Design and fabrication of rotor lateral shifting in the axial-flux permanent-magnet generator

<p>The development of axial-flux permanent-magnet (AFPM) machines has become a mature technology. The single-stator double-rotor (SSDR) AFPM structure has advantages on the compactness and the low up to medium power applications so the microscale size and low-cost applications are reachable to be designed. The research main objectives are designing and manufacturing the lateral shifting from the north poles of the first rotor face the north poles of the second rotor (NN) to the north poles of the first rotor face the south poles of the second rotor (NS) categories as well as finding the best performance of the proposed method and implementing in a low cost and micro-scale AFPMG. The novel lateral shifting on the one of the rotors shows performance at 19.2⁰ has the highest efficiency at 88.39% during lateral shifting from N–N (0⁰) to N–S (36⁰) on rotor₂.</p>

A Novel Axial-Flux Dual-Stator Toothless Permanent Magnet Machine for Flywheel Energy Storage

This paper presents an alternative system called the axial-flux dual-stator toothless permanent magnet machine (AFDSTPMM) system for flywheel energy storage. This system lowers self-dissipation by producing less core loss than existing structures; a permanent magnet (PM) array is put forward to enhance the air–gap flux density of the symmetrical air gap on both sides. Moreover, its vertical stability is strengthened through the adoption of an axial-flux machine, so expensive active magnetic bearings can be replaced. The symmetry configuration of the AFDSTPMM system is shown in this paper. Then, several parts of the AFDSTPMM system are optimized thoroughly, including stator windings, number of pole pairs and the PM parameters. Further, the performance of the proposed PM array, including back-EMFs, air–gap flux density, average torque, torque ripple and over-load capacity, are compared with the Halbach PM array and spoke PM array, showing the superiority of proposed configuration. Finally, 3D simulations were made to testify for the 2D analyses.

Innovative Construction of the AFPM-Type Electric Machine and the Method for Estimation of Its Performance Parameters on the Basis of the Induction Voltage Shape

The article presents an innovative construction of the Axial Flux Permanent Magnet (AFPM) machine designed for generator performance, which provides the shape of induced voltage that enables estimation of the speed and rotational angle of the machine rotor. Design solutions were proposed, the aim of which is to limit energy losses as a result of the occurrence of eddy currents. The method of direct estimation of the value of the rotational speed and rotational angle of the machine rotor was proposed and investigated on the basis of the measurements of induced voltages and machine phase currents. The advantage of the machine is the utilization of simple and easy-to-use computational procedures. The acquired results were compared with the results obtained for estimation performed by using the Unscented Kalman Filter (UKF).

Axial-Flux Permanent-Magnet Generator Design for Hybrid Electric Propulsion Drone Applications

This paper presents the design of an axial-flux permanent-magnet (AFPM) generator used for hybrid electric propulsion drone applications. The design objectives of the AFPM generator are high power density, which is defined as output power per generator weight, and high efficiency. In order to satisfy the requirements for the target application and consider the practical problems in the manufacturing process, the structure of the AFPM generator comprising a double-rotor single-stator (DR-SS) was studied. In order to determine the rotor topology and stator winding specifications that had the greatest impact on performance in the DR-SS type design process, we selected three rotor models according to the arrangement of the magnetization direction and three stator models according to the coreless winding specifications. These models were first compared and analyzed. Then, a 3-D finite element method was performed to calculate the magnetic, mechanical, and thermal characteristics of the designed models. By consideration of the output power, efficiency, temperature, and mechanical stability, etc., a topology suitable for the design of generators for UAV systems was determined and manufactured. The reliability of the design result was confirmed through the test.

A new robust control strategy for axial flux permanent magnet motor applied on legged lunar robots

Legged robots have the advantage of strong terrain adaptability in lunar exploration. A new robust controller is designed for axial flux permanent magnet motors applied on the legged lunar robots to diminish the disturbance from uncertainty and external circumstance. The theoretical verification is carried out through Lyapunov stability theory. The numerical simulation and real-time experiment are carried out to access the stability and dynamic property of the systems adopting the proposed controller. The results are compared with the traditional control strategies to demonstrate the advantages of the proposed controller. The new robust controller contributes to the dynamic stability of legged lunar robots and is also appropriate for the similar mechanical systems.

A comparative study on the performance of SSDR coreless AFPM generators with conventional and Halbach magnet arrays

An axial flux permanent magnet (AFPM) generator is known to be a good candidate for both low- and high-speed applications. In this paper, a comprehensive comparison of four coreless AFPM generators is presented with conventional and Halbach magnet arrangement combined with iron and ironless rotor (epoxy). With the same coreless stator structure, four different AFPM generators with different rotor magnet arrangement and materials are compared in terms of voltage, current, power, machine weight, and power density. The analytical design approach is first presented and is subsequently validated using ANSYS Maxwell electromagnetic finite element analysis (FEA) software. Results show that AFPM machine with fully coreless topology using Halbach array with epoxy rotor can deliver similar power density but has a lower cost compared to conventional magnet array with iron rotor. Hence, this topology is favorable for low power low cost applications.