Energy management of space probe based on fuzzy-model predictive control strategy

Effective control of the electric propulsion and the charge–discharge current of the battery is crucial in energy management for space probes. A two-level energy management strategy based on a Fuzzy-Model Predictive Control (FMPC) algorithm is proposed in present work. First, in the upper-level, decision layer, the operating level of the electric propulsion is preliminarily determined. Fuzzy rules are employed to assess state of health (SOH) of the battery, guiding the charge–discharge modes and modifying the operating level of electric propulsion. Second, in the lower-level, control layer, a discretized state-space model of the battery is established. Using quadratic programming, the battery current is controlled to ensure a stable energy supply to both the electric propulsion and the other loads. Simulation results indicate that by applying the FMPC strategy, the over-charge or over-discharge time is reduced by 23 %, and the battery capacity degradation is decreased by 12.5 %, and the battery life is extended by 13 %. The battery current also shows good tracking performance, with a maximum transient deviation rate of only 4 %. Finally, hardware-in-the-loop tests are conducted. The experimental results demonstrate that, the electric propulsion operates at a lower power level in the later stages compared to the early stages of the experiment due to a lower state of charge (SOC). The battery current tracking deviation rate is maintained around 5 %. The power distribution and tracking performance of the power system of the space probe are satisfactory, validating the feasibility and effectiveness of the FMPC strategy.