A PQ Improved Two-Mode Control Scheme for for Two-Switch Two-Switch Buck-Boost DC-DC Converter

The usage of power electronic systems has expanded to new and wide application range. In recent years, the use of Buck-Boost converters are more when compared to other type of converters. When compared with the basic converters like Cuk, Zeta, two-switch Buck-Boost converter (TSBBC) presents less voltage losses on the switches. The two-switch buck boost converter is suitable for wide input voltage applications. The two switch buck boost converter requires fewer passive components. In order to achieve high efficiency over the entire input voltage range, the TSBBC operated in buck mode at high input voltage and boost mode at low input voltage. Such operation is called two mode control scheme. The objective of this paper is to reduce the influence of the input voltage disturbance on the output voltage by implementing two-mode control scheme and obtain enhanced efficiency with low harmonic distortion. The TSBBCs have been extensively used in telecommunications, battery operated vehicles, etc. with wide input voltage range. So it is thus important to improve the efficiency of TSBBC over a high input voltage range.