Influence of Magnet Dimensions on Torque Components and Cost of Synchronous Machine with Interior Magnets

The paper presents a study on interior permanent magnet (PM) synchronous machine (SM). The influence of PM dimensions on the electromagnetic torque and its components (torque from PM and reluctance torque) is investigated. The SM torque is calculated using an approach proposed by the authors based on FEM analysis and analytical formulae. The results show influence of the magnet width and magnet height on the torque of the machine. It is proven that the torque of the machine is affected much more by the width of the magnets than by their height. As a result from the study it is concluded that there are possibilities for significant reduction of the volume of magnets without sacrificing the machine torque. In the paper, it is also discussed the possible financial savings due to reduction of PM mass and price.