Characterization of a high-power Hall thruster operation in direct-drive

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 socalled 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.

Automated summary

This paper presents in-depth investigations on the performance and controllability of a direct-drive Hall thruster system. Three different thruster control laws were implemented and proven effective in controlling the thruster behavior amidst varying solar array characteristics. The study revealed minimal differences in thruster performance parameters between direct-drive and conventional power supply, with a focus on the impact of grounding on thruster plume interaction with the spacecraft.