d-q Space vector analysis for line-starting permanent magnet synchronous motors

In order to boost up the calculation precision of d-q space vector analysis, new approach for estimating parameters of line-starting permanent magnet motors is developed. Introducing leakage-flux and magnetizing-flux variations dependant on not only stator excitation but also rotor one, transient characteristics and steady-state performance are calculated. Thorough the comparison with finite element analysis, the validity of the proposed method is verified. Especially, it is notable that it can provide at short times accurate quasi-steady-state average torque and precise critical load torque for self-starting.