Internal network actual information based method for external network static equivalents of two ports

Abstract

The invention provides an internal network actual information based method for external network static equivalents of two ports, which comprises the following steps of: (1) establishing a simplified Ward equivalent circuit (SWM for short) of an external network; (2) establishing a multiperiod least-squares estimation model of an SWM equivalent parameter according to boundary nodes and state information of an internal network in multiple periods, and solving the SWM equivalent parameter by using Gauss-Newton method; (3) establishing a Ward equivalent circuit of an expanded voltage source branch (EWM for short) of the same external network; (4) establishing a multiperiod least-squares estimation model of an EWM equivalent parameter according to the constrain relation between the SWM parameter and the EWM parameter, the boundary nodes and the state information of the internal network in multiple periods, and solving the EWM equivalent parameter by using a Gauss-Newton method, wherein the obtained EWM is the final equivalent circuit of the external network. The method has the advantages of no need of any information of the external network, high engineering adaptability and very high equivalent accuracy no matter the tidal current of the internal network changes greatly or slightly.

Description

technical field [0001] The invention belongs to the technical field of static equivalence of electric power systems, and in particular relates to a static equivalence method of a two-port external network based on measured information of the internal network. Background technique [0002] The online calculation of large-scale multi-regional interconnected grids usually requires that the uninteresting or unobservable part, that is, the part of the external network, be equivalent. Among them, the equivalent method used to study the steady-state behavior of the power system such as power flow and static security is called the static equivalent method. [0003] The traditional static equivalence methods include Ward equivalence method, REI equivalence method and various improved methods, such as the extended Ward equivalence method that retains the buffer network, etc. What these methods have in common is that the complete model and state information of the external network are...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that it must rely on multiple disconnection operations of the internal network branch, the applicable conditions are very harsh, and the practical value of the project is limited.

Images