Solar Array Voltage Regulation Study

This study investigates the advantages and limitations of regulating solar array voltage in space power systems. The technique has application to systems in which the array sources current-mode battery chargers, load converters, or arcjet thrusters. The negative input impedance of these devices normally results in array voltage collapse if operated on the high-impedance (or low-voltage) side of the array. By regulating array voltage, and following the criteria developed through this study, voltage collapse is precluded and the array may be operated at any voltage. This eliminates the need to bias peak-power tracking systems short of the maximum power point for stability, and has the added advantage of attenuating bus transients from pulsed loads. The major drawback to this technique is that the regulation loop is at best conditionally stable when operated on the high impedance side of the array, so the design must ensure that a significant gain loss cannot occur.