Universal Power Converter for a Lunar Power Grid

NASA’s Universal Modular Interface Converter (UMIC) is a bidirectional, modular power electronics converter that transfers power between a 120 V DC space power bus, and a medium-to-high-voltage, three-phase AC power grid. The UMIC system contains multiple parallel AC/DC UMIC modules that convert between 120 V DC and low voltage AC, as well as one or more transformers that convert power from the low voltage AC bus to the grid voltage. The UMIC module consists of multiple subsystems, including the power stage, gate driver, Field Programmable Gate Array (FPGA)-based controller, output filter, signal conditioning and sensing circuits, and thermal management subsystems. An FPGA-based controller is included within each AC/DC module and is used to regulate desired power system variables; synchronize power switching events and share load current between modules; synchronize the modules with existing service on the grid; receive commands; and share telemetry. The FPGA-based controller subsystem includes the FPGA Integrated Circuit, associated flash memory, and a controller area network (CAN) transceiver. It is envisioned that future UMIC designs can support lunar grid expansions, a Mars surface grid, or large space stations. These applications may necessitate different grid voltages or frequencies, or different control logic and communication systems. However, the core UMIC architecture and functionality will remain the same. The related patent is now available to license. Please note that NASA does not manufacture products itself for commercial sale. NASA’s Universal Modular Interface Converter (UMIC) innovation is a bidirectional AC/DC power converter designed to connect lunar surface power assets and enable power sharing over long distances between sources (e.g. solar) and loads. The UMIC module is intended to be lightweight and readily deployable. The UMIC innovation can essentially serve as the backbone of an electrical power grid for lunar surface exploration and development missions operated by NASA or the commercial space industry. The UMIC architecture is flexible to different grid voltages and frequencies, as well as to different controller and communication systems. The NASA inventors of this technology envision it becoming a standardized system that all users can access similarly.