Strategy to minimise the load shedding amount for voltage collapse prevention

This study presents a practical approach for determining the best location and the minimum amount of the load to be shed for the event-driven-based load shedding schemes. In order to find the above key parameters, a non-linear optimisation problem needs to be solved. A multistage method is proposed to solve this non-linear problem. The main idea of this method is to solve the optimisation problem stage by stage and to limit the load shedding to a small amount at each stage. Using this approach, the non-linear optimisation problem will be converted into a series of linear optimisation problems. By solving these linear optimisation problems stage by stage, the optimal solution to the original non-linear problem is obtained. Furthermore, in order to quickly identify the candidate load shedding locations in the multistage method, a novel multiport network model is proposed. Based on the multiport network model, fast ranking of the load locations and of the generators´ participation factors can be done with little calculation efforts. Details of the problem formulation and the solution strategy are presented here. The proposed strategy is illustrated and verified by using the IEEE 14-bus system, IEEE 118-bus system and a real 2038-bus power system.