High-power Multi-channel Electrical Power System Module (EPSM1)

The EPSM 1 serves as the nexus of a complete, high-performance and highly efficient FPGA-driven, GaNFET-based multichannel power system for small satellites. Its advanced functionality takes the guesswork out of managing high and varying power levels in small satellites. The EPSM 1’s power-handling circuitry is comprised of twelve non-isolated 250kHz switching blocks divided into three groups under FPGA and MCU control: the solar array inputs (SAI1-SAI6), the batteries (BAT1 & BAT2), and the outputs (3V3, 5V0, 12V & 28V).

The six SAI blocks collect power for the outputs and for battery charging as required. Each SAI block independently implements a kHz-speed perturb-and-observe MPPT algorithm, with programmable maximum current setpoints and automatic power equalization across all six SAIs. The SAI blocks can handle up to 480W total solar input power. Each independent battery block provides reserve power (up to 112W per battery) when output loads exceed the total SAI input power. The EPSM 1 charges each connected 16.8V Li-Ion battery in CC/CV modes at up to 6A, with automatic CHG/DSG switchover; the recommended battery is Pumpkin’s BM 2 4S2P battery module (not included), and the EPSM 1 is compatible with the BM 2’s battery balancing, heaters, and all telecommands and telemetry.

Each output block provides a regulated output voltage at up to 5A (3V3 & 5V0) and 8A (12V & 28V), for a total of ~300W. Each output block has a programmable current limit, and the 28V block is switchable and can operate at lower voltages. A Pumpkin SupMCU handles telecommands and telemetry via SCPI over I2C, and implements sophisticated additional features including a programmable WDT, programmable overtemperature limits OT1 & OT2, smart RBF and separation inhibits, automatic recovery from power deficit conditions and automatic recovery from solar panel shading. All telemetry is timestamped and fully formatted in engineering units. The EPSM 1 is provided with an integrated heat spreader and a built-in overvoltage clamp, and operates within substantially derated operating conditions. Three internal and eight external temperature sensor ports are provided. The FPGA is SEU immune, and multiple EPSM 1s can be paralleled together. Per-block efficiency is typically >99% at moderate-to-high currents.

Includes an EPSM1 module (with one of three H1/H2 connector options: none, stackthrough or non-stackthrough), a Development Board 2 with EPSM1 installed, a Load Board B, four SAI harnesses, RBF and Separation inhibit harnesses, a USB Debug Adapter with flex/USB cables, and downloadable Windows-based and Python-based GUIs. Does not include batteries, solar panels, external power sources, or flying-lead battery harnesses (can be ordered separately). Compatible with all CubeSat architectures that employ the 104-pin connector, solar cell strings up to 28V and 2A (SAI1-SAI4) / 4A (SAI5 & SAI6), 16.8V batteries chargeable via CC/CV scheme, and Pumpkin’s SUPERNOVA Remote GSIM.