Model Reference Adaptive System Based Input Voltage Estimation for ISOP Converter With Inverse-Droop Strategy

In power converter systems composed of isolated DC/DC converters configured in an input-series-output-parallel (ISOP) structure, input voltage sharing (IVS) is essential to ensure uniform and stable system operation. This paper proposes a voltage feedforward inverse-droop control strategy based on estimation to automatically balance the input voltages among different modules in an ISOP system. The proposed feedforward control method addresses the key challenge of simultaneously optimizing output voltage regulation and IVS accuracy. The input voltage is characterized as a system parameter, enabling the derivation of adaptive parameters via Model Reference Adaptive System (MRAS) estimation. Consequently, the system eliminates the need to directly sample the high-voltage side input, thereby avoiding insulation issues between the primary and secondary circuits. This method enhances the system’s stability and reliability. The fundamental principles and design methodology of the proposed approach are thoroughly described, and its effectiveness is validated through both simulation and experimental results.