电力系统自动化2019，Vol.43Issue(5)：143-151,9.DOI:10.7500/AEPS20180625015
实现相位和频率检测解耦的快速锁相环
Fast Phase-locked Loop to Realize Decoupled Detection of Phase and Frequency
摘要
Abstract
Detection of phase and frequency by synchronous reference frame phase-locked loop (SRF-PLL) and its improved versions are closely coupled. If the voltage with an unvaried frequency has a step change in phase angle, the detected frequency will suffer a transient process, causing errors to the detection of frequency. Thus, based on the structure of quasi-type-1 phase-locked loop (QT1-PLL), a modified quasi-type-1 phase-locked loop (MT1-PLL) is proposed with a decoupled unit, which is able to achieve decoupled detection of phase and frequency. In order to improve the ability of MT1-PLL to reject unbalance, harmonics, etc., cascaded delayed signal cancellation (CDSC) is combined with a proposed mathematical filter, forming a pre-loop filtering module to extract fundamental positive sequence voltage. The module features the elimination of 2 nd harmonics, and a fast filter process takes only 0.635 cycles. Meanwhile, the phase errors in the module caused by deviations of grid frequency, and sampling frequency are also considered, which are compensated by an error feedforward method. Finally, simulations are conducted in PSCAD/EMTDC under various operation conditions to verify the effectiveness of MT1-PLL, filtering module and cancellation method of phase error.关键词
同步旋转坐标锁相环/改进型准一阶锁相环/级联延迟信号消除法/2次谐波/相位与频率检测解耦/频率偏移Key words
synchronous reference frame phase-locked loop (SRF-PLL)/modified quasi-type-1 phase-locked loop (MT1-PLL)/cascaded delayed signal cancellation (CDSC)/2nd harmonics/decoupled phase and frequency detection/frequency deviation引用本文复制引用
李子林,傅闯,汪娟娟,龚英明,李瑶佳..实现相位和频率检测解耦的快速锁相环[J].电力系统自动化,2019,43(5):143-151,9.基金项目
国家自然科学基金资助项目(51777079) （51777079）
国家自然科学基金委员会-国家电网公司电网智能电网联合基金资助项目(U1766213) （U1766213）
中国南方电网有限责任公司科技项目(ZBKJXM20180104) （ZBKJXM20180104）
This work is supported by National Natural Science Foundation of China (No. 51777079) , National Natural Science Foundation of China-State Grid Joint Fund for Smart Grid (No. U1766213) and China Southern Power Grid Company Limited(No. ZBKJXM20180104). （No. 51777079）
