虚拟瞬时功率数字锁相法应用于谐波检测研究

Research of Digital Phase Locked Loop Appling in Harmonic Detection

对传统基于瞬时无功功率理论的谐波检测方法进行了改进,提出d-q谐波检测方法。该方法中锁相环性能直接影响其谐波检测性能。由于传统锁相环无畸变电压抑制能力,在畸变电压条件下不能准确跟踪所需相位信息,为此提出一种基于虚拟瞬时有功功率数字锁相方法,该方法在电压畸变条件下能够快速跟踪电压基波正序分量的频率和相位,能够很好地抑制电压畸变。仿真与实验结果表明,该数字锁相方法稳态精度高,动态响应快,将其应用于d-q谐波检测方法能够快速准确地检测谐波电流,证明了d-q谐波检测方法和该锁相理论的正确性和可行性。

The d,q harmonic detect method is presented by improving traditional harmonic detect method based on the theory of instantaneous power of no use.The performance of phase locked loop directly influence its harmonic detect performance.Traditional PLL is unavoidably affected by the distorted voltages and thus in this condition easily leads to wrong phase angle outputs.Operation of digital phase locked loop based on virtual instantaneous power is presented. Phase angle of the positive sequence of fundamental wave voltage is tracked fleetly and precisely, having a strong restrain ability to the distorted voltage.The simulation and experiment results indicate that the digital PLL has a good performance of steady and dynamic response, which can be used to detect harmonic current fleetly and precisely in the d, q harmonic detect method, proving the d, q harmonic detect method and the digital PLL theory are right and reliable.