Analog Maximum Peak Power Tracking Techniques for Small Satellites

This work describes the implementation of three maximum peak power tracking methods devised for small satellites. The three methods are the analog oscillating maximum power point tracking, the analog global maximum peak power tracking, and the analog global maximum output power tracking. An interplanetary mission (Mars-Asteroid belt) with complex power-voltage solar array characteristics, including several local maximum power points, is considered to evaluate each peak power tracking technique. The three peak power tracking techniques have been integrated into an unregulated battery bus topology using synchronous buck converters as solar array regulators. High-reliability design is achieved using analog electronic parts with space-qualified counterparts. Each peak power tracking method has been optimized individually for the best performance and then compared with the others. The experimental validation suggests that the preferred method strongly depends on the expected power-voltage solar array characteristics and mission parameters.