Dynamic Voltage Restorer Based on RTH Optimized PID and MPR Composite Control Strategy

The dynamic voltage restorer (DVR) controls the inverter through a double PID control system of inductor current and load voltage, but its compensation effect and stability are poor when the voltage contains more harmonics. A compound control strategy based on Red-tailed hawk algorithm (RTH) optimized PID and Modified Proportional Resonant (MPR) double closed-loop controller is proposed. In view of the problems existing in the present control method, MPR control is proposed for the voltage loop, which can realize no static error compensation for the load voltage under harmonic injection. The optimized PID control is adopted for the current loop, which can ensure that the DVR device can effectively and stably compensate the load voltage sag. Ultimately, the proposed composite control strategy's efficacy and superiority are substantiated through theoretical scrutiny and simulations.