A smart PWM-modulated power filter for single phase motorized loads

The paper presents a simple PWM power filter for single phase motorized inrush-current loads such as air conditioning, ventilation and water pumping. The paper presents the simulation results and prototype laboratory testing and validation of the smart modulated passive filter using a dynamic RMS-current tracking controller. The smart filter/energy miser ensures supply power quality enhancement, less source current/load voltage waveform modulation, as well as enhanced electric energy efficiency for cyclical, inrush current nonlinear motorized loads. The PWM switching scheme establishes a dynamic on-line varying duty cycle ratio α that modulates the apparent smart filter impedance to provide an effective compensating filter current level to cope with load current waveform distortion