Parameter characterisation of a doubly-fed induction machine using series-coupling and IEEE Std.112 test methods

The use of the doubly-fed induction machine variable speed ac drives has increased in recent years and this has led to an increased interest in obtaining an accurate equivalent circuit model for the machine. This paper presents a novel method for characterising a doubly-fed induction machine and compares the results with IEEE Standard 112. The method comprises the open-circuit stator, the open-circuit rotor and series-coupling tests to characterise the machine. Initially, the conventional IEEE Standard 112 testing procedures are reviewed and used to characterise the machine. The series-coupling tests are then presented, and are shown to allow for a more direct method of measuring the resistive and inductive components of the machine. An extended short-circuit test is used as a further test procedure to generate a machine model. The various models are validated by comparing the model predictions with the experimental torque-speed curve. Of all the models the series-coupling test models perform best and correlate well with the measured results.