Research On Security Risk Assessment And Emergency System Of Power System

In recent years, the consistent development of national economy infuses new vitality to the development of electric power industry. As a result, the requirement of electric power has been increasing greatly, and the scale of the power system is becoming larger and larger, all of which make the complex characteristics of power system more and more obvious. The power system in China has become a complex and huge system of which the voltage level is the highest and the scale is the largest in the world with the AC-DC hybrid operation. As a result it leads to higher demands and challenges for the security and stability control of modern power system. People have more confidence in guaranteeing power system to be secure and stable with the promising prospect of smart grid. However they have to face the reality that the large-area-blackout risk always exists. And it can be concluded that the traditional methods for security assessment, including the deterministic stability analysis and probabilistic assessment method, have some shortages by analyzing the recent series of large-area-blackout incidents so that it can not fulfill the development requirements of modern power system. So except for continuing developing the present methods, more comprehensive risk assessment system should be established from the application point of view. At the same time the emergency system in which the government is dominant, power enterprises play the main role and the whole society take part commonly should be made up so that the influence of sudden incidents and the loss of people's life and wealth can be decreased as much as possible.A government-supervisor-based power system security risk assessment system is established from the large-area-blackout risk point of view in this thesis. In this system the fundmental factors that can cause large-area-blackout are considered fully. And the fundmental factors are divided into several layers based on the practical situations so that a hierarchical assessment index system with four levels is established. The index system is the bridge connecting risk assessment theory and practice. It provides an important basis for the government supervisory departments and electric power enterprises to carry out the work of power system security risk assessment together. More importantly, it can give guidance to the daily risk management of power system. What's more, it is good to master the risk level of the whole system in time from the macroscopic point and find out the weak places of the system from the microscopic point if taking this security risk assessment system into the daily risk management of power system. As a result that the large-area-blackout risk can be decreased greatly by eliminating the weak places.The proposed security risk assessment index system has been checked and verified by the risk assessment work of Guangdong power system. Firstly, based on the characteristics of Guangdong power system, the fourth-level indeices is constructed and explained, and the total large-area-blackout risk of Guangdong power system is calculated out with the hierarchical analysis method. And then, by further analysis of the results of risk assessment, the weak places of Guangdong power system are found out and some countermeasures to eliminating the weak places are put forward. By comparing with the real situations of Guangdong power system, it proves that the results of risk assessment are right, and the reasonability and practicality of the proposed assessment system are also verfificated.Generally the work of power system security risk assessment is carried out during the system's normal operation period. As we know that the sudden incidents in power system may occur momentarily and have great and bad influences on power system and society. So in this situation, only by emergency disposal can the bad influences be reduced. And it has a direct impact on the efficiency and result of emergency disposal whether the emergency system is reasonable and comprehensive or not. Emphasizing the construction of emergency system is the key part of emergencey management. At the same time, a scientific and comprehensive emergency management mechanism can guide the construction of emergency system. Now the domestic research on power system emergency system is not mature. So great efford on the study of emergency system of power system has been made and a comprehensive emergency system is brought up based on the existing emergency management experiences in chapter 5 of this thesis. The proposed emergency system is made up by emergency laws and regulations system, emergency prediction scheme system, emergency organization system and emergency indemnification system. So it provides laws indemnification, prediction scheme indemnification, conduct indemnification goods and people indemnification. And it is emphasized most importantly that not only the "double-core" emergency conduct mode which includes the government emergency conduct center and power grid dispatch center should be established, but also the constructiong of emergency communication and the improvement of rescue technology for emergency groups should be strengthen. Above all the proposed emergency system will play an important role in the development of power system emergency management.Finally the whole works of this thesis are summarized and the future prospect on the development of power system security risk assessment and emergency system is highlighted.