A Design Optimization of Asymmetric Air-gap Structure for Small 3-phase Permanent Magnet SPM BLDC Motor

This paper focuses on the design of a flux-biased rotary electromagnetic actuator with compact structure for fast steering mirror (FSM). The actuator has high force density and its torque output shows linear dependence on both excitation current and rotation angle. Benefiting from a new electromagnetic topology, no additional axial force is generated and an armature with small moment of inertia is achieved. To improve modeling accuracy, the actuator is modeled with flux leakage taken into account. In order to achieve an FSM with good performance, a design methodology is presented. The methodology aims to achieve a balance between torque output, torque density and required coil magnetomotive force. By using the design methodology, the actuator which will be used to drive our FSM is achieved. The finite element simulation results validate the design results, along with the concept design, magnetic analysis and torque output model.

Design of a Rotary Electromagnetic Actuator with Linear Torque Output for Fast Steering Mirror

Long¹,

Mo²,

Chen³

et al. 2015

Comparative Study of Armature Reaction Field Analysis for Tubular Linear Machine with Axially Magnetized Single-sided and Double-sided Permanent Magnet Based on Analytical Field Calculations

Shin¹,

Park²,

Cho³

et al. 2015

This paper presents a comparative study of a Tubular Linear Machine (TLM) with an Axially Magnetized Single-sided Permanent Magnet (AMSPM) and an Axially Magnetized Double-sided Permanent Magnet (AMDPM) based on analytical field calculations. Using a two-dimensional (2-D) polar coordinate system and a magnetic vector potential, analytical solutions for the flux density produced by the stator windings are derived. This technique is significant for the design and control implementation of electromagnetic machines. The field solution is obtained by solving Maxwell's equations in the simplified boundary value problem consisting of the air gap and coil. These analytical solutions are then used to estimate the self and mutual inductances. Two different types of machine are used to verify the validity of these model simplifications, and the analytical results are compared to results obtained using the finite element method (FEM) and experimental measurement.

Measurements of Magnetic Properties of Electromagnetic Actuator in High-Temperature Environment

Noh¹,

Gi²,

Kim³

et al. 2015

Electromagnetic actuators are versatile and able to meet demanding requirements, such as operation in very low or very high temperatures. When the actuator is used in a high-temperature environment up to 500°C, we need to know how the force-producing capability of the actuator is affected by the operating temperature. Specifically, it is necessary to know the temperature-dependence of magnetic properties that determine the mechanical forces. In this paper, we measure the changes in magnetic properties of SUS410 material in hightemperature environment. We also devise a novel signal processing technique to remove the integration drift. At the field strength of 18,000 A/m, we found that the flux density at 500°C is decreased by 26%, compared to the result at room temperature. Therefore, the actuator must be sized appropriately, if it is to operate in hightemperature settings.