Energy storage capacity optimization of wind-energy storage hybrid power plant based on dynamic control strategy

The construction of wind-energy storage hybrid power plants is critical to improving the efficiency of wind energy utilization and reducing the burden of wind power uncertainty on the electric power system. However, the overall benefits of wind-energy storage system (WESS) must be improved further. In this study, a dynamic control strategy based on the state of charge (SOC) for WESS is proposed to maintain a healthy SOC for energy storage system (ESS). Then, four scenarios with different operation strategies are set based on the historical operation data of a wind farm in China. Particle swarm optimization is used to solve the problem, with the goal of optimizing the overall system benefit. The results show that the dynamic control strategy is the most cost-effective while maintaining reliability. When compared to other scenarios, the profit of the dynamic control strategy is extended by 7.63 %, 327.69 % and 9.75 % respectively, and the energy storage life is extended by 10.02 %, 62.89 % and 21.61 % respectively, demonstrating that different working state of energy storage will significantly affect the storage life and, ultimately, affect the economic benefit of the system. Finally, the influences of feed-in tariff, frequency regulation mileage price and energy storage investment cost on the optimal energy storage capacity and the overall benefit of wind-energy storage hybrid power plant are discussed.