Abstract: Technology is disclosed herein for a power control and distribution unit (PCDU) of a spacecraft that has a microcontroller to control battery charging from solar arrays. Using a microcontroller within the PCDU reduces the complexity of the PCDU. The microcontroller may be programmable and reprogrammable, which allows the charging of the battery to be adapted to various conditions. For example, the microcontroller can be programmed in accordance with the mission to optimize battery charging for that mission.

Abstract: A spacecraft includes a power train that includes a solar array, an electric propulsion subsystem, and a power conversion module. The power conversion module receives power from the solar array at a voltage, Vi; and delivers power to the electric propulsion subsystem at a voltage, Vo. The spacecraft is configured to operate at a varying distance, D, from the sun within the range of Dmin to Dmax, Dmax being at least 1.3×Dmin. The solar array is configured to deliver power to the power conversion module at a voltage approximately equal to Vo when the spacecraft is proximate to Dmax.