MXPA00005156A - Traction motor and drive system - Google Patents

Abstract

A three-phase traction motor, or a transformer or rotating convertor in a drive system for a traction motor, comprises a winding including insulation consisting of at least two semiconducting layers (32, 34) each providing a substantially equipotential surface, and solid insulation (33) between the semiconducting layers.

Description

MOTOR HANDLING AND TRACTION SYSTEM Field of Invention The present invention relates to a system for driving and traction of a motor, for example for railway locomotives and motor cars, in which the traction motor and / or other electrical machines included in the system is provided with a magnetic circuit comprising a magnetic core and at least one winding.

Background of the Invention The magnetic circuit in electrical machines usually comprises a laminated core, for example of a steel sheet around and determined with a welded construction. To provide ventilation and cooling, the core is often divided into piles with radial and / or axial ventilation ducts. For larger machines the laminations are perforated in segments that are attached to the structure of the machine, the laminated core being joined together by pressure fingers and pressure rings. The winding of Ref: 120087 magnetic circuit is placed in openings in the core, the openings generally having a cross section in the form of a rectangle or t rapecio.

In electric multi-phase machines the windings are processed either as single or double layer windings. With single layer windings, this is only one spiral side per opening, while with the double winding layer these are two spiral sides per opening. On the spiral side means one or more combined conductors see 11 cation e hori zonta lmente and provided with a common spiral insulation, that is, an insulation designed to withstand the voltage range of the machine to ground.

The double layer windings are generally made as diamond windings whereas the single layer windings in the present context can be made as diamond or uniform windings. Only one wide spiral (possibly two) exist in diamond windings while the uniform windings are made as concentric windings, that is, with a spiral width that varies widely. By spiral width means the distance in the dimension of the arc between the two sides of the spiral belonging to the same spiral.

Normally all large machines are made with double-layer windings and spirals of the same size. Each spiral is placed with one side in one layer and the other side in the other layer. This means that all the spirals cross each other at the end of the spiral. If these are more than two layers, they cross the wound work complicatedly and the end of the spiral is less satisfactory.

Before the industrial use of frequency (50 or 60 Hz) for traction motors was possible, the first alternative voltage systems were electrified with a ba-frequency voltage (15 to 61A3 or 25 Hz). The traction motor used for a long time in such systems was a simple phase series switch motor, also known as a single phase traction motor. These functions were almost equal to those of the current motor, except that both the field and the current rotor recede every half period since these are supplied with an alternative current. In order for the communication to take place without damaging the electric arc formation in the commutator, low frequency and motors with low speed are chosen.

The main advantage with alternative systems opposed to direct current systems is that the alternative voltage can be transformed (although the voltage can now be transformed with the so-called pushbuttons). In this way it is possible to maintain a relatively high voltage in the overhead conductor in relation to the voltage with which the motor operates. Due to the high voltage in the aerial conductor, the current becomes low, thus giving better power of transmission ability and reducing losses in the transmission line. The supply stations can be located far away (30-120 km).

The most commonly used traction motor is now the three-phase asynchronous motor due to its simplicity and which is not robust. This is powered by a three-phase current with a variable voltage and frequency that is produced by the power semiconductor circuit of the voltage line (DC system) or the secondary voltage transformer (AC system).

Machines of the aforementioned type, with conventional stator winding, are not connected to a high voltage transmission line at for example 15 kV without the use of a transformer to reduce the voltage. The use of a motor of this type, connected to the transmission line by means of a transformer, causes a number of disadvantages as compared if the motor can be connected directly to the high voltage transmission line. The following disadvantages can be noted, among others: the transformer is expensive, it increases the cost of transport and it requires space the transformer reduces the efficiency of the transformer consumes reactive power a conventional transformer contains oil, with the associated risks.

Description of the invention.

The object of the present invention is to provide an engine and a handling system thereof for the operation of electric trains and the like, which solves some of the problems inherent in the systems known in this area.

The present invention provides an engine according to claim 1 and a handling system according to claim 6 or claim 7.

The invention is based in this way on a special technique for the construction of electric machines, motors, generators, transformers, etc., in which the electrical windings are produced with a different isolation from oil, and preferably dry, in a special way. This allows both the elimination of the transformer and / or the construction of transformers without the disadvantages inherent in the conventional ones mentioned above.

The invention can naturally include such special machines combined with conventional machines.

In this way a machine of the type of which the invention relates can be a transformer or a traction motor that does not need any transformer at that time. The alternatives can of course be combined.

The operating system and the components according to the invention can be adapted to the power supply system of several train systems and, with applicable modifications, are intended for train systems with external power supply or with their own power supply system, for trains with different voltage levels and different frequencies and for both alternative and direct current systems, as well as for the operation of both synchronous and asynchronous motors.

In the case when a transformer is very necessary, it is an object of the present invention that the transformer be made using a cable of the same type and correspondingly as for the other electric machines included in the handling system.

The advantage achieved by satisfying the above objects is to avoid the reaction of a transformer filled with oil, intermediate, which otherwise consumes reactive power.

To do this, the magnetic circuit and its conductors in at least one of the electric machines included in the vehicle are produced with cable permanently insulated from the track, the exterior of which is connected to a power selected as earth.

The major and essential difference between the known technology and the embodiment according to the invention is that the latter includes at least one machine which, due to the nature of its magnetic circuit can be connected directly by means of switches and isolators for a high voltage supplied, up to between 10 and 800 kV. The magnetic circuit thus comprises one or more cores laminated with a winding consisting of a track cable having one or more permanently insulated conductors having a semiconductor layer both in the conductor and outside the insulation, the outer semiconductor layer It is connected to the potential earth.

To solve the problems arising with the direct connection of electrical machines, whether rotary and static machines, for all types of high voltage power transmission channels, at least one machine in the handling system according to the invention has A number of presentations as mentioned above, which differs distinctly from known technology. The additional descriptions and additional embodiments are defined in the dependent claims and are discussed in the following.

The descriptions mentioned above and other characteristics of the operating system and at least one of the electric machines included in this according to the invention, include the following: The winding for the magnetic circuit is produced from a cable that has one or more permanently insulated conductors with two semi-conductive layers, one surrounding the cables and the other forming a sheath. Some typical conductors of this type have cross-linked polyethylene insulation or ethylene propylene rubber. For the purpose, the drivers can further develop either how the cables are seen in the driver and the nature of the outer casing.

Cables with circular cross-section are preferred, but cables with some other cross-sections can be used in order to obtain the best packing density, for example.

Such a cable allows the laminated core to be designed in accordance with the invention in a new and optimum manner as seen in the openings and teeth.

The winding is preferably done with isolation in steps for its best use of the laminated core.

The winding is preferably made as a multi-layer, concentric wire winding, thus allowing the number of intersections of spiral ends to be reduced.

The design of the opening may be appropriate for the cross section of the winding cable so that the openings are in the form of a number of cylindrical openings running axially and / or radially outward from each other and having a narrowing running between the layers of the coiled armor.

The design of the openings can be adjusted to the relevant cross-cable cross-section and to the width of the winding passages. The isolation in steps allows the magnetic core to have a substantially constant sub-tooth width, independent of the radial extension.

The additional descriptions mentioned above appreciate the outlet of the envelope which causes that at appropriate points along the length of the conductor, the outlet of the envelope is completely cut off, each length of the partial cut being connected to the potential ground.

The use of a cable of the type described above allows the full length of the jacket outlet of the semi-conductor of the winding, as well as other parts of the handling system, to be guarded as potential earth. An important advantage is that the electric field closes to zero within the outlet of the region of the spiral end of the outer semiconductor layer. With the potential earth in the outer layer, the electric field does not need to be controlled. This means that non-field concentrations can occur in the nucleus, in the regions of the end of the spiral or in the transition between them.

The mixture of insulated or uninsulated impact cables, or transported cables, results in low deviations lost.

The high-voltage cable used in the magnetic circuit winding is constructed of an inert core / conductor with a plurality of cables, at least one semi-conductor layer, the inner one surrounded by an insulating layer, which in turn is surrounded by an outer semi-conductive layer having an outlet diameter in the order of 6-250 mm and a conductor area in the order of 10-3000 mm2.

If at least one of the machines in the plant according to the invention is constructed in a specific manner, the ignition and control of the engine (s) used in the car of the engine locomotive can be carried out with ignition methods, known per se.

According to a particularly preferred embodiment of the invention, at least two of these layers, preferably all three, have the same coefficient of thermal expansion. The decisive benefit is thus achieved that defects, ruptures and the like are avoided during the thermal movement in the winding.

Since the winding systems, properly installed, are designed so that from a thermal and electrical point of view it is dimensioned by more than 10 kV, the system can be connected to high voltage power transmission lines without any step transformer intermediate reducer, therefore allowing the advantages referred to above.

The aforementioned and other advantageous embodiments of the invention are defined in the dependent claims.

Brief Description of the Drawings The invention can be described in more detail in the following description of a preferred embodiment of the construction of the magnetic circuit of an electrical machine, with reference to the accompanying drawings in which: Figure 1 shows a schematic end view 'of a sector of the stator in an electrical machine in the plant according to the invention; Figure 2 shows a final view, presented in steps, of a cable used in the stator winding according to Figure i; Y Figures 3 to 5 show traction motor management systems in accordance with different embodiments of the invention.

Description of the Preferred Modalities.

In a final schematic view of a sector of the stator 1 according to Figure 1, conceming a rotary-type electric machine that includes in the plant according to the invention, the rotor 2 of the machine is also indicated. Stator 1 is composed of a laminated core. Figure 1 shows a sector of the machine corresponding to an armed pole. A number of teeth A radially extended in the form of a bonded part 3 of the core towards the rotor 2 and are separated by openings 5 in which the winding stator is placed. The cables 6 forming this winding stator are high voltage cables which can be substantially of the same type as those used for the distribution of power, for example PEX cables. One difference is that the mechanical protective cover, the output, and the metal shield normally around such power distribution cables are removed so that the cable of the present application comprises only the conductor and at least one semi-conductor layer in each case. side of an isolated layer. In this way, the semiconductor layer a is located uncovered on the surface of the cable.

The cables 6 are illustrated schematically in Figure 1, only the central conductive part of each side of the spiral or part of the cable being drawn. As can be seen, each opening 5 has several cross sections with alternating wide portions 7 and narrow narrowing portions 8. The wide portions 7 are substantially circular and surround the wiring. The constricting portions 8 serve to radially fix the position of each cable. The cross section of the opening 5 also narrows radially inwards. This is because the voltage in the parts of the cable is less than that located closest to the radially inner part of the stator 1. The thin wiring can therefore be used inwards, while the thick wiring is necessarily outward. In the example, cables of three different dimensions are used, arranged in the three dimensioned sections correspondingly 51, 52, 53 or openings 5.

The above description of the magnetic circuit for a rotary electric machine constructed with the cable 6 also that applicable to static electric machines such as transformers, winding reactor and the like. The following important advantages are obtained both from the design and the manufacture of the point of view: the windings of the transformer can be constructed without consideration to any electric distribution field and the problematic transposition of the parts in the known technology is thus not necessary, the transformer core can be designed without taking into account any electric distribution field, oil is not required for electrical insulation of the cable and winding and instead, the cable and the winding can be surrounded by air or a flammable or slow-burning liquid, in many applications special lining is not required as in the case of oil filled transformers, for electrical communication between the transformer output connections and the spirals / windings located in it, the lack of much oil reduces the risk of fire and explosion in a transformer of the invention, the transformer can become stiffer than a conventional transformer, increasing its ability to withstand short circuits, The transformer is noise-free, clean and requires minor maintenance, and The manufacturing and testing technology required for a dry transformer with magnetic circuit as described above, is considerably simpler than that required for transforming conventional res / re actives.

Figure 2 shows a terminal view of stripping in steps of a high voltage cable for use in an electrical machine included in the plant in accordance with the present invention. The high voltage cable 6 comprises one or more conductors 31, each of which comprises a number of cables 36 which together give a circular cross section of copper (Cu), for example. These conductors 31 are arranged in the middle of the high voltage cable 6 and are surrounded in the mode shown by an insulated part 35. However, it is possible for the insulated part 35 to be omitted in one of the conductors 31. In this embodiment of the invention, the conductors 31 are surrounded by a first semi-conductive layer 32. Around this first semi-conductive layer 32, there is an insulation layer 33, for example PEX insulation, which is again surrounded by a second layer. Semi-conductive layer 34. In this way the high voltage cable need not include any metallic screen or outer cover of the type that normally surrounds such cables for power distribution. As the pulling equipment frequently becomes very hot, the insulation layer 33 may comprise heat resistant polymers, for example, silicone rubber or fluorinated polymer. The semi-conductive layers 32, 34 may comprise similar materials for the insulation layer but with conductive particles, such as carbon black, soot or metal particles, within these. It has generally been found that a particular insulation material has similar mechanical properties when it does not contain, or something, carbon particles.

The use of electric machines provided with magnetic circuits of the type described above allows the electrical supply of traction motors, as well as the traction motors themselves, to be greatly simplified and made more efficient. In the operation of trains with alternative voltage, the supply of currents of voltages used are generally 15 kV, 162/3 Hz, 11 kV 25 Hz or 25 kV, 50/60 Hz in the supply line 104 from which the collector Current 112 of the locomotive supplies one or more traction motors 114, as shown in Figures 3 through 5.

The known traction motors for alternative voltages are normally driven by voltages of more than 1 kV and the locomotive must, therefore, be equipped with a transformer and with a speed control equipment, the latter being constituted of thyristors in the locomotives mode r na s The transformers used in the known locomotives are filled with oil and have a number of mechanical and electrical disadvantages, as well as incur environmental problems. Rotary machines and those used for conversion and operation in known locomotives have several problems, both mechanical and electrical, which can be distributed with a more or less satisfactory extent.

The aforementioned problems can be eliminated or minimized by designing magnetic circuits in at least one of the electrical machines of the system according to the present invention.

Figures 3 through 5 show a 3 phase asynchronous motor 114 which provides the mechanical power for the locomotive and has a winding formed of a high voltage cable as exemplified in Figure 2. The motor winding 114 has the advantages that it is have described previously.

Figure 3 shows a management system for the engine, comprising a transformer 122 and a thyristor bridge 123, connected by means of a filtered and smooth circuit 124 to a c.d./ 3 phase c.a. 125 which supplies the 3-pass motor 114. The transformer 122 has a winding formed from a cable such as that shown in Figure 2. This transformer therefore has the advantages listed above and is also lighter and less bulky than the transformer filled with known oil.

Figure 4a shows a management system including a rotary converter 130 comprising a motor M supplied directly from the current collector 112 and a generator G supplying the 3-phase motor 114 by means of a regulating device 131. The upper connections 132a 132b can be used to control the voltage supplied to motor 114 and the number of poles connected for coarse speed control.

Figure 4b shows an alternative system in which the rotary converter 130, which preferably generates multi-phases, for example six phase alternating current, is connected to the rectifier bridge 133 which supplies the motor 114 by means of a direct current converter of 3 phases / alternating current 125. Figure 4c shows an additional alternative system in which the supply of the rotary converter 130 to the motor 114 is by means of an ac frequency converter. /c.a.134.

In the systems shown in Figures 4a, 4b and 4c, each or both of the engine M and the generator G use a cable as exemplified in Figure 2. The engine and the generator can be separate machines by sharing a common handle, or alternatively the rotary converter may comprise a simple unit as described, for example, in German Patents 372390, 386561 t 406371. The rotary converter may also be a phase converter as described in "Das Handbuch. der Lo komot i come ", pages 254-255," Electrischer Bahnen "eb, 85. Jahrgang, Helft 12/1987, pages 388-389, or Lueger," Lexicon der Technik ", page 395.

Figure 5 shows a system in which the motor 114 is a high voltage motor that is supplied by a regulating device 135 connected to the current collector 112. The regulating device is preferably a semi-conductive converter c.a. /AC. direct. Since the motor 114 is supplied with high voltage, a transformer or other means of changing voltage is not required and the operating system has the advantage of being compact and lightweight.

Although certain voltage values have been noted above, these will only be considered as examples. Similarly, various combinations of conventionally designed electric machines and electric machines provided with the magnetic circuit according to the invention are possible. The invention will not therefore be considered as restrictive for the systems described with reference to the drawings, but covers all possible systems defined in the appended claims.

Although it is preferred that the electrical insulation be ejected in position, it is possible to construct a hermetically sealed electrical insulation system by skipping layers of film or sheetlike material. Both the semiconductor layers and the electrically insulated layer can be formed in this way. An insulation system can be made of all synthetic films with inner and outer semi-conductive layers or portions made of polymer thin film, for example PP, PET, LDPE or HDPE with embedded conductive particles, such as carbon black or metal particles and with an insulating layer or portion between the semiconductor layers or portions.

For the coating concept, a sufficiently thin layer must have small extreme spaces that are also called minimum Paschen, thus interpreting the liquid impregnation not necessary. An isolated, dry multi-layer open thin film also has good thermal properties.

Another example of an electrical insulation system is similar to conventional cellulose-based cable, where a synthetic or thin cellulose-based paper or a non-woven material is wrapped in the opening around the conductor. In this case, the semi-conductor layers, on both sides of an insulating layer, can be made of cellulose paper or of nonwoven material made of fibers of insulated material and with embedded conductive particles. The insulating layer can be made of the same base material or another material can be used.

Another example of an insulation system is obtained by the combination of the film and fibrous insulation material, either as a laminate or as co-enveloped. An example of this isolation system is the commercially available one also called laminated polypropylene paper, PPLP, but several other combinations of film and fibrous parts are possible. In these systems, various impregnations such as mineral oil can be used.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Claims (21)

Claims

1. A 3-phase traction motor, comprising a winding, characterized in that the winding includes an insulation consisting of at least two semi-conductor layers, each layer providing a substantially equipotential surface, and a solid insulation between the semi-conductive layers. .

2. The motor as claimed in claim 1, characterized in that it is an asynchronous motor.

3. The motor as claimed in claim 1, characterized in that it is a synchronous motor.

4. A driving system for a locomotive or a motor car, characterized in that it comprises a motor as claimed in claim 1, 2 or 3, and a regulator device connected to it.

5. The system as claimed in claim 4, characterized in that the regulated device is a semiconductor converter c.a. /AC.

6. A driving system for a locomotive or a motor car, comprising a transformer having a winding, a thyristor bridge supplied by the transformer, and a c.d./c.a converter. supplied by the thyristor bridge and ordered to supply power to the traction motor, characterized in that the winding includes insulation consisting of at least two semi-conductive layers, each layer providing a substantially equipotential surface, and a solid insulation between the semi-conductive layers s.

7. A driving system for a locomotive or a motor car, comprising a rotary converter having a winding and ordered to supply power to the traction motor, characterized in that the winding includes insulation consisting of at least two semi-conductor layers. , - each layer providing a substantially equipotential surface, and a solid insulation between the semiconductor layers s.

8. The system as claimed in claim 7, characterized in that the rotary converter comprises a simple machine that has both motor and generator functions.

9. The system as claimed in claim 8, characterized in that the rotary converter is a phase converter.

10. The system as claimed in claim 7, 8 or 9, characterized in that the rotary converter supplies a regulating device.

11. The system as claimed in claim 7, 8 or 9, characterized in that the rotary converter supplies a rectifier bridge that supplies a converter c. d. /AC.

12. . The system as claimed in claim 7, 8 or 9, characterized in that the rotary converter supplies a frequency converter c.a. /AC.

13. The engine or system as claimed in any of the preceding claims, characterized in that at least one of the layers has substantially the same coefficient of thermal expansion as the solid insulation.

14. The engine or system as claimed in any of the preceding claims, characterized in that the flow paths in the core of the magnetic circuit in the motor, transformer or rotary converter, consist of plates of laminated sheets and / or rough wrought iron and / or pure iron and / or iron base powder.

15. The engine or system as claimed in any of the preceding claims, characterized in that the innermost semi-conductive layer surrounding at least one conductor has substantially the same potential as the conductor (s).

16. The engine or system as claimed in any of the preceding claims, characterized in that the outer semi-conductive layer is connected to the potential selector.

17. The motor or system as claimed in claim 16, characterized in that the potential selector is the potential earth.

18. The motor or system as claimed in any of the preceding claims, characterized in that the conductor carrying the current of the winding comprises a plurality of cables, only a few of the cables not being insulated from one another.

19. The engine or system as claimed in any of the preceding claims, characterized in that the winding (s) and also the permanently insulated connection conductors for high voltage current between the system units, are produced using a cable with insulation solid for high voltage and comprises at least two semiconductor layers, and also cables that can be insulated or not insulated.

20. The motor or system as claimed in claim 19, characterized in that the high-voltage cables have a conductive area of between 10 and 3000 mm2 and have an output cable diameter of between 6 and 250 mm.

21. The motor or system as claimed in any of the preceding claims, characterized in that the winding is designed to carry a voltage range of at least 10 kV.