Study on Low-Voltage Ride-Through Control Strategy for Grid-Connected Renewable Energy Inverters Considering Phase-Locked Loop Error

Under the high penetration of renewable energy, phase-tracking errors introduced by the phase-locked loop (PLL) during grid fault disturbances disrupt the decoupling between active and reactive power, leading to transient overvoltage and current control deviations, thereby degrading the low-voltage ride-through (LVRT) performance of grid-connected inverters. To address this issue, this paper proposes an LVRT control strategy that explicitly considers the impact of PLL error. The strategy involves real-time extraction of the dq components of the point of common coupling (PCC) voltage to estimate the phase error angle, which is then used to implement phase compensation within the PLL control loop for improved phase accuracy. Furthermore, a current reference correction method is introduced to mitigate control deviations caused by the phase error, enhancing the dynamic performance of current regulation. Simulation results demonstrate that the proposed strategy effectively mitigates transient overvoltage during fault recovery, enhances reactive power support, and significantly improves the inverter’s LVRT capability.