Evaluation of bus impedance on the SPOT multimission platform

A numerical model for the performance of a boost-type regulator for solar-array voltage regulation through shunting excess energy into dissipative elements or shorting the array strings is presented. Equations and variable waveforms which define static operation are described and a dynamic model is configured using the current-injection principle. The resulting small-signal equivalent model is tested against operation of a breadboard model and verified, and further confirmed in comparison with the unit in the SPOT power system. Note is taken of the bus impedance in the three boost sections of the SPOT power circuitry. Attention is also given to the effect of batteries wired in parallel to the user load.