Study of cogging torque in shaft permanent magnet synchronous generator

Traditional marine induction motors or synchronous motors are often occupy a large space, severe vibration and noise and difficult to meet the requirements of high energy index under different load rates. This paper presents that permanent magnet synchronous generator (PMSG) is used as shaft motor to utilize the excess power of main engine effectively. Based on analytical analysis of cogging torque on radial magnetized PMSG, influence of pole arc coefficient, alveolar ratio, slot width, slot number and pole matching on cogging torque are discussed. Finite element method is used to obtain the optimal parameter combination which can reduce the cogging torque effectively. Experimental result of a 55kW, 4 pole prototype shows that this method can weaken cogging torque effectively.