Electromagnetic Characteristics Analysis of a Tubular Moving Magnet Linear Generator System

Abstract

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%.

Electromagnetic–Thermal Characteristics Analysis of a Tubular Permanent Magnet Linear Generator for Free-Piston Engines

“…Linear generators possess the advantages of fine control features, high thrust density, and good dynamic characteristics. In recent years, different types of LGs have been used for wave energy converters [4,5] and FPEs [6][7][8]. Compared with other types of LGs, permanent magnet linear generators (PMLGs) are widely used in converting kinetic energy of linear motion into electricity, especially with FPEs due to high efficiency and power density [9].…”

Analysis and testing of internal combustion engine driven linear alternator

“…In studies [2,[6][7][8][9][10], it has been shown that the free piston mechanism and the crank connecting mechanism exhibit a very similar movement profile. Newer forms of ICE, including the free piston system [11][12][13], are being investigated as multi-fuel, high efficiency, low emission options.…”

“…Investigation of linear generator with finite element analysis (FEA). A linear machine converts mechanical energy into electrical energy or converts electrical energy into mechanical energy via linear motion [11]. Designs may vary according to application, with different values of speed, frequency, stroke distance, and force.…”