A Two-stage Converter with Constant Current Input for Undersea Power Supply

The traditional converter for current source input consists of a DC-DC converter casade with a zener diode array. The system has high cost, high loss, low efficiency and low reliability. This paper proposes a two-stage converter circuit with constant current input. The first stage is a Boost circuit with current source input, and the second stage is a Phase-Shifting full-bridge LLC resonant circuit. Its working principle and parameter design are analyzed. The input to the converter is a current source and the output is a voltage source, which can achieve high efficiency, high reliability and electrical isolation. An experimental prototype is designed at last to validate the accuracy of the theoretical analysis.