Optimal load management in a low power off-grid wind-photovoltaic microhybrid system

The most significant problem is to balancebetween generation and consumption in power systemsranging from small to large scales. This may be done by dailyload scheduling in small-scale systems using metaheuristicoptimization techniques such as the GA, the PSO and the SAetc. In the case of an off-grid low power wind-photovoltaichybrid system, it is expected to power the loads withoutshedding and this may require scheduling loads on the basis ofpower balance, continuously energizing loads and lowoperation cost as much as possible at each interval of in a day.The fact is that it is a complex optimization problem withseveral constraints and this problem should be solved 24 timesfor an hour time interval. Due to incapability of deterministictechniques the GA or similar techniques may be the bestapproach to solve this problem for optimal powermanagement. The construction of objective function isconsidered to reduce operation cost and use stored energy inthe micropower system consisting of a 1 kW wind turbine, 8photovoltaic panels, a diesel generator and 4 gel batteries. Theproblem under consideration is solved by the GA for an hourtime interval during a day. The results indicated that thebalance between generation and consumption can mostly bemaintained and operation cost and energy efficiency areimproved with respect to an unscheduled case.

Keywords:

Renewable energy applications , Photovoltaic energy generation , Wind turbines , Power management , Genetic algorithms