Current Sensor-less Control for Boost DC-DC Converter Based on Switched Observer

In this paper, a current sensor-less control strategy for boost dc/dc converter is proposed. A switched observer is first designed for switched model of boost converter to estimate the inductor current and output voltage under arbitrary switching. Then based on the estimation of inductor current and output voltage, a two-loop control structure is employed for the average model of boost converter which consists of voltage loop (outer loop) and current loop (inner loop). In the inner loop, a second order sliding mode (SOSM) controller based on a super-twisting algorithm (STA) is established to drive the estimated inductor current towards its reference. The proportional-integral (PI) controller is applied in the outer loop to regulate the output voltage. Finally simulation results are provided to testify the effectiveness of the presented approach.