Parameter Estimation of Multiphase Machines Applicable to Variable Phase-Pole Machines

Variable phase-pole machines are envisioned in applications requiring a large torque-speed operating area. The control of these machines relies on accurate models and parameters but research on their parameter identification is scarce. This article presents an offline parameter-identification method for variable phase-pole machines adopting a harmonic-plane decomposition model. The method employs standard tests with single-frequency three-phase excitation in multiple pole configurations and uses the results to minimize a constrained, regularized weighted least-squares problem. It relies on identifying a set of parameters common to all phase-pole configurations and transforming them into the adopted model. Good agreement is exhibited when comparing experimental results to an analytical harmonic-plane decomposition model using the inferred parameters. Steady-state, as well as pole transitions, are compared. The article emphasizes the importance of performing measurements in multiple pole configurations and weighing these measurements appropriately to render an accurate set of parameters.