Performance investigation of odd primary pole linear switched-flux PM machine with mechanical flux adjuster

Abstract

Linear switched-flux permanent-magnet machines (LSFPMMs) exhibit high thrust force density and low cost, which is especially suitable for long stroke application. They have big normal force so that the assembly becomes difficult. The mechanical flux adjuster is a suitable method to lower the big normal force. This paper investigates the performances of two kind odd primary pole LSFPMMs with mechanical flux adjuster based on FEA, including E- and C-core structure. The analysis results show this method can effectively lower the magnetic field in air gap. The structure parameters of mechanical flux adjuster are also optimized, and the operating curves are calculated with or without mechanical flux adjuster. With this method, not only does the assembly become easier, but also the operating range extends at small load.