Design of Flux-Switching Permanent Magnet Machine Considering the Limitation of Inverter and Flux-Weakening Capability

Abstract

In this paper, a general design procedure for the flux-switching permanent magnet (FSPM) machine with different topologies is proposed. Firstly, a 3-phase 12-stator-tooth/10-rotor-pole topology is introduced and its operation principle is described. Then, the basic design method, including determination of the stator, rotor and magnet dimensions, is proposed under the constraints of some dimensions and electrical parameters. The winding turns are obtained by iteratively solving the base-speed and current equations simultaneously. The influence of current density and slot packing factor on the flux-weakening capability is investigated in the design stage to satisfy the torque and wide-speed operation requirement. Further, the output power equation, consequently, the sizing equation is derived for determining the initial dimensions of a FSPM machine, in which the traditional D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">si</sub> l <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> is replaced by D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">so</sub> l <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> . Hence, the power density of different topologies can be compared directly by the equation. It reveals that the 3-phase 12/10-pole topology can offer higher power and power density than those of the 2-phase 8/6-pole machine by ~11% in theory under the same conditions. The experiments on the prototype motor verify the performance predictions