Three-port ZVS converter with PWM plus secondary-side phase-shifted for photovoltaic-storage hybrid systems

A full bridge three-port converter (FBTPC) with PWM plus secondary-side phase shift (PWM+SSPS) is proposed for photovoltaic-storage hybrid systems in this paper. Employing the parasitized control variables along with the potential power transmission paths from the primary side, the proposed TPC, which consists of two bidirectional ports and an isolated output port, is derived. Moreover, the primary switch´s duty cycle and the phase shift between the leading primary and the corresponding lagging secondary switches are employed as two control freedoms to achieve the voltage regulation within the power conversion between any two of the three ports, namely the PWM+SSPS control scheme. Furthermore, zero-voltage-switching (ZVS) performance is achieved for both the primary and secondary side switches due to the proposed PWM+SSPS. As a result, high power density and efficiency can be implemented. The operation principle of the proposed converter is analyzed in detail and experimental results of an 800W prototype are provided to verify the feasibility and advantages of the proposed converter along with the control scheme.