Development And Application Of Load Forecasting System For Urban Power System Planning

Distribution network planning is the support of network development, and its planning level directly affects the security, reliability and economy of power supply. The overall load forecasting is the basis of distribution network planning; it decided the city's electricity demand and the city grid power supply capacity in the future, the level of accuracy of its direct impact on the quality of the grid planning. Therefore, the overall load forecasting is the key issue of the urban power network planning.Load forecasting is a kind of complex work which has to deal with a big volume of data, there are shortcomings like labour-intensive and low accuracy if it is completed manually, and the computer auxiliary forecasting system could increase efficiency and enhance the reasonable, the scientific and the standardized of forecasting. However, the traditional load forecasting system for the power network planning is only isolated desktop forecasting tools, do not have the abilities of collecting, collating and managing the load of the entire sequence of voltage power gird and the whole power supply company, need the historical data inputed manually, can not share the forecasting results and meet the needs of daily planning work. This paper combined the scientific forecasting theory and the actual content of forecasting work, used the advanced software design methods and computer technology, designed and realized an overall load forecasting system for the urban power network planning which can be embedded in the information systems of the power supply company.The load forecasting system in this paper can be divided into basal data platform, load forecasting and analysis system. Basal data platform is the basis for automatic data acquisition and pre-processing, providing accurate data for forecasting and analysis system. Load forecasting and analysis system which can be divided into analysis model and forecasting model is the core of the system. Analysis model is for various historical data analysis, looking for the law of the historical load changing, providing decision-making support for forecasting. Forecasting model built-in variety models for the multi-path load and electricity forecasting, supporting experts intervention after model forecasting, sufficiently using the valuable experience of experts. This system combining close with the actual demands of the planning not only realized the multi-path forecasting and aggregate balance function of load and electricity, but also the function of the sub-voltage load forecasting. The multi-path includes the overall, the sub-regional, the sub-sector and the substation. At the same time, the system also provides some convenient and practical functions such as one-press forecast, volume forecast and auto-generate report to meet the requirements of being a daily work-platform of load forecasting.As a part of the computer-assisted network planning system (CNP4.0) which developed by Tianjin University, the system of this paper can not only operate independently, but also work together with the other parts of CNP4.0. The load forecasting system in this paper has been successfully applied in the load forecasting work of power network planning projects in many cities like Shenzhen and Tianjin.