Due to the inconsistency of power grid indicators in various countries around the world, export electrical appliance manufacturers need power supplies to simulate the power grid conditions of different countries to provide engineers with pure and reliable applications in design and development, production line testing and quality assurance product testing, life, over-voltage/low-voltage simulation testing , Low harmonic distortion, high stable frequency and steady-state sine wave power output; users of imported original electrical appliances and equipment also need to transform and frequency change China's power grid to ensure the normal operation of imported electrical appliances and equipment; meet avionics And high-frequency demand for military equipment.