An active power filter

The utility model discloses an active power filter, including the power connecting wire, electric current tracking control circuit, relay protection circuit, instruction circuit arithmetic circuit and drive circuit, electric current tracking control circuit connects in parallel on the power connecting wire, the current signal on the power connecting wire is gathered to the instruction circuit arithmetic circuit, output control current signal to electric current tracking control circuit, and electric current tracking control circuit output PWM signal arrives drive circuit, drive circuit pass through the inductive circuit and export offset current to the load. The utility model discloses an active power filter adopts parallel, through the harmonic and the reactive component of real -time detection load, adopts the PWM converter technique, will equal with harmonic and reactive component size, opposite direction's current injection power supply and distribution system, realizes suppression harmonic, the function that the dynamic compensation is idle.