Research Of Paralleled DC/DC Converters Based On Automatic Current Sharing Technology

With the rapid development of power electronics technology, the application of electricity is constantly expanding. The electric propulsion becomes a new way of propulsion to be used for ship’s power system. Electric propulsion system is recognized as the development direction of today’s Marine power plant. The main characteristic is the energy of propulsion and other electric appliance concentrated in a power system.The DC/DC converter designed in this paper is mainly used in the electric propulsion unmanned submarine power system. It provides reliable power for the inverters in the submarine. In order to improve the reliability of the power system, we use n+1 paralleled converters based on current sharing control. The n+1 paralleled converters provide sufficient reserve capacity to the power system to improve the reliability of the power system. When a single power module fails, there is still enough power output. Paralleled DC/DC converters based on appropriate current sharing technology is convenient for not only power module’s installation and maintenance with hot-swap technique, but also the combination of power system capacity. This paper makes a detailed analysis of DC/DC converter topologies and current sharing technologies, design a module of full-bridge boost topology with voltage-mode PWM controller UC3525 and a parallel DC/DC system with automatic current sharing controller UC3907. The harmonics of the switching power supply often affects the other system. This paper takes some measures to prevent some potential EMC problems in the design to ensure other equipments in the submarine can work as usual.PSPICE is used to simulate the design. And the simulation results show the validity and feasibility of the design. The paper shows the test results of circuit board to confirm the correctness of the circuit design as well. At the end, a summary of the paralleled DC/DC converters based on automatic current sharing technology is given. This paper also provides a suggestion for improving existing design.