Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/46—Fastening of windings on the stator or rotor structure
  • H02K3/50—Fastening of winding heads, equalising connectors, or connections thereto
  • H02K3/51—Fastening of winding heads, equalising connectors, or connections thereto applicable to rotors only

Definitions

• the present invention relates to the field of electric machines. It relates to an electrical machine according to the preamble of claim 1.
• Double-fed asynchronous machines in the power range from 20 MVA to 500 MVA can be used for variable-speed energy production. These machines are characterized by a distributed three-phase winding on the rotor.
• the rotor winding consists of individual rods, which are embedded in grooves in the rotor core. In the winding head, the individual rods are connected to form a winding. The arrangement of the rod connections is evenly distributed around the circumference.
• the winding heads are exposed to centrifugal forces, against which they must be mechanically secured by means of winding head restraint systems.
• three types of winding head restraint systems are known today: 1. Attachment by means of a steel cap, as is the case with turbogenerators.
• such an asynchronous machine 10 is shown in fragmentary form in a greatly simplified form. It comprises a rotatable about an axis 18 rotor 19 which is concentrically surrounded by a stator lamination 14 with a corresponding stator winding and a stator winding 17.
• the rotor 19 comprises a central body 11, which merges at the ends in each case in a shaft 11 '.
• the central body 11 is enclosed by a rotor laminated body 12, in which the rotor winding 13 extends.
• On one of the shafts 11 'slip rings 15 are arranged, which serve to supply the rotor winding 13 with power.
• the rotor winding head 16 which is shown enlarged again in a vertical orientation in FIG.
• FIG. 2 (a) is equipped with a winding head restraint system 29 which, according to FIG. 2 (a), has retaining elements in the form of nuts 21 extending radially through the rotor winding head 16 provided threaded rods 20 or bolts or the like. Equipped.
• the retaining elements 20, 21 catch the centrifugal forces acting on the rotor winding head 16 during operation of the machine and introduce them into the massive part of the rotor arranged below the winding head. It can now happen during operation over a long period of time that the mechanically heavily loaded retaining elements 20, 21 break or otherwise lose their mechanical integrity. But it may also be that the nuts 21 or Versch robberies solve and the function of the retaining elements 20, 21 is lost in this way. Solves in the context of this failure Part of the retaining elements 20, 21 and is thrown to the outside, consequential damage to the machine can occur, leading to a prolonged failure of the machine and thus high follow-up costs.
• the object is solved by the entirety of the features of claim 1.
• the retaining elements are provided with securing means which secure the retaining elements against accidental loosening and / or flying away in the event of breakage.
• Retaining elements as in the radial direction through the winding head extending through threaded rods or bolts are formed, which are provided at the outer end with a nut or a screw head for supporting the winding head.
• the securing means may comprise a fabric securing, which, in particular in the form of a fabric band, preferably tight-fitting and in the circumferential direction, is stretched over the outsides of the nuts or screw heads.
• the securing means may also comprise a wire lock, which is in the form of a wire, preferably tight-fitting and in the circumferential direction, stretched over the outer sides of the nuts and / or threaded rods or screw heads.
• a wire lock which is in the form of a wire, preferably tight-fitting and in the circumferential direction, stretched over the outer sides of the nuts and / or threaded rods or screw heads.
• slots are preferably provided on the retaining elements, in which the wire lock is inserted, which simultaneously secures the retaining elements against rotation.
• Another embodiment of the invention is characterized in that the winding head restraint system is equipped with monitoring means with which the proper function of the winding head can be monitored.
• the monitoring means preferably comprise voltage measuring devices, which measure the mechanical tension of the securing means in the winding head restraint system and pass it on to an evaluation unit for evaluation.
• Fig. 1 in a highly simplified representation of a section of an asynchronous machine with stator and rotor winding and a
• Rotor winding head of Figure 1 in a vertical orientation (Fig. 2a) and two types of fuses for the retaining elements according to various embodiments of the invention
• FIG. 4 shows the exemplary installation of monitoring means in the restraint system according to another embodiment of the invention.
• Fig. 5 shows the scheme of a monitoring device
• the bolts or screws of the winding-end restraint system 29 are to be secured in the rotor winding head 16.
• the retention elements according to FIGS. 2 a and 3 are threaded rods 20 with nuts 21, it is necessary to secure the nuts 21 against unintentional loosening. However, should it come to an undesirable break in a screw or a bolt, it is necessary to retain the released parts in order to prevent destruction of the machine.
• the safeguard against flying away can be done according to the invention by a wire (wire lock 23 in Fig. 2b) or a tissue (fabric fuse 22 in Fig. 2b), which are stretched over the screw heads or nuts 21 in the circumferential direction.
• the screws can not move in the radial direction.
• the forces which are absorbed by the screws (or threaded rods 20) are large, since they must bear the centrifugal forces, which arise due to the weight of the winding head 16. If there is a break in the screw (or threaded rod 20), only the centrifugal force of the mass of the released screw piece acts on the fuse. This force is relatively small. For this reason, it is possible to retain a broken screw or threaded rod 20 by means of a wire or cloth.
• a suitable material for the fabric or fabric tape is a highly tear-resistant, even at higher temperatures stable tissue into consideration.
• the fabric band of the fabric securing 22 according to FIG. 2b can be made wide over the nuts 21 or screw heads, it is advantageous when using the wire lock 23 in the nuts 21 or threaded rods 20 or in the screw heads according to FIG. 3 in the circumferential direction to provide extending slots 24, in which the wire lock 23 is inserted. Through the running in the slots 24 wire, the nuts 21 and bolts can not rotate. At the same time the wire itself is secured against slipping.
• the tension (tension) in the wire or fabric tape is monitored by means of a suitable electronic sensor (voltage measuring device 25) (for example with a load cell). If a part of a screw breaks loose due to breakage, the mechanical tension in the wire (wire lock 23) increases and can be detected.
• a suitable electronic sensor voltage measuring device 25
• the sensor or the voltage measuring device 25 can be integrated directly in the wire running on the circumference (upper part in Fig.
• the measuring signals of the various sensors or voltage measuring devices 25 in the rotor winding head 16 are fed to a central evaluation unit 26 in a corresponding monitoring device (28 in FIG. 5) and evaluated there. If unusual changes in the voltage pattern of the fuses of the winding head restraint system 29 are detected during operation, a message is sent to a subsequent display unit 27 and displayed there. The message can be routed simultaneously to a central control of the machine and there initiate an automatic shutdown, so that the machine can be inspected in time.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Insulation, Fastening Of Motor, Generator Windings (AREA)
• Manufacture Of Motors, Generators (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2010
  • 2010-04-19 CN CN201080017929.5A patent/CN102414959B/zh not_active Expired - Fee Related
  • 2010-04-19 KR KR1020117025006A patent/KR20120027162A/ko active Search and Examination
  • 2010-04-19 WO PCT/EP2010/055111 patent/WO2010121987A1/de active Application Filing
  • 2010-04-19 BR BRPI1014282A patent/BRPI1014282A2/pt not_active IP Right Cessation
  • 2010-04-19 RU RU2011147717/07A patent/RU2544179C2/ru not_active IP Right Cessation
  • 2010-04-19 CA CA2759459A patent/CA2759459C/en not_active Expired - Fee Related
  • 2010-04-19 EP EP10715793A patent/EP2422430A1/de not_active Withdrawn
• 2011
  • 2011-10-18 US US13/275,438 patent/US8643248B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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