Research On Power Network Planning Based On Reliability Assessment

Network planning is an important part of preliminary work of electrical engineering. It is a decisive factor of network operation level. Therefore, in order to improve the reliability level of power grid operation, it is much effective to consider the reliability effectiveness and evaluate the reliability of programs in the network planning stage. In this thesis, study of theoretical and practical methods for network planning based on reliability assessment was made. Study of practical reliability evaluation models and processes in power system planning was also made.Firstly, the thesis conducts research on power system reliability evaluation theory and practical procedures, and describes the application of the large-scale commercial software RAMSES on power system reliability evaluation at the planning stage. The paper proposed a time-weighted average method based on the S-curve dealing with sample data, which has achieved good results.The thesis presents a practical plan for power grid comprehensive assessment system and extracts the mathematical models and processes of power network planning based on reliability evaluation. The system took into account the reliability, security and economy, and each index can be solved by commercial software. Based on the comprehensive assessment system, a multi-level, multi-objective optimization mathematical model for network planning is proposed.The thesis focuses on the application of reliability evaluation on assessing the actual power grid. For the basic data statistical methods of distribution network, a formula deriving the maintenance data was put forward, which transforms maintenance events of switch and circuit breaker into maintenance events of overhead lines and cable. A study of an actual distribution network was made as an example, also practical recommendation programs for network planning were summarized. For UHV AC and DC transmission system, reliability modeling was put forward. A study of the impact with the reliability of the main network before and after UHV systems access to the 500kV network was made as an example.Finally, the thesis studies the application of reliability assessment on choosing recommended planning programs. The thesis conduct research on comprehensive analysis of reliability and economy of the medium voltage distribution networks selection and overhead line switch optimization, and put forward recommended program.