Optimisation of a transverse flux linear PM generator using 3D Finite Element Analysis

[摘要] ENGLISH ABSTRACT: Several transverse flux and longitudinal flux linear generator topologies exist for freepistonStirling engine applications. In this thesis the transverse flux permanent magnetlinear generators are investigated together with a back-to-back converter which candeliver the electrical energy from the linear generator to the electrical network.The transverse flux permanent magnet linear generator is geometrically optimisedwith the aim to maximise the power-to-weight ratio while maintaining preset powerand efficiency levels. An optimised 3 kW linear generator is built and the measuredresults correlate to the simulation results.A close-loop current control scheme is introduced to control the current of the rectifier,which is part of the back to back converter. The transverse flux permanent magnetlinear generator is connected to the input of the rectifier which has the ability to forcea specific current from the generator. The measured results of the rectifier correlateto the results of the simulations that were done. The current control present somecomplications and it is suggested that another control scheme is used.A close-loop voltage control scheme is introduced for the control of the DC bus voltage.The DC bus is connected between the rectifier and the inverter, which is the otherpart of the back-to-back converter. A close-loop current control scheme is introducedto control the inverter current that flows from the inverter to the electrical network.The measured results of the inverter and the DC bus correlate to the results of thesimulations that were done.The results of the system, including the generator, rectifier and inverter, tested as a unitis presented and discussed.

[发布机构] Stellenbosch University