Abstract: For interior permanent magnet synchronous motor(IPMSM) , accuracy of its discrete-time model is

usually at the cost of complexity. To find out a way out of the dilemma, stator flux is chosen as the state variable,

allowing its model be represented in the complex form and resulting in a concise model in appearance. However,

discretization of the model would still be affected by the current state through the voltage drop on the stator

resistance. Under this background, several different representations of the stator current during one sample interval

were presented and their effects on the discrete-time model accuracy were discussed. By this process, an ideal

representation of the stator current was found out to yield a high accurate discrete-time model, by which, the

IPMSM was allowed to be modelled in concise form, with mild calculation load, as well as in high accuracy.

Finally, a typical control scheme was used to build the current control loop but based on the discussed several

different discrete-time models, to further verify the accuracy of these models.

    Key words: interior permanent magnet synchronous motor (IPMSM) ; discrete-time model; low carrier-wave

frequency ratio; complex vector model