Research And Development Of Faults Calculation Software Of AC-DC System

Transmission of long distance and high capacity is imperative, the national power grid interconnection is the inevitable trend of China’s power grid. With HVDC transmission project commissioning increasing, Run characteristics of DC system itself and many kinds of operation mode of AC/DC power system parallel operation and so on bring many new problems to power grid, and bring to protection setting of AC/DC system with great difficulty. Aimed at the present status of research of AC/DC system failure analysis model and protection setting, this paper will use the simple and practical method to studies AC/DC system fault calculation model, provide theory technology support to the development of system software, and improve Function of the software system.The paper researches and summarizes the present situation of the protection configuration and setting calculation of AC/DC system, and Mainly aimed at complex modeling of fault analysis and difficult realization, analyzes the required electric parameters of setting, discusses and studies AC/DC system fault analysis method of facing setting calculation. The papers studies the dynamic pharos model which base on the switch function, uses the switch function to express the interface model of AC/DC system, establishes the dynamic pharos model of AC/DC system fault calculation, And models and simulates by Matlab/Simulink model simulation tools, analyzes and combines with the detailed model simulation result. Base on the advantages and disadvantages of the dynamic model, the paper studies the segmentation analysis method being based on the AC base wave, creates the unified AC/DC system fault calculation model. Matlab programming language is used to simulate and verify this model, Several model of characteristics and the result is combined and analyzed to further test its effectiveness, and realized in setting software finally。the segmentation analysis method being based on the AC base wave not only can express DC system transient process accurately, but also meets the requirements of steady-state protection setting, with a simple structure and simplified calculation process, and calculation speed is greatly improved, computers can realize easily, it provides the possibility to solve the current setting calculation problem, and have broad prospect of application.