유도전동기 효율향상에 따른 역률 보상 콘덴서 최적 선정에 대한 연구

Kim, Jong-Gyeum

  • 투고 : 2016.06.02
  • 심사 : 2016.06.20
  • 발행 : 2016.07.01


Induction motor requires a rotating magnetic field for rotation. Current required to generate the rotating magnetic field is immediately magnetizing current. This magnetizing current is associated with the reactive power. Induction motor is always required reactive power. If reactive power is supplied only to the power supply side, the power factor is low. Therefore, it is to compensate the power factor by connecting capacitors in parallel to the motor terminal. If the capacitor current is greater than the magnetizing current of the motor, there is a possibility that the self-excitation occurs. High voltage generated by the self-excitation leads to insulation failure on the motor. So it is necessary to calculate the power factor correction capacitor capacity the most suitable to the extent that the magnetizing current does not exceed the capacitor current. In this study, we first computed the magnetization current and the reactive power of the induction motor and then calculates a limit of the maximum power factor by comparing the magnetizing current and the capacitor current installed in order to achieve the target power factor.


Active power;Capacitor;Magnetizing current;Power-factor;Reactive power


  1. Theodore Wildi, "Electrical Machines, Drives and Power Systems", Prentice Hall, 2002
  2. Jong-Gyeum Kim, "Characteristics for Current and Power of Induction Motor by Load Variation", KIIEE, Vol.25, No.8, pp. 82-87, 2011. 08
  3. Minho Park, Induction Machines, Dongmyungsa, pp.315, 1990
  4. IEC 60034-30(2008) std, "Efficiency classes for low voltage AC motors".
  5. Jong-Gyeum Kim, "Characteristic Comparison Analysis for Standard and High-efficiency Induction Motor", KIEE, Vol. 56P, No. 4, pp. 186-109, 2007.12
  6. IEC 60831-1, "Shunt power capacitors of the self-healing type for a.c. systems having a rated voltage up to and including 1,000V-Part 1: General-Performance, testing and rating-Safety requirements-Guide for installation and operation", 2014
  7. Ramasamy Natarajan, "Power System Capacitor", Taylor & Francis, 2005
  8. Jong-Gyeum Kim, "Suitability Review for Power Correction Parameter of Induction Motor", KIIEE, Vol.22, No. 12, pp. 101-109, 2008.12
  9. Jong-Gyeum Kim, Youn-Jeen Park, "A Characteristic Study on the Power Factor Correction Application for the Induction Motor", KIIEE, Vol. 22, No. 9, pp. 25-31, 2008.09
  10. IEEE Std 141-1993, "Power factor and related considerations"
  11., "Self-Excitation Concerns with Power Factor Correction on Induction Motors", pp.1-4.
  12. Jong-Gyeum Kim, "A Research on Self-excitation and Power Factor Compensation of Induction Motor", KIEE, Vol. 63P, No. 4, pp. 236-240, 2014.12