A continuous input and output current quadratic buck-boost converter with positive output voltage for photovoltaic applications

•A quadratic buck-boost converter with continuous input-current is proposed for photovoltaic applications.•Detailed discussion about principle operation, steady-state investigation, efficiency analysis and small signal modeling.•The proposed converter is compared with other quadratic buck-boost topologies•Validation through experimental prototyping. This paper proposes a transformerless buck-boost DC-DC converter with positive output voltage. The voltage gain of the proposed buck-boost converter is square of voltage gain of conventional one. Therefore, the proposed converter can operate in a wide range of output voltage. Contrary to the conventional buck-boost converter, the proposed converter benefits from continuous input current, which makes it more suitable for renewable energy applications. Furthermore, the output current of the proposed converter is also continuous, which alleviates the current stress on the output capacitor and brings down the output voltage ripple. Principle operation, steady-state investigation, efficiency analysis and small signal modeling are addressed in detail for continuous conduction mode (CCM). Moreover, the proposed converter is compared to other quadratic buck-boost topologies in terms of different criteria. Finally, the performance of the proposed converter is verified through experimental results.