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PL
Układy napędowe o podwyższonej częstotliwości to grupa urządzeń, która w ostatnich latach najmocniej zaznaczyła swoją obecność na rynku Oil & Gas. Podwyższona częstotliwość napięcia wyjściowego przekształtnika umożliwia regulację prędkości obrotowych w szerszym zakresie. Zwiększa to wydajność i uniwersalność całego napędu, ale jednocześnie powoduje dodatkowe zagrożenia dla izolacji kabli zasilających, transformatora podwyższającego jak i samego silnika. Niezbędnym elementem takiego układu staje się filtr sinusoidalny, który zapewnia ochronę i niezawodność całego napędu. W artykule przedstawiono analizę doboru elementów składowych filtru sinusoidalnego LC i ich parametrów względem podwyższonej częstotliwości pracy i częstotliwości przełączeń. Przedstawiono wyniki badań wpływu tych parametrów na pracę filtru oraz na przebieg napięcia wyjściowego i współczynnik odkształcenia THDu.
EN
Drive systems with increased frequency are a group of devices that has made a significant presence in the Oil & Gas industry in recent years. Increased frequency of the converter output voltage allows speed changes in a wider range. This increases the efficiency and versatility of the entire drive, but at the same time causes additional stresses for the insulation of the power cables, the step-up transformer and the motor itself. Therefore, an indispensable element of such a system is a sinusoidal filter, which ensures protection and reliability of the entire drive. The article presents an analysis of the selection of components of a sinusoidal LC filter and its parameters in a relation to the increased operating frequency and switching frequency. The results of the research on the influence of these parameters on the filter operation, output voltage and the THDu coefficient have been presented.
PL
W artykule przedstawiono metodę bezczujnikowego sterowania wysokoobrotowego silnika PM BLDC bazującą na napięciach międzyprzewodowych silnika. Ponadto w artykule porównano niniejszą metodę z innymi bezczujnikowym metodami sterowania pod kątem możliwości implementacji w silniku wysokoobrotowym. W szczególności zwrócono również uwagę na możliwość implementacji w zależności od kąta komutacji.
EN
The paper presents a sensorless control method based on phase-to-phase voltages of a high-speed PM BLDC motor. In addition, the paper compares this method with other sensorless control methods considering the possibilities of implementation in a high-speed motor. In particular, also highlighted the possibility of implementation depending on the commutation angle.
3
Content available remote Bezczujnikowe sterowanie wysokoobrotowego silnika PM BLDC
PL
W artykule rozpatrzono możliwości sterowania bezczujnikowego wysokoobrotowego silnika PM BLDC o maksymalnej prędkości obrotowej 100000obr/min i mocy 1 kW zaprojektowanego w Katedrze Energoelektroniki, Napędu Elektrycznego i Robotyki – KENER Politechniki Śląskiej. W artykule opisano metody oparte na całkowaniu napięć fazowych oraz trzeciej harmonicznej, ponadto przedstawiono metodę rozruchu w otwartej pętli oraz sposoby określania położenia zatrzymanego wirnika. Opisane metody sterowania bezczujnikowego przebadano komputerowo, celem sprawdzenia możliwości ich implementacji w projekcie silnika wysokoobrotowego.
EN
In the paper were examined the possibilities to control a high-speed sensorless PM BLDC motor, with a maximalspeed 100 000 rpm and power 1 kW, designed in the Department of Power Electronics, Electrical Drives and Robotics - KENER, Silesian University of Technology. The article describes methods based on phase voltages integration and the third harmonic, also presents a method of open-loop starting and ways of determining the position of the stopped rotor. Described sensorless control methods were examined by computer simulation, in order to test the possibilities of their implementation in the high-speed motor project.
EN
High-speed motors are mainly used in the bearing, precision engineering and textile industries. In Poland, only one-off motors of this kind are produced. The developing high-speed technologies encourage work towards implementation of the production of high-speed motors for a suitable range of power, rotational speed and rotational speed regulation. Most of the operations performed during the production of rolling bearings are grinding operations. For this operation to be carried out in a precise manner, it is necessary to provide a grinding wheel with a peripheral speed of several dozen meters per second, which corresponds to 12 to several hundred thousand revolutions per minute. The basic components of grinders are high-speed asynchronous squirrel-cage motors, which have different characteristic properties than classic motors supplied with power-line frequency. Also laboratory testing of those motors is done in a different way. They are supplied from motor or thyristor frequency converters with a voltage of 200 ÷ 2000kH . The problem of loading a high-speed motor under laboratory conditions follows from the difficulty of mechanically coupling it to the test bench. In this article, an attempt was made to choose a simple, classical motor loading method for high-speed motors using known types of mechanical, electromagnetic and electrodynamic brakes.
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.
EN
In designing the high-speed low-power induction motors should be pursued to obtain operating characteristics similar to characteristics of general purpose motors and the greatest efficiency at rated load. One way to increase the efficiency of induction motors, particularly those working at higher frequencies, is applied to the motor core electrical sheets with improved magnetic properties and less core losses, including amorphous iron. The paper presents a comparison of measured operating characteristics of several low-power induction motors, a core made from three types of electrical steel, working with supply from the inverter voltage with a frequency varying in a wide range (from 0 to 200 Hz), and grid-supplied frequency 50 Hz and 100 Hz. In the case of grid-supplied motors paper presents the results of calculations made using the available methods from the literature, with particular emphasis on determining the additional losses in both the no-load and at rated load. The calculations used, experimentally determined for the tested motors, the mechanical loss characteristics, and also measured the magnetization characteristics for electrical sheets and sheet specific losses as a function of magnetic flux density for a wide range of frequencies.
EN
In the paper the authors compare properties of high-speed brushless DC motor with slots and slotless stator. The authors take in consideration open-slots, half-open slots, closed slots and slotless construction of stator. Depending on type of slots motor have different parameters like electromotive force EMF, ripple and cogging torque. As a result of analyse the authors show waveforms of electromotive force EMF end distribution of induction diagram. Maxwell software is used for simulation.
PL
Przedstawiono wyniki prac związanych z projektowaniem i budową wysokoobrotowego silnika bezszczotkowego prądu stałego PM BLDC.
EN
The paper presents results of works connected with design and cotistruction of high-speed brushless DC (PM BLDC) motor.
9
Content available remote Wysokoobrotowy silnik PM BLDC
PL
W artykule przedstawiono prototypowy wysokoobrotowy bezszczotkowy silnik prądu stałego PM BLDC. Podano jego zasadę działania i sterowania oraz przedstawiono koncepcję rozwiązania. Omówiono niekorzystne zjawiska występujące przy projektowaniu oraz sposoby ich ograniczenia. W ostatniej części artykułu zamieszczono wybrane wyniki badań symulacyjnych i laboratoryjnych.
EN
The prototype of high-speed permanent brushless DC motor is presented in the paper. The principle of operation, control method and construction of high-speed motor are described. Disadvantageous phenomena appearing in high-speed PM BLDC motor and their methods of limitation during design process are considered. Selected cases of computer analyses and results of laboratory tests are presented in final part of paper.
EN
In the paper, circuit and field-circuit analyses of the stator no-load current and core losses in the high-speed induction motors with stator core made from different magnetic materials are presented. The circuit analysis is possible only for the first harmonic of the supply voltage. For the real shape of the voltage which has many higher harmonics accurate field - circuit analysis is necessary. The circuit and field-circuit analyses were done for 2-D structure of the motor. The results of calculation of the stator core loss are compared with the measurement.
PL
W artykule przedstawiono analizę obwodową oraz obwodowo-polową prądu jałowego oraz strat mocy w rdzeniu dla wysokoobrotowych silników indukcyjnych o rdzeniu stojana wykonanym z różnych materiałów. Analiza obwodowa była wykonywana dla pierwszej harmonicznej napięcia zasilającego natomiast metoda polowo-obwodowa pozwoliła na analizę pracy silnika przy rzeczywistym kształcie napięcia.
EN
Nowadays the high-speed induction motors are widely used in many industrial installations and also in aircraft industry. Many of them are designed as converter-fed induction machines. Some electrical drives with not so sophisticated speed control have voltage shape with many higher harmonics. The main aim of the paper will be analysis of the no-load current and magnitude of magnetic flux density for some small power induction motors feed with voltage of frequency from 50 to 250 Hz with different U-f ratio. For this problem circuit and field-circuit methods will be use and the results will be validating basing on experimental results.
PL
W artykule przedstawiono analizę obwodową oraz obwodowo-polową prądu jałowego oraz indukcji magnetycznej w rdzeniu silnika indukcyjnego małej mocy zasilanego napięciem o częstotliwości od 50 do 250 Hz, przy różnym stosunku U/f. Wyniki obliczeń wykonanych z wykorzystaniem modelu obwodowego oraz obwodowo - polowego porównano z wynikami pomiarów.
12
Content available Wysokoobrotowy silnik wzbudzany magnesami trwałymi
EN
The prototype of high-speed permanent brushless DC motor is presented in the paper. The principle of operation, control method and construction of high-speed motor are described. Disadvantageous phenomena appearing in high-speed PM BLDC motor and their methods of limitation during design process are considered. Selected cases of computer analyses and results of laboratory tests are presented in final part of paper.
13
EN
Mechanical resonance problem which occur in high-speed permanent magnet brushless DC motor is presented in the paper. The authors describe a vibration which appears in motor drive and show calculation procedure of transverse vibration as a significant part of proper vibration. Laboratory test with prototype high-speed brushless DC motor is presented in the last part of the paper. Waveforms of stator vibration and lines currents are shown as results of conducted experiment with prototype high-speed brushless DC motor. Laboratory test confirms theoretical analyses.
EN
The paper presents analysis of simulation results of a high speed brushless motor for different kinds of the motor magnetic circuit. There are considered four constructions of the stator core: with open slots, half-open slots, closed slots and a slotless core. The design criteria are: the waveforms of phase voltages, amplitude and frequency of cogging torques, the winding inductance values and the frequency of magnetizing the core. A prototype of the motor with amorphous core and half-open slots was designed and realised. The investigation results of the motor are given in a form of the waveforms.
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.
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.
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.
EN
In the introductory part of the paper a application review and achievements outline of high speed motors from the beginning of applying, i.e. from 40 years of XX century are presented. Then the attention was directed on issues concerning structure of high speed motors and additional phenomena connected with supplying from high frequency voltage source, i.e. mechanical stresses; skin effect; power losses and their increasing caused by non-sinusoidal shape of supplying voltage. The extends and supplements of calculation algorithm and computation program concerned: mechanical power losses calculations (friction and windage losses), calculations of winding resistances and reactances by increased frequency and air gap thickness are presented. Moreover are presented the general technological requirements connected with start of motors production in examined rated power and rotation speed range. The software presented in the paper enabled high speed motors calculations of rated power up to 100 kW. As an example the calculations are performed for five two-pole motors of synchronous rotating speed 18 000 rpm, i.e. of supply voltage frequency 300 Hz.
PL
Głównym celem prowadzonych prac było opracowanie wysokoobrotowego silnika o wzbudzeniu magnesami trwałymi, przeznaczonego do napędu turbiny gazowej z zastosowaniem proszkowych materiałów magnetycznych, zarówno magnetycznie miękkich, jak i magnetycznie twardych. Zastosowanie tego typu materiałów spowodowało konieczność opracowania nowych metod projektowania jak i technologii wytwarzania tego typu silników elektrycznych.
EN
New powder magnetic materials allow changing of design and technology of manufacturing of electric machines. Such changes simplify technology and make production process less time consuming, reducing the production costs. Combination of advantages of powder magnetic materials together with modern computational methods creates new opportunity for designers and makes possible working out modern and effective electric machines. The main goal of presented research is working out the high speed motor excited with permanent magnets designed as drive of the gas turbine joining application of both soft and hard powder magnetic materials in one electric machine.
PL
W artykule poruszono zagadnienie opłacalności i perspektyw stosowania regulacji zmiennymi obrotami w dmuchawach przepływowych stosowanych do drobnopęcherzykowego napowietrzania ścieków. Omówiono aspekty techniczne i ekonomiczne napędu silnikami wysokoobrotowymi, wskazano na wysoką efektywność sprzężenia regulacji dyfuzorem nastawnym i regulacji zmiennymi obrotami.
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