Some problems related to using automatic control of voltage of synchronous generators in case of frequency change

Abstract

Considered is the possibility of using a proportional type automatic excitation regulation implemented in the form of compounding devices with an electromagnetic voltage corrector changing excitation depending on the frequency and voltage at the generator terminals in particular power supply systems. It is demonstrated that the suggested solution is more efficient compared to automatic excitation regulators having no frequency control. Graphs are provided showing changes in consumption of active and reactive power by an equivalent load characteristic of industrial customers, depending on frequency, and depending on voltage. Analysis of the evaluation results shows that implementation of the proposed solution reduces the active power imbalance from 6.5% to 3.5% (with a 10% frequency decrease). Proportional type automatic excitation controls with frequency control may find application in in-house power supplies of companies with a continuous operation process, where high quality of power supply is achieved by using a second independent power supply generated on a standalone basis, with no connection to the power grid. As the record of operation of such enterprises shows, the effectiveness of such a solution is quite high due to minimization of damage from voltage dips that occur in the external power supply system due to damage and abnormal conditions in 110 and 220 kV networks. As recommendations, features are assessed of the proposed automatic excitation regulator with frequency control in an embodiment providing for generators of the companies’ own power supplies operating in parallel with the external power grid, as well as in cases of some disruptions of static stability.