PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników
Powiadomienia systemowe
  • Sesja wygasła!

Znaleziono wyników: 17

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Wybrane własności eksploatacyjne silników asynchronicznych klatkowych zasilanych napięciem o dużej częstotliwości
Zielińska M. J.
Maszyny Elektryczne : zeszyty problemowe
|
2013
|
Nr 1(98)
149-152
PL
Indukcyjne silniki klatkowe zasilane napięciem o dużej częstotliwości stosowane są głównie w przemyśle łożyskowym, precyzyjnym i włókienniczym. Są więc mało znaną grupą maszyn. Skromna jest również literatura dotycząca tego typu silników. Największe częstotliwości, czyli najwyższe prędkości obrotowe wynikają z potrzeb technologicznych i ograniczone są możliwościami wykonawczymi. Silniki te posiadają swoją specyficzną konstrukcję i mają określone własności eksploatacyjne różniące je od maszyn indukcyjnych klatkowych zasilanych napięciem o częstotliwości 50 Hz. Różnice te wynikają głównie z wprowadzenia intensywnego chłodzenia dla zmniejszenia wymiarów gabarytowych, zastosowania żłobka zamkniętego w wirniku celem ograniczenia drgań i hałasu oraz zasilania silnika napięciem o dużej częstotliwości. W niniejszym artykule na podstawie rozważań teoretycznych i badań laboratoryjnych podjęto próbę określenia własności silników asynchronicznych klatkowych zasilanych napięciem o dużej częstotliwości. Rozważania dotyczą parametrów elektromagnetycznych, bilansu strat jak również doboru wartości napięcia zasilania celem zapewnienia zadanych parametrów eksploatacyjnych.
EN
Induction squirrel-cage motors powered by high-frequency voltage are mainly used in industrial bearing, precise and textile industries. They are so little known group of machines. Literature concerning engines of this type is also modest. The highest frequency, which is the highest speeds on the needs of technological and regulatory capabilities are limited. These motors have their specific design and have specific operational properties differ them from cage induction machines supplied voltage with a frequency of 50 Hz. These differences result mainly from implementing the intensive cooling for reducing dimensions, of applying the groove closed in the rotor in order to limit pulses and the noise and contributing towards the engine stretching about the great frequency. In the present article based on theoretical deliberations and laboratory tests an attempt to determine the ownership of squirrel-cage asynchronous motors was made fed with stretching about the great frequency. Deliberations concern electromagnetic parameters, balance of losses as well as the selection of the value of the supply voltage in order to ensure set exploitation parameters.
2
Content available Wpływ strumienia zbocznikowanego na parametry schematu zastępczego dla silników klatkowych o dużych prędkościach obrotowych
Zielińska M.J., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
2012
|
Nr 2(95)
143-146
EN
Influence of the permanent magnet assembly on the single-phase permanent magnet synchronous motor on the running motor properties was investigated. Field-circuit synchronous motor models were applied in Maxwell ver. 14. EMF, THD and cogging torque were investigated. The optimum permanent magnet assembly motor solution with the best auxiliary winding parameters was presented.
3
Content available Wpływ nasycenia obwodu magnetycznego i wypierania prądu na przebiegi momentu elektromagnetycznego i prądu podczas rozruchu wysokoobrotowych silników klatkowych
Zielińska M.J., Zieliński W.G.
Maszyny Elektryczne : zeszyty problemowe
|
2011
|
Nr 3(91)
183-186
EN
High speed squirrel-cage motors are a relatively unknown group of machines, mainly due to their particular application. High rotational speed is achieved by supplying the motors with 400-1500Hz frequency voltage. Their operation in special conditions results in the fact that their structure and some properties differ from those of squirrel-cage induction machines supplied with 50Hz frequency voltage. The use of closed rotor slots causes strong saturation of the magnetic circuit for the slot leakage flux. Changes in the current in the slot causes a varying state of saturation and thus rotor leakage inductance is not a constant parameter. When determining the rotor winding leakage inductance for classic induction motors supplied with 50Hz frequency voltage, the influence of the saturation of the magnetic circuit for the leakage flux is usually omitted. This is a standard approach and an equivalent scheme, mentioned in literature, is used in such a case. Identification of the inductance in motors supplied with high frequency voltage, in which the phenomenon of core saturation occurs, is a relatively complex issue due to the complicated distribution of magnetic flux, and especially the leakage flux. The value of leakage inductance was determined experimentally. The paper presents differential equations describing a mathematical model and transients of the current and electromagnetic torque, obtained by simulating the start-up of a squirrel-cage high-speed motor.
4
Content available Opracowanie algorytmów regulacji napięcia zasilania wysokoobrotowych silników klatkowych celem zapewnienia zadanego momentu krytycznego lub rozruchowego
Zielińska M.J., Zieliński W.G.
Maszyny Elektryczne : zeszyty problemowe
|
2010
|
Nr 86
247-250
EN
Obtaining a high value of the breakdown or starting torque in an asynchronous motor is a very important issue from the point of view of improving its operational properties. These values can be determined based on data of a typical equivalent scheme. This refers to motors without the skin effect in the cage bar or those in which the phenomenon has been omitted. In a high-speed motor, the phenomena of core saturation and skin effect influence the parameters of the equivalent scheme, which are not constant values and depend on the frequency of supply voltage and the value of the current in the bar of the rotor's cage. In consequence, an equivalent scheme valid for classic motors should not be used for analysis of the performance of a high-speed motor. Based on an equivalent scheme which takes into account the influence of frequency on its parameters, the article describes how supply voltage was selected in order to guarantee the preservation of the given breakdown or starting torque. The calculations were made for three motors representing low, medium and high power machines.
5
Content available Metoda wyznaczania poślizgowych charakterystyk admitancji wysokoobrotowego silnika klatkowego
Zielińska M.J., Zieliński W.G.
Maszyny Elektryczne : zeszyty problemowe
|
2010
|
Nr 86
251-254
EN
High speed squirrel-cage induction motors are supplied with a high frequency voltage ranging from 400 to 1500Hz. The highest frequencies, i.e., the highest rotation speeds, arise from technological needs and are limited by manufacturing possibilities. These motors have a structure and electromagnetic properties that differentiate them from classic machines. In particular, they are distinguished by the high frequency of supply voltage, intensive cooling introduced to reduce the size of the motor, and closed rotor slots used to minimize vibrations and noise. The paper presents how slip characteristics of admittance of a squirrel-cage motor were determined on the basis of laboratory measurements conducted with current of variable frequency. This characteristic is the geometric locus of motor admittance with the slip ranging from + ∞ to - ∞ and an assumed constant frequency of supply voltage. The image of these characteristics differs considerably from a typical pie chart and it evidences the differences in electromagnetic properties in comparison with typical induction motors. Changes in the current in the slot causes a varying state of saturation and thus rotor leakage inductance is not a constant parameter.
6
Content available Przebiegi nieustalone prądu i momentu elektromagnetycznego podczas rozruchu w silnikach indukcyjnych wysokoobrotowych
Zielińska M.J., Zieliński W.G., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
2009
|
Nr 82
249-252
EN
High-speed motors are produced in Poland outside the machine-building industry. Only a few motors, adapted to specific purposes, are manufactured, for example, by plants that produce rolling-element bearings. These motors have found their application in driving high-speed grinders in bearing ring raceway production lines. The properties of motors fed with high-frequency voltage result mainly from the use of a closed slot in the rotor and the high frequency of supply voltage. The use of the closed rotor slot causes strong saturation of the magnetic circuit by the leakage flux around the slot. Taking account of the phenomenon of saturation of the magnetic circuit due to the leakage flux around the closed rotor slots is a complex issue. In the present article, this phenomenon was taken into consideration by introducing into the mathematical model of the motor, derived for a linear magnetic circuit, rotor leakage inductance dependent on rotor current. The relation was determined experimentally.
7
Content available Wykorzystanie metody pośredniej do określania momentu krytycznego silnika indukcyjnego
Zieliński W.G., Zielińska M.J., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
2008
|
Nr 80
151-154
EN
Pull-out torque and the corresponding pull-out slip of induction motors is determined, with a fair degree of accuracy, by measurements in the short-circuit and idle-running states. This refers to motors without the skin effect in the cage bar or those in which the phenomenon has been omitted. The paper compares analytical methods for determining pull-out torque based on the method of equivalent graphs and a simplified Kloss formula. The analysis was carried out for two induction motors: squirrel cage and slip ring. Pull-out slip and torque diagrams were used. An advantage of this method is the fact that determination of pull-out torque does not require the knowledge of pull-out slip.
8
Content available Metoda wyznaczania rezystancji wirnika z uwzględnieniem wypierania prądu dla silników szybkoobrotowych
Zielińska M.J., Zieliński W.G.
Maszyny Elektryczne : zeszyty problemowe
|
2008
|
Nr 80
155-157
EN
High speed motors are supplied with 400-1500Hz frequency voltage. They operate in special conditions and have a structure and properties that differentiate them from classic machines. In particular, they are distinguished by the high frequency of supply voltage, intensive cooling introduced to reduce the size of the motor, and closed rotor slots used to minimize vibrations and noise. In the discussed motors, the closed rotor slot was replaced with an open slot due to saturation of the magnetic circuit by the slot leakage flux. The resistance increase coefficient for rotor cage bar as a function of current flowing through the bar was estimated and then total rotor resistance was determined. Subsequently, the resistance calculated on the basis of geometric dimensions with skin effect taken under consideration was verified against results obtained from measurements. It was proved that short-circuit resistance is not a constant and depends on the value and frequency of current. It also includes a component which derives from additional losses occurring in solid construction elements and in rotor cage bars. The paper also presents descriptions showing changes in short-circuit resistance as a function of the motor's current determined on the basis of measurements with parametrically variable frequency.
9
Content available Uwzględnienie zjawiska nasycenia rdzenia przy wyznaczaniu indukcyjności rozproszenia uzwojenia wirnika dla silnika asynchronicznego klatkowego zasilanego napięciem o dużej częstotliwości
Zielińska M.J.
Maszyny Elektryczne : zeszyty problemowe
|
2007
|
Nr 77
117-120
PL
Indukcyjne silniki klatkowe zasilane napięciem o częstotliwości 400-1500 Hz są mało znaną grupą maszyn ze względu na swoje nieliczne zastosowanie. Stosowane są głównie w przemyśle łożyskowym, precyzyjnym, włókienniczym. Największe częstotliwości, czyli najwyższe prędkości obrotowe wynikają z potrzeb technologicznych a ograniczone są możliwościami wykonawczymi. Silniki te stosuje się do szlifowania otworów i bieżni łożysk tocznych oraz do napędu pomp dyfuzyjnych. Pracują one w specyficznych warunkach, posiadają swoją specyficzną konstrukcję oraz niektóre własności odbiegające od maszyn indukcyjnych klatkowych zasilanych napięciem o częstotliwości 50 Hz. Przy wyznaczaniu indukcyjności rozproszenia uzwojenia wirnika dla klasycznych silników indukcyjnych zasilanych napięciem częstotliwości 50 Hz zwykle pomija się wpływ nasycenia obwodu magnetycznego dla strumienia rozproszenia. Jest to postępowanie typowe i obowiązuje wówczas znany z literatury schemat zastępczy. Identyfikacja tej indukcyjności w silnikach zasilanych napięciem o dużej częstotliwości w których występuje zjawisko nasycenia rdzenia jest zagadnieniem dość złożonym z uwagi na skomplikowany rozkład strumieni magnetycznych w szczególności strumieni rozproszenia. Dodatkowym utrudnieniem jest tutaj uwzględnienie wpływu nasycania się przesmyku nad zamkniętym żłobkiem wirnika. W artykule przedstawiono metodę uwzględnienia nasycenia obwodu magnetycznego przy wyznaczaniu indukcyjności rozproszenia uzwojenia wirnika dla silników klatkowych zasilanych napięciem o dużej częstotliwości.
10
Content available Ocena oszczędności energii elektrycznej przy skokowej regulacji napięcia w silniku asynchronicznym klatkowym
Zielińska M.J., Zieliński W.G.
Maszyny Elektryczne : zeszyty problemowe
|
2007
|
Nr 77
121-124
EN
In order to enhance energy indices and obtain electrical energy savings for an asynchronous squirrel-cage motor operating on a long-time basis at a load lower than the rated load it needs to reduce its supply voltage. Efficient operation obtained that way can apply to a single motor or a set of motors driving the same machines. Motor load can vary within a wide range depending on the operation kind. Particularly disadvantageous is operation at little load or at idling, when energy indices of the motor are very low. In such a case it is necessary to apply voltage that can be varied depending on the load factor. When voltage is changed simultaneously with a load change the motor runs at higher values of the indices that decide over electrical energy consumption. At the rated load a motor should be supplied with rated voltage and when the load gets reduced the supply voltage should also be adequately decreased. The lowest voltage is required at the idle run. Relative value of the voltage is then of ca 0.3. Voltage reduction brings about a decrease of voltage-dependent energy losses and an increase of efficiency and the power factor, which leads to the power input reduction and consequently to electrical energy savings. The paper presents motor operation conditions that should be met at a sudden voltage change and rules for enhancing energy indices on the basis of algorithms that maintain such parameters as: minimal current, maximal power factor and maximum efficiency at a preset level. Additionally, runs of the basic motor quantities such as: current input, power factor, efficiency, and slip at step-regulated supply voltage have been determined
11
Content available Poślizgowa charakterystyka admitancji stojana silnika indukcyjnego uzyskana przy zastosowaniu symulacji komputerowej
Zielińska M.J., Zieliński W.G.
Maszyny Elektryczne : zeszyty problemowe
|
2006
|
Nr 75
47-51
EN
Slip characteristic of induction motor admittance is the admittance locus at varied slip and constant frequency of feeding voltage. Circle diagram can graphically represent the characteristic only in the case when electromagnetic parameters of a machine are constant. Circle diagram makes an important tool at the evaluation of an asynchronous motor operation. Based on the diagram it is possible to find for an arbitrary slip not only values of electrical parameters but also mechanical parameters such as torque, mechanical power and rotational speed. The paper presents a comparative analysis of classical methods for circle diagram elaboration and of their accuracy. Computer simulation of an admittance slip characteristic has been performed with the Matlab-Simulink software, based on dependences that determine admittance of a motor. The analysis concerns conditions when equivalent network parameters of an asynchronous motor are constant and the characteristic is represented by a circle. When electromagnetic parameters of a motor are not constant then the characteristic essentially differs from a typical circle diagram. It mainly concerns a squirrel-cage motor with closed slots in the rotor, fed with high-frequency voltage. In the mentioned case saturation of the closure occurs under the influence of a leakage flux. It has been shown that a shape of the characteristic depends on many parameters of a motor as well as on the way the leakage reactance changes.
12
Content available Optymalna praca silników indukcyjnych przy zmianach napięcia źródła zasilania
Zielińska M.J., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
2005
|
Nr 72
225-228
EN
Most of induction motors operate at a load that is considerably lower than the rated load. It brings about a change in such energy indicators as power factor and efficiency that decide over electrical energy consumption. Economic efficiency of a drive system operation depends on those indicators and therefore optimum conditions for the motor operation should be created. If the motor load is lower than the rated load, voltage should be reduced or frequency should be changed to such a value that can ensure maximum values of the energy indicators. Possibilities of energy-saving operation of an induction motor with the regulation of voltage and feeding voltage frequency have been considered. Rules for the enhancement of such energy indicators as current input to the motor, power factor, and efficiency have been given. It is advantageous to feed a motor with voltage and feeding-voltage frequency that vary depending on the load degree as then energy consumption gets reduced. At the rated load a motor has to be fed with rated voltage and rated frequency but with decreasing load the voltage should be adequately reduced and the frequency adequately adjusted. Minimal feeding-voltage values are required at the open-circuit operation. Additionally, algorithms of voltage regulation that can ensure maintaining energy indicators at an adequate preset level have been presented. The indicators have been enhanced and electrical energy savings for various algorithms of voltage and frequency adjustment have been calculated.
13
Content available remote Wybrane algorytmy regulacji napięcia zastosowane przy energooszczędnej pracy silników indukcyjnych
Zielińska M.J., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
2004
|
Nr 69
145-148
EN
Economic efficiency of a driving system depends on rated energy indicators of a motor. The article considers energy-saving operation possibilities for an induction motor at feeding voltage control. Factors that can enhance energy indicators, such as current input to the motor, power factor and efficiency, have been given. Motor load can vary within a wide range depending on the kind of its operation. Energy indicators can be enhanced by applying varied voltage depending on the load rate. Therefore, simultaneous change of voltage and load makes the motor operate at higher values of energy indicators, which decide over energy consumption. At rated load a motor has to be fed with rated voltage, while decreasing load should be accompanied by an adequate voltage reduction. Minimal voltage is required at open-circuit operation condition. Voltage reduction brings about a decrease of voltage-dependent energy losses and an increase of power factor and efficiency, which leads to a reduced power input and consequently to saving of electrical energy. The article presents voltage control algorithms, which ensure maintaining energy indicators at an adequate predefined level. The indicators have been enhanced and energy savings have been calculated for various algorithms of voltage control.
14
Content available remote Wpływ zmian nasycenia obwodu magnetycznego na parametry elektromagnetyczne szybkoobrotowego asynchronicznego silnika klatkowego
Zielińska M.J.
Maszyny Elektryczne : zeszyty problemowe
|
2003
|
Nr 66
115-118
EN
High-speed squirrel-cage motors fed with voltage of high frequency exhibit considerable differences as compared to typical squirrel-cage motors fed with the voltage of 50Hz frequency and the differences do not only concern mechanical properties. It is mainly high frequency of the feeding voltage and intensive cooling introduced to reduce the dimensions as well as reduced vibrations and noise that cause the differences. The article attempts to determine electromagnetic properties of high-speed motors. The considerations mainly concern spreading resistance and leakage inductance of a rotor. Analytical determination of the mentioned parameters for the discussed type of motors makes a rather complex task. To simplify calculations and determine correction factors a so called 'substitute slot opening' has been determined. With the mentioned opening known it is possible to calculate resistance increasing at the current displacement and leakage inductance of a cage bar for given frequency of the rotor current.
15
Content available remote Bilans strat w silniku asynchronicznym zasilanym napięciem o dużej częstotliwości
Zielińska M.J.
Maszyny Elektryczne : zeszyty problemowe
|
2003
|
Nr 66
109-113
EN
Squirrel-cage induction motors fed with a high frequency voltage make an indispensable driving element in the industry branches producing bearings, precision elements and devices, and textiles. Their range of frequency variation is very wide - from 400 to 1500 Hz - which follows from technological requirements in the above mentioned industry branches. The discussed motors significantly differ from typical induction motors fed with the voltage of 50Hz frequency not only by their mechanical design but also by their electromagnetic properties. Big value of the applied feeding voltage frequency makes the phenomenon of current displacement in the rotor cage bars conspicuous. The application of closed slots in the rotor brings about high saturation of a magnetic circuit for the rotor leakage flux. The above mentioned phenomena make a justification for undertaking laboratory research to establish an effect of feeding voltage variations on the magnitude of individual losses and to determine what part of the total losses those individual losses make. Three motors representing machines of low, medium and high power have been tested. Typical literature-given distribution of losses has been assumed and losses in the stator iron and winding, the rotor core and winding as well as mechanical losses have been determined. Power balance changes depending on the feeding voltage frequency have been presented. The share of power losses in the stator and rotor windings following from increased current density as well as the effect of frequency changes on the increase of additional losses have shown up to be significant.
16
Content available remote Cechy konstrukcyjne szybkoobrotowych indukcyjnych silników klatkowych
Zielińska M.J., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
2000
|
Nr 61
261-264
PL
W artykule przedstawiono próbę określenia cech konstrukcyjnych indukcyjnych silników szybkoobrotowych w porównaniu z typowymi silnikami zasilanymi napięciem o częstotliwości technicznej. Uwzględniono szczególne systemy zabezpieczeń jak również wpływ warunków eksploatacji na ich pracę. Silniki te pracują w specyficznych warunkach dlatego też ich budowa różni się znacznie od budowy typowych silników klatkowych.
17
Content available remote Wybrane własności indukcyjnych silników klatkowych zasilanych napięciem o dużej częstotliwości
Zielińska M.J., Zieliński W.
Maszyny Elektryczne : zeszyty problemowe
|
1999
|
Nr 59
27-31
PL
Indukcyjne silniki klatkowe zasilane napięciem o częstotliwości 400-1500Hz stosowane są głównie w przemyśle łożyskowym, precyzyjnym, włókienniczym. W artykule przedstawiono próbę określenia własności tego typu silników w porównaniu z typowymi silnikami klatkowymi zasilanymi napięciem o częstotliwości technicznej nie tylko pod względem konstrukcji mechanicznej ale również pod względem własności elektromagnetycznych.
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.