VP11-04 The Influence of Different Slot Permanent Magnet Magnetization Directions on the Power Density Enhancement of Transverse Flux Linear Generator
Creators: Minshuo Chen
Zhengyuan Zhu
Wei Qin
Gaojun Meng
Tao Xia and Lei Huang
Publisher: name: IEEE
Year: 2025

I.Introduction In the past decades, low speed high power density machines have been widely used in direct drive wind power generation, direct drive wave energy conversion and ship propulsion system. Longitudinal flux linear generators are difficult to further improve their power density due to the mutual restraint of electromagnetic loads. In transverse flux linear generator (TFLG), the plane where the main magnetic flux path is located is perpendicular to the direction of secondary motion, thus the electrical and magnetic loads are decoupled and the problem of mutual constraints of electromagnetic loads is solved. Therefore, TFLG can achieve higher power density [1]. Placing permanent magnets (PMs) in the slot is a feasible method to further improve the power density and back electromotive force (EMF) quality [2]. In-depth research should be conducted on the shape and magnetization direction of the slot PMs, and adjustments should be made when considering actual prototype manufacturing and PM placement problems to obtain a better machine topology design solution. In this paper, a TFLG for direct drive wave energy conversion is proposed. Analysis is made on the shape and magnetization direction of the slot PMs. The simulation results prove that tangential magnetization can achieve higher power density than radial magnetization. II.Machine Configuration As shown in Fig. 1, the proposed TFLG consists of two primaries and a secondary. The slot PMs are inserted between the outer primary shoes and their magnetization directions are indicated in the figure. The secondary is composed of magnetic bars and nonmagnetic bars and it moves back and forth in a straight line along the z-axis. Fig. 1. III.Results As shown in Fig. 2, the average thrust and power density of tangential magnetized and radial magnetized slot PM types are 247.01N, 8.518kN/m3 and 196.02N, 6.759kN/m3, respectively. Fig. 2. IV.Conclusion Simulation results show that the outer primary slot PMs can help enhance thrust/power density and tangential magnetized slot PM type can achieve higher power density than radial magnetized one.References: [1]M. Chen, L. Huang, Y. Li, J. Zhang, P. Tan and G. Ahmad, "Design and Analysis of a Field Modulated Transverse Flux Linear Generator Used in Direct Drive Wave Energy Converter," IECON 2023- 49th Annual Conference of the IEEE Industrial Electronics Society, Singapore, Singapore, 2023, pp. 1-6. [2]X. Zhao and S. Niu, "Design and Optimization of a Novel Slot-PM-Assisted Variable Flux Reluctance Generator for Hybrid Electric Vehicles," in IEEE Transactions on Energy Conversion, vol. 33, no. 4, pp. 2102-2111, Dec. 2018.
I.Introduction In the past decades, low speed high power density machines have been widely used in direct drive wind power generation, direct drive wave energy conversion and ship propulsion system. Longitudinal flux linear generators are difficult to further improve their power density due to the mutual restraint of electromagnetic loads. In transverse flux linear generator (TFLG), the plane where the main magnetic flux path is located is perpendicular to the direction of secondary motion, thus the electrical and magnetic loads are decoupled and the problem of mutual constraints of electromagnetic loads is solved. Therefore, TFLG can achieve higher power density [1]. Placing permanent magnets (PMs) in the slot is a feasible method to further improve the power density and back electromotive force (EMF) quality [2]. In-depth research should be conducted on the shape and magnetization direction of the slot PMs, and adjustments should be made when considering actual prototype manufacturing and PM placement problems to obtain a better machine topology design solution. In this paper, a TFLG for direct drive wave energy conversion is proposed. Analysis is made on the shape and magnetization direction of the slot PMs. The simulation results prove that tangential magnetization can achieve higher power density than radial magnetization. II.Machine Configuration As shown in Fig. 1, the proposed TFLG consists of two primaries and a secondary. The slot PMs are inserted between the outer primary shoes and their magnetization directions are indicated in the figure. The secondary is composed of magnetic bars and nonmagnetic bars and it moves back and forth in a straight line along the z-axis. Fig. 1. III.Results As shown in Fig. 2, the average thrust and power density of tangential magnetized and radial magnetized slot PM types are 247.01N, 8.518kN/m3 and 196.02N, 6.759kN/m3, respectively. Fig. 2. IV.Conclusion Simulation results show that the outer primary slot PMs can help enhance thrust/power density and tangential magnetized slot PM type can achieve higher power density than radial magnetized one.References: [1]M. Chen, L. Huang, Y. Li, J. Zhang, P. Tan and G. Ahmad, "Design and Analysis of a Field Modulated Transverse Flux Linear Generator Used in Direct Drive Wave Energy Converter," IECON 2023- 49th Annual Conference of the IEEE Industrial Electronics Society, Singapore, Singapore, 2023, pp. 1-6. [2]X. Zhao and S. Niu, "Design and Optimization of a Novel Slot-PM-Assisted Variable Flux Reluctance Generator for Hybrid Electric Vehicles," in IEEE Transactions on Energy Conversion, vol. 33, no. 4, pp. 2102-2111, Dec. 2018.