Abstract: As the equipment of high power and motor load are increasingly put into electric power system, the demand on the quality of power supply is enhanced, such as low power factor and large voltage fluctuation etc. After analyzing the theory and algorithm of reactive power compensation in detail, a system based on STM32 thyristor switched capacitor (TSC) reactive power compensation control is stadied, which includes compensation, control algorithms of nine-zone diagram, controller hardware design and software design. STM32 chip is accepted as the main control chip. CF6G-3 type of silicon controlled trigger controller is used in executing module and CS5463 power measurement chip is used in signal acquisition. An improved nine-zone diagram control strategy is selected to avoid misoperation and switching oscillation phenomenon, so that the system can carry out real-time dynamic compensation of reactive power. The experimental results show that, this TSC system can realize a faster and more accurate measurement and switching, which lead to an obvious effect of compensation and a safe and efficient automatic operation of the system.

Key words: STM32, TSC, reactive power compensation, nine-zone diagram