Reduction of Harmonics to Improve Power Factor in Critical Conduction Mode(CRM) Boost Converters

This paper presents modified critical conduction mode (CRM) boost converter for low and high-power applications. The main aim is to improve the power factor (PF) reduce the total harmonic distortion (THD) of the CRM boost converter. The converter consists of EMI filter, bridge rectifier and a boost stage. The power factor correction (PFC) in ac-dc power conversions can improve PF and reduce THD. The CRM mode for this converter makes switches turn-on at zero current crossing and no reverse recovery losses for diodes. In this configuration the PI controller improves the PF and lowers THD value. The boost converter with variable on time (VOT) controller makes the circuit bulky and losses are more. In the proposed converter the PF and efficiency can be improved. Also, the controller reduces the size of the circuit and lower the THD. Hence CRM boost converter PFC controller based on PI controller is used to improve the above-mentioned parameters. Using MATLAB Simulink software, the existing and the modified controller is verified, and results proves the effectiveness of the controller for the CRM boost converter.

Keywords:

Critical conduction mode , Power factor correction , Total harmonic distortion.