非理想电源电压下的谐波检测方法研究

Study on the Harmonics Detecting Method Under the Non-Ideal Source Voltage

准确、快速、方便的谐波检测方法是实现有源滤波的重要前提。提出了一种非理想电源电压下的谐波检测方法。该方法首先通过对电源电压的预处理得到了电压基波正序分量的相位信息,然后对电流做dq变换,利用积分环节提取直流分量,最终实现了电流基波正序有功分量的准确检测。运算量明显小于同类方法;为提高动态性能,给出了一种缩短检测信号移相延时的策略;仿真表明该方法能准确快速地进行谐波检测,且动态过程不存在振荡超调。

The exact, fast and convenient detecting method for harmonics is the important precondition to implement the active filtering. It＇s present that a harmonics detecting method under the non-ideal source voltage. With this method, the phase information of the voltage fundamental positive component can be obtained by pretveating the source voltage firstly, then carry through the dq transformation on current. The DC component can be picked up by using the integration link. Finally, it is implemented that the current fundamental positive-active component is exactly detected. The operand is markedly less than congener algorithms. In order to improve the dynamic performance, a strategy to shorten the phase-shift time lapse of the detected signal. The simulation results show that this method can be used to detect harmonics fast and exactly, and that no surge overshoot exists during the dynamic process.