Stator module for a linear transport system

{
  "publication_number": "US2023208335A1",
  "country": "US",
  "kind": "A1",
  "title": "Stator module for a linear transport system",
  "abstract": "A stator module of a linear transport system includes a plurality of drive coils, which are energizable and form part of a stator of a linear motor. The stator module also includes actuation electronics, where the drive coils are actuatable by the actuation electronics. The actuation electronics includes at least an actuation element, which is arranged to energize a number of drive coils. The actuation element has a number of half bridges, each comprising a first half-bridge connection, a second half-bridge connection, and a half-bridge center. The first half-bridge connections of the half bridges are connected to one another, and the second half-bridge connections of the half bridges are connected to one another. The half bridges and the drive coils form a chain, with the half-bridge centers and drive coils arranged alternately within the chain, at least one half-bridge center being connected to two drive coils.",
  "claims": [
    "1. A stator module of a linear transport system, comprising: a plurality of drive coils, wherein the drive coils are energizable and form part of a stator of a linear motor, wherein the stator module further comprises actuation electronics, wherein the drive coils are actuatable via the actuation electronics, wherein the actuation electronics comprise at least one actuation element, wherein the actuation element is configured to energize a number of drive coils, wherein the actuation element has a number of half bridges, wherein the half bridges each comprise a first half-bridge connection, a second half-bridge connection, and a half-bridge center, wherein the first half-bridge connections of the half bridges are connected to one another, wherein the second half-bridge connections of the half bridges are connected to one another, and wherein the half bridges and the drive coils form a chain, wherein half-bridge centers and drive coils are alternately arranged within the chain, wherein at least one half-bridge center is connected to two of said drive coils. 2. The stator module according to claim 1, wherein the number of half bridges is larger by one than the number of drive coils. 3. The stator module according to claim 2, wherein an initial center of an initial half bridge is connected to a first drive coil, wherein the first drive coil is connected to an intermediate center of an intermediate half bridge, wherein an end center of an end half bridge is connected to a second drive coil, wherein the second drive coil is connected to an intermediate center of an intermediate half bridge, and wherein third drive coils are connected to the intermediate half bridges and/or to further intermediate half bridges in accordance with the number of drive coils. 4. The stator module according to claim 1, wherein the number of half bridges is identical to the number of drive coils. 5. The stator module according to claim 4, wherein an initial center of an initial half bridge is connected to a first drive coil, wherein the first drive coil is connected to an intermediate center of an intermediate half bridge, wherein the initial center of the initial half bridge is connected to a second drive coil, wherein the second drive coil is connected to an intermediate center of an intermediate half bridge, and wherein third drive coils are connected to the intermediate half bridges and/or to further intermediate half bridges in accordance with the number of drive coils. 6. The stator module according to claim 1, wherein the number of drive coils equals three. 7. The stator module according to claim 6, wherein the three drive coils actuatable by the actuation unit form a three-phase system. 8. The stator module according claim 1, further comprising a communication input, wherein the stator module is arranged to receive data regarding the actuation of the drive coils via the communication input and to switch the half bridges of the actuation element according to the data. 9. The stator module according to claim 8, further comprising a control regulator, wherein the control regulator is configured to determine actual current values of the drive coils and to switch the half bridges of the actuation element based on the actual current values. 10. The stator module according to claim 9, further comprising current meters for determining the actual current values, wherein the current meters are arranged within the half bridges and/or in series with the drive coils. 11. The stator module according to claim 8, wherein the switching of the half bridges is carried out using pulse-width modulation. 12. The stator module according to claim 8, further comprising: a limiting controller, wherein the data comprises current setpoints or voltage setpoints for the drive coils, wherein the limiting controller is configured to change the current setpoints or voltage setpoints, respectively, in such a way that a sum of voltages of the drive coils of an actuation element does not exceed a maximum voltage. 13. The stator module according to claim 12, wherein the limiting controller is configured to: calculate a cumulative sum of a time curve of the voltage to be applied to the drive coils of an actuation element, determine a maximum value and a minimum value of the cumulative sum, and check whether a difference of the maximum value and the minimum value exceeds a design voltage; and in a case that the difference exceeds the design voltage, to reduce the voltage setpoints in such a manner that the difference no longer exceeds the design voltage when the calculation steps are repeated. 14. A linear transport system comprising at least one stator module according to claim 1, and at least one slide. 15. The linear transport system according to claim 14, further comprising: at least a controller, wherein the controller is configured to forward data to a communication input of the stator module via a communication output, and wherein the data comprises current setpoints or voltage setpoints for the drive coils of the stator module. 16. The linear transport system according to claim 15, wherein the controller comprises a limiter, wherein the limiter is configured to change the current setpoints or voltage setpoints in such a way that a sum of voltages of the drive coils of an actuation element does not exceed a maximum voltage. 17. The linear transport system according to claim 16, wherein the limiter is configured to: calculate a cumulative sum of a time curve of the voltage to be applied to the drive coils of an actuation element, determine a maximum value and a minimum value of the cumulative sum, and check whether a difference of the maximum value and the minimum value exceeds a design voltage; and in a case that the difference exceeds the design voltage, to reduce the voltage setpoints in such a way that the difference no longer exceeds the design voltage when the calculation steps are repeated. 18. A method for operating a stator module of a linear transport system according to claim 1, wherein drive coils of the stator module are actuated with the aid of half bridges, and wherein the actuation of the half bridges takes into account that at least one half bridge is connected to two drive coils. 19. The method according to claim 18, wherein the stator module receives data comprising current setpoints or voltage setpoints for the drive coils, and changes the current setpoints or voltage setpoints in such a way that a sum of voltages of the drive coils of an actuation element does not exceed a maximum voltage. 20. The method according to claim 19, wherein the stator module: calculates a cumulative sum of a time curve of the voltage to be applied to the drive coils of an actuation element, determines a maximum value and a minimum value of the cumulative sum, and checks whether a difference from the maximum value and the minimum value exceeds a design voltage; and in a case that the difference exceeds the design voltage, reduces the voltage setpoints in such a way that when the calculation steps are repeated, the difference no longer exceeds the design voltage."
  ],
  "description_excerpt": "The invention relates to a stator module for a linear transport system, as well as to a linear transport system comprising such a stator module and an operating method for such a stator module.\n\nFrom the prior art, linear transport systems are known which comprise stator modules, wherein the stator modules form a stator of a linear motor and each comprise a plurality of drive coils, wherein the linear transport system further comprises a movable slide, wherein a permanent magnet assembly is arranged on the slide and forms a slide of the linear motor. In this regard, the drive coils may be energized with the aid of full bridges. A half bridge consisting of two transistors is then arranged at the two connections of each drive coil, so that the drive coil may be energized depending on the switching state of the transistors. However, this embodiment is very complex, since four transistors are required for each drive coil. The half bridges may also have other switching elements or special transistors such as MOSFETs, IGBTs or HEMTs.\n\nThe manner in which the drive coils may be energized in general may be found in DE 10 2015 102 236 A1 and is in this publication in particular described in connection with FIGS. 6 to 14.\n\nEP 3 249 803 A1 proposes to connect each drive coil with only one half bridge and to connect the respective free connection of the drive coils with one another, thus providing a star circuit. In this way, two transistors may be saved per drive coil. The publications U.S. Pat. No. 10,256,023 B2, EP 3 461 667 A1, U.S. Pat. Nos. 10,164,555 B1 and 10,250,176 B2 also propose such a star circuit.",
  "cpc": [
    "H02P 25/064",
    "H02K 41/02",
    "H02M 7/44",
    "H02P 25/18"
  ],
  "ipc": [
    "H02P 25/064",
    "H02M 7/5395"
  ],
  "assignees": [
    "Beckhoff Automation GmbH and Co KG"
  ],
  "inventors": [
    "Tim Kaulmann",
    "Dirk Otterpohl",
    "Marc Hegselmann"
  ],
  "filing_date": "2023-03-03",
  "publication_date": "2023-06-29",
  "priority_date": "2020-09-29",
  "application_number": "US-202318177845-A",
  "family_id": "78049230",
  "cited_by_count": 1
}