STS(static transfer switch) is a key power equipment that integrates power electronics technology, intelligent control algorithms, and energy management strategies. It is mainlyused to achieve safe, fast, and seamless switching between grid connected and off grid independent operation modes of distributed generation systems (such as photovoltaics, wind power, energy storage, etc.). The device prioritizes connecting to the public power grid during normal operation, achieving efficient energy exchange; When the power grid is abnormal or faulty, it automatically switches to off grid mode and is powered by local distributed power sources or energy storage systems to ensure continuous power supply to critical loads, effectively solving problems such as grid fluctuations, power outages, and power restrictions etc.