High Step-Up Common Grounded Switched Quasi Z-Source DC-DC Converter Using Coupled Inductor With Small Signal Analysis

In this article, a new common grounded switched quasi Z-source DC-DC converter is proposed. In the proposed converter, an additional switch and a diode are used compared to the conventional quasi Z-source converter. The proposed converter provides some benefits by using a coupled inductor and switched capacitor unit. These features are providing voltage-boosting capability using a small range of duty cycles, low voltage stress on semiconductors (switches and diodes), and continuous input current waveform. In this topology, the null of the load is connected to the negative terminal of the input DC source, directly. So, the common mode voltage is kept constant. In this case, the proposed DC-DC converter is suitable for photovoltaic (PV) power generation systems to boost the voltage of PV panels. In this paper, the proposed converter and operation modes are described completely. Also, in order to show the advantages and differences of the proposed topology with other DC-DC high-step up converters, a comparative comparison study is considered. Also, the small signal analysis and control strategy of the proposed converter are provided. In addition, design considerations of the used components are given. Then, the power loss analysis of the converter is provided. Finally, in order to prove the accurate performance of the suggested topology and verify the advantages and analysis, an experimental prototype is built at 250 W output power and the related results are provided.