Research on Power Grid Imbalance and Harmonics Based on Improved Phase-Locked Loop

2018 5th International Conference on Advanced Composite Materials and Manufacturing Engineering

Yuan, Liyue^1 ; Gu, Peng^1 ; Yang, Zhixiong^2 ; Yuan, Shuai^1 ; Li, Jun^1 ; Ma, Aikun^1 ; Wang, Yuting^1 ; Hong, Bo^1

State Grid Liaoyang Electric Power Supply Company, Liaoyang

111000, China^1

Kunming Institute of Physics, Kunming

650223, China^2

关键词: Grid synchronizations;    High-frequency harmonics;    Improved phase-locked loops;    Phase Locked Loop (PLL);    Positive sequence voltage;    Power generation control;    Power generation systems;    Synchronous information;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/394/4/042012/pdf
DOI  :  10.1088/1757-899X/394/4/042012

来源: IOP

【 摘 要 】

In the new energy grid connected power generation system, accurately extracting the grid synchronization signals such as frequency, phase and amplitude of the grid voltage is the basis for effective control. A new design method of phase-locked loop (PLL) in static coordinate system is proposed for the demand of synchronous signal detection under unbalanced and harmonic conditions. This method uses the resonator to extract and filter the high frequency harmonics in the grid voltage, and combines the adaptive trap (ANF) and the positive and negative sequence elimination loop (PNSC) to complete the voltage positive and negative sequence separation, and then accurately extracts the synchronous information of the positive sequence voltage of the power grid. The simulation and experimental results show that under the conditions of unbalanced and harmonic grid, the designed PLL can quickly and accurately lock the property of the grid voltage, and has the advantages of high detection precision and strong robustness to frequency fluctuation. It can provide reliable reference signal for the new energy grid connected power generation control.