计及模式可观度的阻抗网络聚合方法

Aggregation of Impedance Network Model Considering Modal Observability

为研究大规模可再生能源系统的振荡问题,提出了一种基于模式可观度的阻抗网络聚合方法,将高维度的阻抗网络简化为一个聚合阻抗,使其保留系统全部振荡模式的信息。首先定义了节点(支路)对模式的可观度,然后基于节点(支路)可观度矩阵提出了阻抗网络的聚合判据和聚合指标,从而找到对各模式均可观的网络端口,接着计算该端口的等效阻抗,作为网络的聚合阻抗。最后将所提方法应用到实际风电并网系统中,利用获得的聚合阻抗分析系统的振荡稳定性,并通过仿真验证了该方法的有效性。

1:For the oscillation of the large-scale renewable integrated power system,this paper develops an aggregation method to simplify a complicated impedance network into an aggregated impedance,reserving the information of all system modes based on the modal observability.The modal observability in each node(branch)is firstly defined,and then based on the modal observability matrix,the aggregation criterion and index are proposed to identify the network port that can observe all concerned modes.By calculating the equivalence impedance of the port,the aggregated impedance of the network can be obtained.Finally,the proposed method is applied to a practical wind power system,of which the aggregated impedance is obtained and the system stability is analyzed.Electromagnetic transient simulations are also carried out to check the consistency.