Sliding mode control based power balancing for grid connected PV system

Renewable sources of energy are gaining importance with each passing day. In order to increase the penetration of renewable sources of energy, they must have some reserve capacity for stable operation and higher reliability. Generally PV systems are equipped with sufficient battery back up when interfaced with any load network. However, installation and maintenance of batteries for high power systems becomes difficult from economic perspective. On the other hand, grid connected PV systems are relatively more stable and robust. In this paper, a sliding mode based power balancing control strategy for grid connected solar PV systems is proposed. Some of the advantages of sliding mode control are disturbance rejection, insensitivity to parameter variation and simple implementation by means of conventional power converters. The proposed control strategy can provide power balancing and reserve capacity without use of expensive energy storage devices like batteries. Simulations are carried out under varying load demand as well as changing weather conditions to demonstrate the applicability and effectiveness of the proposed sliding mode control strategy.