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D. J. Hanrahan

Bio: D. J. Hanrahan is an academic researcher. The author has contributed to research in topics: Permanent magnet synchronous generator. The author has an hindex of 1, co-authored 1 publications receiving 20 citations.

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Journal ArticleDOI
TL;DR: In this article, a basic feedforward algorithm for executing this type of current vector torque control is discussed, including the implications of current regulator saturation at high speeds, and the key results are illustrated using a combination of simulation and prototype IPM drive measurements.
Abstract: Interior permanent-magnet (IPM) synchronous motors possess special features for adjustable-speed operation which distinguish them from other classes of ac machines. They are robust high powerdensity machines capable of operating at high motor and inverter efficiencies over wide speed ranges, including considerable ranges of constant-power operation. The magnet cost is minimized by the low magnet weight requirements of the IPM design. The impact of the buried-magnet configuration on the motor's electromagnetic characteristics is discussed. The rotor magnetic circuit saliency preferentially increases the quadrature-axis inductance and introduces a reluctance torque term into the IPM motor's torque equation. The electrical excitation requirements for the IPM synchronous motor are also discussed. The control of the sinusoidal phase currents in magnitude and phase angle with respect to the rotor orientation provides a means for achieving smooth responsive torque control. A basic feedforward algorithm for executing this type of current vector torque control is discussed, including the implications of current regulator saturation at high speeds. The key results are illustrated using a combination of simulation and prototype IPM drive measurements.

853 citations

Journal ArticleDOI
V. B. Honsinger1
TL;DR: Two methods are presented by which the performance of ac permanent magnet machines can be predicted using the concept of machine admittance, which defines the shape of the current locus as a function of voltage induced by the magnets.
Abstract: Two methods are presented by which the performance of ac permanent magnet machines can be predicted. The first method utilizes phasor diagrams to include core-loss. The second method uses the concept of machine admittance; this admittance is also adjusted for the effects of core-loss. The admittance also defines the shape of the current locus as a function of voltage induced by the magnets.

137 citations

Journal ArticleDOI
TL;DR: In this paper, the steady-state core-loss characteristics of synchronous motors operating from a sinusoidal constant frequency voltage supply are investigated, and it is shown that the additional loss due to the time-harmonic fields can increase core loss by a factor of six over the loss associated with only the fundamental component field at low motor flux levels.
Abstract: The steady-state core-loss characteristics of buried-magnet synchronous motors operating from a sinusoidal constant frequency voltage supply are investigated. Measured and calculated core loss, with constant shaft load, is shown to increase with decreasing terminal voltage due to an increase in armature reaction-induced stator flux-density time harmonics. Finite-element modeling is used to show that the additional loss due to the time-harmonic fields can increase core loss by a factor of six over the loss associated with only the fundamental component field at low motor flux levels. A simple air-gap model of motor flux components shows that this increased loss is due to localized rotor saturation. Thus, stator-core harmonic fields should be expected for all buried-magnet rotor synchronous motors (with or without a cage) operating at low flux levels. This factor becomes increasingly important when the motors are operated in the high-speed low-flux mode in conjunction with a variable-speed drive. >

81 citations

Journal ArticleDOI
TL;DR: In this paper, a general model for synchronous motors with permanent magnet excitation is established and the dependence of the electric and magnetic loadings on the angle between the armature and field excitations is put in evidence.
Abstract: Design guidelines are presented for synchronous motors with permanent magnet (PM) excitation. A general model is established and the dependence of the electric and magnetic loadings on the angle between the armature and field excitations is put in evidence. For this angle there exists an optimal value which yields maximum torque for maximum allowable flux density in the teeth. Another value yields the minimum volume for the permanent magnets. These values guide the selection of the operating point of the motor and its preliminary design. It is found that, when the pole pitch exceeds a certain value, the magnet requires more space than a current carrying winding.

28 citations