The dynamic voltage restorer (DVR) tracks the grid voltage in real time and quickly switches (< 2ms) to the super capacitor circuit in case of abnormality, which can greatly protect the power supply of sensitive loads (such as chip packaging, automobile manufacturing, airport, precision manufacturing and other scenes) and provide more high-quality power. DVR has been widely used in integrated circuit, power electronic chip manufacturing, aircraft, automobile, mobile phone and other manufacturing in the field of high precision requirements, and in the field of high security requirements, such as airport, hospital, IT, communication industry, etc.