A Study Of Black-Start Scheme Based On Small Hydropower Units As Self-Starting Power Source

Along with the economic development, the entire society more and more relies on electric power, and asks for an increasing reliability of electricity supply. Once a complete or partial blackout occurred, it would incur huge economic loss and severe social impact.The rapid development of power grid makes its structure become more and more complex. If the local problem doesn't get timely and appropriate treatment, it may spread to nearby grid. Moreover, it may induce a vicious chain reaction and lead to the tremendous accident of the entire network collapse eventually. The restoration after all blackout is very complex. Whether or not having adequate and reasonable restoration plan causes obvious influence of restoration speed once the accident happened. After the research and investigation of Zhaoqing power system's current situation and black-start ability, according to the relevant requirements of the Guangdong Power Grid Corporation, consulting with author's dispatching experience, and referring to the processing procedure of blackout happened in United States, Canada, this paper draws up the black-start scheme suited for Zhaoqing power system. The scheme makes small hydropower units in Zhaoqing local area as main self-starting power source. It has several plans, pointing out the specific process and stages of restoration. This paper also discusses the issues might meet in the black-start of Zhaoqing power system, such as relay protection, self-excitation of generators, switching no-load and inrush current of transformer, overvoltage. The study and simulation about these issues demonstrate the feasibility of Zhaoqing power system black-start. At last it gives some proposals for improvement of Zhaoqing power system, according the analysis of details of restoration plans.