Radioisotope Power Systems (RPS) are critical for future flagship exploration missions in space and on planetary surfaces. Small improvements in the RPS performance, weight, size, and/or reliability can have a dramatic effect on the scientific capability of the vehicle and the overall mission costs. Radioisotope Thermophotovoltaic (RTPV) energy converters are a particular type of RPS that directly converts the heat produced by a General Purpose Heat Source (GPHS) to electrical power using a specialized Photovoltaic (PV) cell. A key element in an RTPV system is the power conversion electronics system that efficiently converts the low-voltage current from each PV cell into useable, stable bus voltage for powering spacecraft systems despite issues such as non-uniform illumination, PV cell degradation, and decay of the GPHS source. In this project, Creare and the Massachusetts Institute of Technology (MIT) propose to develop an advanced, multi-channel maximum power point tracking module (MPPT) that is optimized for RTPV systems. The converter will provide stable output voltage from a 16-cell PV array that, when coupled with advanced PV technology of the RTPV system, will provide high system efficiency. In Phase I, we will design a prototype power tracking module, which will be fully characterized for conversion efficiency. We will also assess the impact of this new MPPT on the overall RTPV system design and performance.
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