Performance metrics for evaluating spacecraft power control and management (PCM)

The power subsystem is the most critical system in a spacecraft due to the dependency of nearly every other subsystem for power. The power system configuration depends on various factors such as amount of power required, type of orbit, duration of the mission, constraints on mass volume, and the impact of the system's hardware on the spacecraft design. Power system encompasses power generation, energy storage and power processing. The organization of control and management circuits to carry out these functionalities is termed as Power Control and Management (PCM). Selection of an appropriate PCM is must for achieving the desired mission goal. This makes its choice a most important one for spacecraft Engineers. Different methods are adopted for finding out a suitable PCM. However availability of indices facilitate the evaluation of electrical performance of PCM systems. Hence a set performance metrics which would serve as benchmark has been detailed here. In the end, a typical case has been enumerated to demonstrate the usefulness of these metrics.