IEEE 1110-2002 pdf download IEEE Guide for Synchronous Generator Modeling Practices and Applications in Power System Stability Analyses
Over the course of a di sturbance that results in frequency instability, the characteristic times of the processesand devices that are activated by the large shifts in frequency and other system variables will range from afew seconds,corresponding to the responses of devices such as generator controls, to severa minutes.corresponding to the responses of devices such as prime mover energy supply systems and load voltageregulators.
3.5 Modeling requirements for synchronous machines
Synchronous machines may be modeled in as much detal as possible in the study of most categories ofpower system stability. This includes appropriate representation (subject to the availability of data) of thedynamics of the field circuit, excitation system, and rotor damper circuits (Kundur (B54]). With today’scomputing tools there is no pressing need to simplify models for specific types of studies In addition,experience has shown that critical problems may be masked by the use of simplified models which aresometi mes percei ved to be acceptable for a particular type of study.
For the analysis of many voltage- stability and frequency-stability problems using time- domain simulati onsthe study periods are in the range of tens of seconds to several minutes To improve computational efficiencyof such long-term dynamic simulations, instead of simplifying the models by neglecting fast dynamics, it isbetter to use singular perturbation techniques to separate fast and slow dynamics and appropriatelyapproximate the fast dynamics(X u et al. [B82]).
Notwithstanding the above, it is important to recognize the following special requirements in representingsynchronous machines for different categories of stability studies:
For large-disturbance rotor-angle stability analysis,particularly for generators with high-initial.aresponse excitation systems, magnetic saturation effects should be accurately represented at fluxevels corresponding to normal operation all the way up to the highest values experienced with theexcitation at its ceiling, With discontinuous excitation controls, such as those described in Lee andKundur [B56] and Taylor et al, (B74], the excitation remains at its ceiling for about two secondseading to very high flux levels f saturati on effects are understated, the results of analysis would beoverly optimi stic.lt is particularly important to represent the dynamics of the field circuit, as it has a significantinfluence on the effectiveness of excitation system in enhancing large-disturbance rotor-anglestability.bFor small-disturbance rotor-angle stability analysis, accurate representation of the field circuit aswell as the rotor damper circuitsis important.cFor voltage stability studies, the voltage control and reactive power supply capabilities of generatorsare of prime importance. During conditions of low system voltages, the reactive power demand ongenerators may exceed their field-current limits In such situations, usually the generator fieldcurrents are automatically limited by overexcitation limiters, further aggravating the situation andpossibly leading to voltage instability (Kundur [B54]). Therefore, the generator models should becapable of accurately determining the transient field currents and accounting for the acti ons of field-current limiters
Frequency stability problems are generally associated with inadequacies in equi pment response andpoor coordination of control and protection equipment, Stability is determined by the overall
IEEE 1110-2002 pdf download
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