Average sliding control method applied on power factor correction converter for decreasing input current total harmonic distortion using digital signal processor

This study presents an average sliding control (ASC) method to be used in power factor correction (PFC) circuits to decrease the total harmonic distortion (THD) of the input current by eliminating the input current harmonics. The ASC algorithm is adapted to TMS320F2812 digital signal processor (DSP) owing to its well-known properties, such as robustness, stability and good regulation in a wide range of operating conditions. The control approach is operated in continuous conduction mode. In this approach, a sinusoidal signal is generated by the DSP and is used as reference in controlling the converter switch to obtain a sinusoidal input current based on zero-crossing points of input voltage. The feed-forward is also used in the control algorithm using maximum value of the input voltage. The implementation of feed-forward improves the converter´s performance to obtain a near-unity PFC with a lower input current THD. The converter used in the simulation and experimental studies is a bridgeless converter. The conduction losses of the switches of this converter are lower compared with the similar PFC converters. The experiments performed in the laboratory for different cases of operation verify the theoretical and simulation studies. The experimental results are satisfied by IEC 61000-3-2 current harmonic standard.