for the current sensor and eliminates the current unobservable area.At the same time,through the dynamic double sampling of the complementary effective voltage vector,the self-detection and self-correction of the current zero drift are realized.Under the experimental conditions,the proposed method recon-struction phase current error is less than 3.57%,and the total harmonic distortion of the phase current is less than 4.02%,which can provide a reliable reconstruction phase current for the control system.