There are currently numerous technologies available for conducting online measurements of power grid equipment. However, the impact of primary-side load current on online measurement results cannot be ignored. To eliminate this influence, the operating principle of an active harmonic compensation power source for primary-side lines was first determined based on the concept of active noise control. Subsequently, a synchronous modulation power source capable of offsetting the primary load current was successfully developed, utilizing synchronous modulation and self-current-sharing techniques. Test results show that the proposed power source can adapt to field conditions with high harmonic content and rapid changes in load current.

high-power supply; active noise control; harmonic compensation; synchronous modulation