基于自适应逆控制的微电网有功频率调节方法

Active Power Conditioning Stralegy Based on Adaptive Inverse Control for Microgrids

针对微电网孤岛运行时配有储能装置的微电源的运行特性,提出一种基于自适应逆控制的有功频率调节方法。其核心思想在于将微电源有功-频率下垂特性视为受控对象,通过一个权系数可变的数字滤波器建立受控对象的"逆",并将其作为前置控制器来产生一个有功-频率下垂系数,以控制下垂特性。当微电网内存在不平衡有功功率时,该方法沿均方误差梯度负方向迅速找到最佳下垂系数,完成不平衡有功功率在不同微电源间的动态分配,同时保证微电网频率维持在额定频率。以2台微电源互联系统为例,仿真验证了所提方法的有效性和可行性。

Considering the performanceof microsources equipped with energy storage devices in an islanded-mode microgrid,an adaptive inverse control strategy applied to active power conditioning is developed.Regarding the P-f droop curve as a controlled object,the primary ideology of this method focuses on building an inverse function of the controlled object as a previa controller by using a digital filter with variable weight coefficients,with which a P-f slope coefficient can be obtained to modify the P-f droop curve.For a given microgrid in which unbalanced active power exists,this strategy can quickly find the best P-f slope coefficient along the negative gradient direction of the mean square error.Through the controlling process,the unbalanced active power among different microsources can be redistributed and the frequency of the microgrid can be preserved at the rated value.The validity and feasibility of this control strategy are verified by the simulation of a two-DG microgrid.