基于MATLAB的改进FBD谐波检测算法研究

Research on Improved FBD Harmonic Detection Algorithm Based on MATLAB

Fyrze定义的电流检测法(FBD)是地铁供电系统常用的谐波电流检测法,文中针对传统FBD法在谐波检测上的不足,提出了一种改进的无锁相环FBD检测方法。利用稳定的正余弦信号发生器代替锁相环电路,以此来求得基波电流,进而得到补偿电流指令。理论分析表明,该方法消除了锁相环提取信号的误差,提高了检测精度且硬件设计简单,因此可应用于电压畸变和不对称的情况。最后对改进的FBD法进行仿真试验,检测出基波中的谐波畸变率降至0.19%,远低于国家标准,仿真结果证明了所提方法的正确性和有效性。

Method of current test（FBD） based on Fyrze is a method of harmonic current test which is commonly used in Metro power supply system, this paper put forward to a improved no phase-locked loop FBD method based on deficiencies of traditional FBD in harmonic test. The phase-locked loop has been replaced by stable sine and cosine signal generator, the fundamental current can be received and offset current order can be received too. theoretical analysis show that, this method eliminates error of extracted signal of phase-locked loop, the test precision has been improved and the hardware is easy, so the method can be used in distortion and asymmetry of the grid voltage. Finally, simulated test has been took place, the harmonic distortion rate is 0.19% in the fundamental harmonic which is far below the national standard, the simulated result shows that the method is correct and effective.