• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.3
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• pp.61-68
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• 2012

This paper deals with a fault diagnosis algorithm for open faults in the switching devices of PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive. The proposed diagnostic algorithm is realized in the controller using the informations of three-phase currents or reference line-to-line voltages, without requiring additional equipments for fault detection. Under switch open fault conditions, the conventional dq model used to control an AC motor cannot directly be applied for the analysis of drive system, since three-phase balanced condition does not hold. To overcome this limitation, a fault model based on the line-to-line voltages is employed for the simulation studies. For comparative performance evaluation through the experiments, the entire control system is implemented using digital signal processor (DSP) TMS320F28335. Simulations and experimental results are presented to verify the validity of the proposed diagnosis algorithm.

• Journal of Power Electronics
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• v.13 no.6
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• pp.985-990
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• 2013

This paper proposes a novel fault diagnosis scheme using parameter estimation of the stator resistance, especially in the case of the open-phase faults of PMSM drives. The stator resistance of PMSMs can be estimated by the recursive least square (RLS) algorithm in real time. Fault diagnosis is achieved by analyzing the estimated stator resistance of each phase according to the fault condition. The proposed fault diagnosis scheme is implemented without any extra devices. Moreover, the estimated parameter information can be used to improve the control performance. The feasibility of the proposed fault diagnosis scheme is verified by simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1066-1067
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• 2015

This paper presents a diagnosis method for the detection and location of open-short switch faults in the three-phase power conditioning system. A method for switch fault diagnosis on the power conditioning system is proposed, based on the concordia transform. The switch fault types and locations on power conditioning system are diagnosed by a method in which analyze the d-q current vector locus and current pattern. The Simulation results confirm the proposed diagnostic method.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.3
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• pp.217-224
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• 2013

This paper presents a diagnostic method for a sparse matrix converter that detects faults in any single switch or a pair of switches. The sparse matrix converter is functionally equivalent to the standard matrix converter but has a reduced number of switches. The proposed diagnostic method is based in the measurement of input and output currents. The currents have respective characteristic according to the location of faulty switches. This method not only detects the switches of open-circuit fault but identifies the location of the faulty switching devices without complicated calculations. The simulation and experimental results verify that, based on the proposed method, the fault of sparse matrix converter can be easily and fast detected.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.2
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• pp.191-198
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• 2011

In this paper, the fault diagnosis scheme for PMSM drives has been proposed to maintain control performance under a switch open-phase fault of inverter. When the open-phase fault occurs, the stator resistances of PMSM are estimated by Extended Kalman Filter (EKF) in real time and can appear differently according to the location of fault occurrence to check the fault detection and identification. The control algorithm is configured without the additional device and low cost by adding the existing control program. Also, by using motor parameter the estimated stator resistance value improves the control performance of the controller affected by parameter variation. The feasibility of the proposed fault diagnosis algorithm is validated in simulation and experiment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.6
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• pp.40-51
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• 2009

To analyze influences under open faults in switching devices of the PWM inverter and under the isolation between the inverter and motor terminal, a faulty model for the inverter-driven permanent magnet synchronous motor is presented. Even though the conventional dq motor model obtained through the transformation of phase voltage model is widely used to analyze and control AC motor, it can not be used under open faults in switching devices since the 3-phase balanced condition is no longer hold under the open fault and it is not easy to obtain motor input voltages in open phase from the pole voltage. To deal with this problem, a faulty model for an inverter-driven permanent magnet synchronous motor is derived by using the line voltage of motor according to switch open, which can be effectively used for performance evaluation of the diagnostic algorithm. The validity of the proposed faulty model is verified through comparative simulations and experiments using DSP TMS320F28335.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.11
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• pp.109-115
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• 2012

Recently, permanent magnet synchronous motor are applied to various applications. Because of the importance of high reliable operation in these areas, many research related to the fault detection and diagnosis of inverter system are conducted. So, a faults model for an inverter-driven permanent magnet synchronous motor is studied by using the fault current of motor according to switch open, which can be effectively used for performance evaluation of the diagnostic algorithm. And fault of the permanent magnet synchronous motor inverter drive system is divided into four types. The feasibility of the proposed method are improved by simulation and experiment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.94-105
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• 2010

To detect faults in an inverter-fed permanent magnet synchronous motor (PMSM) drive under the circumstance having faults in a stator winding and inverter switch, an on-line basis fault detecting scheme during operation is presented. The proposed scheme is achieved by monitoring the second-order harmonic component in q-axis current and the fault is detected by comparing these components with those in normal conditions. The linear interpolation method is employed to determine the harmonic data in normal operating conditions. As soon as the fault is detected, the operating mode is changed to identify a fault type using the phase current waveform. To verify the effectiveness of the proposed fault detecting scheme, a test motor to allow inter-turn short in the stator winding has been built. The entire control algorithm is implemented using DSP TMS320F28335. Without requiring an additional hardware, the fault can be effectively detected by the proposed scheme during operation so long as the steady-state condition is satisfied.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.2
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• pp.88-95
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• 2008

This paper proposes a fast fault detection algorithm under open-circuit fault of a switch for a brushless DC(BLDC) motor drive system. This proposed method is configured without the additional devices for fault detection and identification. The fault detection and identification are achieved by a simple algorithm using the operating characteristic of the BLDC motor. After the fault identification, the drive system is reconfigured for continuous operation. This system is reconfigured by four-switch topology connecting a faulty leg to the middle point of DC-link bidirectional switches. This proposed method can also be embedded into existing BLDC motor drive systems as a subroutine without excessive computational effort. The feasibility of a the proposed fault detection algorithm is validated in simulation and experiment.

• Journal of Power Electronics
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• v.11 no.6
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• pp.801-810
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• 2011

An open circuit fault diagnostic method in IGBTs for the ac to dc converters used in microgrid applications is developed in this paper. An ac to dc converter is a key technology for microgrids in order to interface both distributed generation (DG) and renewable energy resources (RES). Also, highly reliable ac to dc converters are necessary to keep converters in continuous operation as long as possible during power switch fault conditions. Therefore, the proposed fault diagnostic method is developed to reduce the fault detection time and to avoid any other fault alarms because continuous operation is desired. The proposed diagnostic method is a combination of the absolute normalized dc current technique and the false alarm suppression algorithm to overcome the long fault detection time and fault alarm problems. The simulation and experimental results show that the developed fault diagnostic method can perform fault detection within about one cycle. The results illustrate that the reliability of an ac to dc converter interfaced with a microgrid can be improved by using the proposed fault diagnostic method.