Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 15

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  uszkodzenia silnika
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
PL
Zanieczyszczenia znajdujące się w paliwie są często przyczyną uszkodzenia silnika spalinowego lub pogorszenia jego osiągów.
PL
Artykuł związany jest z analizą pracy układu napędowego o zwiększonym stopniu bezpieczeństwa. Sprawdzono wpływ uszkodzeń wybranych elementów układu napędowego z silnikiem indukcyjnym oraz samego silnika na proces detekcji awarii elementów pomiarowych w układzie wektorowego sterowania polowo – zorientowanego. Analizowano wpływ awarii prętów klatki wirnika silnika indukcyjnego, uszkodzenia tranzystora falownika napięcia oraz sprawdzono wpływ zmienności wybranych parametrów maszyny na jakość pracy detektorów uszkodzeń czujników pomiarowych.
EN
The paper is concerned with the analysis of safety electrical drive systems. The analysis of the influence of selected components faults of the drive system with the induction motor on the process of detecting failure of the measuring elements in the vector control system was analyzed. The rotor bars faults of induction motor, IGBT transistor failure, and the influence of machine parameters changes were investigated.
PL
W artykule przedstawiono wyniki badań własnych autora w zakresie ustalenia przyczyn uszkadzania się izolacji uzwojeń silników wysokonapięciowych indukcyjnych klatkowych. Przedstawiono rodzaje uszkodzeń izolacji uzwojeń. Omówiono metody diagnostyki off-line izolacji uzwojeń silników, zaprezentowano wyniki badań własnych w zakresie diagnostyki off-line.
PL
W pracy przedstawiono metodę badawczą pozwalającą na analizę uszkodzenia powierzchni tłoków wykorzystywanych w silnikach spalinowych. Istotą metody jest prowadzenie precyzyjnych pomiarów w różnych temperaturach tłoka uszkodzonego oraz odniesienie uzyskanych wyników do tłoka referencyjnego – nowego. Sposób prowadzenia badań z wykorzystaniem zaproponowanej metody przedstawiono na podstawie przeprowadzonych pomiarów z wykorzystaniem dwóch tłoków.
EN
The paper presents the investigation method allows for an analysis of failure of combustion engines piston surface. The essence of method is realization of precise measurement in various piston temperature and after that comparison of obtained results to reference piston – new one. Method has been presented on the basis of two pistons measurements.
PL
W artykule przedstawiono wyniki badań z zakresu wykrywania uszkodzeń w silnikach elektrycznych. Utworzono modele matematyczne: silnika indukcyjnego pierścieniowego pracującego w układzie kaskady półprzewodnikowej oraz silnika komutatorowego prądu stałego zasilanego z układu tyrystorowego. Elementy półprzewodnikowe i uszkodzenia aproksymowano obwodami rezystancyjnymi. W oparciu o utworzone modele matematyczne wyznaczono przebiegi czasowe prądów silników w stanie bezawaryjnym i w warunkach zwarcia zezwojów wirnika. Wykonano analizę falkową tych prądów dla potrzeb diagnostyki.
EN
The results of research on failure detection in electric motors have been presented in the paper. The mathematical models of a wound-rotor induction motor operating in a semiconductor cascade system, and a DC commutator motor supplied by a thyristor system, have been created: The semiconductor elements and the failures have been approximated by resistive circuits. On the basis of the created mathematical models, the time courses of the currents in motors during failure-free operation and under conditions of short-circuit in rotor coil, have been determined. The Falk's analysis of the currents has been made for the needs of diagnostics.
EN
The cost of an unexpected failure of a large AC motor can be very high. Not only the cost of simple repair (or replace) of the failed motor, but the costs of production breakdown should be taken into consideration. Many of the motor failures may be avoided by careful and proper motor design, especially by propper design of stator winding and its insulation system, bearing housing and bearing selection, rotor squirrel cages. At Komel Centre evaluation and calculation methods of mechanical and thermal stresses occurred in rotor cages of different types (deep bar, double cage, idle bar) at motor starting period are developed. The calculation are verified by special bench tests. The objects of the tests were sample AC motors 315, 500 and 800 kW, 6000 V. The same was performed for stator winding overhangs for 2 and 4-pole 6000 V motors. Very helpful in design process of reliable AC motors are case studies and expert evidences of different motors breakdowns and failures occurred at their exploitation. At Komel Centre many expert evidences of failed large AC motors of variouos manufacturers were carried out (see table 1).
EN
The work presented calculation results of a small power (1.5 kW) squirrel cage motor warm-up. Computation was realized with normal load. There is two models: one with non-damaged rotor and second one with three broken rotor bars. Calculation of coupling transient magneto-thermal field was realized with two-dimensional field-circuit motor model. There is a linear temperature characteristic of aluminum resistivity in squirrel cage, and a linear temperature characteristic of a thermal parameters in squirrel cage and core. Heating characteristic of motor with non-damaged rotor and another one with three broken rotor bars was compared. Heat distribution in rotor was investigated in both situation, in thermal transient state and after.
8
Content available remote Ekspertyzy i oceny przyczyn uszkodzeń silników elektrycznych dużej mocy - cz.2
EN
The main field of activity of the Research and Development Centre of Electrical Machines KOMEL (Katowice, Poland) is designing, redesigning and laboratory testing of different kind of electrical machines, mainly AC motors. But Komel Centre carries out as well: diagnostics, different expert evidences, studies of default causes, especially for large AC motors and driving systems. Expert evidences carried out by KOMEL contain not only a simple list of damages in the machine concerned, but explain its fundamental cause and the most probable course of events of destruction. Results of this expert evidences are exploited in designing process, especially for high power machines of high starting and high performance requirements. In the paper the most interesting study cases for different failures investigated in year 2003 by Komel Centre are shown. These are failure of 4800 kW slip-ring motor and case of high vibration of 522 kW 2 pole motor. The paper is a continuation of paper presented in May 2003 during PEMINE Conference[1], where failures of antifriction bearings, shafts, rotor squirrel cages, stator windings of different AC motors medium and high output have been presented. The design countermeasures taken by KOMEL to avoid such a failure in further exploitation are proposed.
EN
Main devices in electric power station (feed water pumps, coal pulverizers, mill ventilators ect.) are driven by high-power inductive motors 160 - 6300 kW. Analysis of failure frequency ot these motors shows that 50% of failures (Table l) occur in motors which drive feed water pumps and mill ventilators. About 75% of motors' failures occurs in their stators (Table 3). The rest of failures has their proximate source in rotors' squirrel-cage winding and rolling bearing. Statistics shows the mean time to failure of new motor is about 14 years. The mean time from the last failures for rewinded motors is about 10 years (Table 4). In stators usually break down their windings. The main reason of that are short-circuits in coil windings in the stator iron (Fig. 3 and 4) and in end windings coils (Fig. l, 2 and 5 to 7). These short-circuits cause short-circuit currents and in consequence the deformation of coil windings (Fig.8) is caused by the electrodynamic forces. In single squirrel-cage rotors failures usually occur in connection zone of cage bars with ring (Fig. 9 and 10). In double squirrel-cage rotors failures occurring in starting cage are caused by electric arc burning-off of starting cage bars in rotor core grooves (Fig. 11). More frequently electric arc burning-off occurs in starting cage between rotor core and rings (Fig. 12 and 13). Failures of rotors rolling bearings results in stator core seizing by rotor core (Fig 14).
10
Content available remote Ekspertyzy i oceny przyczyn uszkodzeń silników elektrycznych dużej mocy
EN
The main field of activity of the Research and Development Centre of Electrical Machines KOMEL(Katowice, Poland) is designing, redesigning and laboratory testing of different kind of electrica! machines, mainly AC motors. But Komel Centre carries out as well: diagnostics, different expert evidences, studies of default causes, especially for large AC motors and driving systems. Expert evidences carried out by KOMEL contain not only a simple list of damages in the machine concerned, but explain its fundamental cause and the most probable course of events of destruction. Results of this expert evidences are exploited in designing process, especially for high power machines of high starting and high performance requirements. In the paper the most interesting study cases for different failures (anti friction bearings, shafts, rotor squirrel cages, stator windings) of different AC motors medium and high output have been presented, along with the design countermeasures taken by KOMEL to avoid such a failure in further exploitation,
EN
The paper deals with diagnosis problems of the induction motors in the case of rotor, stator and rolling bearing faults. For diagnostic purposes two kinds of neural networks were proposed: multilayer perceptron network and selforgansing Kohonen networks. Neural networks were trained and tested using measurement data of stator current and mechanical vibration spectra. The efficiency of developed neural detectors was evaluated. Feedforward neural networks with very simple internal structure used for the detection of all fault kinds gave satisfactory results, what is very important in practical realization. Experiments with Kohonen networks indicated that they could be used for initial classification of motor faults, as a introductory step before proper neural detector based on multiplayer perceptron. Based on obtained results it can be concluded that neural detectors for rotor and stator faults as well as for rolling bearings and supply asymmetry faults can be developed based on measurement data acquired on-line in the drive system.
12
Content available remote Fuzzy approach for induction motor fault diagnosis
EN
This paper is concerned in the motor fault detection and diagnosis. Using fuzzy logic strategy, a better understanding of the heuristics underlying the motor fault detection/diagnosis process can be achieved. The proposed fuzzy approach is based on the stator currents Park's vector pattern. Stator currents in an induction motor were measured, recorded and employed for computation of the stator currents Park's vector pattern under different operating conditions. Simulated experimental results are presented in terms of motor fault detection accuracy and knowledge extraction feasibility. The results show the effectiveness of the proposed method.
PL
Artykuł poświęcony jest problematyce diagnostyki uszkodzeń silników. Zastosowanie logiki zbiorów rozmytych prowadzi do lepszego zrozumienia praktycznych metod detekcji i diagnozowania uszkodzeń. Proponowane zastosowanie zbiorów rozmytych oparte jest o Parkowskie wykresy wektorowe prądów stojana. Dokonano pomiarów i rejestracji przebiegu tych prądów i przeanalizowano wykresy Parka w różnych stanach pracy silników. Badania symulacyjne prowadzono pod kątem skuteczności i dokładności proponowanej metody w detekcji i diagnostyce uszkodzeń. Rezultaty wskazują, że metoda jest efektywna.
PL
W artykule przedstawiono wyniki badań architektur sztucznych sieci neuronowych, wykorzystywanych w diagnostyce uszkodzeń klatki silników indukcyjnych. Omówiono założenia, jakimi się kierowano przy określaniu architektury poszczególnych sieci, oraz główne problemy i ograniczenia wyboru danych uczących sieci neuronowe.
EN
The assumptions made when determining the architecture of particular networks and the main problems as well as limitations dealing with choice of the data training neural networks are discussed in the paper too.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.