Comparative Analysis of Dynamic Tracking Ability of Phase-Locked Loop in Case of Sudden Change of Power Grid Voltage

In this paper, the dynamic tracking ability of SRF-PLL, DSOGI-PLL, time delay quarter cycle phase-locked loop and DDSRF-PLL, which are commonly used in IIDG grid-connected control at present, is studied under the condition of three-phase grid voltage mutation. The principle differences and similarities of the four PLLs are analyzed, and the transient process duration and overshoot of the four PLLs are studied when the grid voltage changes abruptly. The research results show that under the condition of constant power grid frequency, only the voltage amplitude mutation has little effect on the frequency and phase of the output of the four PLLs, so the phase-locked loop can achieve good frequency and phase tracking. The sudden change of voltage phase has a great influence on the frequency and phase output of four types of phase-locked loops. Its overshoot is related to the principle of positive and negative sequence decomposition and the proportional integral coefficient of PLL. Under the same PLL proportional integral coefficient, the DDSRF-PLL has the largest overshoot. The duration of the transient process is not related to the positive and negative sequence decomposition link, but related to the proportional integral coefficient of the phase-locked loop. Under the same proportional integral coefficient, the duration of the four phase-locked loops in the transient process is basically the same.