10 research outputs found

    Magnetic hysteresis phenomena in electromagnetic actuation systems

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    Force prediction including hysteresis effects in a short-stroke reluctance actuator using a 3d-FEM and the preisach model

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    Magnetic hysteresis effects, present in the force of an E-core reluctance actuator, are examined by simulations and measurements. Simulations have been performed with a 3d finite element method (3d-FEM) and a Preisach model, which is extended with a dynamic magnetic equivalent circuit (MEC) model. Both simulation methods are first examined on the prediction of the magnetic flux density in a closed- and open toroid for dc- and ac excitations. Finally, both methods are used to predict the force of the E-core reluctance actuator, which is compared to ac force measurements performed with a piezoelectric load cell

    Force prediction including hysteresis effects in a short-stroke reluctance actuator using a 3d-FEM and the preisach model

    No full text
    Magnetic hysteresis effects, present in the force of an E-core reluctance actuator, are examined by simulations and measurements. Simulations have been performed with a 3d finite element method (3d-FEM) and a Preisach model, which is extended with a dynamic magnetic equivalent circuit (MEC) model. Both simulation methods are first examined on the prediction of the magnetic flux density in a closed- and open toroid for dc- and ac excitations. Finally, both methods are used to predict the force of the E-core reluctance actuator, which is compared to ac force measurements performed with a piezoelectric load cell

    Finite element analysis and preisach hysteresis model of a toroid compared to measurements

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    Two methods predicting magnetic hysteresis effects are compared to measurements on a closed and open toroid. The soft-magnetic laminated toroids are simulated with a 3-dimensional finite element method (3D-FEM) and the classical Preisach model (CPM). On the closed toroid a direct comparison between both models has been made and the CPM shows better agreement with the measurements, especially at low excitation field strengths. In the open toroid with a 1.0 millimeter airgap, it is shown that the prediction and measurement of the magnetic flux density in the airgap are strongly influenced by leakage and fringing fluxes. Nevertheless, both predictive methods show reasonable agreement with the preformed measurements

    Measurement method for determining the magnetic hysteresis effects of reluctance actuators by evaluation of the force and flux variation

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    A measurement method is presented which identifies the magnetic hysteresis effects present in the force of linear reluctance actuators. The measurement method is applied to determine the magnetic hysteresis in the force of an E-core reluctance actuator, with and without pre-biasing permanent magnet. The force measurements are conducted with a piezoelectric load cell (Kistler type 9272). This high-bandwidth force measurement instrument is identified in the frequency domain using a voice-coil actuator that has negligible magnetic hysteresis and eddy currents. Specifically, the phase delay between the current and force of the voice-coil actuator is used for the calibration of the measurement instrument. This phase delay is also obtained by evaluation of the measured force and flux variation in the E-core actuator, both with and without permanent magnet on the middle tooth. The measured magnetic flux variation is used to distinguish the phase delay due to magnetic hysteresis from the measured phase delay between the current and the force of the E-core actuator. Finally, an open loop steady-state ac model is presented that predicts the magnetic hysteresis effects in the force of the E-core actuator

    Optimization of the force density for medium-stroke reluctance actuators

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    This paper concerns the force density optimization for medium-stroke reluctance actuators applied in anti-vibration applications. The force density in a conventional E-core reluctance actuator is limited for medium strokes by the nonlinear force-displacement characteristic. In this paper, different tooth topologies are analyzed to maximize the force density along the stroke using the finite element analysis. Teeth parameters are tuned in each topology to analyze the influences on the force density. An analytic thermal model is used and verified with finite element simulations
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