Journal of the Korean Society for Railway (한국철도학회논문집)

The Korean Society for Railway (한국철도학회)
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Measurement and Analysis of Transient Voltage for an Inverter-fed Induction Motor

인버터 구동 유도전동기에서 과도전압의 측정과 분석

  • 길경석 (한국해양대학교 전기전자공학부) ;
  • 류길수 (한국해양대학교 IT공학부) ;
  • 박대원 (한국해양대학교 전기전자공학부) ;
  • 조영진 (한국해양대학교 전기전자공학부) ;
  • 천상규 (한국해양대학교 전기전자공학부) ;
  • 최수연 (한국해양대학교 전기전자공학부)
  • Published : 2007.12.31
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Abstract

Induction motors are widely used as a source of driving force in electric vehicles and pulse width modulation (PWM) inverters are applied to their operation. The issue is that insulation of inverter-fed induction motors (IFMs) are more stressed than in line-powered motors by transient voltages. This paper dealt with experimental results on transient voltage produced by the PWM operation of an induction motor. The peak and the dv/dt of transient voltage depending on the length of power feeding cable and operating frequency were investigated. In the experiment, transient voltages up to 3.3PU of the rated-inverter voltage were recorded for the cable length of 50m. As the cable length is increased, the peak voltage appeared at the motor terminals increases. This phenomenon can be explained by the reflection and the transmission of travelling wave. Consequently, special care for the cable length between the motor and the inverter should be taken in the use of IFM to ensure the full life of insulation system.

유도전동기는 전기차량의 주요 동력원으로 광범위하게 사용되고 있으며, 유도전동기의 속도제어에 펄스변조 방식을 이용한 인버터의 사용이 증가하고 있다. 본 논문에서는 유도전동기의 인버터 구동시 발생하는 과도전압에 대해 연구하였다. 전원 케이블의 길이에 따른 과도전압의 크기를 측정하였으며, 시간변화율과 운전주파수에 의한 영향을 분석하였다. 실험결과, 케이블의 길이가 길어짐에 따라 과도전압의 최대값이 증가하였으며 50m 케이블에서 과도전압의 크기는 최대 3.3PU까지 측정되었다. 이러한 현상은 진행파의 반사와 투과에 의해 발생하며, 유도전동기의 인버터 구동시 케이블의 길이에 따른 과도전압의 영향을 고려하여 유도전동기의 절연을 설계해야 할 것이다.

Keywords

References

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