P. M. de la Barrera

Stator winding fault detection in induction motor drives using signal injection

A stator winding turn fault diagnosis strategy in induction motor (IM) drives is proposed in the present work. This strategy is based on the effects of the inductance variations coming from fault, over zero-sequence voltage. This voltage is measured when a predefined inverter-switching pattern is applied, allowing then decoupling the strategy from the motor fundamental excitation. For the evaluation of the feasibility of this proposal, a multiple-coupled circuit model of the IM is used. Experimental results are included to show the ability of the proposed strategy for detecting incipient faults, including a low number of short-circuited turns.

Stator core faults detection on induction motor drives using signal injection

A novel method to detect stator core fault (SCF) for induction motor (IM) drives is proposed in this paper. This approach is based on the effect of the SCF over the zero sequence voltage of the IM when a preset exploratory signal is injected in the machine. The validity of the proposed method is demonstrated by experimental results obtained with a modified standard IM. The modification allows to electrically emulate a SCF. This methodology used to perform SCF is experimentally validated by using the well known loop test. Obtained results show the applicability and the good performance of the SCF detection method.

Experimental generation and quantification of stator core faults on induction motors

A non-destructive method to analyze stator core faults on induction motors is presented and developed in the present work. It allows generating entirely reversible faults of different magnitudes. The quantification of fault severity was performed through the stator core interlaminar insulation test and through no-load test. The obtained experimental results show the feasibility of the method and the detectability of generated faults, which makes it a useful method to develop new diagnosis strategies.

Stator core fault diagnosis for induction motors based on parameters adaptation

A novel on-line stator core fault diagnosis method for Induction Motors (IM) is proposed. This approach is based on an adaptive state observer; it is derived from the IM dynamic model considering stator iron losses. In this model the iron losses are represented by an equivalent iron loss resistance (RFe). Stator core fault causes important variations on iron losses and these variations are reflected on the RFe. Therefore the proposed adaptive state observer estimates RFe with the objective of diagnosing stator core fault. Simulation and experimental results for different fault severity conditions are showed. These results demonstrated the validity of the method. In addition, simulation results proved that the proposal is not sensitive to load torque variations.

Induction motor saliencies analysis using zero-sequence signal injection

This paper presents an analysis of the magnetic saliencies in induction machines based on the injection of a zero sequence carrier. This way of injection allows evaluating those components of the admittance matrix which are not usually considered in the literature. The injection of the zero sequence carrier can easily be implemented, does not perturb the current control and the evaluation of its response is simple. It requires, however, access to the neutral point of the machine. The use of the zero sequence carrier for induction machines is a new approach that is evaluated in this paper. Experimental tests showed that two saliencies can be clearly identified in the carrier response: one due to the rotor bars and other due to the saturation in the main flux path. This would allow to estimate both, the rotor position and flux angle.

Fault detection in magnetic wedges of induction motor

In high power electric motors it is common to use open slots to facilitate the assembly of the coils. Open slots introduce harmonics in the magnetomotive force distribution over the air gap, resulting in additional losses and parasitic torques. In order to reduce these effects, wedges of magnetic material are used. These wedges are prone to apartial or total detachment, which in turn may result in other failures. In this paper a strategy to detect faults in magnetic wedges is presented. This strategy consists of the injection of a zero sequence voltage signal of high frequency. The resulting currents are highly dependent on the magnetic irregularities both the rotor and stator and thus sensitive to asymmetries produced by faults in the wedges. In this way, it is possible to detect and quantify wedges faults without the need to disassemble or remove the IM from the production line. The proposed strategy is applicable offline and required only disconnect the motor of the power supply. Laboratory experimental results are presented to validate the proposal.

Simulation of Electric Vehicles Combining Structural and Functional Approaches

In this paper the construction of a model that represents the behavior of an Electric Vehicle is described. Both the mechanical and the electric traction systems are represented using Multi-Bond Graph structural approach suited to model large scale physical systems. Then the model of the controllers, represented with a functional approach, is included giving rise to an integrated model which exploits the advantages of both approaches. Simulation and experimental results are aimed to illustrate the electromechanical interaction and to validate the proposal.

Multi-domain model of induction motor with stator core faults

In the present work a multi-domain model of an induction machine with stator core fault is presented. Its electromagnetic behavior as well as the thermal dynamics are modeled with Bond Graph. This complete model is used to obtain simulation results aimed to illustrate the thermal impact of different fault severities. Experimental results are provided to validate the proposed model.

Multi-domain model of stator core faults using Bond Graph

In the present work the model of an induction machine with stator core fault is presented. Its electromagnetic behavior as well as the thermal dynamics are modeled with Bond Graph. This complete model is used to obtain simulation results aimed to illustrate the thermal impact of different faults. Experimental results are provided to validate the electromagnetic model.

Modeling of electromagnetic devices using bond graph: An application to faults in AC machines

In the present work the model of an electromagnetic device that corresponds to an electric machine with stator core fault is presented. The acquisition process of the mathematical model and the equivalent Bond Graph model is based on its Magnetic Equivalent Circuit derived from the idealized physical system. From the experimental results, the non-linear characteristic of the magnetic material is reproduced. Experimental and simulation results for different fault severities show a strong correlation validating in this way the proposed model.