Risk Assessment Methodology And Application Of Power Grid Based On Equipment Condition And Dispatching Operation

Power grid work as the core of electric power transmission and distribution in modern society.The safety and stable operation of power grid will be affected by more complex external environment,also its equipment quantity,variety,structure perplexing factors lead to the power grid will face more severe situation in the future.Based on the method of risk identification and evaluation of power grid,it is the key to prevent and reduce the occurrence of power failure.Therefore,in the process of grid operation risk assessment,the comprehensive identification and accurate assessment of the factors which affecting the safe and stable operation of the power equipment is the basis of the risk assessment.The accuracy of the selection and analysis method of the system state is the core of the risk assessment.Identification of critical fragile units is a key point in reducing the risk level of the grid.In this paper,from the perspective of power grid outage risk prevention and control,respectively,research of the following four aspects:(1)Modeling of failure rate of power equipment.According to the different factors of power equipment failure classification the failure rate modeling.The two-state model was used to quantify the influence of weather factors on environmental exposure equipment,and the fault tree analysis was used to identification and evaluate the factors of external damage which have not previously considered.The proportional hazard model was used to the environment closed equipment,taking into account the power equipment service time and running state characteristics,can be more objective and accurate response to the real state of the equipment.(2)State selection and risk assessment of power system.Based on the classification of equipment failure rate,the Monte Carlo simulation method and the optimal load shedding model are used to select and analyze the system state to calculate the whole failure probability and consequence index.Considering the influence of different user on the consequences of power failure,based on the regional typical user classification,a unit power loss function considering the proportion of users is constructed to evaluate the loss of power failure in different areas and the division of the risk of regional power outages.(3)Key unit identification and vulnerability assessment of power grid.Based on the complex network theory,using the non-right topology network and the weighted power network to evaluate the key unit of the power grid.In order to further assess the impact of critical equipment units on the vulnerability of the grid,,the key unit identification and vulnerability indicators is improved to reevaluate the vulnerability of the power grid,and the validity of the improved index is verified.(4)Construction of power grid risk prevention and control system and analysis of power outage emergency capability.Based on different time periods risk control of power grid,this paper puts forward the framework of three levels of power grid risk prevention and control system from three aspects: grid reliability planning,operation risk control and on-line monitoring and early warning,and makes top-level framework design for future power grid risk prevention and control.This paper analyzes the current emergency management system of power failure in domestic power grid,and makes a statistical analysis on the emergency response capability of power grid enterprises,government departments and important users involved in the current power outages,and puts forward some suggestions for improving the emergency management capability of China.