基于预测方法的直流微网混合储能虚拟惯性控制

Virtual Inertia Control of Hybrid Energy Storage in DC Microgrid Based on Predictive Method

为增强直流微网扰动抑制能力,使直流侧电压在系统扰动时呈现惯性响应特性,提出了一种基于变流器预测控制的直流微网混合储能系统虚拟惯性控制策略。该方法采用微网储能系统变流器作为虚拟惯性控制单元,增加直流电压变化作为控制输入变量,增强了其暂态运行稳定性。此外,为提高直流微网本地控制速度,以配合储能系统的快速惯性调节,避免因控制延时造成的滞后控制现象,提出了基于模型预测方法的储能变流器本地控制方法,并采用由蓄电池和超级电容组成的混合储能系统,以弥补蓄电池充放电速率较慢的缺点。基于Matlab建立了风电直流微网系统仿真模型,仿真结果验证了所提策略的有效性。

To enhance disturbance rejection capability of DC microgrid and enable inertial response of DC voltage on system disturbance, virtual inertia control strategy of hybrid energy storage in DC microgridbased on predictive method is proposed. In this method, converter of energy storage system in microgrid is adopted as inertia control unit with DC voltagevariation as input control variable to enhance its transient stability. In order to improve local converter control speed to match fast inertia regulation of energy storage system, a local energy converter control method based on model predictive strategy is proposed. In addition, generally used battery in energy storage system in DC microgrid is replacedwith a hybrid energy storage structure where super capacitor is adopted to absorb high frequency disturbance. In order to verify validity of the proposed control strategy of hybrid energy storage based on predictive method, simulations are conducted and results show that the proposed control method can effectively improve transient response to system disturbance and guarantee DC bus voltagequality and system stability.