A simple assessment of the cogging torque in a transverse flux permanent magnet machine

Much attention is presently focused upon the transverse flux permanent magnet machine (TFPM), especially in electric and hybrid propulsion applications. Although significant improvements have been carried out on the earlier topologies, much work is still required before the TFPM can be regarded as a mature concept. Of particular interest is the cogging torque reduction which is a vital requirement in direct wheel drive applications. The paper describes the principle of the cogging torque production in a double-sided TFPM, and proposes an approach to its analytical prediction taking as a pattern the case of the buried permanent magnet machine.