Research On Operational Risk Grading And Control For Power Grid

With the sustained growth of social economy, power grid is getting an increasingly large scale and a growing complex structure. Under the influence of various uncertain factors, power grid faces more and more potential risks and the operation tasks become more complex and burdensome. We need to explore new risk management method and its system application, in order to fully grasp the operational risk level of power grid. Based on the traditional risk assessment theory, this thesis carries out a research on operational risk grading and control for power grid, by proposing a risk grading method, exploring effective ways of risk control, and practicing system developing and application.Firstly, to solve engineering application defects in risk indexes such as lack of assessment details and risk information, this thesis presents a power grid operational risk assessment and grading method. It redefines risk structure as a set of risk grade, risk kind, risk probability, risk severity, reason set and consequence set, classifies risk categories as loss of load, overload, voltage deviation, grid splitting, blackout of plant/station and blackout of important user. Then, it designs a grading method for risk probability, risk severity and the risk. It also divides the method into five steps as information collection, risk identification, risk assessment, risk rating and risk warning, and illustrates the application effect in Dispatch and Control Center of Anhui Electric Power Company.Secondly, in order to figure out the relations between generator outputs and branch power flows, this thesis presents a new power flow tracing method. Both active and reactive power allocation relations between generators, loads and lines can be acquired by rigorous mathematical derivation and matrix operations. Based on this method, this thesis carries out a further exploration of the relations between generator outputs and branch overload risks. It creates two risk control matrices for both corrective control and preventive control to meet the different needs of risk control, and thus builds a corresponding quadratic programming problem to acquire the adjustment solution of generator outputs. The IEEE9-bus system simulation proves its correctness and validity.Finally, this thesis researches the system application of operational risk grading and control for power grid. The hardware architecture, software architecture, data interfaces, function modules of the system are well designed. The development tools, operating environment and UI effects on the development of the system are also introduced.