Summary This study presents a new undervoltage load shedding (UVLS) method to reduce the amount of power curtailment in emergency conditions. At first, the effect of temperature is considered in an existing multiport network model. Then, a new centralized method called 2-factor UVLS is proposed. The proposed method considers the load reactive power and the multiport network model to determine the effective location of the UVLS. So as to take the actual conditions into account, the main challenges related to the centralized applications are evaluated and then a solution is introduced to overcome these challenges. The proposed 2-factor method and the multiport network model are implemented in the IEEE 57-bus test system, IEEE 118-bus test system, and a real 341-bus power system. Moreover, a comparison is made between 2-factor and sensitivity-based methods. The results show that the proposed 2-factor UVLS method needs less active power shedding than the multiport network model and sensitivity-based method.