Optimal starting frequency of three‐phase induction motor

In its applications, the starting performance of a 3‐phase induction motor (IM) is very important. The starting torque of the motor should be as high as possible within the safe current range of the motor driver. In the study, the optimal frequency for motor starting is derived from the frequency characteristic of the IM. Through the analysis of the characteristics, the optimal frequency point can be found, which is able to generate the maximum torque per unit drive current. Both theoretical analysis and experiments show that the IM with the optimal starting frequency can generate the maximum torque for a given current. The traditional methods, such as soft‐start, can reduce the starting current, but at the expense of lowering starting torque. This starting technology can solve the problem caused by traditional methods, improve the starting performance of the motor system significantly, and lower the requirement for the current redundancy of the motor driver effectively.