单相电路瞬时谐波及无功电流实时检测新方法  

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

作　　者：蒋斌[1] 颜钢锋[1] 赵光宙[1] 

机构地区：[1]浙江大学电气工程学院,杭州310027

出　　处：《电力系统自动化》2000年第21期35-39,共5页Automation of Electric Power Systems

摘　　要：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 ,进而得到瞬时谐波电流。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检测出单相电路中瞬时谐波及无功电流 。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.

关 键 词：谐波 瞬时无功电流 单相电路 电网 实时检测 

分 类 号：TM835[电气工程—高电压与绝缘技术]