A Dual Three-Phase DC-Link Inverter Prototype Powering a Redundant Space Robotics Motor Drive

Like their industrial counterparts, space robotics motor drives require a DC-link inverter to convert the space-craft's DC-bus voltage into a three-phase AC rotating field. The designer of a space grade inverter needs to balance various opposed design objectives. Achieving a high level of operational reliability, including dependable fault monitoring capabilities is essential, while simultaneously keeping design complexity as low as possible. Based on the preliminary results of an earlier on-orbit-servicing project study initiated by German Aerospace Center DLR, the Institute of Robotics and Mechatronics has developed an engineering prototype of a robotic arm for space. This paper describes the design and initial operation of the robotic system's dual three-phase DC-link inverter, which pow-ers the robotic motor drives. It summarizes some lessons learned during the development process and indicates the next steps required to further test and qualify the inverter for a planned in-orbit demonstration of European space robotics servicing technology.