A Novel Voltage Sensor-less Control Technique Synthesis for a Boost AC/DC Pre-regulator

A novel voltage sensor-less control technique, linear ramp follower (LRF), is proposed in this paper for a boost AC/DC pre-regulator. The power factor correction (PFC) pre-regulator controlled by the proposed technique, will require only an inductor current sensor and operate at a constant switching frequency with a simple control circuit. The AC input and DC output voltages are extracted individually from the charging and discharging rate of the sensed inductor current. Thus, this technique reduces the number of sensors required and also accomplishes the noise isolation between the power circuit and the controller. Furthermore, MATLAB simulation results are presented to verify the theoretical analysis