基于风机调频特性的储能配置方法及协调运行策略

针对大规模风电机组(wind turbine,WT)接入电网,导致电网惯量响应能力和调频备用容量不足,进而造成电网频率稳定性下降的问题,文章提出一种风储系统与等容量同步发电机等惯量响应能力的储能(energy storage,ES)配置方法。方法旨在实现WT取代同步发电机接入电网前后,电网惯量响应能力和调频能力不变。并在此基础上,根据WT在不同风速下,具有不同的调频能力这一特性,文章进一步提出了风储协调控制策略,该策略既能在低风速下提供惯量响应支持,又能在中风速下辅助WT转速恢复,避免频率二次跌落。仿真结果表明,仅配置风电场额定功率5%的容量,既可补偿电网惯量响应能力,又能满足WT转速恢复所需功率,大大提升了电网频率运行稳定性。

Energy Storage Configuration Method and Coordinated Operation Strategy Based on Wind Power Frequency-Regulation Characteristics

Large-scale wind power connected to the power grid leads to the decrease of inertia response capacity and frequency-regulation reserve capacity of the power grid, and then the frequency stability of power grid is decreased. A method for energy storage (ES) configuration helps wind power units to provide the same inertia response capacity as equal capacity synchronous generator is proposed. The aim is to realize that the inertia response capacity of the grid and the overall frequency-regulation capacity of the system remain unchanged before and after wind power units instead of the synchronous generator connecting with the grid. On this basis, wind power units have different frequency-regulation ability under different wind speeds. Furthermore, a coordinated control strategy of combined wind and storage system is proposed, which can not only provide inertia response support at low wind speeds, but also assist wind power units to recover their rotating speed at medium wind speed to avoid secondary frequency drops. The simulation results show that energy storage with the capacity equalled to only 5% of the rated power of the wind farm can compensate the inertia response capacity of the power grid, as well as the power needed to restore the wind power units’ speed, which greatly improves the operation frequency stability of the power grid.