单相电路瞬时谐波及无功电流实时检测新方法

为了解决单相电路瞬时谐波及无功电流检测方法算法复杂的问题，对单相电网电流进行了分解，并提出了一种新的单相电路瞬时谐波及无功电流的检测方法，该方法采用与电网电压同频的单位正余弦信号分别与电网电流直接相乘，并经低通滤波后得到电网电流中的瞬时基波有功电流及瞬时基波无功电流，进而得到地谐波电流。对检测方法中锁相环的作用进行了详细的理论分析，指出了其可以省略而简化算法的条件，仿真和实验证明该方法能实时准确地

A NEW METHOD FOR REAL-TIME DETECTING HARMONICS AND REACTIVE CURRENTS IN SINGLE-PHASE CIRCUIT

In order to simplify the detection of harmonics and instantaneous reactive currents in single- phase circuit,the current in single- phase circuit is decomposed and a new method for such a purpose is proposed. Firstly,the single- phase current is multiplied by unit sinusoidal and cosinoidal signals with the same frequency of that of circuit voltage respectively and then sent to two low pass filters. Secondly,the outputs of these two low pass filters are again multiplied by the unit sinusoidal and cosinoidal signals to getthe reactive and active currents.L astly,by subtracting the active currentthus obtained from the original current,the harmonics and reactive currents can be detected.The function of phase lock loop PL L in this method is analyzed in detail and the preconditions of simplifying the algorithm by omitting it are presented.Simulation and experimental results show that harmonics and instantaneous reactive currents in single- phase circuit can easily be precisely detected in real- time by using this simple method.