Fault Detection and Isolation for the Inverter of BLDC Motor Drive using EKF

EKF를 이용한 BLDC 모터 구동기 인버터의 고장 검출 및 분리

  • Kim, SunKi (School of Mechatronics, Korea University of Technology and Education) ;
  • Seong, SangMan (School of Mechatronics, Korea University of Technology and Education) ;
  • Kang, Kiho (School of Mechatronics, Korea University of Technology and Education)
  • 김선기 (한국기술교육대학교 메카트로닉스공학부) ;
  • 성상만 (한국기술교육대학교 메카트로닉스공학부) ;
  • 강기호 (한국기술교육대학교 메카트로닉스공학부)
  • Received : 2013.11.19
  • Accepted : 2014.04.20
  • Published : 2014.07.01


The inverters used to drive Brushless DC motors (BLDC) include switching devices such as FETs and the faults in FETs cause severe performance degradation in systems where a BLDC acts as actuator. This paper presents a fault detection and isolation method for the FETs of an inverter for BLDC motor control systems, which is based on the EKF (Extended Kalman filter). Firstly, an equivalent circuit model for a BLDC motor plus its inverter system was derived. Secondly, a state-space equation was established, where the on-resistance of the FETs is expressed as a state variable and the EKF equation estimates the on-resistance. If the estimated resistance differs greatly from the known value, it can be asserted that there is a fault on that FET. Thirdly, the local convergence of the established EKF was proved. Finally, through the experiments, the performance of the proposed method was verified. The results show that the on-resistance is estimated close to the value specified in the FET data sheet in normal operation, whereas the estimated resistance is a much larger value than the normal one in case an FET fault occurs. Therefore, it is confirmed that the proposed fault detection and isolation method works appropriately in real systems.


Supported by : 한국기술교육대학교


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