787 / 2022-03-31 22:26:43

Intelligent assessment method of pollution status of regional power transmission network combined with meteorological conditions

Pollution Flashover,Meteorological Factors,Equivalent Salt Deposit Density,LSTM,Power Grid Pollution Map

The safe and stable operation of the power system is a major event related to the national economy and people's livelihood, and the most harmful to the safe operation of the power system is the pollution flashover caused by the fouling of insulators. Pollution flashover of insulators is a complex process. At present, scholars usually divide pollution flashover into four stages: pollution accumulation, dampness, dry area formation, and the appearance and development of local arcs. This study hopes to avoid Transmission line pollution flashover accident by affecting the "pollution accumulation" process. The past large-scale pollution flashovers in the power grid show that it is unreliable to rely on manual cleaning without the accurate guidance of real-time pollution data of insulators to achieve safe operation of the power grid. It is very important to obtain the pollution status of insulators in a timely and macroscopic manner, and to carry out predictive pollution flashover risk analysis and assessment. Taking corresponding anti-pollution flashover measures based on the evaluation results can not only save a lot of manpower and material resources, but also prevent hidden dangers of power grid security, eliminate and reduce accidents.

In view of the above problems, this paper starts with real-time weather information and offline macro-prediction analysis methods, proposes a research plan for effective prediction of insulator pollution level status, and establishes an intelligent evaluation method for external insulation status of transmission lines based on meteorological data and salt density distribution. Using GIS The technology conducts all-round processing and analysis of the obtained power grid spatial data, which can extract a variety of effective information, realize the drawing of the pollution area distribution map, and provide reliable decision support for the external insulation configuration of the power grid and the anti-pollution flashover work. The distribution map of the power grid pollution area (hereinafter referred to as the pollution area map) is a zoning map of the degree of influence of the external insulation of the high-voltage overhead lines and the electric porcelain of the power generation and substation on the external insulation strength due to natural pollution. It has been guiding the power transmission and transformation equipment in the power grid for many years. It has also continuously improved the anti-pollution flashover capability of the power grid. What’s more, it has played a certain role in regulating the external insulation configuration of new power transmission and transformation projects.

The main research contents of this paper are:

(1) Based on the existing research results on the factors affecting the contamination degree of insulators, the grey relational analysis method is used to select several factors that have the greatest correlation with the insulator equivalent salt deposit density, and comprehensively consider their influence on the insulator contamination degree. It lays the foundation for the establishment of a dense forecasting model.

(2) The long-term and short-term memory neural network LSTM is used to predict the equivalent salt deposit density of the insulator, and the pollution degree, meteorological data and prediction time series of the insulator are input into the pollution degree prediction model constructed by LSTM. The prediction of the equivalent salt deposit density of the insulator is realized. A prediction model of the equivalent salt deposit density of the insulator with higher accuracy and better performance is obtained after compared with the BP neural network which is widely used at present.

(3) Using ArcGIS 10.6 to draw a dynamic pollution map, it can basically monitor the external insulation state of a certain line at a certain time in Beijing in real time, and provide information support for the power sector. The dynamic pollution map can analyze the pollution level of a certain area, and can intuitively evaluate the pollution status of the transmission network. Improve the power grid management level and provide powerful help for accelerating the informatization process of electric power enterprises.

This study can realize real-time monitoring of changes in salt density in the measured area, predict areas with severe pollution in advance, guide the maintenance work of overhead transmission lines, and achieve early and accurate cleaning of polluted insulators, and can appropriately adjust the cleaning cycle of insulators .