Design And Research Of A Permanent Magnet Linear Generator For Thermoacoustics Technology

Thermoacoustic power generation technology is a new way of energy application. Thelow-quality heat source can be used in this technology with good suitability, high efficiency, simplestructure, long life. When temperature difference of the thermoacoustic engine’s hot end and cold endreaches a critical temperature, it will produce sound wave oscillating. The transformation of sound toelectricity is completed by the linear generator. This major work is to design a linear generator tomatch characteristics of the high frequency and small amplitude, and to calculate parameters of thelinear generator.The magnetic circuit structure and electromagnetic design of motor was studied. The design typeof the generator is cylinder type permanent magnet linear motor, which is single-phase and single poleand single slot. The whole shape of the generator is cylinder, primary uses structure of single and halfclosed slot, secondary adopts traditional structure. The novelty of the motor is dynamic substructure,the traditional dynamic substructure is only composed by single main pole, while the design of themotor is composed by single main pole and auxiliary poles, and permanent magnet’s magnetizing wayis radial, auxiliary poles’ material use silicon-steel sheets. The generator’s structure is simple, andmanufacture process is maturity.No-load electromagnetic parameters are studied. Analyzing the influence of the motor structureparameters for the no-load electromagnetic parameters, which provides reference for the size of themotor and its optimization. No-load electromagnetic parameters including no-load air gap magneticdense, EMF, no-load leakage coefficient, no load inductance.Detent force was studied. Using the virtual displacement method analyzing the generator’s detentforce characteristics and electromagnetic thrust force characteristics, and researching the factors andmeasures to restrain electromagnetic thrust force and the detent force, by the simulation and analysisresults show that, the reasonable motor structure parameters can effectively reduce the motor detentforce and electromagnetic thrust force, and change the auxiliary pole axial length is the most effectivemethod.The external characteristic of generator and efficiency characteristics are analyzed. Analyzingthe factors of impacting these characteristic by the voltage regulation, armature reaction, permanentmagnet working point, iron loss, etc. At the same time, Analyzing the influence of the core materialfor motor’s performance.