A Method for Improving the Performance Characteristics of Induction Motor with Primary Flux Control

For ideal induction motor driving, we must control primary flux to make rotating field according to order. “Primary Flux Control Method for Induction Motor” is one of the useful methods to achieve this control in practical use. Therefore, this method is applied to “General Purpose Inverter for Induction Motor” and this type inverter comes onto market already. However, this method has unstable region under regenerative operation in low speed. Although this problem is discussed in many papers, these are not all enough solution. As general-purpose-inverter are used in wide spread industrial field, induction motor is drive under various conditions. In this paper, we studied about the reason of unstable operating and proposed the method for improving the performance characteristics of induction motor with regenerative load in low speed region. Otherwise, to achieve this control, we have to use the inverter whose output voltage is equal to command voltage. Therefore, we also proposed “Voltage Control Type Inverter” in practical use.