A single switch battery charger with active power filter / Muhamad Taufiq Ramly

This paper present the battery chargers with active power filter for minimizing the input current distortion in a single phase system. The striking feature of this circuit is that it contains only a single switch. The active power filter here is use to mitigate the distortion current by injecting equal but opposite current to shape the pulsating of the supply current to a sinusoidal form that is in-time phase with the supply voltage. The error signal from the supply current is fed into the APF (active power filter). The supplied current would be subtracted by another reference current generated to produce this error signal. The output of the subtraction is then compared to a triangle waveform that resembles a carrier wave to produce a PWM (pulse width modulation) signal that is injected into a switching device. The APF will be implemented fully by the microcontroller PIC16F877A. In this work, the single switch active power filter is used to reduce switching stress, losses and also the cost