同步参考坐标优化谐波与无功电流检测的改进方法

Improved synchronous reference coordinate optimization method for harmonic and reactive current detection

三相电压不对称且畸变时,传统同步参考坐标检测法中的锁相环无法提取正序基波电压,使测得的无功和谐波电流存在较大的误差。采用基于对称分量矩阵的A相基波正序电压提取单元代替传统方法中的锁相环,可以对电源电压矢量进行同步旋转跟踪。该方法省去锁相环和三角函数计算。仿真实验表明:该方法测得的基波正序有功电流和谐波电流较为准确,补偿后的电流曲线平滑且快速趋于稳定,在第二个时间周期,电流与电压达到相位同步,补偿效果较好。

This paper proposes an improved synchronous reference coordinate transformation detection method as an alternative to traditional synchronous reference coordinate method with a phase-locked loop which,due to the asymmetrical and distorted three-phase voltage,fails to extract positive sequence fundamental voltage,producing a great error in the measured reactive and harmonic currents. The study is focused on replacing the phase-locked loop in the traditional method with employing the A phase fundamental sequence positive voltage extraction unit based on the symmetrical component matrix and synchronously rotating the power voltage vector,thus omitting phase locked loops and trigonometric functions.The simulation shows that the method could provide a more accurate fundamental positive sequence active current and harmonic current in such a way that the compensated current curve is more smooth and tends to exhibit a greater stability more quickly and there is a better compensation effect thanks to a synchronization in the phase of the current and voltage in second time periods.