Detection of rotor asymmetries of induction machines in an encoderless control scheme
ABSTRACT Different techniques for the asymmetries in the rotor of asynchronous machines in closed-loop controlled drives have been developed; they usually need to monitor currents and speed. This paper investigates the detection of rotor asymmetries in field oriented controlled induction machines based only on the measured currents and without the measurement of the speed. The paper uses the indicator for asymmetries in the rotor of induction machines that was proposed in an earlier paper and extends it to the case of sensorless control schemes. The main focus of the paper is not in the sensorless control at low speed and supposes therefore that a simple model based on the voltage equation of the machine is sufficient. The region of low operation frequencies represents therefore no problem for the detection procedure. Laboratory measurements corroborate developed algorithm.
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ABSTRACT: In this paper, the impact of control on faulted induction machine behavior is presented. The diagnostic indexes usually used for open-loop operation are no longer effective. Simulation and experimental results show that the spectrum of the field current component i<sub>d</sub> in a field-oriented controlled machine has suitable features that can lead to an effective diagnostic procedure. Specifically, in the case of stator and rotor faults, the i<sub>d</sub> spectrum components at frequencies 2f and 2sf, respectively, are quite independent of control parameters and dependent on the fault extentIEEE Transactions on Industry Applications 10/2000; · 1.67 Impact Factor
Conference Proceeding: Diagnosis of rotor asymmetries in induction machines with different field oriented schemes[show abstract] [hide abstract]
ABSTRACT: Field oriented control schemes may use different methods for the acquisition of the orientation angle and can operate with or without encoder. In this work the usual variants of field oriented control are implemented and the viability of making the detection and diagnosis of incipient rotor asymmetries in the squirrel cage of induction machines (IMs) is discussed. Then, the utilization of an online indicator based only on the torque producing current and on the slip frequency is verified at equivalent operation points for all considered cases, within the normal range of operation of the drive.Industrial Electronics, 2008. IECON 2008. 34th Annual Conference of IEEE; 12/2008
Conference Proceeding: Detection of Rotor Faults in Field Oriented Controlled Induction Machines[show abstract] [hide abstract]
ABSTRACT: This work proposes an online method to diagnose rotor faults due to broken bars in induction machines controlled by a field oriented control scheme. First, control variables are analyzed under the presence of rotor faults. Then, the torque related stator current is proposed as the most suitable indicator. Sensitivity and reliability of this indicator are tested within the normal range of operation. Simulated and experimental results corroborate the proposalIndustry Applications Conference, 2006. 41st IAS Annual Meeting. Conference Record of the 2006 IEEE; 11/2006