Abstract:

To solve the problem of how to improve the solar energy utilization efficiency under the severe condition of energy source limitation for CubeSats, one micro space electrical power system (EPS) with a centralized power supply architecture is proposed in this paper, along with the design of a maximum power point tracking (MPPT) control strategy based on the improved particle swarm optimization (PSO) algorithm to improve the energy conversion efficiency. Firstly, the mathematical model of the solar array is derived, and according to the performance characteristic of the solar array, the physical implementation structure of MPPT control of the EPS is presented. Secondly, the MPPT control algorithm based on the improved PSO is designed and verified by mathematical simulation. Finally, the hardware implementation and experimental verification are carried out for the designed EPS. The results of the ground experiments show that the maximum conversion efficiency of the solar power reaches 95.5%. The EPS has been successfully applied in the spaceflight of the world’s first 12U CubeSat, Aoxiang-Sat. The on-orbit data indicates that the power system is in good working condition during the flight experiments, which provides a beneficial reference for the design of micro/nano satellite power systems.

Key words: CubeSat, Micro/nano satellite, Electric power system (EPS), Maximum power point tracking (MPPT), Particle swarm optimization (PSO)