A low cost on-off modulated power filter for single phase motorized loads

The paper presents a flexible low cost on-off modulated power filter (MPF) for power quality (PQ) enhancement and electric energy conservation of motorized single phase in-rush type, quasidynamic mechanical loads. These nonlinear type loads are typical of ventilation, air conditioning, pumping and other small scale industries such as sewing, shear and press machinery and food processing plants. The proposed low cost on/off triac switched filter scheme (US patent pending) can be switched by either a dynamic RMS current tracking or harmonic ripple regulation controller.