Power Factor Correction Using SEPIC Converter

Controlled rectifiers feeding various loads will have an impact on the supply power factor. Since many equipment will be connected to the same supply, there performances of other connected devices will also be affected. Hence, there is a need to improve the supply power factor. This work proposes a conventional and interleaved Single-Ended Primary-Inductor Converter (SEPIC) for supply power factor improvement. Diode bridge rectifier fed DC load is considered, in this supply current is discontinuous and not in phase with the supply voltage this is because of rectification. This is causing the power factor to be poor, which is around 0.42. The distortion in supply current was high with Total Harmonic Distortion (THD) being 138.6%. With the introduction of conventional and interleaved SEPIC converter between the rectifier and load, the supply power factor improved to 0.8886 and 0.9304 respectively. The input current THD also reduced to 18.61% and 1.25 % for conventional and interleaved SEPIC converters respectively. Though power factor improvement is there by introducing the SEPIC converter, the current THD is not within the permissible limit. Therefore, interleaved SEPIC converter is a better choice over conventional SEPIC for power factor improvement.