考虑源网荷关联戴维南等值的解析与辨识

Analysis and Identification on the Thevenin Equivalent Considering the Correlation of Source-grid-load

针对黑箱式戴维南等值难以计及源网荷关联特性,使电压静态稳定性能提高的预防控制难以实施的问题。根据节点电压方程,将电力系统对戴维南等值节点电压影响解析分解为3个部分,即发电、负荷以及二者间耦合的关系,从而使其源网荷关联特性得到体现。在此基础上,根据戴维南等值电路,将等效电势和等效阻抗予以分解,给出相应的计及这一关联特性的戴维南等值电路,并依此提出基于补偿法的戴维南等值参数辨识方法。此方法在准确辨识节点戴维南等值参数的同时还能定量分析其他各节点变化特性对其参数构成的影响,是对戴维南等值由点到面的一种扩展。因此,其不仅能评估静态电压稳定的性能,而且也能成为给出预防控制实施策略的依据。IEEE 118节点系统算例仿真结果表明此方法的有效性,在广域量测环境下,有良好的工程应用前景。

Black box-type Thevenin equivalent is difficult to calculate the correlation of source-grid-load,making it difficult to implement preventive control to improve voltage static stability.According to the node voltage equation,the influence of the power system on the voltage of the Thevenin equivalent bus was analyzed into three parts,namely the generation,the load and the coupling between the two,so that the correlation of source-grid-load were reflected.According to the Thevenin equivalent circuit,the equivalent potential and the equivalent impedance were decomposed,and the corresponding Thevenin equivalent circuit was given.Based on this,a method of identification of the Thevenin equivalent parameter based on the compensation method was proposed.Therefore,this method can not only evaluate the performance of static voltage stability,but also give the basis for the prevention control implementation strategy.The simulation results of the IEEE 118-bus system show that the method is effective and has good engineering application prospects with wide-area measurement.