This paper proposes the switched impedance source converter (SZSC) or switched quasi impedance source DC-DC converter (S-qZSC) based photovoltaic (PV) grid-connected systems. To increase the voltage from low level to high level, all PV grid-connected systems need step-up DC-DC converters. This step-up factor can be increased by connecting the terminals of a traditional quasi impedance source DC-DC converter with an additional diode and a switch. In this proposed converter, the capacitor not only serves as a filter. It is, however, bound in series to the charging loops of the inductors. On the one hand, saturated inductors can trigger instability, which can be avoided. When used for dc-ac conversion, however, the modulation index of the backend H-bridge can be set to a wider range. As compared to existing Z-source-based systems, a shorter duty period results in a higher boost factor.

Elecetric vehicle batteries require direct current (DC) current for charging; hence the circuit alternating current (AC) is converted to DC by a battery charger. Battery charger mostly consists of a rectifier and DC-DC converter with a controller built in to serve as a protective circuit. A harmonic source load is a type of electric car charger. During the AC-DC change over method, harmonic current is introduced into the power system, affecting power quality. In this study, a charging station consisting of buck boost and a charging station consisting a KY Boost converter were simulated. To maintain output voltage of DC-DC converters constant controller is used, the controller is either PI or fuzzy logic controller. So, four models are developed and simulated which are buck-boost converter controlled by proportional-integral (PI)-controller, KY-boost converter controlled by proportional integral-controller, buck boost converter controller fuzzy logic controller and KY boost-converter controlled by fuzzy logic controller. The total harmonic distortion (THD) of the four models is compared.