It is quite easy to design turbo generator capability. Agn 005 fault currents and short circuit decrement curves. Figure 1 a typical alternator curve of reactive power kvar capability. Nec 2017 requirements for generator set overcurrent protection. Modeling a reactive power capability curve from the generator dialog. In this paper a new challenge about the reactive capability curves of the synchronous generator is discussed. The most common sources of leading power factor are lightly loaded. Capability curve of generator defines the boundaries within which it can deliver reactive power continuously without overheating. The reactive capability curve is modified on the generator dialog and can be savedloaded using the generator reactive capability curve auxiliary files. Alternator reactances are published using the alternator kva rating as a base fault current calculations need to use the same base or the reactances need to be converted to the genset kw rating base ampsentry uses the genset standby kva rating as a base example. The behavior of generators with respect to the generation of the reactive power is provided by the reactive capability curves. Capability curve of a synchronous generator circuit globe.
Estimating generator capability curves universityofwisconsinmadison april22,2015 simplistic generator models often use rectangle constraints for active and reactive output limits. Capability curve of synchronous generator eeeguide. Capability curvebased generator protection minimizes. The generating set industry standard of expecting a 300% short circuit current is no more a given than it is likely that the connected electrical loads will result in the alternator operating at only 0. This paper presents implementation details of a generator protection scheme with characteristics tailored to the machine gcc. If the point f is inside the capability curve, the machine will not be overheated and will not be likely to fall out of. The regulation mode is managed either by parametersetting, or via the d700 digital inputs, or via the various communication modes.
A line from f to the origin o of the i f is at an angle. A reasonable guideline is that a generator set can carry up to 10 percent of its rated kvar capability in leading power factor loads without being damaged or losing control of output voltage. The d700 avr is a digital voltage regulator used to control the alternator field current using separate control loops. That is, generators capabilities are modeled with independent maximum and minimum limits on active and reactive power output i. Pdf considering synchronous generator capability curve. Fast disconnection of the generator during this condition minimizes stress to the generator and maintains power system stability. A line fg through f parallel to ooa give power equal to og. Generator rating is specified in terms of mva and power factor at a particular terminal voltage. Make sure the use capability curve checkbox is checked.