A Research On Risk Assessment And Preventive Control Of Power System Overload In Electrical Market

With the development of economy, electricity demand and the grid scale are in a sustained rapid growth, and the nationwide interconnection has developed greatly. These bring great benefits to power system, but at the same time cause a greater operation risk. Especially as the electricity market reforms, power system operating conditions become more complex in the competitive environment and the factor of uncertainty influenced the gird security more seriously.At present, the assessment method based on risk theory is one of the hot points in current power system security research. Compared with deterministic security assessment method and probabilistic security assessment method, the risk assessment method can reflect the complexity and randomness of power system, can quantize the severity of disturbance for different market participant, and can tradeoff well between security and economy.At the beginning of this paper, the basis of power system security risk assessment is introduced. Then the components fault models in real time operational environment are modeled and the serious indexes of disturbance are established. Then based on the risk theory and market mechanism, a novel method is proposed in the transmission line overloading risk assessment under power electrical market. The method not only contains the uncertainty and randomness analysis of both the transmission line operation state and the load fluctuation, but also analyzes the economic loss of power plants, Grid Company and customers. With the market mechanism, the different consequence models of line overloading are established for power plants, Grid Company and customers respectively. Different compensation of the loss plays an important part in the consequence models. Finally, in the power market, demand management play a subjective dynamic role in the power system overload risk prevention and control, the load curve varies with the power price. So with the load demand elastic matrix, demand management is a good way to reduce the risk of transmission lines overloading and increase the reliability of power system. In electric market mechanism reform, the risk assessment theory proposed in this paper is of great significance to increase the stability and security of power system.