Elevator brake controller, elevator brake arrangement, elevator system, and method for adjusting operation time of electromechanical brake of elevator system

Abstract

An elevator brake controller (100A; 100B; 100C) for an electromechanical brake (110) comprising a brake coil (112) is disclosed. The elevator brake controller (100A; 100B; 100C) comprises one or several electrical energy dissipation elements (102A-102C) for dissipating stored energy in the brake coil (112) when operating the electromechanical brake (110), and a control circuitry (101A; 101B; 101C) in connection with the one or several energy dissipation elements (102A-102C), the control circuitry (101A; 101B; 101C) being arranged to be connected to the brake coil (112). The control circuitry (101A; 101B; 101C) comprises a processing unit (105) and is configured to adjust operation time of the electromechanical brake (110) by regulating energy dissipation of the stored energy in the one or several energy dissipation elements (102A-102C) by the processing unit (105).

Description

[0001] ELEVATOR BRAKE CONTROLLER, ELEVATOR BRAKE ARRANGEMENT, ELEVATOR SYSTEM, AND METHOD FOR ADJUSTING OPERATION TIME OF ELECTROMECHANICAL BRAKE OF ELEVATOR SYSTEM

[0002] FIELD OF THE INVENTION

[0003] The present invention relates in general to elevator brakes. In particular, however, not exclusively, the present invention concerns brake controllers, brakes, arrangement, systems, and methods for electromechanical brakes of the elevators for controlling the energy dissipation in the brakes during braking.

[0004] BACKGROUND

[0005] Elevators commonly use electromechanical brakes that use spring force to prevent elevator movement until brake coils are provided with enough electric power to generate counteracting magnetic force to overcome the spring force and opening the brakes. In case of emergency the electric power is removed from the brake and elevator is stopped. Operational delay in this emergency stop depends heavily on the dissipation of the inductive energy in the brake coil. Common solution is to short-circuit the brake coil and turn the energy into heat in the internal impedance of the brake coil. Furthermore, a resistor may be used in the short-circuit path to dissipate some of the energy therein as heat to provide faster dissipation.

[0006] In the known attempts, the brake energy dissipation arrangements must be carefully designed to operate correctly in all conditions. Brake operation can be too slow, for example in case of power outage of the elevator and when the doors have already been opened, or it can operate too quick and, thus, cause too high deceleration to the elevator car depending on the operating conditions. There is thus still a need to develop solutions for energy dissipation of electromechanical brakes of elevators.

[0007] SUMMARY

[0008] An objective of the present invention is to provide an elevator brake controller, an elevator brake arrangement, an elevator system, and a method for adjusting operation time of an electromechanical brake of an elevator system. Another objective of the present invention is that the elevator brake controller, the elevator brake arrangement, the elevator system, and the method provides solution for controlling the dissipation for adjusting the brake operation time. The objectives of the invention are reached by an elevator brake controller, an elevator brake arrangement, an elevator system, and a method for adjusting operation time of an electromechanical brake of an elevator system as defined by the respective independent claims.

[0009] According to a first aspect, an elevator brake controller for an electromechanical brake comprising a brake coil is provided. The elevator brake controller comprises one or several electrical energy dissipation elements for dissipating stored energy in the brake coil when operating the electromechanical brake, and a control circuitry in connection with the one or several energy dissipation elements, wherein the control circuitry is arranged to be connected to the brake coil. The control circuitry comprises a processing unit and is configured to adjust operation time of the electromechanical brake by regulating energy dissipation of the stored energy in the one or several energy dissipation elements by the processing unit.

[0010] The regulation of the energy dissipation may relate to a dissipation rate of the stored energy.

[0011] The control circuitry may be configured to adjust the operation time by regulating voltage over the brake coil.

[0012] The control circuitry may, alternatively or in addition, be configured to short-circuit the brake coil via one or several first controllable power switches. Optionally, the short- circuit may be arranged to be parallel relative to the one or several electrical energy dissipation elements. Still alternatively or in addition, a current path of the short-circuit may include, in addition to the one or several first controllable power switches, one or several diodes.

[0013] Furthermore, the control circuitry may be configured to adapt a duty cycle of the one or several first controllable power switches during the energy dissipation. Optionally, the one or several first controllable power switches are switched based on a pulse-width modulation technique.

[0014] The control circuitry may comprise one or several second controllable power switches for connecting the one or several electrical energy dissipation elements to dissipate the stored energy.

[0015] Each one of the at least one of the several second controllable power switches may preferably be in series with one of the at least one electrical energy dissipation element. The elevator brake controller may be configured to automatically adjust the operation time to be in an acceptable range.

[0016] The one or several electrical energy dissipation elements may comprise one or several varistors, optionally in series connection with a diode.

[0017] According to a second aspect, an elevator brake arrangement is provided. The elevator brake arrangement comprises an electromechanical brake comprising a brake coil. The elevator brake arrangement also comprises an elevator brake controller according to the first aspect, the elevator brake controller being connected to the brake coil.

[0018] According to a third aspect, an elevator system is provided. The elevator system comprises an elevator car, an elevator motor arranged to cause moving of the elevator car, and the elevator brake arrangement according to the second aspect.

[0019] According to a fourth aspect, a method for adjusting operation time of an electromechanical brake of an elevator system is provided, the electromechanical brake comprising a brake coil. The method comprises regulating energy dissipation of stored energy of the brake coil in one or several energy dissipation elements by an elevator brake controller according to the first aspect.

[0020] The method may comprise adapting, by a processing unit of the elevator brake controller, a duty cycle of one or several first controllable power switches which are arranged to short-circuit the brake coil during the energy dissipation.

[0021] The method may comprise automatically adjusting the operation time to be in an acceptable range.

[0022] The present invention provides an elevator brake controller, an elevator brake arrangement, an elevator system, and a method for adjusting operation time of an electromechanical brake of an elevator system. The present invention provides advantages over known solutions in that since the energy dissipation rate can be controlled, the brake operation time can be, even automatically, adjusted. Furthermore, the operation time can be made to match time delays and / or operation times of other related components and devices of the elevator, if needed. Automatic tuning of the operation time removes need for manual tuning, such as manually changing components and / or connections.

[0023] Various other advantages will become clear to a skilled person based on the following detailed description. The expression "a number of’ may herein refer to any positive integer starting from one (1).

[0024] The expression "a plurality of’ may refer to any positive integer starting from two (2), respectively.

[0025] The terms “first”, “second” and “third” are herein used to distinguish one element from other element, and not to specially prioritize or order them, if not otherwise explicitly stated.

[0026] The exemplary embodiments of the present invention presented herein are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used herein as an open limitation that does not exclude the existence of also unrecited features. The features recited in the appended patent claims are mutually freely combinable unless otherwise explicitly stated.

[0027] The novel features which are considered as characteristic of the present invention are set forth in particular in the appended claims. The present invention itself, however, both as to its construction and its method of operation, together with additional objectives and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

[0028] BRIEF DESCRIPTION OF FIGURES

[0029] Some embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

[0030] Figure 1 illustrates schematically an elevator brake controller.

[0031] Figure 2 illustrates schematically an elevator brake controller.

[0032] Figure 3 illustrates schematically an elevator brake controller.

[0033] Figure 4 illustrates schematically an elevator system.

[0034] Figure 5 shows a flow diagram of a method.

[0035] DETAILED DESCRIPTION OF SOME EMBODIMENTS

[0036] Figure 1 illustrates schematically an elevator brake controller 100 A. The elevator brake controller 100A comprises an electrical energy dissipation element 102A for dissipating stored energy in the brake coil 112 of the electromechanical when operating the brake 110. The elevator brake controller 100A also comprises a control circuitry 101 A in connection with the energy dissipation element 102A. The control circuitry 101A is arranged to be connected to the brake coil 112. Furthermore, the control circuitry 101 A comprises a processing unit 105 and is configured to adjust operation time of the electromechanical brake 110 by regulating energy dissipation of the stored energy in the energy dissipation element 102A by the processing unit 105. The regulation of the energy dissipation relates, preferably, to a dissipation rate of the stored energy (that is, to power or average power).

[0037] Figure 1 illustrates an optional pre-stage circuit 109 A of the elevator brake controller 100A. In this case, the pre-stage circuit 109A comprises a transformer or a coupled inductor for providing galvanic isolation and / or step-up or step-down transformation regarding electrical quantities. The elevator brake controller 100A could also operate without the pre-stage circuit 109 A, such as with basically any DC power supply or a rectifier in the input thereof.

[0038] The regulation of the energy dissipation of the stored energy is performed, in the example of Fig. 1, by controlling at least the operation of the first controllable power switch 103 A, optionally, also the other first controllable power switch 103B, that is cocontrol thereof. Thus, the control circuitry 101A may be configured to adjust the operation time by regulating voltage over the brake coil 112.

[0039] The control circuitry 101 A may be configured to short-circuit the brake coil 112 via a first controllable power switch 103 A. The short-circuit is, preferably, arranged to be parallel relative to the path of the electrical energy dissipation element 102A.

[0040] As can be understood, before the brake is operated, the electrical current flows from the input, optionally the pre-stage circuit 109A, if any, to the brake coil 112. When the brake is operated (that is, the dissipation of stored energy begins), the other first controllable power switch 103B or, in general, the power supply used at the input, is turned off. This will cause a decrease of the current in the brake coil 112 and change of the polarity of voltage across thereof relative to the situation before the brake operation. Thus, when the first controllable power switch 103 A is turned off, the decreasing current of the brake coil 112 flows only via the energy dissipation element 102A and the optional diode. However, the dissipation rate can now be controlled by switching the first controllable power switch 103 A on, that is to the conducting state, thus providing a parallel path for the current of the brake coil 112 relative to the path including the energy dissipation element 102A. This way the voltage across the brake coil 112 can be regulated and so can be the dissipation rate. As a further note, it should be understood that the first controllable power switch 103 A, as well as the other first controllable power switch 103B can be used to control current of the brake coil 112 also during the times when the brake is open or not-braking.

[0041] The control circuitry 101 A may be configured to adapt a duty cycle of the first controllable power switch(es) 103 A, 103B during the energy dissipation. As understood, the first controllable power switch(es) 103 A, 103B may be switched with a switching frequency being more than zero. The duty cycle thus defines how long the switch(es) 103 A, 103B is / are conducting relative to the total time of one switching cycle / period. For example, the one or several first controllable power switch(es) 103 A, 103B is / are switched based on a pulse-width modulation technique.

[0042] Figure 2 illustrates schematically an elevator brake controller 100B. The elevator brake controller 100B in accordance with Fig. 2 comprises at least two first controllable power switch 103 A, 103B. The two first controllable power switch 103 A, 103B are, preferably, switched in synchronous manner so that they conduct and are in blocking state at the same time.

[0043] In Fig. 2, the pre-stage circuit 109B may be used, including a rectifier or rectifying subcircuit, such as a diode bridge. In this case too, other DC power supplies may, alternatively, be used.

[0044] As with the example of Fig. 1, the two first controllable power switch 103 A, 103B may be used, that is switched, during the times when the brake is open. However, when the brake is activated, the current in the brake coil 112 starts to decrease. When the two first controllable power switch 103 A, 103B are not conducting, the decreasing current of the brake coil 112 flows only via the energy dissipation element 102A and the optional diode. By appropriately switching the two first controllable power switch 103 A, 103B to conducting state, the dissipation rate can be controlled in similar manner as was described with respect to Fig. 1. The two first controllable power switch 103 A, 103B basically provide a parallel current path relative to the path including the energy dissipation element 102A and the optional diode.

[0045] Figure 3 illustrates schematically an elevator brake controller 100C. The pre-stage circuit 109B is identical to one shown in Fig. 2. Furthermore, same remarks about any power DC supply apply. In general, the control circuitry 101 C may comprise at least one second controllable power switch 104 A, that is in addition to the one or more first controllable power switch 103 A, 103B, for connecting the electrical energy dissipation element 102A to dissipate the stored energy, wherein the electrical energy dissipation element 102A is preferably connected in series with the second controllable power switch 104 A.

[0046] In Fig. 3, the control circuitry 101C may comprise several second controllable power switches 104A-104C for connecting the several electrical energy dissipation elements 102A-102C, respectively, to dissipate the stored energy. Optionally, each one of the at least one of the several second controllable power switches 104A-104C is connected in series with one of the at least one electrical energy dissipation element 102A-102C.

[0047] In various embodiments, the several electrical energy dissipation elements 102A-102C may be identical with respect to their electrical properties, such as resistance or impedance, however, they may alternatively be different. Thus, the second controllable power switch(es) 104A, 104B, 104C may be used to even further control the dissipation rate since one or many of the electrical energy dissipation element 102A-102C, optionally even with different electrical properties, may be connected in parallel with the brake coil 112 to dissipate the energy.

[0048] Regarding each one of the examples in Figs. 1-3, the brake controller 100A; 100B; 100C may be configured to automatically adjust the operation time to be in an acceptable range. For example, the acceptable range may have some lower limit and / or higher limit, wherein the operation time should be therebetween.

[0049] Regarding each one of the examples in Figs. 1-3, a current path of the short-circuit includes, in addition to the one or several first controllable power switches 103 A, 103B, one or several diodes, or other components.

[0050] Regarding each one of the examples in Figs. 1-3, the one or several electrical energy dissipation elements 102A-102C comprises one or several varistors, optionally in series connection with a diode.

[0051] Figure 4 illustrates schematically an elevator system 200. The brake controller 100; 100A; 100B; 100C may be used in connection thereto. The elevator system 200 may comprise a motor controller 204, such as including an electric converter (a frequency converter and / or an inverter). The elevator system 200 may comprise an elevator, or “hoisting”, motor 202, such as a permanent magnet electric motor, for moving an elevator car 201 comprised in the elevator system 200. The elevator motor 202 may be arranged to rotate a traction sheave 208. The elevator car 201 may be mechanically coupled to the electric motor 202, preferably, by a hoisting rope 206, for example, extending via the traction sheave 208.

[0052] The operation of the electric motor 202 may be controlled by the motor controller 204, such as including the frequency converter or the inverter. The elevator car 201 may be moved in and / or along an elevator shaft 242. The elevator car 201 may be moved in a normal operation mode to serve landings 240 or landing floors 240 in accordance with elevator calls. Also shown are the elevator car doors 280 and the landing floor doors.

[0053] The hoisting rope 206 may comprise, for example, steel or carbon fibers. The term ‘hoisting rope’ does not limit the form of the rope anyhow. For example, the hoisting rope 206 may be implemented as a rope or a belt. The elevator system 200 may also comprise a counterweight 234 in connection with the elevator car 201, such as via the hoisting rope 206.

[0054] The elevator system 100 may comprise an elevator control unit 290 for controlling the operation of the elevator system 100, such as various devices thereof. The elevator control unit 290 may be a separate device or may be comprised in the other components of the elevator system 200 such as in or as a part of the motor controller 204. In various embodiments, the elevator control unit 290 comprises the motor controller 204. The elevator control unit 290 may be in connection with the brake controller 100 to control the operation thereof.

[0055] In some embodiments, the elevator control unit 290 may comprise the motor controller 204, however, in other embodiments, they may be separate entities, in which case the elevator control unit 290 may be in communication connection with the motor controller 204, such as providing input signal / data thereto and / or therefrom.

[0056] The elevator system 200 preferably comprises an elevator brake arrangement 150 comprising an electromechanical brake 110 comprising a brake coil 112, and an elevator brake controller 100 connected to the brake coil 112.

[0057] There may be also a main electrical power supply 225 such as a three-phase or singlephase electrical power grid, an electrical connection 230 between the power supply 225 and the motor controller 204, another electrical connection 235 between the motor controller 204 and the electric motor 202.

[0058] Figure 5 shows a flow diagram of a method. Item or step 1000 refers to an optional start-up phase of the method. Suitable equipment and components are obtained, and systems assembled and configured for operation, if these have not previously been set up.

[0059] At least part of the rest of the method steps, if not all, may, optionally, be performed by the elevator brake controller 100; 100A; 100B; 100C and / or the elevator control unit 290.

[0060] Item or method step 1010 refers to regulating energy dissipation of stored energy of the brake coil 112 in one or several energy dissipation elements 102A-102C by an elevator brake controller 100; 100A; 100B; 100C.

[0061] The method may be stopped at item 1099.

[0062] The method may comprise, shown in item or method step 1020, adapting, optionally by a processing unit of the elevator brake controller 100; 100A; 100B; 100C, a duty cycle of one or several first controllable power switches 103 A, 103B which are arranged to short-circuit the brake coil 112 during the energy dissipation.

[0063] The method may comprise, shown in item or method step 1020, automatically adjusting the operation time to be in an acceptable range.

[0064] It is also noted herein that while the above describes example embodiments, these should not be viewed in a limiting sense. Rather, there are several variations and modifications, which may be made without departing from the scope of the present disclosure as defined in the appended claims.

[0065] The previously presented considerations concerning the various embodiments of the device may be flexibly applied to the embodiments of the method, and vice versa, as being appreciated by a skilled person.

[0066] Some advantageous embodiments of the phone and method according to the invention have been described above. The invention is not limited to the embodiments described above, but the inventive idea can be applied in numerous ways within the scope of the claims. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated.

Claims

CLAIMS1. An elevator brake controller (100A; 100B; 100C) for an electromechanical brake (110) comprising a brake coil (112), the elevator brake controller (100A; 100B; 100C) comprising: one or several electrical energy dissipation elements (102A-102C) for dissipating stored energy in the brake coil (112) when operating the electromechanical brake (110), and a control circuitry (101 A; 10 IB; 101C) in connection with the one or several energy dissipation elements (102A-102C), wherein the control circuitry (101A; 101B; 101C) is arranged to be connected to the brake coil (112), wherein the control circuitry (101 A; 101B; 101C) comprises a processing unit (105) and is configured to adjust operation time of the electromechanical brake (110) by regulating energy dissipation of the stored energy in the one or several energy dissipation elements (102A-102C) by the processing unit (105).

2. The elevator brake controller (100A; 100B; 100C) according to claim 1, wherein the regulation of the energy dissipation relates to a dissipation rate of the stored energy.

3. The elevator brake controller (100A; 100B; 100C) according to claim 1 or 2, wherein the control circuitry is configured to adjust the operation time by regulating voltage over the brake coil (112).

4. The elevator brake controller (100A; 100B; 100C) according to any of claims 1- 3, wherein the control circuitry (101A; 101B; 101C) is configured to short-circuit the brake coil (112) via one or several first controllable power switches (103 A, 103B).

5. The elevator brake controller (100 A; 100B; 100C) according to claim 4, wherein the short-circuit is arranged to be parallel relative to the one or several electrical energy dissipation elements (102A-102C).

6. The elevator brake controller (100A; 100B; 100C) according to claim 4 or 5, wherein the control circuitry (101 A; 101B; 101 C) is configured to adapt a duty cycle of the one or several first controllable power switches (103 A, 103B) during the energy dissipation.

7. The elevator brake controller according (100A; 100B; 100C) to claim 6, wherein the one or several first controllable power switches (103 A, 103B) are switched based on a pulse-width modulation technique.

8. The elevator brake controller (100A; 100B; 100C) according to any of claims 1- 7, wherein the control circuitry (101A; 101B; 101C) comprises one or several second controllable power switches (104A-104C) for connecting the one or several electrical energy dissipation elements (102A-102C) to dissipate the stored energy.

9. The elevator brake controller (100A; 100B; 100C) according to claim 8, wherein each one of the at least one of the several second controllable power switches (104A- 104C) is in series with one of the at least one electrical energy dissipation element (102A-102C).

10. The elevator brake controller (100A; 100B; 100C) according to any of claims 1- 9, configured to automatically adjust the operation time to be in an acceptable range.

11. The elevator brake controller (100A; 100B; 100C) according to claim 4, wherein a current path of the short-circuit includes, in addition to the one or several first controllable power switches (103A, 103B), one or several diodes.

12. The elevator brake controller (100A; 100B; 100C) according to any of claims 1- 11, wherein the one or several electrical energy dissipation elements (102A-102C) comprises one or several varistors, optionally in series connection with a diode.

13. An elevator brake arrangement (150) comprising: an electromechanical brake (110) comprising a brake coil (112), and an elevator brake controller (100A; 100B; 100C) according to any one of claims 1-12 connected to the brake coil (112).

14. An elevator system (200) comprising an elevator car (201), an elevator motor (202) arranged to cause moving of the elevator car (201), and the elevator brake arrangement (150) according to claim 13.

15. A method for adjusting operation time of an electromechanical brake (110) of an elevator system (200), the electromechanical brake (110) comprising a brake coil (112), the method comprising regulating (1010) energy dissipation of stored energy of the brake coil (112) in one or several energy dissipation elements (102A-102C) by an elevator brake controller (100A; 100B; 100C) according to any of claims 1-12.

16. The method of claim 15, comprising adapting (1020), by a processing unit of the elevator brake controller (100 A; 100B; 100C), a duty cycle of one or several first controllable power switches (103 A, 103B) which are arranged to short-circuit the brake coil (112) during the energy dissipation.

17. The method of claim 15 or 16, comprising automatically adjusting (1030) the operation time to be in an acceptable range.

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