The emergency control of modern power systems is based on the use of mathematical models that describe transient and steady processes. In order to solve the problem of accelerated selection of preventive actions aimed at ensuring the sustainability of power systems, the equivalent of calculation models is used. Today, there are a large number of methods aimed at obtaining equivalent mathematical models of power systems. Dimo's methods, artificial neural networks, Ward Injection Method, as well as high-frequency and low-frequency equivalent methods are widely used. The main disadvantage of these methods is low performance and the inability to use them in real time. The paper presents a method for accelerated equivalence of mathematical models of power systems based on the Dimo's method and synchronized vector measurements. The speed of the developed method is ensured using accelerated methods for evaluating synchrophasors and the nodal representation of the protected fragment of the power system. Approbation of the proposed algorithm was carried out on the mathematical model of Kundur, which includes four synchronous generators. Equivalence was carried out in steady state and transient processes. Settling and transient modeling is performed in Matlab Simulink. As a result of a series of experiments, it was found that for steady and transient processes, the error in obtaining the equivalent of the protected fragment of the power system is less than 5%. © 2023 IEEE.