Abstract In Hall propulsion systems, a direct and non-isolated connection between the thruster discharge and the solar array implies a significant change in terms of spacecraft grounding, thruster operation and control. In this so-called direct-drive architecture, since discharge voltage and current are no more fixed by a power processing unit but are constrained by the solar array characteristic, which changes during a space mission, specific control laws need to be developed and tested to assess the feasibility of thruster operation. In this paper, in-depth investigations performed in SITAEL on thruster performance and operation controllability of a direct-drive Hall thruster system are presented. The HT5k, a 5 kW-class Hall thruster, was connected to a solar array simulator (SAS) and tested at different operating conditions. Three different thruster control laws were implemented and were proved effective in controlling the thruster behavior with respect to on-orbit-representative variations in the SAS characteristics. The results also highlighted minimal difference between thruster performance parameters in direct-drive and with a conventional power supply. Finally, the impact of grounding on thruster plume interaction with the spacecraft was analyzed.

中文翻译：

---

直接驱动下大功率霍尔推进器操作的表征

摘要 在霍尔推进系统中，推进器放电和太阳能电池阵列之间的直接和非隔离连接意味着航天器接地、推进器操作和控制方面的重大变化。在这种所谓的直接驱动架构中，由于放电电压和电流不再由功率处理单元固定，而是受太阳能电池阵列特性的约束，在太空任务期间会发生变化，因此需要开发和测试特定的控制律以评估推进器操作的可行性。在本文中，介绍了在 SITAEL 中对直接驱动霍尔推进器系统的推进器性能和操作可控性进行的深入研究。HT5k 是一个 5 kW 级霍尔推进器，连接到太阳能电池阵列模拟器 (SAS) 并在不同的操作条件下进行测试。实施了三种不同的推进器控制法则，并证明在控制推进器行为方面是有效的，因为 SAS 特性的在轨代表性变化。结果还突出了直接驱动和传统电源中推进器性能参数之间的最小差异。最后，分析了接地对推进器羽流与航天器相互作用的影响。