A current sensorless power factor correction control for LED lamp driver

This paper proposes a new control technique to achieve a unity power factor at the input AC supply for light-emitting diode (LED) lamps controlled by AC-DC converter, without using a current sensor. Only two analog to digital converters (ADCs) for measuring the input and output voltages are used. This technique achieves isolation between power circuit and controller; it can be implemented by using a zero-crossing processing, which has a greater accuracy than other techniques. Simulation and experimental results illustrate the effectiveness and feasibility of the proposed control technique, which achieves low harmonic contents in the supply current, a near unity power factor (PF), a sinusoidal current waveform, and a fast dynamic response under transient operation.