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The aging of the insulation system of large rotating machines in frequency domains
(2019-07-01)
Phloymuk, Natthawut
;
Pattanadech, Norasage
The insulation of stator winding in a rotating machine consisted of mica and epoxy resin materials. The structure was also composed of junctions, so, a diagnostic monitoring condition of this insulation was taken into consideration. First, the results of the polarisation and depolarisation current measurement (PDC) of the test sample (stator winding rate of 13.8 kV) were investigated, as an experiment in the laboratory. The conditions of the experiment were conducted under different thermal stresses of 25°C and 100°C. The test sample was full stator bar. As found, the trend of the temperature of the winding rise if the current of the polarisation and depolarisation was increased. Second, the results of the PDC were calculated from the time domain to the frequency domain. The aim found that the aging point of the insulation system should take into consideration the results of the calculation of the frequency domain. The aging of the insulation system was a variant by the thermal stress, which was an effect from the complex capacitance and polarisation losses in the insulation winding system. Finally, this identified the phenomenon of the aging of the machine insulation system.
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The investigation of insulation performance evaluation of the large electrical rotating machine in frequency domain
(2019-01-01)
Phloymuk, Natthawut
;
Kando, Masaaki
;
Pattanadech, Norasage
The insulation structure of winding in a large electrical rotating machine consists of epoxy resin and mica material. The insulation structure is composed of many junctions. The insulation problems generate different kinds of signals, such as electromagnetic waves, which may get released from the non-perfect characteristics of the enclosure. This signal may interfere with the functioning of other nearby electronic devices. Therefore, maintaining an excellent condition of the insulation system of the machine is very important. For a condition monitoring of this insulation as proposed in this research, it is taken into consideration the results of the polarization and depolarization current (PDC) measurement of the test sample, and the stator winding rated 13.8 kV was investigated. The experiments were conducted under different thermal stresses, i.e., 25<sup>◦</sup>C (the room temperature) and 100<sup>◦</sup>C (the operation temperature). The test samples were divided into three types: I. haft-overhang, II. overhang and III. full stator bar. From the PDC measurement data record, the complex capacitance and polarization losses (ion migration polarization, slow relaxation polarization and interfacial polarization) were calculated. It was found that the aging of the insulation related to the complex capacitance and polarization losses can be contributed for research in future wireless technology.
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Condition monitoring based on failure modes and effects analysis using scada software for wirelesshart devices
(2018-04-01)
Kummool, Sart
;
Thepmanee, Teerawat
;
Pongswatd, Sawai
This paper presents the design and implementation of condition monitoring for WirelessHART devices by using the supervisory control and data acquisition (SCADA) software called WW InTouch. The design of the proposed system is based on a concept of failure modes and effects analysis (FMEA) for creating the human machine interface (HMI) on the operator workstation. The implementation of the proposed system is based on a technique of WirelessHART-Modbus TCP data transfers by mapping the HART tag names from the field wireless devices to the Modbus registers in the WirelessHART gateway. The script functions running on the HMI for detecting the published diagnostic data of the monitored devices and for identifying the FMEA results of device and power supply failures are created. A WirelessHART temperature transmitter and a wired HART control valve positioner connected with Wireless THUM adapter are employed as the interested field devices for monitoring their abnormal operating conditions to verify the workability of the proposed system. Experimental results from the failure mimic show that the proposed system based on FMEA can function correctly.
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Integration of WirelessHART and ISA100.11a field devices into condition monitoring system for starting IIoT implementation
(2017-11-10)
Tanyakom, Apisit
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Pongswatd, Sawai
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Julsereewong, Amphawan
;
Rerkratn, Apinai
This paper presents a technique to integrate wireless field devices using WirelessHART and ISA100.11a technologies into a condition monitoring system based on Wonderware InTouch software. The proposed integration brings the data from a field site with digital multi-device networking for automatic data collection to support the condition monitoring of instruments or smart connected equipment in preparation of the Industrial Internet of Things (IIoT) implementation. Data including process variables and diagnostics from WirelessHART and ISA100.11a devices are buffered and mapped into Modbus/TCP registers for real-time monitoring at the operator workstation. Experimental results confirm that the proposed integration functions correctly.
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SVM-based stator fault diagnosis for induction motors using DQ0 voltage components
(2010-10-01)
Manop, Chalermchat
;
Kinnares, Vijit
;
Chunwiphat, Suphot
This paper presents a new technique for diagnosis of stator winding shorted turns in three phase induction motors using support vector machine (SVM) as a classifier in conjunction with a voltage signature analysis as feature extraction. The proposed dqO voltage components related to three phase voltages are obtained by using Park's transformation. Unlike general dqO quantity, the required dq components are considered from only harmonics in a certain range resulted from the stator shorted turn fault whilst the required zero component is determined from the fundamental voltage excitation only. The procedure for finding the harmonic spectrum associated with the stator fault employs a FFT technique together with digital signal processing in order to enlarge such harmonics to be easily detected. The data of d, q and zero components will be used as the input features for a SVM classification and diagnosis. In order to confirm that the dqO voltage components could be used as quantity for identifying the stator fault, patterns of dqO voltage components in three-dimension are plotted. The obtained trajectories are obviously different depending on the severity of the shorted turn fault. In training and testing with a multiclass-SVM classification, the good accuracy is obtained under various load conditions for both healthy and stator fault conditions. The SVM classification performance of the proposed method has high accuracy greater than 98% comparable to other feature extraction processes such as a motor current signature method (MCSA) but the number of training data and features for the proposed technique are less. © 2010 ICIC International.
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Stator faults detection based on the dq0 voltage components
(2008-10-30)
Manop, Chalermchat
;
Kinnares, Vijit
This paper presents the technique for detection of shorted turns in stator winding of induction motors. The strategy is based on the dq0 voltage components. The proposed technique determines dq components of time domain of harmonics obtained from Park transformation instead of the stator phase voltage. Zero component (0) is calculated from the fundamental voltage excitation only. In the testing, the supply is sinusoidal waveform and the motor must be star connected with floating neutral. From experimental results, pattern of dq0 voltage components in order to use for the stator faults detection is possible. ©2008 IEEE.
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A low cost prototype for testing stator winding shorted turns in 3-phase induction motors
(2005-12-01)
Manop, Chalermchat
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Senavongse, Wongwit
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Kinnares, Vijit
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Tangsiriworakul, Chanwit
This paper presents a prototype of stator winding shorted turns detector for three-phase induction motors. The focus condition is turn-to-turn short circuit, because this condition is the initial problem. The diagnosis technique is detectable from the voltage sum of the three instantaneous line to star-point voltage. In the testing, the supply is sinusoidal waveform and the motor must be star connected with floating neutral. Before diagnosis, this instrument will also determine the level of supply voltage imbalance, if it is over the limit, the test instrument will not diagnose shorted turns. From experimental results, 3-hp and 5-hp induction motors were used for testing this equipment which is capable of accurately identifying percentage of stator winding shorted turns. © 2005 IEEE.

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