Papers by Daniel Morinigo-Sotelo
Applied Sciences, 2021
A proper diagnosis of the state of an induction motor is of great interest to industry given the ... more A proper diagnosis of the state of an induction motor is of great interest to industry given the great importance of the extended use of this motor. Presently, the use of this motor driven by a frequency converter is very widespread. However, operation by means of an inverter introduces certain difficulties for a correct diagnosis, which results in a signal with higher harmonic content and noise level, which makes it difficult to perform a correct diagnosis. To solve these problems, this article proposes the use of a time-frequency technique known as Dragon Transform together with the functional ANOVA statistical technique to carry out a proper diagnosis of the state of the motor by working directly with the curves obtained from the application of the transform. A case study is presented showing the good results obtained by applying the methodology in which the state of the rotor bars of an inverter-fed motor is diagnosed considering three failure states and operating at different l...
Energies, 2021
The fault diagnosis of electrical machines during startup transients has received increasing atte... more The fault diagnosis of electrical machines during startup transients has received increasing attention regarding the possibility of detecting faults early. Induction motors are no exception, and motor current signature analysis has become one of the most popular techniques for determining the condition of various motor components. However, in the case of inverter powered systems, the condition of a motor is difficult to determine from the stator current because fault signatures could overlap with other signatures produced by the inverter, low-slip operation, load oscillations, and other non-stationary conditions. This paper presents a speed signature analysis methodology for a reliable broken rotor bar diagnosis in inverter-fed induction motors. The proposed fault detection is based on tracking the speed fault signature in the time-frequency domain. As a result, different fault severity levels and load oscillations can be identified. The promising results show that this technique ca...
Energies, 2020
In this work, a new time-frequency tool based on minimum-norm spectral estimation is introduced f... more In this work, a new time-frequency tool based on minimum-norm spectral estimation is introduced for multiple fault detection in induction motors. Several diagnostic techniques are available to identify certain faults in induction machines; however, they generally give acceptable results only for machines operating under stationary conditions. Induction motors rarely operate under stationary conditions as they are constantly affected by load oscillations, speed waves, unbalanced voltages, and other external conditions. To overcome this issue, different time-frequency analysis techniques have been proposed for fault detection in induction motors under non-stationary regimes. However, most of them have low-resolution, low-accuracy or both. The proposed method employs the minimum-norm spectral estimation to provide high frequency resolution and accuracy in the time-frequency domain. This technique exploits the advantages of non-stationary conditions, where mechanical and electrical stre...
Shock and Vibration, 2016
Mechanical Systems and Signal Processing, 2017
Nowadays, timely maintenance of electric motors is vital to keep up the complex processes of indu... more Nowadays, timely maintenance of electric motors is vital to keep up the complex processes of industrial production. There are currently a variety of methodologies for fault diagnosis. Usually, the diagnosis is performed by analyzing current signals at a steady-state motor operation or during a start-up transient. This method is known as motor current signature analysis, which identifies frequencies associated with faults in the frequency domain or by the time-frequency decomposition of the current signals. Fault identification may also be possible by analyzing acoustic sound and vibration signals, which is useful because sometimes this information is the only available. The contribution of this work is a methodology for detecting faults in induction motors in steady-state operation based on the analysis of acoustic sound and vibration signals. This proposed approach uses the Complete Ensemble Empirical Mode Decomposition for decomposing the signal into several intrinsic mode functions. Subsequently, the frequency marginal of the Gabor representation is calculated to obtain the spectral content of the IMF in the frequency domain. This proposal provides good fault detectability results compared to other published works in addition to the identification of more frequencies associated with the faults. The faults diagnosed in this work are two broken rotor bars, mechanical unbalance and bearing defects.
IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society, 2014
ABSTRACT Up to now, detection of rotor faults in inverter-fed induction motors has received very ... more ABSTRACT Up to now, detection of rotor faults in inverter-fed induction motors has received very little attention. This fault is difficult to be detected, since the fault-related components are too close to the fundamental (the inverter usually operates at low slip). Moreover, classic techniques cannot be applied since steady states are not common. The causes of this type of fault are analyzed in the paper, showing its importance. Particularly, cases of real faults in electric traction are exposed. Then, the paper explores the use of linear time-frequency transforms to detect the time-frequency evolution of the fault-related components. It is shown how the most common linear transforms, such as the Short Time Fourier Transform, do not enable the fault detection. The Chirplet Transform (which has never been used for diagnosing purposes), is proposed to obtain the components evolutions, even if they are too close in the time-frequency plane. The technique is validated through startup tests, in which the presence of the fault is quantified when analyzing the stator current.
... D. Moriñigo-Sotelo is also with the Light Alloys Division, CIDAUT Foundation, 47151 Valladoli... more ... D. Moriñigo-Sotelo is also with the Light Alloys Division, CIDAUT Foundation, 47151 Valladolid, Spain. (e-mails: [email protected], [email protected]) ... 54, pp. 1410-1419, 2007. [11] D.Morinigo-Sotelo, LA Garcia-Escudero, O. Duque-Perez, and Marcelo Perez-Alonso ...
ABSTRACT This paper presents the results of an ongoing investigation focused on the development o... more ABSTRACT This paper presents the results of an ongoing investigation focused on the development of an expert system for condition monitoring of induction motors fed by Voltage Source Inverters (VSIs), extrapolating a previously successfully proven method suited for utility supply. However, when trying to obtain a generic method valid for any type of converter and at any operating frequencies further considerations have to be made. A controlled laboratory experiment has been performed in which a great deal of tests was carried out progressively drilling a hole in one of the rotor bars of an induction motor. A statistical analysis of the results is presented in detail and some conclusions useful for condition monitoring are drawn.
Proceedings - 2013 9th IEEE International Symposium on Diagnostics for Electric Machines, Power Electronics and Drives, SDEMPED 2013, 2013
ABSTRACT Condition monitoring has become necessary to detect failures in induction motors (IM) wh... more ABSTRACT Condition monitoring has become necessary to detect failures in induction motors (IM) where the detection of incipient faults is of great concern. However, the detection of partially-broken rotor bars at an early stage is not so easily achieved. Therefore, it is necessary to use suitable condition monitoring accompanied with signal processing techniques to detect partially-broken rotor bar. This paper presents a comparative study of various condition monitoring methods accomplished for IM with the aim of early detection of one partially-broken rotor bar by steady-state current spectrum analysis and different supply conditions, such as two different variable speed drives providing three fundamental supply frequencies, and the line supply case. The study includes three different load conditions for each case. Results show that the most accurate and robust analysis methodology for early detection of broken rotor bars under different supply conditions, fundamental supply frequencies and load conditions during steady-state analysis, are the subspace methods.
ABSTRACT This paper presents a procedure for broken rotor bar diagnosis in induction motors based... more ABSTRACT This paper presents a procedure for broken rotor bar diagnosis in induction motors based in data extracted from stator current, which is calculated in the time and frequency domains. Data comes from a tested motor fed by different types of supply: direct line and two different Voltage Source Inverters. Diagnosis is always difficult in Voltage Source Inverter fed motors due to inherent noise level and the presence of additional non-related fault harmonics in the stator current spectrum. Moreover, the motor was tested under different load conditions, from no-load to full-load. Diagnosis is also more difficult at lower load levels. Previous to fault classification, a variable reduction was carried out using Principal Component Analysis. Fault classification was performed using Linear Discriminant Analysis. The motor was tested with different fault severities, what allowed us to perform an analysis oriented to different maintenance approaches, considering the criticality of the motor.
International Journal of Electrical Power & Energy Systems, 2013
Reduction of costs is an important component of competitiveness. This paper proposes a methodolog... more Reduction of costs is an important component of competitiveness. This paper proposes a methodology for the reduction of electrical costs for large customers, such as industrial companies or hospitals, whenever the electric supply tariff contains a time of use factor and penalizations due to excess of capacity demand (which are usual in a lot of countries). The proposed methodology uses statistical and optimization tools to take advantage of the information obtained from the historical behavior of the customer in order to balance the contract and excess terms in the bill and to allow an appropriate forecast of its future needs. To prove the usefulness of the proposed methodology, a case study is presented in which the electric bill of a large Spanish hospital is substantially reduced.
IEEE International Conference on Electric Machines and Drives, 2005., 2005
Detection of faults in cage induction motors based on spectral analysis of line current is a well... more Detection of faults in cage induction motors based on spectral analysis of line current is a well-known technique in the case of sinusoidal supply. Nevertheless, nowadays there are a huge number of applications for the induction motor fed by frequency converter and, therefore, it is necessary to validate, or even modify, the existing fault detection methods, in order to use reliable and effective techniques. In this paper, first we approach, from a theoretical point of view, the effect of bearing faults on the harmonic frequencies of line current, taking into account the presence of numerous harmonics, not related to the fault, injected into the current by the converters themselves. As a result, we propose a novel formulation for the calculation of fault frequencies, suitable for any kind of supply. Finally, this innovative formulation is experimentally verified with tests of traction motor drives, and some conclusions and guidance for the early detection of these kinds of faults are provided, modifying and enriching the methods currently used.
Electric Power Systems Research, 2015
Condition monitoring of induction motors fed by Voltage Source Inverters is challenging since the... more Condition monitoring of induction motors fed by Voltage Source Inverters is challenging since the influence of the supply complicates the use of methods valid for utility fed motors. When trying to obtain a fault detection scheme valid for any kind of supply and at any operating frequency is necessary to analyze the influence of the different operating conditions. To obtain generic conclusions, a statistical analysis has been performed over the data obtained in a controlled laboratory experiment where a hole was progressively drilled into a rotor bar. Additive models have been obtained to stand out the influence of the operating conditions over the fault signatures. Conclusions useful for condition monitoring are drawn.
8th IEEE Symposium on Diagnostics for Electrical Machines, Power Electronics & Drives, 2011
) Abstract - With the aim of developing an expert system for condition monitoring of cage rotor i... more ) Abstract - With the aim of developing an expert system for condition monitoring of cage rotor induction motors fed by power inverters, laboratory tests have been performed on a motor with artificially created eccentricity in order to identify as many fault signatures as possible. The technique used to detect faults is Motor Current Signature Analysis and in this paper
2011 International Conference on Power Engineering, Energy and Electrical Drives, 2011
In this paper, we present a work in progress about the development of an expert system to detect ... more In this paper, we present a work in progress about the development of an expert system to detect incipient faults related to asymmetries in the rotor cage in induction motors fed by Voltage Source Inverters. The expert system is based on a condition monitoring technique based on robust statistical tools, and it makes use of the Fast Fourier Transform to
2014 International Conference on Electrical Machines (ICEM), 2014
The fault detection in an induction motor (IM) operated by a variable speed drive (VSD) is an act... more The fault detection in an induction motor (IM) operated by a variable speed drive (VSD) is an actual industrial need as most of the line-fed machines are replaced by a VSD, due to their improved speed regulation and fast dynamic response. However, undesired harmonics are always present when the IM is fed through a VSD. Under this operating condition, most developed techniques are unable to detect faults in the IM. This paper presents a technique based on the multiple signal classification (MUSIC) method, and it is applied to a VSD-fed IM during the startup transient; in order to verify the capability of the method to identify one broken rotor bar. From the experimental results, the proposed method is proven to be sensitive enough to detect one broken rotor bar, enabling a reliable diagnosis under different fundamental supply frequencies and load conditions.
2012 XXth International Conference on Electrical Machines, 2012
ABSTRACT The induction motor is the most widely used in industry, covering approximately 85% of t... more ABSTRACT The induction motor is the most widely used in industry, covering approximately 85% of the total electric loads. As an unpredicted shutdown can be very costly, early detection and diagnosis of electric motors faults yields to economical losses reduction and operational efficiency improvement. Neural networks have been proposed to solve the induction motor broken bar detection and diagnosis problem. Current spectrum data are generally used but some statistical features of time domain data have also been considered. In this paper, a performance comparison of both types of incoming data for the neural network is accomplished.
The XIX International Conference on Electrical Machines - ICEM 2010, 2010
ΦAbstract -- The introduction of Voltage Source Inverter fed motors has produced significant chan... more ΦAbstract -- The introduction of Voltage Source Inverter fed motors has produced significant changes in the field of diagnostics being necessary further research to overcome various challenges. To enhance the diagnosis of motor faults it is advisable to consider as many ...
The XIX International Conference on Electrical Machines - ICEM 2010, 2010
ΦAbstract -- Bearing lubrication is very important to ensure a satisfactory and long operation of... more ΦAbstract -- Bearing lubrication is very important to ensure a satisfactory and long operation of bearings. An excess of lubrication can be as damaging as a lack of lubrication. An excess of oil or grease has damaging effects in the short term such as difficult heat evacuation, ...
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Papers by Daniel Morinigo-Sotelo