Minimization of solar cell hot-spots on GPS solar arrays using SABER modeling

The GPS Block IIR solar array originally was designed with circuits consisting of 160 4/spl times/6 cm. silicon solar cells connected as 2 cells in parallel with 80 cells in series. Because each cell in the 2/spl times/80 cell circuits was connected in parallel there was a concern that severe hot spot heating of individual cells could occur under array shadowing conditions. An analog model was developed to simulate solar array operation in order to better the implications of this condition. A number of different circuit topologies were simulated in order to reduce the hot spot heating. Eliminating the parallel connections between each individual cell was found to be the best way to minimize cell heating without resorting to bypass diodes.