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This study introduces a new structure of the magnetic lead screw (MLS) intended for wave energy conversion (WEC) applications. One of the key challenges in the application of MLS technology for wave energy lies in the manufacturing of its complicated ideal helix. Structural simplification and processing technology are quite essential in promoting the development of the magnet screw. This study proposes a new method for shaping the desired ideal helix in a simple way with parallelly magnetised magnets. This simple structure reduces manufacturing complexity while maintaining good force density. The magnets with parallel magnetisation are also easier and cheaper to manufacture than the magnets with radial magnetisation. A prototype is manufactured and tested in the laboratory. In addition, the electromagnetic performance of the new structure is evaluated as compared with the magnet screw with ideal helix using the three‐dimensional finite element analysis, verifying the advantages of the proposed structure. [ABSTRACT FROM AUTHOR]

This study proposes an effective diagnosis method for single and multiple open‐switch faults (OSFs) in three‐phase permanent magnet synchronous motor (PMSM) drives. The proposed method is based on the real‐time estimation of the three‐phase motor currents using three Kalman filters (KFs). Three residual signals are defined as the differences between the three‐phase measured and estimated stator currents. The averaged normalised residual signals are used as diagnostic criteria for the detection of OSFs. The proposed method accurately detects the OSFs, localises the faulty switches and effectively discriminates between the OSFs and current sensor faults. The main superiorities of the proposed KF‐based method are its fast detection time and high robustness to measurement noises/errors and load variations. Moreover, the proposed method is useful for both closed‐loop and open‐loop PMSM drives. The proposed method can be embedded as a subroutine in the drive control unit without any hardware extension. The effectiveness of the proposed method is confirmed through extensive simulations and several hardware‐in‐the‐loop experiments on a testbed with a 1.5 kW PMSM and dSPACE1104 control board. In addition, the real‐time feasibility of the proposed method using low‐cost microprocessor technology is guaranteed by testing it on TMS320F28335 from Texas Instruments©. [ABSTRACT FROM AUTHOR]

This study proposes a magnetic lead screw (MLS) as a continuous propulsion device for the general transport system (GTS). By integrating the outer rotor machine with the MLS, it is possible to construct a high force design with the improved operating surface area. Initially, a brief statement of the novel GTS is given, leading to an introduction of the MLS. Besides, a scaled 2.6‐kN MLS demonstrator is presented to verify the propulsion principle and thrust force. Furthermore, the MLS design focuses on several types, which use different materials and magnetic structures. The three‐dimensional finite element analysis is used to optimise design, with the goal of force performance. Moreover, the shear stress, cost‐effectiveness, magnetic losses, and mechanical stress of the different topologies are compared, revealing that the MLS made by ferrite magnet is more suitable for employed in GTS applications. Finally, a dynamic model of the GTS is developed to verify the acceleration and speed responded. [ABSTRACT FROM AUTHOR]