New adaptive and centralised under-voltage load shedding to prevent short-term voltage instability

This study proposes a new adaptive and centralised under-voltage load shedding (UVLS) to prevent short-term voltage instability; it then examines the challenges related to the centralised UVLS. The proposed method uses a local measurement to estimate the amount of load shedding. It decreases the amount of load shedding by selecting the proper location of UVLS and shedding more powers within seconds after activating UVLS. Dynamic simulations are performed on the IEEE 118-bus test system, New England test system, and on Isfahan regional power grid (IRPG) as the case studies. Simulation results, when compared with the conventional multi-port network model and sensitivity-based methods, provide a considerable reduction in the active power shedding in addition to the number of the load shedding steps. Moreover, it indicates that the measurement bias errors have a considerable effect on UVLS. Finally, a method is introduced to overcome the effect of measurement errors.