The Study On Security Criterion Of Power Supply In Urban Power Network

As the major load centers of power system and one of the most important urban facilities, urban power network calls for enormous investment, high security and reliability of power supply. Therefore, it is very significant to perform deep research on security criterions of power supply with technical & economic evaluation methods, so as to constitute practical security standard and solve the contradiction among reliability, security and economy.This paper firstly discusses the basic concept and evaluation indices about "security of power supply", based on those of "reliability of power supply". Secondly, considering the actual situation of urban power network, basic principles for security criterion of power supply in urban power networks of Britain and China are explained and compared in detail. Then, the "Economic Evaluation Method of Network Investment based on Security Level of Power Supply" is studied, as well as the related mathematical model, evaluation flow and computing program, whose correctness and effectiveness are proved by the practical examples in Britain and Nanjing urban power networks. Finally, according to the results of comparative analysis and economic evaluation, reasonable proposals and feasible implementation steps on improving security standard in networks of China are put forward.The contributions of this paper are listed as follows:(1) elucidating the basic concept and evaluation indices about "security of power supply", as well as the distinctions and relations between security and reliability; (2) providing detailed explanations on security criterion of power supply in urban power networks of Britain and China; (3) based on security level of power supply, setting up the economic evaluation model of network investment, which could give reasonable security level under the balance between investment and returns. The above results could provide scientific basis and advanced method for the improvement of security standard of power supply in urban power networks of China.