Modeling and Simulation of Synchronous Generator Dynamics

Synchronous generators are extensively used in power stations, supplying bulk electric power over high‐voltage (HV) or extra‐high‐voltage (EHV) transmission lines to load centres. This chapter considers detailed models of a generator including machine model, excitation, and prime mover controllers. It is common to express voltages, currents, and impedances in per‐unit quantities by choosing appropriate base quantities. The stability of power systems is affected by rotor swings of the synchronous generators. Even in steady state, the system is subject to slow variations and perturbations in the connected loads. The synchronous generator is provided with two automatic controllers for the regulation of the terminal voltage and frequency. In steady state the average electrical frequency of all synchronous generators connected to an AC grid must remain identical. This condition is termed "synchronous operation". The extended Equal Area Criterion (EAC) is applicable for a single‐ or two‐machine system. However, it is feasible to extend the EAC to multi‐machine systems.