Explicit and implicit representation of saturation for induction machines modelling in state-variable transient simulators

Classical low-order qd saturable induction machine models are available as built-in component models in commonly used state-variable-based transient simulation packages/toolboxes. This paper investigates the implementation of the main flux saturation in symmetrical squirrel-cage induction machines using the so-called flux correction (FC) method, wherein implicit (with algebraic loop) and explicit (without algebraic loop) implementations are possible. The presented computer studies demonstrate accuracy and efficiency of several commonly used low-order models and approaches. The explicit FC method is proposed as a very effective and accurate way of representing the effects of saturation even at large time steps, which is a very desirable property.