The Dynamic Voltage Regulator (DVR) is a series-connected power electronic device installed on the load side. Its core function is to inject a compensation voltage rapidly, correcting grid voltage sags, swells, or fluctuations within milliseconds to maintain the voltage at the sensitive load end within the rated range. 

This prevents equipment shutdowns, data loss, or hardware damage caused by short-term voltage anomalies. It is mainly used in fields such as industrial precision manufacturing, medical care, data centers, financial transaction systems, new energy grid connection, and special industries (e.g., metallurgy, chemical industry).