Design Issues in Implementing MPPT for Improved Tracking and Dynamic Performance

In solar cells, the output power is maximized only at a specific output voltage. This output power and the corresponding operating voltage is also affected by solar irradiation and ambient temperature leading to continual variation in total power available at the output of the solar cells. Considering high installation costs, it is required to track this maximum power point (MPP) at all times. This is done using a system called MPP trackers (MPPT). MPPTs utilize a power converter in series with the solar panel to extract energy from solar cells. The operating point at which the power is maximized is located using a variety of algorithms essentially based on well-known gradient following method. Algorithmic deficiencies, in this method lead to a tradeoff between dynamic performance and steady state oscillations. With continually changing atmospheric conditions, this tradeoff leads to poor utilization of solar cells - an avoidable situation for obvious reasons. The present work discusses design issues in implementing algorithms to eliminate this tradeoff