Study on Installation of Power Factor Correction Capacitor and Self-Excitation Phenomenon in Reactor Starting Induction Motor

Induction motors are one of the most widely used rotating machines as a driving force for rotating loads. These rotating machines are inductive loads and have different power factors during starting or when rotating at rated speed. The most commonly used method to compensate for low power factor is using a stationary reactive power compensation device such as a capacitor. Induction motors have the problem of causing a voltage drop due to the generation of high current when starting. Therefore, when the capacity of the induction motor is large, the reactor starting method is sometimes applied despite the decrease in torque due to the voltage drop. The problem with applying the reactor starting method is that it takes a long time to reach the rated speed. In the reactor starting method, the characteristics may vary depending on the installation location of the power factor correction device as well as whether or not a switch is installed in the power factor correction device. In this way, it is necessary to analyze what effect the installation of a power factor correction device has when the starting time of the induction motor becomes longer. In this study, we analyzed whether self-excitation occurs depending on the installation location of the power factor correction capacitor when starting an induction motor with a reactor. ©The Korean Institute of Electrical Engineers.