Design criteria for stator winding coil pitch choice in AC inverter-fed multi-phase motors

In conventional three-phase electric machines, coil pitch ratio is usually selected around 5/6 so as to minimize the 5 th and 7 th flux linkage harmonics. In the electromagnetic deign of inverter-fed multi-phase motors different criteria should be adopted, depending on motor and inverter typology and possibly on the number of phases too. In this paper the main design issues involved in this choice are discussed showing that the final decision has to be the best compromise among various design needs and objectives.