Method and device for determining corona initial voltage

Abstract

The invention discloses a method and a device for determining a corona initial voltage. The disclosed method comprises the steps of: calculating a potential distribution value of a boundary region ofa nominal electric field when a specified voltage is applied to a selected electrode model based on a charge simulation method; solving a Laplace equation based on an SOR algorithm to calculate a potential distribution value of a non-boundary region of the nominal electric field; and iteratively performing the steps of solving a charge continuity equation by using an FCT algorithm based on the potential distribution value of the nominal electric field at the first time or based on the potential distribution value obtained through calculation by calling the SOR algorithm previously when not atthe first time, calculating a potential distribution value corresponding to the called SOR algorithm at this time by adopting the SOR algorithm, and determining the potential distribution value as a corona initial voltage corresponding to a designated position when the designated position meets a corona generating condition. The disclosed method and device can determine the corona initial voltagedirectly by adopting the method different from a numerical value calculation method in the prior art without performing an experiment.

Description

technical field [0001] The invention relates to the fields of power system simulation, high-voltage corona discharge and high-voltage insulation, in particular to a method and device for determining the initial voltage of corona. Background technique [0002] In the power system simulation, at present, the technical scheme of electric field simulation combined with PEEK formula to analyze and calculate the equipment under high voltage is mostly used. That is, first use the method of electric field simulation to calculate the electric field distribution of the equipment in a high-voltage environment, and then use the PEEK formula to judge whether discharge will occur around the equipment under this electric field distribution. [0003] However, the technical solution of electric field simulation combined with PEEK formula has the following disadvantages: [0004] 1. The method of electric field simulation is only applicable to the case of single DC or single AC, and cannot c...

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Problems solved by technology

[0004] 1. The method of electric field simulation is only applicable to the case of single DC or single AC, and cannot calculate the synthetic electric field under the combined voltage of AC and DC

[0005] 2. The PEEK formula is an empirical formula based on experiments. Although it has been optimized and improved by a large number of scholars, its scope of application is still very limited: on the one hand, the current PEEK formula is only applicable to pure AC voltage environments or pure DC voltage environments; On the other hand, the electrode structure applicable to the PEEK formula is very limited (the earliest PEEK formula is suitable for the straight wire structure, and later scholars have obtained the PEEK formula suitable for rod-plate electrodes, wire-plate electrodes and other structures through a large number of experimental analysis. These formulas are more accurate in calculating the corona inception electric field of the corresponding structure, but they are not suitable for calculating complex equipment structures)

Therefore, this method cannot obtain the corona inception voltage of the equipment under the composite voltage, and cannot realize the optimal design of the internal insulation of the AC-DC converter valve in actual engineering

[0006] 3. PEEK formula and various derivative formulas based on PEEK formula: calculate the corona initial electric field value of some specific structures (such as wire structure, rod plate electrode structure, etc.), but only applicable to the application of pure DC voltage or pure AC voltage Happening

[0009] 1. Through the experimental method, only the corona inception voltage of the electrode equipment used in the experiment can be obtained. If the shape of the electrode is changed, or the gap distance between the electrodes is changed, the experiment needs to be repeated, which is time-consuming and laborious.

[0010] 2. For some large-scale equipment, it is difficult to conduct experimental simulations in advance. If the equipment is produced and tested, the purpose of prediction and optimization will not be achieved.

[0011] 3. There are certain dangers in the process of high pressure experiment

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