基于高通滤波器的电网谐波电流检测方法研究

摘要

The existence of harmonic current will make the grid components to generate additional harmonic los-ses, reduce the power generation, transmission efficiency, but also seriously affect the normal work of various electri-cal appliances. In order to simplify the detection circuit and to improve system's real-time performance, this paper proposed a detection method of harmonics current based on high pass filter (HPF), and theoretically deduced and proved the method's validity. The method does not need the subtraction step of detected current and fundamental cur-rent, and the harmonic current can be obtained directly, which can not only simplify the system, also can make the real-time performance be improved greatly. In order to verify the correctness and effectiveness of the method, the model of SIMULINK circuit simulation was established with MATLAB simulation software. By means of real time data of simulation and the analysis of the simulation results, the correctness and effectiveness of proposed method were ver-ified.%由于谐波电流的存在会使电网中的元器件产生附加谐波损耗，降低发电、输电效率，严重的还会影响各种电器的正常工作，有源电力滤波器是抑制谐波的重要途径，而有源电力滤波器的关键在于谐波电流的检测。如何快速、准确地检测出电网中的谐波电流是目前研究的热点和难点问题。传统的谐波电流检测大都采用基于低通滤波器的瞬时无功功率理论检测方法，在检测谐波电流时需要一个检测电流与基波电流相减的环节来得到谐波电流，不仅使得电路复杂化，也增加了检测环节的延迟性。为了简化检测电路和提高系统的实时性，提出了一种基于高通滤波器( HPF)的电网谐波检测方法，并从理论上推导和证明了该方法的有效性。改进方法无需经过检测电流与基波电流的相减环节可直接得出谐波电流，不仅可使系统简化，还可使检测的实时性有较大的提高。为了验证上述方法的正确性和有效性，利用MATLAB仿真软件中SIMULINK建立仿真电路进行仿真，结果分析验证了改进方法的正确性和有效性。