Options for a multikilowatt modular power subsystem

Three approaches have been proposed to achieve a modular spacecraft electrical power processing and energy storage system with a load capability of up to 10 to 20 kW. All of the approaches are based on using modified versions of the flight-proven modular power subsystem (MPS), a portion of NASA´s multimission modular spacecraft bus. The three concepts being developed are: a distributed microprocessor-based control system to coordinate the workings of the multiple units; a separate central digital controller to achieve coordinated operation; and the use of transformer-isolated buck-boost regulators to combine the parallel outputs of three independent units. The differences among approaches, which vary in sophistication, in terms of performance, complexity, cost and development schedule are discussed