Large Spacecraft Electric Propulsion Using Multiphase Generator

A high-power high-voltage electric propulsion system for spacecrafts is proposed in this paper. For the spacecrafts with power levels below 10 kW, the conventional propulsion systems such as photovoltaic (PV) solar with battery energy storage, fuel cell, and radioisotope thermoelectric generator (RTG) have been viable energy sources. The chemical-based propulsions can be scaled for megawatts (MW)-scale spacecraft propulsions in missions with relatively short durations. For missions longer than a few weeks and MW power requirements, such as in-space Mars travel, heat source-based propulsions are required. This paper proposes a new concept for MW-scale electric propulsion (EP) system driven from a heat source that converts mechanical power at its input to an electric direct current (DC) power at its output suitable for an electric thruster. The proposed system has the following features: (i) It consists of two main components, a high-voltage dual rotor 9-phase rotating electric generator, and a stationary integrated 9-leg passive electric rectifier. The 9-phase generator converts mechanical from heat source to a high-voltage alternating current (AC) electrical power feeding it to the 9-leg rectifier which converts AC to high-voltage DC for a high-energy electric thruster.