畸变电流实时检测的无锁相环正交变换法研究

Research on Orthogonal Tansformation without Phase Lock Loop of Distorted Current Real-time Detection

畸变电流的实时检测是有源电力滤波器控制的基础,是决定有源电力滤波器工作特性的关键因素之一,提出一种无锁相环正交变换的畸变电流实时检测新方法。该法可检测出三相三线制系统基波电流的正、负序分量,并将其相加得到基波电流,三相电流减去基波电流便得到畸变电流;而去掉锁相环,通过预设正交变换矩阵中的角频率,从而简化电路,并解决了锁相环对检测准确性的影响,加快了动态响应速度。理论分析和仿真结果表明,该法可以准确、实时的检测出畸变电流。

The real-time detection of distorted current technology is the basis of active power filter and is one of the key factors to decide the active power filter operating characteristic.The paper puts forward a new method of distorted current real-time detection of orthogonal transformation with phase lock loop.The method can detect posittive-sequence component and negative sequence component of fundamental current of three-phas three wire system and add them to obtain the fundamental current,the three-phase current substracts the fundamental current to obtain distorted current and get rid of the phase lock loop,through pre-set orthogonal transform matrix in the angular frequency,solving the PLL impact of detecting accuracy,It not only saves the cost but also accelerating the speed of dynamic response.By the theoretical analysis and simulation,the result shows the proposed approach can detected distorted current accurately and real-time.