Method for operating a switch, switch, and computer program

Abstract

The invention relates to a method for operating a switch (10) for medium and high voltages, said switch (10) being operated by an electromagnetic drive (20). The electromagnetic drive (20) is actuated and operated by switch control electronics (100), and the electromagnetic drive (20) additionally has an electromagnet (30) with a coil (35), wherein a process is carried out of indirectly determining a variable of an air gap (40) in the electromagnet (30), said air gap (40) being arranged between an armature (32) of the electromagnet (30) and a yoke (36) of the electromagnet (30), and the determined variable of the air gap (40) is assigned to one of at least two possible switch positions, i.e. an open position (44) or a closed position (46).

Description

[0001] Description

[0002] Method for operating a switch, switch and computer program

[0003] The disclosure relates to a method for operating a switch, such a switch, a computer program for carrying out the method and a computer-readable storage medium with the computer program.

[0004] Methods for operating a switch are known in the prior art, in which the switching state is determined using microswitches. Furthermore, switches that check the correctness of the control signal are also known in the prior art. For example, DE 10 2020 210 206 discloses a control system for a circuit breaker drive in which the validity of the control signal is checked before the actuator begins to move.

[0005] There is also a need for methods for operating switches, particularly contactors, in which the correct end position can be checked after the switching operation from "off" to "on" or from "on" to "off" in order to detect an error when the desired switching movement is reached. There is also a need for methods in which an unwanted drop from the desired switching position can be detected in the static state. There is also a need to detect the current switching position at the start time.

[0006] The object of the invention is to provide an improved method for operating a switch, in particular a switch for medium voltages or high voltages.

[0007] The problem is solved by the independent claims and the claims dependent on them.

[0008] A first aspect relates to a method for operating a switch for medium and high voltages, wherein the switch is operated with an electromagnetic drive, wherein the electromagnetic drive is controlled and operated by switch control electronics, and wherein the electromagnetic drive further comprises an electromagnet with a coil, wherein an indirect determination of a size of an air gap in the electromagnet takes place, wherein the air gap is arranged between an armature of the electromagnet and a yoke of the electromagnet and the determined size of the air gap is assigned to one of at least two, an open position or a closed position, or is assigned to three or at least three possible switching positions, an open position, an intermediate position or a closed position.

[0009] The indirect determination of the size of the air gap is preferably carried out by determining the decay time of an electric current in the coil(s). The method thus takes advantage of the fact that different switching positions, each with a different air gap in the electromagnet, result in different decay times of the current in the coil(s).

[0010] The indirect determination of the size refers to the fact that the position of the armature in the electromagnet is not determined directly, for example without a microswitch, but by means of other measured variables, such as current and / or voltage and / or magnetic field strength, in particular in or on the coil or coils.

[0011] It is preferred that a) when the switch is open, the coil of the electromagnetic drive is energized with an electric current by the switch control electronics in such a way that a closing movement of the open switch is not initiated and after the energization has ended, the decay time of the electric current in the coil of the electromagnet is determined, and / or b) after the switch has ended, the decay time of an electric current in the coil of the electromagnet is determined, wherein in the case of an applied holding current, only the decay time until before or equal to reaching the holding current is determined or considered, and / or c) when the switch is closed, the coil of the electromagnetic drive is energized with an electric current by the switch control electronics in such a way thatthat an opening movement of the closed switch is not initiated and after the energization has ended, the decay time of the electric current in the coil of the electromagnet is determined, whereby the respective determined decay time is compared with predetermined decay time bands.,

[0012] By comparing the determined decay time with the predetermined decay time bands, a switching state of the switch is preferably determined. The comparison of the determined decay time with the predetermined decay time bands and the determination of the switching state are preferably carried out with the switch control electronics or with a separate microcontroller or in a protective device. The control electronics or the protective device are either implemented in a single unit, or the control electronics or the protective device are distributed across different units, or the control electronics or the protective device are based partially or entirely on a distributed system, in particular a cloud-based system.

[0013] The electric current in the coil is also called the excitation current. This process takes advantage of the fact that different switching positions, each with a different air gap in the electromagnet, lead to different decay times of the current in the coil(s).

[0014] It is also preferred that the predetermined decay time bands include a first decay time band, a second decay time band and a third decay time band.

[0015] It is particularly preferred that the first decay time band comprises decay times between 35 ms and 45 ms, preferably between 35 ms and 43 ms, the second decay time band comprises decay times between 45 ms and 55 ms, preferably between 47 ms and 53 ms, and the third decay time band comprises decay times between 55 ms and 65 ms, preferably between 57 ms and 65 ms. In this case, further preference is given to either the lower limit of the interval or the upper limit of the interval being contained in the respective decay time band, or alternatively, for better differentiation, a spacing being provided between the adjacent intervals.

[0016] It is further preferred that switch states are assigned to the decay time bands and if the expected state of the switch does not correspond to the switch state determined by means of the decay bands, a warning signal is generated, output and / or displayed.

[0017] It is also particularly preferred that the decay times for different switching positions, such as closed position, open position and / or intermediate position, are stored and compared with subsequent, i.e. current, determined decay times for the respective switching positions and that in the event of a deviation by a predetermined value, a warning message and / or maintenance recommendation is generated.

[0018] In particular, it is preferred that, based on the comparison of the current determined decay times for the respective switching positions with the previous determined decay times for the respective switching positions, a remaining service life of the electromagnetic drive is calculated and a predictive maintenance recommendation is given which preferably minimizes downtimes of the switchgear based on a stored usage behavior or predetermined usage profiles.

[0019] It is also preferred that the predetermined decay time bands be predetermined based on a number of identically constructed switches. This has the advantage of time-optimized production. Furthermore, it is also preferred that the predetermined decay time bands of each switch be predetermined individually. This leads to greater accuracy in determining the switching state.

[0020] It is preferred that the electromagnetic drive has an air gap between a yoke and an armature of the electromagnetic drive and the first decay time band is assigned to a decay behavior at a first air gap size, the second decay time band is assigned to a decay behavior at a second air gap size, and the third decay time band is assigned to a decay behavior at a third air gap size.

[0021] In particular , it is preferred that the first air gap size corresponds to a smallest air gap size , the second air gap size corresponds to a medium air gap size , and the third air gap size corresponds to a largest air gap size .

[0022] It is preferred that the electric current in the coil and the decay time of the electric current in the coil are determined by means of a shunt arranged in series with a freewheeling diode.

[0023] Furthermore, a method is preferred in which the electric current in the coil and the decay time of the electric current in the coil are determined by means of a Hall sensor.

[0024] It is also preferred that an analog measurement signal, which determines the value of the measured electrical current in the coil, is converted into a digital signal by means of an ADC, an analog-to-digital converter, and is evaluated by the switch control electronics with regard to the decay time of the electrical current in the coil.

[0025] A second aspect relates to a switch with switch control electronics, an electromagnetic drive and an electromagnet with a coil, wherein the switch is designed to carry out a method according to one of the above methods.

[0026] A third aspect relates to a computer program comprising instructions which, when the program is executed by a computer or programmable component, cause the computer or programmable component to carry out the method according to the above statements.

[0027] In particular, the computer program can be executed partially or entirely on a cloud-based system.

[0028] Particularly preferably, a digital twin is formed by means of the computer program, i.e. a digital representation of the electromagnetic drive and / or the switchgear, which digital twin digitally reproduces the state of the electromagnetic drive and / or the switchgear and compares it with a forecast and adapts maintenance intervals or replacement intervals to the current state.

[0029] A fourth aspect relates to a computer-readable storage medium on which the above computer program is stored.

[0030] With regard to the device according to the invention, all statements made above and below regarding the method according to the invention apply correspondingly, and vice versa. In particular, the device according to the invention is designed to carry out the method according to the invention in any desired embodiment or a combination of desired embodiments. With regard to the advantages of the device according to the invention, reference is also made to the advantages described for the method according to the invention.

[0031] Regardless of the grammatical gender of a particular term, persons with male, female, or other gender identities are included. The invention is explained in more detail below using an exemplary embodiment. The specific embodiment of the exemplary embodiment is in no way to be understood as limiting the general design of the method and device according to the invention; rather, individual design features of the exemplary embodiment can be freely combined with one another and with the features described above in any manner.

[0032] Figure 1. Schematic representation of a switchgear for medium and / or high voltages;

[0033] Figure 2. Schematic representation of a side view of a switch for medium and / or high voltages

[0034] Figure 3. Schematic representation of an electromagnetic drive for a switch for medium and / or high voltages;

[0035] Figure 4 . Schematic graphic representation of two decay times for a current in a coil of the electromagnetic drive;

[0036] Figure 5 . Schematic graphic representation of three exemplary decay time bands .

[0037] Figure 1 shows a schematic representation of a front view of a switchgear for medium and / or high voltages 1 . In the example shown, the switchgear 1 consists of a first switchgear panel 2 and a second switchgear panel 3 . Both the first switchgear panel 2 and the second switchgear panel 3 have an optional display and control unit 5 and optional display elements 4 . The display elements 4 are, for example, pressure displays, status displays, voltage displays, current displays or other parameter displays . The display and control units 5 are preferably human-machine interfaces which display switchgear parameters such as pressure, voltage, current, operating times, remaining service life, maintenance instructions or other parameters and also provide monitoring, i.e. control, of switching operations and the setting of parameters .

[0038] Furthermore, the first control panel 2 has an optional first manual control unit 6 and the second control panel 3 has an optional first manual control unit 7.

[0039] Figure 2 shows a schematic representation of a side view of a switch 10 for medium and / or high voltages. The switch 10 is formed with a switching element 17, here, for example, with an air-insulated vacuum switch in a pole housing. Alternatively, and not shown, the switch 10 can also be formed with a gas-insulated switch, wherein the gas-insulated switch is in turn formed with a vacuum interrupter or a switch in a switching gas.

[0040] In the example shown, the switch 10 further comprises a drive and control unit 12. The drive and control unit 12, in turn, optionally comprises a manual control unit 14. Optionally, the manual control unit 14 is identical to a first manual control unit 6 or a second manual control unit 7.

[0041] The drive and control unit 12 is provided with a drive part 16 of the kinematic chain 50 (not shown here) for driving the switching element 17. The switching element 17 has a first electrical contact 18 of the switch 10 and a second electrical contact 19 of the switch 10 for electrically connecting the switching element 17 to a switchgear 1.

[0042] Figure 3 shows an exemplary schematic representation of an electromagnetic drive 20 for a switching element of a switch 10 for medium and / or high voltages. The electromagnetic drive 20 is designed to transfer a switching element 17 from an open switching position to a closed switching position in the closing direction 21 and from a closed switching position to an open switching position opposite to the closing direction 21. The electromagnetic drive 20 has a kinematic chain 50 for this purpose. In the kinematic chain 50, a drive linkage 51, a contact pressure spring 52, an open hold spring 53 and a moving contact rod 54 are shown here by way of example and optionally, wherein the representation of deflections, buffers, stops or adjustment options has been omitted for reasons of clarity.

[0043] The electromagnetic drive 20 here has an electromagnet 30 with an armature 32, in particular a solenoid armature, and projections 33 on the armature 32. The armature is movably mounted in the electromagnet 30 and designed to drive the switching linkage 51 of the kinematics 50. The electromagnet 30 further has a yoke 36 with coils 35 and permanent magnets 38. In the open switching position, the open position 44, the electromagnet 30 has an air gap 40 between the armature 32 and the yoke 36 and at the same time the optional projections 33 close an optional further air gap between the yoke 36 and the armature 32 in order to enable a magnetic short circuit. Furthermore, the air gap 40 has a largest air gap size 43 in the open position 44 here.

[0044] In an intermediate position 45 between the open position 44 and a closed position 46, the air gap 40 has a medium air gap size 42.

[0045] In the closed position 46, i.e., the position in which the switching element 17 is closed in this example, the air gap 40 has a smallest air gap size 41. To determine the decay times 1100 of the electrical current in one or more coils 35, the current is determined, for example, via a shunt, or a Hall sensor, a so-called Hall probe, is used to measure the current.

[0046] Figure 4 shows a schematic graphic representation of two decay times 1100 for a current in a coil 35 of the electromagnetic drive 20, as shown by way of example in Figure 3. The time t in ms is plotted on the x-axis and the current intensity I in A is plotted on the y-axis. The first decaying current 1010 is an example for an electromagnetic drive 20 in a closed position 46, that is to say with a smallest air gap size 41. The determined decay time 1100 is 40 ms here, for example. The second decaying current 1020 is shown by way of example for an electromagnetic drive 20 in an open position 44, that is to say with a largest air gap size 43. The determined decay time 1100 is 60 ms here, for example. The decay times 1100 are determined, for example, when the current in the coil 35 drops by 66 + / - 3%, for example when the current drops from 6 A to 2 A.The specific difference between 40 ms and 60 ms is sufficiently large to allow a reliable differentiation of the switching states, in particular the detection of an intermediate position 45 .

[0047] Figure 5 shows a schematic graphic representation of three exemplary decay time bands 1500, with the time t in ms being plotted on the x-axis. The measurements start at the same current strength and are shown one above the other only for better comparability. A first decay time band 1501 is shown, which first decay time band 1501 is characteristic here, for example, for a smallest air gap size and thus for a closed position 45. Also shown is a second decay time band 1502, which second decay time band 1502 is characteristic here, for example, for a medium air gap size 42 and thus for an intermediate position 45. Also shown is a third decay time band 1503, which third decay time band 1503 is characteristic here, for example, for a largest air gap size 43 and thus for an open position 44. Reference symbol list

[0048] 1 switchgear for medium and / or high voltages;

[0049] 2 first switchgear panel of switchgear 1 ;

[0050] 3 second switchgear panel of switchgear 1;

[0051] 4 display elements;

[0052] 5 Display and control unit;

[0053] 6 first manual control unit;

[0054] 7 second manual control unit;

[0055] 10 switches for medium and / or high voltages;

[0056] 12 drive and control unit of the switch 10 ;

[0057] 14 Manual control unit of the switch 10 ;

[0058] 16 Drive part of the kinematic chain 50 for driving a switching element 17 ;

[0059] 17 switching element, in particular vacuum interrupter of a switch 10;

[0060] 18 first electrical contact of the switch 10 ;

[0061] 19 second electrical contact of the switch 10 ;

[0062] 20 electromagnetic drive for the medium and / or high voltage switch 10 ;

[0063] 21 Closing direction of the electromagnetic drive 20

[0064] 30 Electromagnet of the electromagnetic drive 20 ;

[0065] 32 Armature, in particular plunger armature, of the electromagnetic drive 20 in the open switching position;

[0066] 32 ' anchor shown dashed in the closed

[0067] Schal tpos it ion;

[0068] 33 projection on the anchor 32 ;

[0069] 35 coil in the electromagnet 30 of the electromagnetic drive 20 ;

[0070] 36 yoke of the electromagnet 30 ;

[0071] 38 permanent magnet of the electromagnet 30;

[0072] 40 Air gap between yoke 36 and armature 32 ;

[0073] 41 smallest air gap size;

[0074] 42 average air gap size;

[0075] 43 largest air gap size;

[0076] 44 open position;

[0077] 45 intermediate position;

[0078] 46 closed position; 50 kinematic chain between the electromagnetic drive 20 and the switching element 17 ;

[0079] 51 drive linkage in the kinematic chain 50 ;

[0080] 52 Contact pressure spring in the kinematic chain 50 ; 53 Open hold spring in the kinematic chain 50 ;

[0081] 54 moving contact rod in the kinematic chain 50 ;

[0082] 1010 first decaying current;

[0083] 1020 first fading current;

[0084] 1100 cooldown; 1500 cooldown bands;

[0085] 1501 first decay band;

[0086] 1502 second decay band;

[0087] 1503 third cooldown band .

Claims

Patent claims 1. Method for operating a switch (10) for medium and high voltages, wherein the switch (10) is operated with an electromagnetic drive (20), wherein the electromagnetic drive (20) is controlled and operated by switch control electronics (100), and wherein the electromagnetic drive (20) further comprises an electromagnet (30) with a coil (35), characterized in that an indirect determination of a size of an air gap (40) in the electromagnet (30) takes place, wherein the air gap (40) is arranged between an armature (32) of the electromagnet (30) and a yoke (36) of the electromagnet (30), and the determined size of the air gap (40) is assigned to one of at least two possible switching positions, an open position (44) or a closed position (46).

2. Method according to claim 1, characterized in that a) when the switch (10) is open, the coil (35) of the electromagnetic drive (20) is energized with an electric current by the switch control electronics (100) in such a way that a closing movement of the open switch (10) is not initiated and after the energization has ended, the decay time (1100) of the electric current in the coil (35) of the electromagnet (30) is determined, and / or b) after the switch (10) has ended, the decay time (1100) of an electric current in the coil (35) of the electromagnet (30) is determined, wherein in the case of an applied holding current, only the decay time until before or equal to reaching the holding current is determined or considered, and / or c) when the switch (10) is closed, the coil (35) of the electromagnetic drive (20) is energized by the switch- Control electronics (100) is supplied with an electric current in such a way that an opening movement of the closed switch (10) is not initiated and after the energization has ended, the decay time (1100) of the electric current in the coil (35) of the electromagnet (30) is determined, wherein the respectively determined decay time (1100) is compared with predetermined decay time bands (1500).

3. Method according to claim 2, characterized in that the predetermined decay time bands (1500) include a first decay time band (1501), a second decay time band (1502) and a third decay time band (1503).

4. Method according to one of the preceding claims 2 to 3, characterized in that the predetermined decay time bands (1500) are predetermined on the basis of a number of identical switches (10).

5. Method according to one of the preceding claims 2 or 3, characterized in that the predetermined decay time bands (1500) are predetermined for each switch (10) individually.

6. Method according to one of the preceding claims 3 to 5, characterized in that the electromagnetic drive (20) has an air gap between a yoke and an armature of the electromagnetic drive (20) and the first decay time band (1501) is assigned to a decay behavior at a first air gap size, the second decay time band (1502) is assigned to a decay behavior at a second air gap size, and the third decay time band (1503) a decay behavior at a third air gap size is assigned.

7. The method according to claim 6, characterized in that the first air gap size corresponds to a smallest air gap size (41), the second air gap size corresponds to a medium air gap size (42) and the third air gap size corresponds to a largest air gap size (43).

8. Method according to one of the preceding claims 2 to 7, characterized in that the electric current in the coil and the decay time (1100) of the electric current in the coil are determined by means of a shunt arranged in series with a freewheeling diode.

9. Switch (10) with switch control electronics (100), an electromagnetic drive (20) and an electromagnet (30) with a coil (35), characterized in that the switch (10) is designed to carry out a method according to one of the above methods.

10. A computer program comprising instructions which, when executed by a computer or programmable component, cause the computer or component to carry out the method according to claims 1 to 8.

11. A computer-readable storage medium on which the computer program according to claim 10 is stored.

Images