Download praktyczna diagnostyka maszyn indukcyjnych klatkowych

Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
Witold Rams, Jan Rusek
AGH Kraków
PRAKTYCZNA DIAGNOSTYKA MASZYN INDUKCYJNYCH KLATKOWYCH
PRACTICAL DIAGNOSTICS OF SQUIRREL CAGE INDUCTION MACHINES
Abstract: The paper present diagnostic reports produced by diagnosing some machines in the industry. The machines
investigated drive coal mills, air blasters, water-feed pumps and smoke exhausters. Diagnoses of the state of their cages are
accounted for by scheduling reparations of these machines. Assessment of cage states was based on measurements of the
magnitude of the (1±2s)f0 current components, where: s – slip, f0 – frequency of the supply system. The measurements of
these components were performed during stationary operations by current loads. Additionally, the (1-2s)f0 component was
measured during starting up as well. The measurements relied on non-invasive, digital registration of the secondary currents
in the on-site current transformers. All the on-site circuits were left intact, as only the Dietz mini clamps surrounded the leads
with secondary currents. The currents were registered in two phases, though only one signal was used for diagnostics. Two of
the machines were found to show up cage asymmetry characteristic for at least one broken bar. Discrepancy between the
magnitude of the (1-2s)f0 component during starting up and steady state allowed to conclude that in the case of a double-cage
machine the damage must have taken place in the starting cage.
Sławomir Szymaniec
Politechnika Opolska
ASPEKTY METROLOGICZNE DIAGNOSTYKI PR DOWEJ SILNIKÓW
ELEKTRYCZNYCH
THE METROLOGICAL ASPECTS OF CURRENT DIAGNOSTICS
OF THE ELECTRICAL MOTORS
Abstract: This paper describes the metrological aspects of current diagnostics of the electrical motors. The author exchanged
most often met damages of motors, which can be diagnosed with taking into consideration measurement and current analysis.
One turned attention on errors commited during of measurements and analyses of current for needs of diagnostics. One talk
overed met in industry arrangements measuring to current diagnostics of electrical motors with used Rogowski coils,
halleffect transducers and current transformers.
Tadeusz Glinka
BOBRME Komel, Katowice
KLASYFIKACJA STOPNIA ZU YCIA IZOLACJI UZWOJE
MASZYN ELEKTRYCZNYCH
CLASSIFICATION OF ELECTRICAL MACHINES WINDINGS’ INSULATION DEGREE OF
WEAR
Abstract: Classification of electrical machines windings’ insulation degree of wear has been presented on the basis of
twenty electrical machines operating in rolling mill. Four of these are synchronous machines, eight are d.c. generators and
remaining eight are rolling mill driving motors. The insulation diagnostic tests include:
- measurement of insulation resistance (for steady-state conditions) vs. supply voltage R60=f(U),
- measurement of leakage current versus time ip=f(t), after a unit step voltage of rated value was applied ,
- measurement of voltage recovery curve Uod=f(t); this is measured after the system had been earlier charged with rated
voltage, and then short-circuited for tz seconds.
Basing on the measurements the criteria indices of insulation system are developed; these are set out in Table 1. These indices
help to assess the insulation’s degree of wear according to mark system: from 5 (very good insulation) downto 1 (worn
insulation) – Table 2. Figures 2-4 show the characteristic curves: R60=f(U) (Fig.2), Uod=f(t) (Fig.3) and ip=f(t) (Fig.4) for
selected windings, while Table 3 sets out criteria indices for these windings’ insulation.
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
Jarosław Mielczarek
Biuro Projektów i Usług Inwestorskich PRO-MAC
MONITORING STANU IZOLACJI PRZEMYSŁOWYCH
UKŁADÓW NAP DOWYCH
INSULATION MONITORING OF INDUSTRIAL DRIVES
Abstract: This article describes principles of insulation control in electrical networks with drives. Especially phenomenon
caused by frequency converters are taken into account, like DC leakage currents, large earth capacitances, high harmonic
distortions. Methods are described separately for earthed (TN, TT) and for unearthed (IT) systems. Additionally article shows
possibility of continuous insulation condition control of unsupplied motors, to keep them on standby.
Mirosław W siel, PUP Eltur-Serwis Sp. z o. o.
Janusz Wo niak, Politechnika Wrocławska
DIAGNOSTYKA EKSPLOATACYJNA NAP DÓW
ELEKTRYCZNYCH DU YCH MOCY – DIAGNOZOWANIE
ŁO YSK TOCZNYCH
OPERATING DIAGNOSTICS OF HIGH POWER ELECTRIC DRIVES
– DIAGNOSING OF ROLLING BEARINGS
Abstract: In many cases the most unreliable elements of driving systems are rolling bearings. Their insufficient durability
makes them one of the sore points taken into consideration when analysing the reliability of the whole equipment. The
variety of the phenomena accompanying the course of wear and tear of the rolling bears makes it possible to use many
diagnostic methods. The paper presents some examples of a diagnostic study of the state of rolling bearings in electric drives
with the use of the frequency analysis of vibrations. Purposefulness of introducing vibroacoustic diagnostics has been
demonstrated, selected operational states of unfitness of electric drives have been presented. The study carried out on the
basis of frequency analysis of vibrations made it possible to observe the progress of damage over time and to identify the kind
of the damage. Pictures of the damaged rolling elements have been presented. They reflect the purposefulness of the decisions
taken. On the basis of the obtained study results the assessment of currently applied methods of operational diagnostics of
rolling bearings was made.
Tomasz Gawro ski, Krzysztof Skulimowski, ZREW S.A.
Wojciech Urba ski, Politechnika Warszawska
PROFILAKTYCZNE BADANIA SILNIKÓW W DIAGNOSTYCE
PRZEMYSŁOWYCH NAP DÓW ELEKTRYCZNYCH
PREVENTIVE DIAGNOSTIC TESTS OF INDUSTRIAL ELECTRICAL DRIVES
Abstrakt: The article presents, against the background of technical diagnostics development, diagnosing and monitoring
methods for equipment and process engineering lines, reliable and offered at present by the Company Zakłady Remontowe
Energetyki Warszawa S.A. (ZREW). These, usually very responsible and sophisticated, technical systems are driven by
electric motors. Many years of experience justifies the selection of, indicated in the paper, physical quantitative, the
measurement of which allows efficient elaboration of a diagnosis. First of all, an important role of the vibration signal in
examination of this type of objects was singled out. The ZREW uses high class equipment and specialised diagnostic
programming. The above-mentioned means make possible, after a logistic reconnaissance of objects, elaboration of proper for
them, diagnostic, monitoring and supervising procedures, and of methods for measurement signals processing. The article
points out the significance of organisation of computer databases and of ergonomic ways of communication with services
performing measurements and with their principals.
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
An important conclusion is the proof of how important is the firm’s quality system for correct performance of diagnostic tests
and for satisfactory cooperation with the company’s customers. In the ZREW it is organised according to the ISO 9001:2000
norm provisions.
Works, performed by the diagnostic staff of the ZREW, bring as the result, every time, lowering of operating costs of
equipment with simultaneous increase of the equipment’s availability and reliability. They influence directly high economic
effectiveness of the company, which ordered the diagnostic tests.
Antoni Nykli ski, Witold Rams, AGH Kraków
Michał Rams, Uniwersytet Jagiello ski Kraków
SYSTEM POMIAROWY DO DIAGNOSTYKI
MASZYN I URZ DZE ELEKTRYCZNYCH
MEASUREMENT SYSTEM FOR DIAGNOSTIC OF ELECTRICAL
MACHINES AND APPARATUS
Abstract: The paper presents the diagnostic system made for electric machines and apparatus diagnostic in laboratories and
in the industry. The system is portable and easy to transport. One can use them for tests on rotating machines and
transformers after manufacture or after erection on site in accordance with standard specifications. These tests cover
insulation resistance, winding resistance and impedance and some further tests on different types of machines and apparatus
which are required to meet customer’s requirements or to obtain some particular data. For transformers it is possible to
measure the ratio and to check interphase connection. Each measured value has obtained its uncertainty. Calibration of
system can be done for traceability assurance. System can record and to archive results of measuring. Fourier analysis of
recorded processes is also available.
Maciej Bernatt
BOBRME Komel, Katowice
O AWARYJNO CI SILNIKÓW KLATKOWYCH
WYSOKIEGO NAPI CIA
BREAKDOWNS AND FAILURES OF HIGH VOLTAGE
SQUIRREL CAGE AC MOTORS
Abstract. Break-down rate of high voltage AC squirrel cage motors is not very high. But any failure of large AC motor
involves for its user costs and losses uncomparable higher than the simple cost of repair or even replacing of the motor. In the
paper the main reasons of large AC motors failures are discussed, most of them occur, or at least just begin, at starting period
of the motor (when DOL starting method applied). Possible ways of minimizing break-downs number
41 are presented,
importance of proper diagnostic tests underlined. Two break-down examples: 1000 kW, 1500 RPM and 515 kW, 3000 RPM,
6000 V motor are discussed. After failure both motors were redesigned and renewed at their repair process. After redesigning
the motors work satisfactory.
Jakub Bernatt, Maciej Bernatt
BOBRME Komel, Katowice
EKSPERTYZY I OCENY PRZYCZYN USZKODZE SILNIKÓW
ELEKTRYCZNYCH DU EJ MOCY – CZ.2
EXPERT EVIDENCES AND DEFAULT CAUSES OF LARGE AC MOTORS- part 2
Abstract: 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
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
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.
Szymon Liszka
Fundacja na Rzecz Efektywnego Wykorzystania Energii, Katowice
ZAANGA OWANIE RODKÓW GLOBALNEGO FUNDUSZU OCHRONY
RODOWISKA (GEF) W DZIAŁANIA ZMIERZAJ CE DO RACJONALIZACJI
ZU YCIA ENERGII ELEKTRYCZNEJ
W POLSCE POLSKI PROGRAM EFEKTYWNEGO WYKORZYSTANIA ENERGII W
NAP DACH ELEKTRYCZNYCH (PEMP)
POLISH ENERGY EFFICIENT MOTORS PROGRAM - PEMP.
GLOBAL ENVIRONMENTAL FUND FINANCING ENERGY EFFICIENCY
IN ELECTRIC MOTOR SYSTEMS IN POLAND
Abstract: After six year of preparation phase Polish Energy Efficient Motors Program - PEMP was approved and signed by
Global Environment Facility (GEF). In the article the way the project was developed and final shape of the implementation
phase of the project is described. Description focuses on the PEMP Center which is responsible for the capacity building and
awareness activity, such as:
- establish a sustainable institutional mechanism for the provision of information and services for the energy efficient electric
motors market;
- gather and provide information on the energy efficient motors market in Poland, thereby establishing a market baseline and
providing a resource on market activities and a source of information for benchmarking;
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- document and compile information on the benefits of energy efficient motors;
- provide technical and business advisory services for pilot projects and business project development;
- train project developers, industry, and financial institutions on energy audits, feasibility studies, funding applications, etc.
Stefan Gierlotka
KWK Wujek, Katowice
ZAGRO ENIA PORA ENIA PR DEM POWODOWANE MASZYNAMI
ELEKTRYCZNYMI WYŁ CZANYMI Z RUCHU
DANGER OF ELECTRICAL SHOCK CAUSED BY SWITCHING OFF ELECTRICAL
MACHINES
Abstract: The paper describes danger of electrical shock caused by rotating electrical motors after switching them off. When
the motor rotates after cutting off the supply voltage the dangerous voltage (U > 50 V) remains in the motor and in the cable.
The measured voltages after switching off motors of output 36 ÷ 400 kW indicate that the time with electrical shock danger
is 1,2 ÷ 5,3 seconds.
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
Jerzy Szyma ski
Politechnika Radomska
OCHRONA PRZECIWPORA ENIOWA INSTALACJI NAP DOWYCH Z
NAPI CIOWYMI PRZEMIENNIKAMI CZ STOTLIWO CI ZASILANYMI Z
SIECI TN-S DO 1 kV
ELECTRIC SHOCK SAFETY IN INDUSTRIAL MOTOR DRIVE INSTALLATION WITH
VOLTAGE FREQUENCY CONVERTER SUPPLIED FROM TN-S POWER SYSTEM UP TO
1 kV
Abstract: Voltage frequency converter for driving systems is complicated power electronic device, in aspect of assurance
proper protections against electric shock. Increases it large difficulties at designing and building of it power supply system.
In this paper author passed analysis of supply power system with drive VFC in rules of electric shock protection, according
to norm IEC 60364. One proposed realization of additional shock protection in typical installation, is only by use quick
disconnection of VFC from power supply by fuses and proper drive equipments connection to the earth. Proper appointment
of impedance loop of short-circuit on VFC power supply connectors has basic meaning for selection value of input quick
fuses. Using connections to earth of VFC protective connector PE with little impedance for high frequency waves, indeed
limits disturbances about radio frequencies emitted to environment. In normal work of these drive systems accrues high
frequencies currents which dependents from VFC configuration and conditions of installation work. These currents make
impossible usage high sensitive RCD switches. In supplement safety protection only, as protection against fire, author
allows usage of RCD switches type A with earth currents from 100 - 500mA. This paper can have controversial discuss
because positions different specialists are here strongly not uniform.
Mieczysław Zielichowski, Tomasz Szlezak
Politechnika Wrocławska
BEZPIECZE STWO EKSPLOATACJI GENERATORÓW ZE WZGL DU NA
ZAGRO ENIA ZIEMNOZWARCIOWE
GENERATORS EXPLOITATION SAFETY IN RESPECT OF GROUND-FAULT HAZARDS
Abstract: Optimization of operating conditions of ground-fault protection systems for unit-connected generators may be
achieved solely after estimation of effects of ground-faults in generator stator winding, with simultaneous consideration both
stator core and insulation damages, and ground-fault overvoltages. In this paper estimation of ground-faults effects in
generators with neutral isolated and grounded through resistor was presented. Both ground-fault damages and ground-fault
overvoltages were considered. The analysis was performed for 200MW unit-connected generator running in domestic power
system.
Tadeusz Glinka, Mieczysław Jakubiec, Wojciech Poprawski
BOBRME Komel, Katowice
ENERGOOSZCZ DNO
NAP DÓW O REGULOWANEJ PR DKO CI
OBROTOWEJ
ENERGY-SAVING VARIABLE SPEED DRIVES
Abstract: Energy-saving electrical drive (Fig.1) is the type of drive working at its minimum required rotational speed (1).
The algorithm of energy-saving drive operation can be applied to (Fig.2):
- d.c. motor with electromagnetic excitation,
- d.c. motor with permanent magnet excitation (Fig.4),
- cage induction motor,
- brushless motor with electronic commutator.
The paper gives the comparison of these four motor types.
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
The comparison criterion is the motor’s volume, i.e. all the motors have identical outer dimensions as shown in Fig.3. If it is
assumed that during steady-state operation the active power loss in all motors is kept constant ∆P 4900 W, then each
motor’s ratings (power and efficiency) are different (Table 1). The brushless motor is characterized by highest rated power
(77 kW) and efficiency (94%). If rated power of brushless motor is decreased down to 53 kW, i.e. to the induction motor
rated power value, then power loss in brushless motor drops down to 2300 W, and the efficiency rises to 95,8%.
Zbigniew Szulc, Jerzy Przybylski
Politechnika Warszawska
TECHNICZNE I EKONOMICZNE ASPEKTY ZASTOSOWANIA
SOFT-STARTU DO SILNIKA INDUKCYJNEGO KLATKOWEGO
O MOCY 3,7 MW I NAPI CIU 6 kV
TECHNICAL AND ECONOMICAL ASPECTS OF THE APPLICATION
OF THE SOFT-START FOR INDUCTION MOTOR 3,7 MW/6 kV
Abstract: This paper presents technical and economical effects after applying a soft-start to the 3,7 MW, 6kV squirrel-cage
motor driving paper refiner. The soft-start is voltage controller based on phase controlled SCR. Simulation and practical
results after a nine-month exploitation confirmed that proposed solution achieved preliminary requirements like: current limit
and decrease of pulsating torque during the first few seconds of starting the motor. These requirements allowed to increase
motor lifetime and to eliminate the necessity of reconfiguration power grid before starting the motor. Additional economical
effect is a possibility of saving energy due to decreasing the idle run time of the drive.
Bronisław Firago, Białoruska Pa stwowa Akademia Techniczna w Mi sku
Leszek Pawlaczyk, Politechnika Wrocławska
DOPUSZCZALNY MOMENT SILNIKA INDUKCYJNEGO
W PRZYPADKU STEROWANIA CZ STOTLIWO CIOWEGO
THE CONTINUOS USABLE TROUGE OF A FREQUENCY – CONTROLLED INDUCTION
MOTOR WITH THE SELF - VENTILATION
Abstract: The article deals with the determination of the continuous usable torque for a frequency - controlled induction
motor with the self – ventilation and stabilization of the magnetic flux linkage. The developed technique takes into account
the heating power losses and the ambient temperature. On the basis of this technique takes into account the continuous steady
state electromagnetic torque can be calculated for a given frequency of the induction motor including a standstill condition.
The results of calculations for three induction motors of 3, 55 and 160 kW are presented in curves: torque versus frequency.
Stanisław Azarewicz, Adam Zalas
Politechnika Wrocławska
CZ STOTLIWO CIOWE STEROWANIE NAP DÓW PO REDNICH
PRZENO NIKÓW TA MOWYCH
FREQUENCY STEERING OF INDIRECT DRIVE FOR BELT CONVEYORS
Abstract: Indirect drive in long belt conveyors can lessen the stresses in the belt and in the load bearing structure of the
conveyor because of the distribution of the belt′s pulling force into several components of force. The indirect drives without
pouring point are interesting solutions both from the technical, and the economical points of view. Most frequently used
solution is an auxiliary conveyor which drives the runners of the main conveyor. The problem in manufacturing this sort of
drives is both the variability of thermal compression between the belt and runners in belt load function, and the necessity to
adjust the driving velocity of the auxiliary drive′s motor to the current parameters of the main belt′s load. All these
requirements cause the driving motors of the auxiliary drive to be powered from the frequency converter Typical methods of
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
frequency changer control do not always provide satisfactory results in the difficult working conditions of the auxiliary
drives, the use of positioning system of induction motors was suggested. Conducted laboratory tests of the drives showed the
advisability of usage of machine tool motor for the realization of indirect drive for belt conveyors.
Jadwiga Płoszy ska
Politechnika Rzeszowska
DYSKUSJA NIEPO DANYCH ZJAWISK
WYST PUJ CYCH W SILNIKACH INDUKCYJNYCH
DISCUSSION ON UNDESIRABLE PHENOMENA OCCURED
IN INDUCTION MOTORS
Abstract: During operation of squirrel-cage motors, undesirable phenomena can be observed. They influence on the life of
motors and have an unfavourable influence on the environment. Duration, place and intensity of occurrence of these
phenomena are diverse. Complete elimination of reasons of the side-effects is not possible. The aim of detailed recognition of
undesirable phenomena in induction motors is an explanation of reason of their formation and to show the actions leading to
their minimization.
Trial of systematization of undesirable phenomena occurring in induction motors was undertaken in the article. During
systematization, place of occurrence and reasons of phenomena were taken into account. The results demonstrated during
steady state and starting of motor were shown. Taking into account the place of occurrence, the zone of gap of magnetic
circuit, the part of squirrel-cage winding outside the sheet pack, sheet pack of rotor core and bearings should be considered.
The effect of flow of large starting current is emission of considerable amount of energy in the squirrel cage winding of the
rotor. This energy causes thermal effects. During steady operation, the undesirable effects in the form of decreased efficiency,
increased noises and vibrations, deformed mechanical characteristic, flow of crosswise currents in the pack of rotor, may be
expected in the process of conversion of electric energy.
Tomasz Zawilak, Ludwik Antal, Jan Zawilak
Politechnika Wrocławska
ROZRUCH SILNIKÓW INDUKCYJNYCH
Z ROZDZIELONYMI UZWOJENIAMI STOJANA
START UP OF INDUCTION MOTOR
WITH TWO SEPARATED STATOR WINDINGS
Abstract: This paper presents a method of attenuating start up processes of high power AC motors. In this method two
separated thee-phase windings are used. During start up one of the winding is supplied from the network and the second one
is connected to capacitor bank. Reactive component of the starting current is partially compensated by secondary winding
current that is caused by transformation voltage. A mathematical model of this motor is presented. There were made
calculations of transient characteristics which are compared to measured transients of manufacturing model.
Ludwik Antal, Jan Zawilak
Politechnika Wrocławska
WYNIKI BADA DWUBIEGOWEGO
SILNIKA SYNCHRONICZNEGO
TWO SPEED SYNCHRONOUS MOTOR TESTING RESULTS
Abstract: The work presented testing results of a 600/1050kW, two-speed synchronous motor, with two synchronous speeds
500 and 600 rev/min. destined to drive a main mine ventilating fan. The excitation winding of the tested motor may be
connected using 8 or 10 poles. Theoretical evaluation as well as tests results conclude that a complete disconnecting of two
poles has a positive influence on motor’s work at lower speed and negative on work at higher speed. The conducted tests
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
permitted an assessment of motor work quality at each of the two speeds. During tests, voltage, armature and excitation
currents course as well as direct start-up, steady asynchronous speed, synchronization and motor loading were recorded for
both rotating speeds. Armature current recording and harmonic analysis of these courses showed the degree of current
deformation caused by asymmetry of the excitation circuits, which is the condition to obtain the second, lower rotating speed.
An asynchronous run with small slip, permitted to establish motor’s synchronous reactance in both its axis. Two-step starting
of a two-pole motor is characterized by lower than a single pole motor starting current. Vibration measurements had shown
that the vibration level is higher than in a single pole motor. Thermo-visual temperature measurements demonstrate that the
maximal temperature appears on some bolts of the stator core and is higher at lower speed operation. The increased values of
vibration and temperatures of the tested two-pole motor do not exceed the permitted values.
Tadeusz Glinka, Mieczysław Jakubiec, Robert Rossa
BOBRME Komel, Katowice
SILNIKI SYNCHRONICZNE O ROZRUCHU ASYNCHRONICZNYM
LINE START SYNCHRONOUS MOTORS
Abstract: In this paper a new concept of line start synchronous reluctance motor (LSRM) and line start synchronous
reluctance motor co-excited by permanent magnets (LSRMPM) is shown. The paper describes construction and shows
parameters of LSRM and LSRMPM also comparing them with parameters of induction motors (IM). The main advantage of
these motors is asynchronous start-up and synchronous operation. While the LSRM have got lower output than IM of the
same cubature, the LSRMPM have the output equal to IM. It allows to use the LSRM and LSRMPM in all drives requiring
the constant speed (not depending of the load) or in group drives where all motors must work together synchronously. Since
the excellent working parameters the LSRM and LSRMPM are subject of number of patents (pending).
Tadeusz Glinka, Artur Polak
BOBRME Komel, Katowice
MAGNESOWANIE MAGNESÓW TRWAŁYCH
- MO LIWO CI LABORATORIUM BOBRME KOMEL
MAGNETISING OF PERMANENT MAGNETS IN LABORATORY OF KOMEL CENTRE
Abstract: Magnetising of NdFeB permanent magnets is performed in electromagnetic circuit shown in Fig.1. Charged
condenser battery acts as a source of pulse magnetizing current – Fig.2. Exciter’s current, which flows after the charged
condenser’s battery is switched on reaches its maximum value, along hyperbolic sine (Fig.4a) or cosine curve (Fig.4b).
Current change is aperiodical, with exciter’s electromagnetic time constant. Laboratory of Komel Centre uses condenser
battery of maximum energy equal to 9600 J. The battery consists of four sections (Fig.5), which can be connected: in parallel
(120 mF, 400 V), in mixed connection (30 mF, 800V) or in serial connection (7,5 mF, 1600 V).
Jakub Bernatt
BOBRME Komel, Katowice
WYKORZYSTANIE PR DNIC SYNCHRONICZNYCH DO BUDOWY
MAŁYCH ELEKTROWNI WIATROWYCH
SYNCHRONOUS ALTERNATOR USED IN CONSTRUCTION
OF SMALL WIND-MILLS
Abstract: The paper describes small a wind-mill built by a farmer. The synchronous alternator with permanent magnets
manufactured by Komel was implemented in this wind-mill. Electricity produced by the wind-mill is consumed for heating
purposes (water and house). It is stated that use of synchronous alternators in small wind-mills is necessary for satisfactory
performance of the wind power station. The alternator used in the described wind-mill is characterised by low rotating speed
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to reduce power loses in gear box. Synchronous alternator with PM is self excited and can supply separated grid. It can be
overloaded even by 50% without any damage.
Author’s intention was to show that construction of the wind-mill for self use of electricity is easy and not expensive, but
special attention to rotor of the wind-mill and to alternator should be paid.
Ryszard Dziworski
Lubelska Wytwórnia D wigów Osobowych Lift Service S.A.
METODYKA POMIARÓW I OCENA ENERGOCHŁONNO CI
ELEKTRYCZNYCH NAP DÓW D WIGÓW OSOBOWYCH
METHODS OF MEASUREMENTS OF THE ENERGY CONSUMPTION
IN ELECTRICAL DRIVE SYSTEMS IN LIFTS
Abstract: In above report there were presented methods of measurements the energy consumption and the intensivity of
exploatation the different drive systems in electrical lifts as well as the preeliminary summary of the measuring results done
on four lifts.
Here are presented the most important calculated faktors received as the result made measurments by using specjally created
to this purpose measurement devices.
Ryszard Rut
Politechnika Rzeszowska
SKUTECZNO
OBNI ENIA HAŁASU
W SILNIKACH WYSOKIEGO NAPI CIA REDNIEJ I DU EJ MOCY
EFFICIENCY OF NOISE REDUCTION IN MIDDLE AND HIGH OUTPUT
HIGH VOLTAGE AC MOTORS
Abstract:. Large part of high power electric motors used in polish industry are at least 20-30 years old products. The motors
were designed in 60-ties or 70-ties of the last century. Noise level of industry machinery was regarded as of minor importance
in those days. Replacing a high voltage, high power motor just because of its noise level is not always economically justyfied.
In the paper methods of diminishing of the noise level of high voltage induction motors are given, several examples are
presented, as well.
Roman Krok, Politechnika l skia
Janusz Wróblewski, D browska Fabryka Maszyn Elektrycznych „DAMEL” S.A.
BADANIA WPŁYWU ZMIAN WARUNKÓW CHŁODZENIA
NA STAN CIEPLNY SILNIKÓW INDUKCYJNYCH
PRACUJ CYCH W PODZIEMIACH KOPAL
INVESTIGATIONS OF THE INFLUENCE OF COOLING CONDITIONS
CHANGES ON THERMAL STATE OF INDUKTION MOTORS WORKING
IN COAL-MINE UNDERGROUND
Abstract: The paper presents a model for calculating temperature fields in water-cooled induction motors. The model was
worked out basing on the method of thermal-electrical networks. It was the basis for developing the computer program for
thermal investigations of mine motors. In order to determine the accuracy of representing the thermal state of a motor by
means of the worked out model there were made thermal measurements of the motor. Thermal investigations of mine motors
of 400 kW working in coal-mine underground were performed by means of the computer program. The influence of changes
of load as well as parameters characterizing operating conditions (for instance: the ambient temperature, the temperature
of water at the inlet to the frame) on the thermal state of the motor was determined basing on the obtained results of the
simulation investigations.
Zeszyty Problemowe – Maszyny Elektryczne Nr 68/2004
Jurij Czuczman, Denys
aksimovicz
Uniwersitet Narodowy „Politechnika Lwowska”
MODERNIZACJA UZWOJE WSYPYWANYCH SILNIKÓW
ASYNCHRONICZNYCH PODCZAS REMONTÓW
THE ANALYSIS OF THE USE AND MODERNIZATION OF INDUCTION MOTORS WITH
FILLING WINDINGS DURING THE REPAIR
Abstract: This article deals with the interrelationship of performance characteristics of the induction motors with the fillings
windings that are dependent on the type of windings which are used during the repair. In order to decrease the laborintensiveness of the technological process one could make wider use of a lathe for the mechanized working of this kind of
motors. At the same time it could cause an increase in the losses in the magnetic wires, the size of power loss, the decreasing
of its reliability, and the term of its operation. This type of motor could be mainly repaired by service station whose
technological equipment is different from the equipment of big businesses. A solution for all of these problems could be a
process of modernization of the stators’ windings during the repair. This modernization includes the replacement of singlelayer or single-double-layer concentric windings in favor of single-layer equipment windings or double-layer windings. There
are examples of the realization of the different types of windings that could provide the minimization of copper use without
increasing the labor-intensiveness of the procedure. At the same time it provides the decrease of power lose in the motors
with invariably power factor.
Henryk Borecki
ENERGOKONSULTING Lubliniec
ROZWÓJ LOKALNYCH WYŁADOWA ELEKTRYCZNYCH
W IZOLACJI MI DZYZWOJOWEJ STOJANA
HYDROGENERATORA
DEVELOPMENT OF LOCAL ELECTRICAL DISCHARGES
IN HYDROGENERATOR TURN-TO-TURN STATOR INSULATION
Abstract: Voltage distribution in gaseous solid or liquid inclusions is determined by local capacities. Author made studies
and tests of turn-to-turn insulation of a stator coil of hydrogenerator, using DC test method. Results are presented in the
paper.