三相电压不平衡下DDSRF-PLL与DSOGI-PLL的锁相误差检测与补偿方法  

Phase Estimation Error Detection and Compensation Method of DDSRF-PLL and DSOGI-PLL under Three-Phase Voltage Unbalance

作　　者：祁永胜 李凯[1] 高畅毓 薛腾跃 游小杰[1] Qi Yongsheng;Li Kai;Gao Changyu;Xue Tengyue;You Xiaojie(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044 China;State Grid Shanxi Electric Power Company Xinzhou Subsidiary ,Xinzhou 034000 China)

机构地区：[1]北京交通大学电气工程学院,北京100044 [2]国网山西省电力公司忻州供电公司,忻州034000

出　　处：《电工技术学报》2024年第2期567-579,共13页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52007005)。

摘　　要：由于高渗透的分布式电源、多样化的负荷类型以及电网故障等因素,并网点三相电压不仅存在幅值不平衡,而且会出现相位不平衡现象。这种情况下,广泛应用的解耦双同步坐标系锁相环(DDSRF-PLL)和双二阶广义积分器锁相环(DSOGI-PLL)无法获得精确的同步信息。为此,该文在论证这两种锁相环具有理论等价性的基础上,阐释三相电压不平衡与锁相误差的内在关系,进而提出一种锁相误差的补偿方法,实现幅值和相位不平衡下的准确锁相。所提方法仅需对电压采样值进行简单计算即可获得不平衡相位和锁相误差,实现开环相位补偿,无需修改原有锁相结构,具有良好的拓展性。最后,通过仿真和实验验证了所提方法的有效性。Due to the combined effect of high-permeability distributed power supply and various types of loads,the three-phase voltage of the actual grid-connected point has deviations in amplitude and phase angle.However,phase-locking methods based on single synchronous reference frame phase-locked loop(SSRF-PLL),such as decoupled double synchronous reference frame phase-locked loop(DDSRF-PLL)and double second-order generalized integrator phase-lock loop(DSOGI-PLL),generally ignored these differences,and,hence,only acquiring synchronization information at phase-balanced three-phase voltage.More is needed to support coordinated control among devices at the grid-connected point.Recently,some methods were presented to obtain phase information of three-phase voltage under phase unbalance,but most suffered from high computation costs and poor expansibility.Therefore,a compensation method for phase estimation error is proposed.The phase estimation error can be accurately compensated under phase-balanced three-phase voltage by detecting the unbalanced phase angle deviation of B and C phases.Firstly,the three-phase unbalanced voltage specified in the national standard is used as the input signal for DDSRF-PLL and DSOGI-PLL,and the equivalent relationship between unbalanced voltage and phase estimation error of the two phase-locked loops is obtained.The functional relationship between phase estimation error and unbalanced phase angle deviation is based on steady-state characteristics.Secondly,three approximate solutions for the phase estimation errors are given to simplify the calculation.Then,based on the zero-crossing point of the A phase,the unbalanced phase angle deviation of B and C phases is obtained by calculating the sample value of three-phase voltage.Finally,precise compensation of phase estimation error can be achieved by substituting the phase angle deviation in the function of phase estimation error,overlaying the output of phase estimation error to the original PLL reversely.The phase angle deviation detection and pha

关 键 词：三相电压不平衡 锁相环(PLL) 不平衡相位检测 锁相误差补偿 

分 类 号：TM46[电气工程—电器]