Patent ID: 7885087

Claim:
A modularized active power filter comprising: a control module; a control signal bus; and at least one power module electrically connecting with the control module through the control signal bus; wherein the control module automatically identifies the number of the at least one power module and generates one set of PWM signals to control at least one applied power module, with the at least one applied power module generating a final compensating current to suppress harmonic currents and compensate for fundamental reactive current of a load; wherein the control module comprises a module counting circuit, a primary control circuit, a PWM circuit, a voltage sensing circuit, and a current sensing circuit, with outputs of the module counting circuit, the voltage sensing circuit, and the current sensing circuit coupling to the primary control circuit, with the output of the primary control circuit being sent to the PWM circuit that connects with a PWM signal line for sending the PWM signals to the at least one power module.