Minimum excitation limiter effects on generator response to system disturbances

Minimum excitation limiters (MEL) have been in use since the first applications of voltage regulators to synchronous machines, and are presently in widespread use throughout the power industry. However, a cursory literature search indicates scant examination of the dynamic behavior of these devices. Although the minimum excitation limiter is rarely called into action, its effect can be particularly significant to the final outcome of some severe disturbances. The digital computer modeling of two common MEL devices is described, and their effect on power system dynamics is addressed