Method for Determining the Minimum Capacity Scale of Generators Under Voltage Stability Constraints

As the proportion of power received by the receiving end of the power grid increases., the voltage characteristics of the power grid also deteriorate. To maintain the stability of the power grid voltage., requirements have been put forward for the minimum capacity scale of the generator units in the system. This paper proposes a calculation method for effectively evaluating the minimum capacity scale of generators under voltage stability constraints. In this technique., the proposed method is based on the node impedance matrix of system and the capacity of all synchronous machines to obtain the equivalent synchronous machine capacity of the weak points of voltage stability characteristics., then the equivalent impedance of the equivalent synchronous machine at that point can be obtained. By comparing the magnitude of the equivalent impedance with the self-impedance of that point., the voltage stability characteristics of that point are determined., and it is further known whether the system generator capacity meets the voltage stability constraint. Extensive simulation results of a system connected with a high proportion of DC indicate that the proposed calculation method can effectively evaluate the minimum capacity scale of the generators under voltage stability constraints.