| As an important development trend in the field of power electronics, power electronics system integration has drawn more and more attention in recent years. The series and parallel connection of standardized modules becomes one subject of the vigorous research field. The input-parallel output-series (IPOS) converter, which consists of multiple DC-DC modules connected in parallel at the input and in series at the output, is very suitable for high output voltage and high power applications.In order to make the IPOS converter work normally, output voltage sharing among the modules of IPOS converter should be ensured. This paper reveals the relationship between the input current sharing and the output voltage sharing of the modules in IPOS converter, based on which, a control strategy for output voltage sharing which has no influence on the system output voltage is proposed. Phase-shifted PWM DC-DC full-bridge (FB) converter is chosen as the standard module and the small-signal model of the IPOS converter is derived. It is verified by mathematical method that the output sharing voltage loop has no effect on the output voltage loop based on the proposed control strategy. The design of the compensation network of the output voltage sharing closed-loop and the output voltage regulation closed-loop is discussed in details in this paper. Interleaving technique is adopted in the IPOS converter, with the ripple cancel effect for the input current, the input voltage capacitor can be reduced, and with the ripple cancel effect for the output voltage, the output filter capacitor of each module is reduced, so the power density is improved.A 2kW IPOS prototype consisting of two full-bridge DC-DC modules is built in the lab. Simulation and Experimental results are given to verify the effectiveness of the propose control strategy.
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