Undervoltage load shedding to avoid voltage instability

The paper presents a technique for undervoltage load shedding (UVLS) in power systems. The undervoltage load shedding criterion has been developed using a dynamic load model. The parameters of the dynamic load model are estimated online using a nonlinear least squares technique, namely the Gauss-Newton method. The amount of load to be shed is calculated using the parameters of the dynamic load model. In the event of a voltage unstable situation, the proposed undervoltage load shedding criterion can be used to calculate the minimum amount of load to be shed at any point in time to avoid a voltage collapse. The criterion is general and can be applied to any power system.