由于分布式电源及负荷的特殊性，稳定性成为了制约微电网发展的因素之一．文中针对微电网孤岛运行模式下多个逆变器参与系统调压调频时的微电网小干扰稳定问题，对逆变器采用 P- f 和 Q- V 下垂控制，并考虑控制器和负荷网络的动态特性，建立微电网系统的小干扰稳定模型．利用该模型计算系统特征值，直观分析微电网的稳定性，证明所研究的系统能够稳定运行．文中还进一步探讨了系统参数改变时特征值的相应变化，并计算了特征值参与因子， 将其作为度量的标准，为控制器参数的优化设计提供了依据，为有效提高微电网小干扰的稳定性提供了参考

Due to the particularity of distributed generators and loads,system stability has become an important fac-tor that restricts the development of micro- grid.In order to implement the small- signal stability of micro- grid duringthe isolated island operation when several inverters participate in the system voltage and frequency control,a small-signal model of micro- grid containing inverters with P- f and Q- V droop control,which takes into consideration thedynamic characteristics of the controller and the network,is established.Then,the model is used to calculate thesystem eigenvalues and analyze the small- signal stability of micro- grid intuitively,with its effectiveness being alsoverified.Moreover,the variation of engenvalues with the system parameters are discussed,and the parameter par-ticipation factors are calculated and are used as the measurement indexes for the optimization design of controllerparameters.The research provides a foundation for the stability improvement of micro- grid.