New dynamic inductance concept and its application to synchronous machine modelling

The transformer voltage terms in the generalised equations that describe the performance of the saturated electrical machine under dynamic conditions, involve some error. In this paper, a method is presented for the calculation of dynamic saturated inductances that, when used instead of the static ones, removes this error. The rotational voltage terms are still correctly calculated using the conventional static saturated inductances. To verify the validity of the dynamic inductance concept, a system consisting of a laminated salient-pole alternator with direct thyristor excitation has been studied. The predicted results for the sudden application and removal of balanced zero power factor loads shows good agreement with test results.