Discrete-time design of adaptive current controller for interior permanent magnet synchronous motors (IPMSM) with high magnetic saturation

IPMSM for automotive traction applications exhibits a rather high magnetic saturation as a result of the maximization of power and torque densities. Additionally due to the high speed range high electrical frequencies in proportion to the converter switching frequencies occur. That results in a small number of samplings per electrical fundamental. Both effects have to be taken into account to design a suitable current controller. In this paper a discrete-time IPMSM model considering parameter variations due to magnetic saturation as well as the effect of a small number of sampling instants per electrical rotation is derived. Then the design of an adaptive current controller is presented and evaluated by experimental results.