提出一种以三端口变换器(three-port converter,TPC)为基本单元构成的航天器分布式供电系统架构及其功率控制方法.该系统包含多个独立的分布式输入源,分别连接各TPC 模块的输入端;而集中式输出母线和储能母线则分别由各 TPC 模块的储能端和输出端并联连接得到.由于多个输入源之间功率存在差异且单个TPC含有3条功率路径,系统中各条传输路径上的功率难以确定.为了实现每条功率路径可控,提出"在储能装置处于放电状态时平均分配放电电流、在储能装置处于充电状态时按输入功率分配输出端功率"的新型功率控制方法,以保证系统所有工况下均能稳定运行并能够自然切换.实验结果表明了所提出分布式供电系统及其功率控制方法的可行性.
A novel distributed power system (DPS) with modular three-port converters (TPC) and its power control were proposed for spacecraft applications in this paper. The DPS was composed of several TPC modules, interfacing the distributed energy sources, a common energy storage element (ESE) and a regulated voltage bus, with the bidirectional and output ports of the TPCs connected in parallel, respectively. Considering that the input sources are distributed and there are three power paths in each TPC, it is difficult to determine the power transferred on each path of the DPS. To achieve accurate power distribution of the multiple paths, a system level hybrid power control was proposed: current-sharing control when the ESE discharges and proportional power control based on the ability of sources when the ESE charges. With the proposed control, the DPS can work steadily under different states and achieve smooth transitions between them. The experimental results demonstrate the feasibility and effectiveness of the proposed system structure and power management strategy.