Design of Isolated Bi-Directional DC-DC Converter for Aerospace

The servo power supply is the key power supply equipment of aerospace electromechanical servo systems, and its volume, specific energy, and instantaneous output power directly determine the overall performance of the system. This paper proposes a two-stage topology that can satisfy the capacitive voltage with a wide input range based on the technical specification requirements of an isolated bi-directional DC-DC converter for aerospace applications. Firstly, the operation principle of the topology is analyzed, and the volume and weight of the converter can be reduced with magnetic integration technology. Moreover, the whole control scheme is introduced and the fast charge and discharge control strategy of the capacitor is analyzed in detail. Finally, a prototype with a peak output power of 7.6 kW was developed, the overall weight was 2.24 kg (with the case), and the volume was
$\mathbf{286.4}\times \mathbf{146.4}\times \mathbf{63.5} \mathbf{mm}^{\mathbf{3}}$
. The experimental results show that the rising and falling time of the output current is less than 1.5 ms, and the stabilized current precision is less than 10%. At the same time, the prototype can achieve 50 times continuous charge and discharge, which effectively meets the requirements of complex power conditions of the aerospace electromechanical servo system.