AC/DC hybrid power distribution network harmonic analysis method based on augmented node admittance matrix

Abstract

The invention provides an AC / DC hybrid power distribution network harmonic analysis method based on an augmented node admittance matrix. The method mainly builds a topological structure of an AC / DC interconnection converter and a state equation of a controller, and carries out the integration to obtain a state equation of a system; a generalized two-port admittance matrix of the interconnection converter is obtained by using an input and output relation of a control theory; on the basis of a generalized two-port network matrix of the interconnection converter, an appropriate model of each element of the system is established; according to the Kirchhoff voltage and current law, bus voltage and current are linked, node admittance matrixes of the direct current subsystem and the alternating current subsystem are formed respectively, finally, an augmented node admittance matrix of the AC / DC hybrid power distribution network is formed, and power quality analysis of the AC / DC power distribution network is carried out in combination with a modal analysis method. The method provided by the invention can effectively solve the harmonic analysis problem of the AC / DC interconnection network and identify the specific transmission path of the harmonic in the AC / DC hybrid power distribution network.

Description

technical field [0001] The invention relates to a harmonic analysis method of an AC / DC hybrid distribution network based on an augmented node admittance matrix, which belongs to the power quality analysis technology in the field of renewable new energy. Background technique [0002] The distribution network is divided into a DC distribution network and an AC distribution network. At present, the main power generation still comes from the AC power generated by the power plant, and most of the loads are also AC loads. At the same time, with the continuous introduction of power electronic equipment, DC loads are also At the same time, the energy loss of DC transmission is less than that of AC transmission, and there will be no stability problems in AC transmission. Therefore, AC and DC are in a state of simultaneous development and coexistence. The research on AC-DC hybrid distribution network also has great reality. significance. [0003] On the other hand, the harmonics gene...

AI Technical Summary

Problems solved by technology

However, due to the heterogeneous network of AC and DC in the AC-DC hybrid distribution network, the original node admittance modeling method is only suitable for pure DC or pure AC power networks, and cannot directly establish the augmented node admittance of the AC-DC hybrid power grid. matrix, so constructing a compatible AC / DC subnetwork augmented node admittance matrix is ​​critical for broadening the application of power quality analysis to AC / DC hybrid distribution networks

[0005] This method aims at the problem that there are only pure AC or pure DC node admittance matrix establishment methods in traditional harmonic analysis and cannot break through the limitations of AC-DC hybrid distribution network, and proposes an AC-DC hybrid distribution network based on augmented node admittance Power grid harmonic analysis method, the method is mainly to establish the topology structure of the AC-DC interconnected converter and the state equation of the controller, integrate the state equation of the system, and use the input-output relationship of the control theory to obtain the state equation of the interconnected converter, etc. Efficient Two-Port Network Matrix

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