Voltage Regulation Method for Active Distribution Networks Based on Rotary Voltage Regulator

Due to the dominant resistive component in distribution lines, the voltage upper and lower limits may occur in the same scenario. The voltage upper limit is caused by daytime photovoltaic power injection, while the voltage lower limit is caused by nighttime line voltage drop. Load tap changer (LTC) voltage regulation and dynamic reactive power compensation voltage regulation devices have certain limitations. A method using a Rotary Voltage Regulator (RVR) is proposed, which injects a constant amplitude and continuously adjustable phase voltage phasor into the line by controlling the relative angle of the rotor. Regarding the four-quadrant bidirectional voltage regulation characteristics of RVR, the method to improve the power factor under the premise of voltage regulation is studied. Furthermore, the overshoot problem caused by the mechanical structure during the voltage regulation process is analyzed, and a variable speed control scheme for RVR is designed. Finally, a 380 V/40 kVA RVR prototype is developed, and experimental results show that RVR can effectively improve the power factor at the access point while satisfying the voltage regulation requirements, thus verifying the effectiveness and correctness of the proposed control strategy.