Research on Reactive Power Compensation of Deep-Sea Underwater High-Voltage Motor Based on STATCOM

In the deep-sea operation system, high-power three-phase asynchronous motors are often powered by shore-based or platform through long-distance umbilical cables. Limited by cable distribution parameters and load characteristics, it is easy to cause voltage drop, surge in reactive power demand and power quality problems, which seriously threaten the stable operation of the system. In this paper, a Voltage Frequency Ratio (VF) control strategy combined with Static Synchronous Compensator (STATCOM) dynamic reactive power compensation is proposed. In Matlab/Simulink environment, a complete simulation model of three-phase asynchronous motor drive system including long cable model, voltage and current double closed-loop VF control and STATCOM compensation device is constructed. The proposed scheme combines the embedded voltage outer loop and current inner loop to improve the dynamic response performance. At the same time, STATCOM is introduced to compensate the inductive reactive power caused by long cable transmission in real time, which can effectively suppress the bus voltage fluctuation, improve the power factor and reduce the line loss. The simulation results show that the integrated control architecture can significantly improve the power quality and stability of the power supply system under different load conditions, which provides theoretical support and engineering reference for the design and optimization of deep-sea underwater motor drive system.