flathill wrote:you could probably double the torque with a v shape mag config
partly due to the increased reluctance torque
and partly due to the increased magnet surface area (research papers and multi variate sims dont pick up on this)
you may call this flux focusing but the important thing is the increases surface area for a given pole surface area
increasing magnet thickness hits a point of diminishing returns so the v config allows two thinner magnets meaning you save money
internal permanent magnets motors gives about 30% more torque with the reluctance/saliency effect produced.
so you can design with more torque in mind or use less magnets for same torque, you choose (for car makers it's no doubt less $)
BUT it require special driving parameters to obtain the boost compared to classical PM motor.
there is more and more studies data about these IMPM, as this one