As a new type of advanced electrical power generation system, free-piston engines can be applied to many fields, such as electric vehicles and communication base stations. In this paper, a novel tubular moving magnet linear generator system is designed for free-piston engines. A three-dimensional finite element model of the designed linear generator is presented using a transient computing method with a motion solver. The electromagnetic force, electromotive force, and generating efficiency of the designed linear generator are analyzed in detail. A prototype is manufactured and tested under laboratory conditions, and then the main performance of the prototype is evaluated using the validated finite element model. The electromagnetic analysis in this paper indicates that a generating efficiency of 91.4% can be obtained by the moving magnet linear generator under the rated working frequency of 50 Hz. Compared with the existing moving coil linear generator prototype, the power volume density and the power mass density of the new designed moving magnet linear generator prototype are increased by 150% and 35%.

中文翻译：

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管状动磁线性发电机系统的电磁特性分析

自由活塞发动机作为一种新型的先进发电系统，可应用于电动汽车、通信基站等诸多领域。在本文中，为自由活塞发动机设计了一种新型的管状动磁线性发电机系统。使用带有运动求解器的瞬态计算方法，提出了所设计的线性发电机的三维有限元模型。详细分析了设计的线性发电机的电磁力、电动势和发电效率。在实验室条件下制造和测试样机，然后使用经过验证的有限元模型评估样机的主要性能。本文中的电磁分析表明，发电效率为 91。动磁直线发电机在额定工作频率50Hz下可获得4%。与现有动圈直线发电机样机相比，新设计的动磁直线发电机样机的功率体积密度和功率质量密度分别提高了150%和35%。