WO2023161250A1

WO2023161250A1 - Electric protection device comprising a measuring module

Info

Publication number: WO2023161250A1
Application number: PCT/EP2023/054373
Authority: WO
Inventors: Gerhard Grosse-Holz; Jürgen Reich; Hans Dieter Storzer; Simon Brose
Original assignee: EBG innolab GmbH
Priority date: 2022-02-24
Filing date: 2023-02-22
Publication date: 2023-08-31
Also published as: DE102022104394A1

Abstract

The invention relates to an electric protection device (10), in particular in the form of a fuse strip, comprising at least one receiving chamber (12) for a fuse (13) which has at least one fuse blade (14a, 14b), in particular two fuse blades, for electrically contacting at least one electric contact (15a, 15b) of the electric protection device (10), said at least one electric contact being installed in a fixed manner. Each fuse (13) has a window-like opening (17a) which can be closed by means of a closure element (17b), wherein the opening (17a) is arranged such that one of the fuse blades (14a) can be electrically contacted through the opening. The invention is characterized in that a measuring module (18) can be inserted and/or plugged into the opening (17a).

Description

Electrical protection device with measuring module

The present invention relates to an electrical protective device, in particular in the form of a fuse strip, with at least one receiving space for a fuse, which has at least one, in particular two, fuse blades for making electrical contact with at least one permanently installed contact of the electrical protective device, with each fuse being assigned a cover and the cover has a window-like opening which can be closed in particular by means of a closure element, the opening being arranged in such a way that one of the safety knives can be electrically contacted through it.

Current measurements in the energy supply sector are carried out as standard using current sensors, which are electrical components with which the current intensity in cables and busbars is usually measured in a galvanically isolated (non-contact) manner using the magnetic flux density caused by electrical currents.

A distinction is made between sensors that can only detect alternating currents and those that can detect direct and alternating currents.

AC sensors are referred to as current transformers in the narrower sense. They usually consist of a ring core and are designed like a transformer. The alternating magnetic field of a conductor through which the alternating current to be measured flows induces an alternating current in the measuring coil which is proportional to the measuring current via the reciprocal turns ratio. In principle, direct current sensors can also detect alternating currents and transient processes.

In particular, the current transformers described above are built correspondingly large and can usually be retrofitted only with difficulty without removing covers or housing parts of the respective electrical device. Electrical devices of this type, in particular in the form of fuse strips in cable distribution cabinets, can usually not be retrofitted with appropriate current measuring devices during ongoing operation.

Figures 1a and 1b show from DE 10 2017 011 374 previously known electrical (current) measuring devices 5 for low-voltage fuse strips 1, which have electrical fuses for each electrical phase, which are each arranged behind covers 2. In the embodiment shown in FIG. In the embodiment shown in FIG. 1b, the electrical measuring device 5 is arranged in the housing 4a of the fuse strip 1. A disadvantage of these embodiments is that the fuse strip must first be switched off before the measuring device can be mounted and connected.

A protective device of the type mentioned is known, for example, from European patent application EP 1 058 283 A2 and German published application DE 199 13 017 A1.

Newly installed low-voltage switchgear, within the electrical energy supply or industrial plants, are increasingly equipped with appropriate measuring technology for recording electrical variables in addition to the protective devices. It is about low-voltage switchgear that is equipped for selective line protection with, for example, NH fuse switch disconnectors or NH fuse switch-disconnectors that use fuses of the so-called low-voltage, high-performance (NH) type according to DIN 43620/1 (also in English). "Square body fuse" called). These have a body with a rectangular cross section from which a solid, flat blade contact protrudes on opposite sides, which can be inserted into a corresponding receptacle in the base body of the protective device. The fuses are therefore also referred to as fuse inserts.

In such systems, attempts are increasingly being made to integrate the measurement technology as part of the basic unit of a protective device of this type. For example, DE 199 13 017 A1 discloses the integration of measuring devices or similar systems in or on the pivotable flaps of such protective devices, each carrying a fuse link. By pivoting a flap, the fuse link with its blade contacts is inserted into the corresponding receptacles in the base body. The flap thus covers the space in which the NH fuse is located.

In the following, the acquisition of electrical variables within low-voltage switchgear is discussed with reference to the current state of the art. As a rule, the current in the low-voltage outgoing feeders, the voltage on the busbar or the voltage on the outgoing side of the protective devices are recorded. Other variables (power, energy, etc.) can be derived from these variables. Furthermore, temperature sensors for detecting the temperature in the interior of a low-voltage switchgear can be integrated.

For current measurement, it is known, for example, to attach a module to the output terminals of an NH fused switch-disconnector, in which current transformers are integrated and to which the lines of the line output can finally be connected. Such measuring modules are described in the European patent application EP 2 259 284 A2 for NH fuse switch disconnectors and in the German patent application DE 10 2011 052 499 A1 for NH fuse switch disconnectors.

In addition, there are so-called transformer load switch strips for NH fuse switch disconnectors. A transformer load disconnector differs from typical NH fuse load disconnectors in that a current transformer is integrated into the disconnector. For example, DE 10 2007 051 419 A1 discloses one LV HRC fuse switch disconnector, in which a current transformer encompasses a connecting element that is attached to the back of the disconnector at its base and connects the receptacle of a blade contact to the busbar.

In another variant, current transformers are already integrated during production of the strip, in that the strip is designed in such a way that a current transformer can be plugged onto the blade contact receptacles, as is described in the application EP 2 546 856 A1.

There are also special LV HRC fuse links, the body of which encompasses the fusible conductor has a lower overall height than the LV HRC fuse links designed according to DIN 43620/1. Due to this lower overall height of the body, there is enough space in the lower part of the NH fused safety edge to attach a special current transformer, adapted to this application, to the blade contact of the fuse, which itself has a grip tab and thus a transformer fuse combination with the dimensions of DIN 43620/ 1 forms. This is disclosed, for example, in DE 199 13 017 A1.

To measure voltage, it is known, for example, to use voltage taps on the blade contact receptacles. Patent application EP 1 058 283 A2 offers a solution for detecting and monitoring the voltage within low-voltage switchgear. In this case, both a voltage measurement and a differential voltage measurement are carried out via the NH fuse links within an NH fused isolating switch strip in such a way that the voltage taps within the strip take place directly at the receptacles (contact tongues) for the blade contacts of the fuses.

The measuring lines are then routed through the lower part of the bar (base body) to a monitoring system that is mounted directly on the bar. A temperature measurement can also be carried out by simply integrating temperature sensors within the housing of the low-voltage switchgear. By distributing different temperature sensors, the temperature of individual areas can also be recorded in a differentiated manner. As a further element of measurement electronics within a low-voltage distribution system, in addition to the sensors (current transformers, temperature sensors, voltage taps), the measurement value conversion and processing must be taken into account. In the current state of the art, this is usually done by a central device outside the protective device, with all connections from the sensors to the external central device being realized by cables of appropriate length. In the European patent application EP 1 058 283 A2, the measuring lines are connected to a monitoring unit that is installed above an NH fused load switch.

In detail, all of the solutions presented offer adequate approaches for detecting the respective physical variable, whereby attention has already been paid to a small space requirement and a reduced amount of wiring. However, none of the solutions offers a simple and cost-effective way of retrofitting or the optional possibility of providing a measuring device with corresponding fuse strips.

There are also previously known fuse strips, as shown by way of example in Figure 2, in which the covers 17 of the fuses 13 each have openings 17a, which are each opened and closed by means of a closure means 17b, usually in the form of a cover that is slidably mounted on the cover These openings 17b are used to plug contact terminals, not shown, into the open openings 17b, which are electrically connected to the blades of the fuses 13 located below the respective opening 17b. The contact terminals are electrically connected to electrical cables, which allows energy to be tapped during operation of the fuse strip.The fuses 13 each have fuse blades 14a, 14b, which make contact with electrical contacts 15a, 15b fixedly arranged in the fuse strip 10 as soon as the fuse 13 is in the fuse strip 10 is introduced by means of the pivotably mounted covers 17. The fuses 13 are arranged one behind the other in the longitudinal extension direction of the fuse strip 10 and are connected to the outlets and busbars of the fuse strip 10 via the electrical contacts 15a, 15b. The object of the present invention is to provide a simple way of retrofitting or equipping an electrical protective device according to the invention, in particular in the form of a fuse strip described, with a current measuring device.

According to the invention, this object is achieved with an electrical protective device according to claim 1 and by means of an electrical measuring module according to claim 6 . Advantageous configurations of both the electrical protective device and the electrical measuring module result from the respective dependent claims.

The invention is based on the idea of using the so-called "construction power opening" or other existing openings in the cover in order to determine at least one physical variable through this by means of a measuring module. The measuring module according to the invention can also be pushed onto an exposed safety knife. Usually the measuring module according to the invention will at least be designed to determine the electric current flowing through the associated fuse This can be done by means of a Hall sensor or a current transformer, which is part of the measuring module.

The measurement module is advantageously designed in such a way that no separate attachment means are required to attach the measurement module to the electrical protective device. It is particularly advantageous if the measuring module is held on the protective device after installation, e.g. by means of a snap-in connection or form fit.

The measuring module is advantageously designed to be small and compact, so that it can be accommodated in the installation space of the electrical protective device itself, such that no further modifications to the protective device are required.

The measurement module can have a wide variety of sensors for detecting a number of physical quantities. A Hall sensor, current transformer, position sensor, temperature sensor, acceleration sensor, moisture sensor and/or pressure sensor can be provided as sensors. Advantageously, by means of the measuring module according to the invention, at least the Fuse blade current I and / or the temperature T measured or determined in the receiving space of the fuse or in the area of the fuse blade.

As a rule, one measuring module should be provided for each electrical phase.

It is also possible for the measuring modules to be electrically connected to one another and/or to communicate with one another and/or to communicate with one in or on the electrical protective device or in a control cabinet in which the electrical protective device is arranged, or to communicate their data to them send and/or are in electrical connection with it. If they are electrically connected to one another, power can also be tapped off jointly via the phases of the electrical protective device, with which the measuring modules are supplied with power. The measuring modules can also have energy stores, which make them functional even when the protective device is not carrying current. The energy stores can also be of the rechargeable type.

The measuring module according to the invention advantageously has a data processing unit which processes the signal from the at least one sensor. Optionally, the measurement module can also have a memory, which can be arranged in particular in the data processing unit, which is used to store the determined measurement data.

Furthermore, it is advantageous if the measuring module has a communication interface, in particular in the form of a radio module, via which the measuring module communicates with a further data processing unit arranged remotely from the measuring module or which transmits the determined data.

This further data processing unit can be arranged or integrated on or in the electrical protective device or in a control cabinet in which the electrical protective device is arranged.

The measuring module can advantageously have means, in particular an electrical contact, for tapping off energy from the safety knife. For example, two phases of a three-phase network for a voltage tap for the energy supply are used. In this case, an electrical connection would have to be provided between at least two measurement modules. If the measuring module is in the form of a current transformer, it does not require any galvanic contact to tap off the energy.

The measurement module advantageously has a housing which is designed in such a way that it closes the opening alone or together with the closure element when installed, so that the necessary protection against accidental contact and protection against dirt is provided.

The measuring module according to the invention can have at least one leg which extends in the direction of the safety knife and is fastened on or in the housing of the measuring module. A Hall sensor, for example, can be arranged on this leg, which is located in the immediate vicinity or next to the safety knife when the measuring module is inserted or installed.

The at least one leg can be designed in one or more parts, in particular in two parts, with one leg part being pivotably attached to the other, for example. However, it is also possible for the leg or legs to be formed from a resilient material and/or to be pivotably mounted on the housing of the measuring module.

It is advantageous if, depending on the sensor used, the legs of the measuring module are designed and their material selection is also adapted to the measuring method used. In particular, insulation and/or a distance between the leg(s) and the safety knife should be provided if necessary. In particular, the leg can also be made of an electrically and/or magnetically conductive material, which is optionally also encased with a plastic, at least in some areas. In addition, electrical connecting lines can be provided along one leg, with which the sensor or sensors are connected to the data processing unit of the measuring module.

The measuring module according to the invention can also be designed in such a way that its legs extend on both sides along the safety knife and encompass it, in particular with their free ends touch/contact and form a closed loop around the fuse blade so that the measurement module can form a current transformer.

The measuring module can also have at least one interface, in particular in the form of a plug, for the electrical connection to at least one further measuring module or evaluation electronics. In this way, the individual measurement modules can be easily wired together. Of course, it is also possible for each measuring module to be designed with a connecting line with which it can be connected to the other measuring modules and/or an external data processing device.

If the measuring module has a position sensor, this can advantageously also be used to monitor the switching state of the fuse, since the measuring module also changes its position in space when the fuse is covered.

The invention is explained in more detail below with reference to drawings.

Show it:

1a: First embodiment of an electrical protective device according to the prior art;

1b: second embodiment of an electrical protective device according to the prior art;

Fig. 2: third embodiment of an electrical protective device according to the prior art with "construction power openings" for each fuse;

FIG. 3 shows a detail representation of FIG. 3 without a cover but with a measuring module according to the invention, which is designed as a current transformer;

4: first possible embodiment of a measurement module according to the invention;

FIG. 5 shows a detail representation of FIG. 3 with a cover and with a mounted measuring module according to the invention according to FIG. 4; FIG. 6 shows a detail representation of FIG. 3 with a cover and with a fitted measuring module according to the invention, which has a Hall sensor for current measurement as the sensor;

7a: Measuring module with Hall sensor for current measurement and electrical contacting of the fuse blade;

Fig. 7b: Measuring module with a Hall sensor and a further sensor for measuring a further physical variable.

FIG. 3 shows a detail representation of FIG. 3 without cover 17 but with measuring module 18 according to the invention, which is designed as a current transformer. The measuring module 18 is shown only as a block module and can in reality have a completely different shape and contour. The measuring module 18 has a housing 18a in which, as shown in FIG. 4, a data processing unit 23, optionally also with a memory 24, is arranged. Below the housing 18a, the legs 18s extend in the direction of the safety knife 14b and enclose it with their free ends 18sf, which are connected to one another after the measuring module has been pushed into the opening 17a of the cover 17 from above. The legs 18s are pushed apart by the fuse blade 14b and then spring back towards each other so that their free ends touch and the legs 18s together form a loop around the fuse blade 14b, which is necessary to form a current transformer. The measurement module 18 can transmit either the pure measurement signal or already evaluated or converted data to a remote data processing and evaluation unit. For this purpose, the measuring module can have a communication unit, in particular the data can also be transmitted by radio signal.

It is also possible for the individual measurement modules 18 to be or can be connected to one another and/or to externally arranged evaluation electronics by means of electrical cables, in particular data cables. FIG. 5 shows the embodiment described above with a cover 17 and with a fitted measuring module 18 according to the invention as shown in FIG. 4, with the opening 17a being released by the displaced cover 17b.

FIG. 6 shows a further possible embodiment in which the measuring module according to the invention has a Hall sensor for current measurement as the sensor. In principle, only one leg 18s is necessary for this, through which the Hall sensor 20 can be placed in the immediate vicinity of the safety knife 14b. In contrast to the current transformer variant according to FIG. 4, the leg 18s can be made shorter. A measuring module 18 with a Hall sensor 20 for current measurement and electrical contacting of the fuse blade 14a is shown in FIG. 7a. The Hall sensor is on the left leg 18s

20 arranged, wherein the Hall sensor 20 does not come into contact with the fuse blade 14b. This can also be realized by a non-illustrated plastic sheathing of the leg. The second leg 18s', on the other hand, is in electrical contact with the fuse blade 14a, so that the measuring module 18 can be supplied with energy via this contact.

FIG. 7b shows a measuring module 18 with a Hall sensor 20, which is arranged on the left leg 18s. A further sensor 21 for measuring a further physical variable, such as the temperature, is arranged on the opposite second leg 18s'. The two sensors 20,

21 are connected via the electrical lines 24 to the data processing unit 23 of the measuring module.

Claims

patent claims

1. Electrical protective device (10), in particular in the form of a fuse strip, with at least one receiving space (12) for a fuse (13), which has at least one, in particular two, fuse blades (14a, 14b) for electrical contacting of at least one permanently installed electrical contact (15a, 15b) of the electrical protective device (10), each fuse (13) being assigned a cover (17) and the cover (17) having a window-like opening (17a) which can be closed in particular by means of a closure element (17b). wherein the opening (17a) is arranged in such a way that one of the safety knives (14a) can be electrically contacted through it, characterized in that a measuring module (18) can be pushed and/or plugged into the opening (17a).

2. Electrical protective device (10) according to claim 1, characterized in that in each case a cover (17) is provided which is in particular designed to be pivotable or displaceable.

3. Electrical protective device (10) according to claim 1 or 2, characterized in that the measuring module (18) for measuring the current (I) flowing through the fuse blade (14a) and/or the temperature (T) in the receiving space (12) or of the safety knife (14a).

4. Electrical protective device (10) according to claim 1, 2 or 3, characterized in that the measuring module (18) is fastened or can be fastened to the cover (17) by means of a latching connection and/or a form fit.

5. Electrical protective device (10) according to any one of claims 1 to 4, characterized in that a measuring module (18) is provided for each electrical phase.

6. Electrical protective device (10) according to claim 5, characterized in that the measuring modules (18) are electrically connected to one another and/or communicate with one another and/or communicate with a device in or on the electrical protective device (10) or in a control cabinet in which the electrical protective device (10) is arranged, or send their data to it and/or communicate with it in electrical connection are. Measuring module (18) for installing, plugging in or introducing into the opening (17a) of a cover (17) of the electrical protective device (10) according to one of Claims 1 to 6 or for plugging onto a fuse blade (14a, 14b) of a fuse (17) , characterized in that the measuring module (18) has at least one sensor (20) which is used to measure a physical variable. Measuring module (18) according to Claim 7, characterized in that the sensor (20) is used to determine the magnetic field generated by the current (I) to be measured. Measuring module (18) according to Claim 7 or 8, characterized in that the sensor (20) is a Hall sensor, current transformer, temperature sensor, acceleration sensor, position sensor, humidity sensor and/or pressure sensor. Measuring module (18) according to one of Claims 7 to 9, characterized in that the measuring module (18) has a data processing unit (23) which processes the signals of the at least one sensor (20). Measuring module (18) according to one of Claims 7 to 10, characterized in that the measuring module (18) has a memory (24), which is arranged in particular in the data processing unit (23), which is used to store determined measurement data. Measuring module (18) according to one of Claims 7 to 11, characterized in that the measuring module (18) has a communication interface, in particular in the form of a radio module, via which the measuring module (18) can be connected to a further data processing unit ( ZDV) communicated.

13. Measuring module (18) according to claim 12, characterized in that the further data processing unit (ZDV) is arranged or integrated on or in the electrical protective device (10) or in a control cabinet in which the electrical protective device (10) is arranged .

14. Measuring module (18) according to one of claims 7 to 13, characterized in that the measuring module (18) has means (21), in particular an electrical contact, for tapping energy from the fuse blade (14a).

15. Measuring module (18) according to one of claims 7 to 14, characterized in that the measuring module (18) has an energy store (22), in particular in the form of a battery or a rechargeable accumulator.

16. Measuring module (18) according to one of claims 7 to 15, characterized in that the measuring module (18) has a housing (18a) which is designed such that it has the opening (17a) in the assembled state alone or together with the Closure element (17b) closes.

17. Measuring module (18) according to one of claims 7 to 16, characterized in that the measuring module (18) has at least one leg (18s) which extends in the direction of the safety knife (14a) and is fastened on or in the housing (18a).

18. Measuring module (18) according to claim 17, characterized in that the at least one leg (18s) is formed in one or two parts, formed from a resilient material and/or is pivotably mounted.

19. Measuring module (18) according to claim 17 or 18, characterized in that at least one sensor (20), in particular a Hall sensor, is arranged on at least one leg (18s). 0. Measuring module (18) according to any one of claims 17 to 19, characterized in that on at least one leg (18s) an electrical Line (24) is arranged or the leg (18s) is formed from an electrically conductive material and / or ferromagnetic material and / or the legs have a plastic sheath.

21. Measuring module (18) according to one of claims 17 to 20, characterized in that the legs (18s) embrace the safety knife (14a) on both sides and touch each other with their free ends (18sf) and form a closed loop around the safety knife (14a). form.

22. Measuring module (18) according to one of claims 5 to 21, characterized in that a measuring module (18) has at least one interface, in particular in the form of a plug, for the electrical connection to at least one further measuring module (18).

23. Measuring module (18) according to one of claims 5 to 22, characterized in that the measuring module (18) can be pushed onto the fuse blade (14, 14b) transversely to the current direction, in particular also during operation.

24. Measuring module (18) according to one of claims 5 to 23, characterized in that the measuring module (18) has a housing (18a) which extends into the opening (17a) in the installed or plugged-in state and/or which at least part of its housing lies within the cover (17) or the electrical protective device (10).

25. Measuring module (18) according to one of claims 5 to 23, characterized in that the electrical measuring components and/or the at least one sensor (20) are arranged in the housing (18a).

26. Measuring module (18) according to one of claims 5 to 25, characterized in that the housing of the measuring module (18) closes the opening (17a) in a sealing manner, at least one seal being arranged between the housing of the measuring module and the cover (17). .

27. Measuring module (18) according to any one of claims 17 to 26, characterized in that the at least one leg (18s) within the Housing (18a) or part of the housing (18a), wherein the sensor (20) is arranged inside or in the housing wall of the housing (18a). Measuring module (18) according to one of Claims 17 to 27, characterized in that a circuit board extends in a leg (18s) of the housing (18a), in particular is cast into the housing (18a).