Systematic approach for dynamic equivalents development of large-scale power system using PSS/E

This paper presents a systematic approach to develop dynamic equivalents of large-scale power systems using the well-known standard utility program of Power System Simulator for Engineers (PSS/E). The proposed approach entails three main steps. Firstly, small power plants connected to high voltage network (< 380 kV level) are netted with loads. Secondly, coherent generators are identified using non-linear time domain simulations and aggregated accordingly. Finally, high and medium voltage networks are reduced statically using PSS/E, while the backbone extra high voltage network is retained. All of the above steps are automated using python program which is supported by PSS/E. Saudi Electricity Company (SEC) power grid is used to demonstrate the accuracy of the developed procedure. A severe three phase fault is applied on both the reduced as well as the full models to compare the dynamic responses of both systems. Steady state and non-linear time domain simulation results prove that the reduced model is accurate and reliable in representing the dynamic characteristics of the complete power system. Consequently, it can be used to perform several power system studies, such as system control design, online dynamic security assessment or electromagnetic transient analysis.