Comparison of switched-flux permanent magnet machines with non-overlapping concentrated winding for open-winding generator system

摘要

The open-winding permanent magnet generator (OWPMG) systems, having the advantages such as high power density, relatively few power switches, high degree of integration and easy to realise power distribution, are suitable for applications like renewable energy power generation systems with multiple power sources. The non-overlapping concentrated winding switched-flux permanent magnet (NOWSFPM) machines, having relatively high torque density and big flux-weakening inductance, are good choices when used in OWPMG systems. The electromagnetic performance of the 6/10 NOWSFPM machine, the 6/7 E-core NOWSFPM machine, the 6/7 E-core NOWSFPM machine with pole shoe and the 6/19 multi-tooth NOWSFPM machine are compared and analysed. Based on the results and according to two defined factors, namely the proportion factor of the power distribution and the speed range, this study mainly focuses on the influence of the flux-weakening coefficient (ρ) on the capability of the power distribution control. The analysis conclusions are verified by experimental results, indicating that the 6/19 multi-tooth NOWSFPM machine (ρ ≃ 1) has relatively strong power distribution capability.