Grid-Connected Hybrid Wind-Solar Farm Hourly Dispatching with Battery and Supercapacitor Energy Storage

The hybrid utilization of photovoltaic and wind turbine, known as the wind-solar hybrid power system (WSHPS), is one of the most promising renewable energy technologies for satisfying the power load demand, since they have complementary energy generation profiles and reduced capacity for energy storage. This paper demonstrates a successful dispatching scheme of the WSHPS for a one-hour dispatching period for an entire day using battery and supercapacitor hybrid energy storage system (HESS). Frequency management technique is utilized to increase the longevity of the batteries through comprehensively utilizing the high power density property of supercapacitors and the high energy density property of batteries in the HESS scheme. Several control algorithms based on the battery state of charge are developed to achieve accurate estimation of the grid reference power for each one-hour dispatching period that helps to minimize the energy storage cost, in addition to ensuring the energy storage system with sufficient capacity to be available for next-day operation. This study also presents an economic comparison to investigate the impact of using different kinds of energy storage systems for hourly dispatching the power of the WSHPS. The simulation results show that HESS outperforms battery-only or supercapacitor-only operation.