Decoupling methodology and application to triple star interior permanent magnet machines

This paper sets forth the decoupling procedures for a triple-star interior permanent magnet machines where the inductances are mutually coupled between the three machine sets when the original model equations are transformed to the rotor reference frame. Dynamic and steady-state analyses based on this coupled model is complicated. It is very hard to ensure total independence of the controllers for the three sets of machine, thereby negatively affecting the dynamic response of the speed or toque control scheme. The proposed decoupling methodology is based on the standard rotor reference transformation of the natural variables, the result of which is decoupled using a transformation based on the eigenvectors of the resulting impedance matrix. The eigenvalues are the new diagonal elements of the impedance matrix. Some simulation results confirm the utility of the proposed decoupling methodology.