A Simulation Method for Transformer Winding Fault Situation under Lightning Impulse Voltage

Abstract

The invention discloses an analogue simulation method of transformer winding fault situation under lightning impulse voltage. According to the distributed capacitance and inductance parameter matrix characteristics of windings of different structures, parts of capacitance and inductance parameters which have a small influence are removed, the capacitance parameter and the inductance parameter of adjacent parts of line reel are selected to obtain different distributed parameter combinations; and a winding voltage distribution calculation result under distributed parameter model lightning impulse under different mutual capacitance and mutual inductance parameters is compared with the calculation result of a multi-conductor transmission line model, and the combination with a smallest difference is selected as the basic parameter of a fault analogue model. By use of the method disclosed by the invention, the capacitance and inductance parameter matrix characteristics of the transformer winding are combined and are subjected to comparison analysis with a calculation result of the multi-conductor transmission line model, and reasonable capacitance and inductance parameters are selected to establish a corresponding distributed parameter model. Compared with an existing distributed parameter model, the distributed parameter model in the method disclosed by the invention has the characteristics that the electrical network characteristics of the distributed parameter model are more consistent with the electrical characteristics of the transformer winding under the lightning impulse, a fault analogue result more approaches to a practical situation, and fault characteristics analysis is more accurate.

Description

technical field [0001] The invention relates to a method for simulating fault conditions of transformer windings under lightning impulse voltage, and relates to the field of transformer winding fault tests under lightning impulse voltage. Background technique [0002] Transformer is one of the most important equipment in the power system. In order to ensure the safe and stable operation of the transformer, the insulation performance of the transformer must be strictly assessed before it is put into operation. Lightning impulse test is one of the main methods of insulation assessment. For ultra-high voltage and ultra-high voltage transformers, once a fault occurs, it is necessary to quickly prepare to determine the type and location of the fault to ensure smooth maintenance and put the transformer into operation on schedule. However, it is very difficult to obtain different fault characteristics of EHV and UHV transformers by means of experiments. Using the simulation head en...

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Problems solved by technology

Among them, the multi-conductor transmission line model considers all the electrical parameters, and can simulate the winding voltage distribution under lightning impact. However, because the electrical network parameters cannot be changed suddenly during calculation, it is difficult to simulate the transient process of faults such as inter-turn breakdown; the distributed parameter model can simulate the gap Transient processes such as breakdown, but it is difficult to model when considering all the mutual capacitance and mutual inductance electrical parameters; the existing model only considers the electrical parameters between adjacent units, resulting in large calculation errors, which is not conducive to fault feature analysis

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