一种谐波电压的实时检测方法

Real-time Detecting Method of Harmonic Voltage

电网谐波实时准确的检测对电力用户的用电质量和电网的经济运行都有着重要的意义。为此,基于瞬时无功功率理论,简化复杂的数学变换,通过计算基波正序电压有功和无功功率检测出用户侧电压谐波及负序分量,并对检测方法作了相应的理论分析。用仿真软件MATLAB/SIMULINK建立的检测谐波电压实验模型仿真负荷恒定和突变时检测模型的结果表明,检测结果在负荷突变时能迅速跟踪变化,得到与实际相符的基波正序电压和谐波电压,兼顾了检测的准确度和实时性,且检测方法因不受电网频率偏移的影响而易于实际应用。

The improving the quality of power supply and economical operation of power system depends on the accurate and real time detection of harmonic voltage. For this purpose, through calculation of fundamental positive sequence active power and reactive power with only a slight mathematic manipulation, the sum of harmonic and fundamental negative sequence voltage is achieved. Based on the instantaneous reactive power theory, the detecting method of harmonic voltage is theoretically analyzed. Finally, a detailed simulation of the detecting method using the MATLAB/SIMUIJlNK program as well as an experimental model was carried out in order to verify the effectiveness of the proposed detecting technique. In the simulation, the constant load and varied load have been adopted respectively, and results show that the new detecting method used in simulation can produce good dynamic response. The new detection method permits a closer tracking of the prospective result under varied load conditions. Furthermore, accuracy and minimal delay are shown in detection if the proposed method is used. The good performance of detection is then validated by simulation studies. Moreover, the detecting results under frequency deviation of power system conditions are still proved to be accurate in simulation, showing that the newly proposed detecting method can keep a good performance in application.