Digital frequency-adaptive PLL technique for three-phase grid-connected inverter

作者：Guo, Xiaorui^*; Guo, Jifeng; Long, Yingwen

来源：Electric Power Automation Equipment, 2013, 33(2): 81-86.

DOI：10.3969/j.issn.1006-6047.2013.02.014

• Adaptive Control
• All-Digital PLL
• Distorted grid voltage
• Frequency variation
• Grid connected systems
• Harmonic components
• Positive sequence
• Second orders
• Three-phase grid-connected inverters

Aiming at the low accuracy of traditional PLL(Phase Locked Loop) under the conditions of seriously distorted grid voltage and abrupt frequency variations, an all-digital PLL algorithm with frequency-adaptation function is presented for the three-phase grid-connected inverters, which adopts the adaptive second-order low-pass filter to effectively suppress the line negative-sequence fundamental and harmonic components and to quickly track the line positive-sequence fundamental phase with little distortion. The proposed method is compared with existing open-looped and closed-looped methods, and the simulative and experimental results show its correctness and feasibility.

• 出版日期2013
• 单位浙江大学; 合肥工业大学