Research On Risk Assessment Of Power System Based On State Space Division And Software Implementation

With the advancing of power market mechanism and the penetration of large-scale renewable energy, the uncertainty faced by power system becomes much more complicated and multivariate than ever before. These uncertainty factors bring huge challenge to the security and stability of power system. In recent years, a lot of large-scale blackouts have happened in the word, which shows that the power systems are still fragile. Therefore, it is essential to study the risk assessment method, which is faster and in consideration of the weather impacts.This paper focuses on the research of the component reliability model considering weather impacts and fast analysis method of risk assessment and its software implementation. The main research work is as follows:Firstly, illustrating a component reliability model based on weather. The mechanism of the weather affecting the risk of power system is analyzed, and then the component reliability model based on weather was illustrated. The transmission line model takes into account of the situation that the line may pass through a variety of climatic zones. Combine the above-mentioned model with the existing risk assessment methods, a new method was obtained. By using of the modified IEEE-RTS79 system with wind power, the feasibility and reasonableness of the proposed model and approach are verified. Besides, the impact of bad weather proportion to system risk and impact of weather to power system with wind farm are studied further.Secondly, proposing a state space division method to assess the risk of power system faster. This method divided all the possible operation system states into two mutually complementary subspaces according to the occurrence probability. In order to shorten the time-consuming, different method was used to calculate the risk of each subspace. Analytical method was used to calculate the risk of the first subspace comprised with the large occurrence probability states, which was identified using the Fast Sorting Technique. System states that have a small occurrence probability comprised the second subspace, whose risk was calculated using Monte Carlo Simulation combined with the adaptive importance sampling technique and scattered sampling technique. Through the case studies conducted on the MRTS, it is validated that the proposed method can assess the risk faster. Besides, the influence of the ceiling probability and the system reliability to this method are studied further.Lastly, developing and applying of static risk assessment software of power system with wind power. Based on the research of this paper and other scholar, the static risk assessment software of power system is implemented by using of the C sharp programming language. As the increased wind power penetration, the risk of power system is tremendously influenced by the wind power. Therefore, this software includes wind power model. This software mainly has four parts, including data inputting, parameter setting, risk assessment and results analysis. This software can be used to assess the risk of planning grid to guide the adjustment and improvement of the planning scheme. By using of this software, the risk of planning grid of Hainan Province in 2015 is assessed. According to the results, the improvement suggestions to the planning scheme of Hainan Province were put forward and the rationality and reliability of this software is proved.