The three major indicators of power system voltage, reactive power and harmonics are crucial to improving the economic benefits of the entire network and improving the quality of power supply. At present, the adjustment methods of traditional group switching capacitor compensation devices and fixed capacitor bank compensation devices in China are discrete, and cannot achieve ideal compensation effects; at the same time, the inrush current and overvoltage caused by switching capacitor banks have a negative It will cause harm in itself; existing dynamic reactive power compensation devices, such as phase-controlled reactors (TCR type SVC), are not only expensive, but also have the disadvantages of large floor area, complex structure, and large maintenance. Magnetically controlled reactor type dynamic reactive power compensation device (referred to as MCR type SVC), the device has significant advantages such as small output harmonic content, low power consumption, maintenance-free, simple structure, high reliability, low price, and small footprint It is the ideal dynamic reactive power compensation device in China at present.