Grid side equivalent impedance modeling method and system

Abstract

The invention provides a grid-side equivalent impedance modeling method and system. The method comprises an aggregation equivalent step of using a grid-connected admittance model of a single VAC STATCOM as a minimum modeling unit, and subjecting the grid-connected admittance models of multiple VAC STATCOMs to aggregation equivalence; and an equivalent impedance model establishment step of establishing a grid-side equivalent impedance model having operation of multiple VAC STATCOMs by using a coupling and impedance relationship between the grid-connected admittance model of the VAC STATCOM anda line admittance model. The method establishes an accurate and highly linear admittance model, verifies theoretically the validity of multiple VSC STATCOM grid-connected admittance models. The grid-side equivalent impedance obtained by a numerical relationship between admittance and impedance and in consideration of the operation of multiple VSC STATCOMs corrects the impedance characteristic of an existing line model, and contributes to providing an impedance reference for the stability of the new energy grid connection.

Description

technical field

[0001] The invention relates to the field of AC power transmission and distribution, and in particular, to a grid-side equivalent impedance modeling method and system considering a voltage source type (VSC) static var compensator (STATCOM). Background technique

[0002] With the increasing depletion of traditional energy sources such as coal, oil and natural gas, and the serious environmental problems caused, the promotion and utilization of renewable energy has become an important means to solve energy problems at this stage. my country has built a number of tens of millions of kilowatts of wind power / photovoltaic bases in the "Three Norths" area, and the use of UHV DC transmission is the dominant form of my country's current renewable energy development and utilization. The DC transmission system of the renewable energy power generation base includes diversified equipment such as wind and solar power generation, reactive power compensation, DC transmission,...

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