Identification method for sub-synchronous/super-synchronous coupling impedance (admittance) model of power device

Abstract

The invention discloses an identification method for a sub-synchronous / super-synchronous coupling impedance (admittance) model of a power device. The identification method for the impedance model comprises the steps of providing the sub-synchronous / super-synchronous coupling impedance model of the power device; connecting the power device into a power grid, applying sub-synchronous / super-synchronous excitation to the power grid, and obtaining sub-synchronous and super-synchronous voltage components and current components of the power device based on the sub-synchronous / super-synchronous coupling impedance model; changing sub-synchronous / super-synchronous excitation parameters or parameters of an external power grid, thereby obtaining multiple groups of measurement results of the power device, and generating an impedance measurement equation according to the multiple groups of measurement results; and carrying out a preset numerical optimization method on the impedance measurement equation to obtain impedance parameters of the sub-synchronous / super-synchronous coupling impedance model. The method has the advantages that the indivisibility between complementary frequency dynamic states of two relatively working frequencies is represented, and the sub-synchronous / super-synchronous resonance and vibration problems of a power system are analyzed and explained well.

Description

technical field [0001] The invention relates to the technical field of power system analysis and control, in particular to an identification method of a sub / supersynchronous coupling impedance (admittance) model of power equipment. Background technique [0002] Under the trend of increasing power electronics in modern power systems, power electronic converter technology not only changes the form of primary equipment in the power grid, but also significantly changes the dynamics of the power system with its unique multi-scale control mechanism and low-inertia wide-band response characteristics. Features, bringing new stability analysis and problems. In recent years, especially the new sub / super synchronous oscillation (Sub Synchronous Oscillation, SSO) problem caused by the large-scale connection of wind power, photovoltaic and other variable power sources to the power grid has become particularly prominent. In addition, the negative resistance characteristics of the convert...

AI Technical Summary

Problems solved by technology

At present, the widely used electromagnetic transient simulation software (such as PSCAD, EMTP) only supports the modeling and analysis of a single step (fixed rate), and it is difficult to balance accuracy and efficiency to realize multiple converters, complex AC and DC networks, and massive working conditions. The time-domain simulation under the following conditions; the traditional eigenvalue analysis method faces the problem of dimensionality disaster, and it is difficult to apply to the actual large power grid including thousands of converters and tens of thousands of nodes

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