Transient effects during 120 VDC spacecraft high voltage DC fuse clearing

Historically, spacecraft power system nominal bus voltages have been increasing over time to accommodate increasing bus load demands while reducing spacecraft mass, particularly in electrical harnesses. The use of higher nominal spacecraft bus voltages requires higher rated circuit protection devices as well as a thorough understanding of power system dynamics during fault clearing events. This paper presents details of the Earth Observing System (EOS) AM-1 power subsystem topology, which is a single point ground 120 VDC /spl plusmn/4% regulated power system, correlation of the power system analytical modeling and subsequent testing of actual fuse blow transients, as well as covering the power subsystem test configuration that was developed to simulate the actual EOS AM-1 spacecraft bus topology. The analytical modeling and test configuration presented in the paper focuses on transient voltage response for 120 VDC line-to-ground and line-to-return fault clearing events involving Mepcopal P600L-135 series 5 and 10 ampere rated fuses and various power cable lengths consisting of shielded 5 and 7 wire AWG 20 wires.