利用风蓄联合削峰的电力系统经济调度

An Economic Dispatching Strategy of Peak Load Shifting by Wind Farm and Pumped Storage Plant

风电出力具有波动性和反调峰特性,大规模风电接入电网间接拉大了负荷的峰谷差,使火电机组频繁启停,系统运行成本增大。抽水蓄能电站因其良好的储能能力以及调度的高度灵活性往往作为系统的调峰电源。将二者结合,提出了风蓄联合系统削峰的调度策略,利用抽水蓄能的储能环节将风电出力时空平移,使原本波动无序的风电成为稳定可调度的电源,具备削峰填谷的能力,平滑净负荷曲线。建模引入最大化风蓄联合出力的目标函数,不仅减少了火电出力的燃煤耗费,而且避免了弃风的遗憾,充分发挥了风蓄节能环保的优势。算例分析验证了所提模型的可行性和有效性。

Power output of wind farm possesses both properties of fluctuation and counter-peak load regulation, therefore grid-connection of large-scale wind power enlarges the peak-to-valley difference of load indirectly and makes frequent start/stop of thermal generating units, thus the operational cost of power grid increases. Due to its excellent energy storage capability and outstanding dispatching flexibility, the pumped storage plant is often used for peak load shaving. Combining the wind farm with the pumped storage plant, a scheduling strategy based on the combination of the wind farm with the pumped storage plant is proposed. Utilizing the energy storage capability of the pumped storage plant the power output of the wind farm during the peak load period is transferred to the pumped storage plant to retain water, thus the stored wind power output, which disorderly fluctuates originally, can be used for peak load shaving. A multi-objective scheduling model of power grid containing the wind farm and the pumped storage plant, in which the minimum operational cost of thermal power generation units, the minimum variance of net load and the maximum power output of combined wind farms and pumped storage plants are taken as objectives, is established. Because the maximized power output of the combined wind farms with pumped storage plants that is regarded as one of the objectives of the established model, not only the coal cost for thermal power plants can be reduced, but also the waste due to wind power curtailment can be avoided, besides, the superiority of wind farm and pumped storage plant in environment protection can be brought into full play. The feasibility and effectiveness of the proposed model are validated by case study.