Modeling of Synchronous Generator with Fast-Response Excitation System for Studying Power Network Transients

Inhalt:
The security and stability assessment of power systems is essentially required to avoid catastrophic consequences of system disturbances. The accuracies of such assessments depend on the accuracy of modelling of the power system components. Lower order models of synchronous generators (SGs) have been considered to assess the ro-tor transient stability analysis of system disturbances in different literatures. However, modern power systems are becoming more complicated due to the increased complexity of control elements that introduce additional transients to the network. Thus, lower order models of SGs are becoming not sufficient to demonstrate the actual dynamic response of transient disturbance in modern networks. In this paper, such limitation is committed with high order model of SGs where high frequency control elements are included in the system dynamics. The aim of this paper is to assess how detailed the SGs need to be modeled for studying accurate dynamic responses of a transient disturbance with reduced modeling complexity. A case study has been modeled and simulated with a nine-bus IEEE test network that has three SGs. Different orders of synchronous generator models, with and with-out the excitation control dynamics, have been considered and the transient disturbance responses are simulated and discussed. The results show that a fourth-order model of synchronous generator is sufficient to demonstrate the realistic response of a transient disturbance. The contribution of this paper is to develop an efficient high order model of SG with fast transients of control elements for a coupled voltage and rotor angle stability analysis. The dynamic mathematical models, nonlinear differential and algebraic equations, are numerically simulated using MATLAB software.