The Operational Risk Assessment For Distribution Grids

To evaluate the customer oriented risk and the urgency of preventive control in theoperation of distribution networks, a new approach of risk assessment is proposed.For operational risk assessment, first of all, this paper presents a simplified Outagetime-varying model, and obtains the area and node load through the load calculation. Basedon the above, customers are regarded as the objects of the evaluation. Through simulating theload transferring in case of various faults occur, the influence on the customers is analyzed. Aseries of customer oriented risk indices considering load variation are proposed, including thecustomer expected outage probability、the customer expected interruption duration and thecustomer expected electricity consumption loss. The system expected interruption index isused to indicate the influence on the whole distribution network. To account for the effects ofoverloads, an overload risk indicator is established.It briefly analysis the risk factors affecting the distribution network based on riskindicators and processes factors for different. It proposes a method of distribution networkreconfiguration based on minimizing the risk to prevention and control. The execution time ofpreventive control is compared with the risk coming time which is forecasted, the urgencylevels of preventive control are defined to indicate the opportunity for an effective preventivecontrol.The IEEE3feeder distribution system and the27feeder distribution system are used astwo examples to illustrate the proposed method in detailed showing its feasibility andeffectiveness.