阅读说明：本技术 用于探测电导线中的电流的电流计 (Current meter for detecting current in electrical conductor ) 是由 马丁·扬科夫斯基 于 2019-08-07 设计创作，主要内容包括：本发明涉及用于探测电导线(30)中的电流的电流计(1),其包括壳体(10)和被包围在该壳体(10)中的磁场传感器(13,14)的组件。在此设定,壳体(10)具有多个形成在壳体壁(101)上的容纳凹槽(100),其中可分别从外部插入一根电导线(30),其中该壳体(10)包围由壳体壁(101)限定的内部空间(102),在该内部空间内部布置有用于探测插入该容纳凹槽(100)中的电导线(30)处的磁场的磁场传感器(13,14)的组件。通过这种方式给出了电流计,其以简单的方式实现了在多个导体处探测电流,可以在室外使用并且在可能情况下可以加装到已存在的设备,尤其太阳能设备上。(The invention relates to a current meter (1) for detecting a current in an electrical line (30), comprising a housing (10) and an assembly of magnetic field sensors (13,14) enclosed in the housing (10). It is provided that the housing (10) has a plurality of receiving recesses (100) formed in a housing wall (101), in which an electrical line (30) can be inserted from the outside in each case, wherein the housing (10) encloses an interior space (102) which is delimited by the housing wall (101) and in which an assembly of magnetic field sensors (13,14) for detecting a magnetic field at the electrical line (30) inserted into the receiving recesses (100) is arranged. In this way, a current meter is provided which, in a simple manner, makes it possible to detect the current at a plurality of conductors, which can be used outdoors and, if applicable, can be retrofitted to existing installations, in particular solar installations.)

1. Ammeter (1) for detecting an electric current in an electrical conductor (30), comprising a housing (10) and an assembly of magnetic field sensors (13,14) enclosed in the housing (10), characterized in that the housing (10) has a plurality of receiving recesses (100) formed in a housing wall (101), in which one electrical conductor (30) can be inserted from the outside, respectively, wherein the housing (10) encloses an inner space (102) defined by the housing wall (101), inside which inner space an assembly of magnetic field sensors (13,14) for detecting a magnetic field at an electrical conductor (30) inserted in the receiving recess (100) is arranged.

2. A current meter (1) according to claim 1, characterized in that a receiving recess (100) is formed on a first side of a housing wall (101) and that an electrical conductor (30) can be inserted into the receiving recess (100) on the first side while components of a magnetic field sensor (13,14) are arranged on a second side of the housing wall (101) facing away from the first side.

3. A current meter (1) according to claim 1 or 2, characterized in that the receiving grooves (100) extend parallel to each other on the housing (10).

4. A current meter (1) according to any of claims 1-3, characterized in that the housing (10) is sealed against the outside in a moisture-tight manner.

5. A current meter (1) according to any of the preceding claims, characterized in that each receiving recess (100) corresponds to at least one magnetic field sensor (13,14) of the assembly of magnetic field sensors (13, 14).

6. A current meter (1) according to any of the preceding claims, characterized in that at least two magnetic field sensors (13,14) are present per receiving recess (100).

7. A current meter (1) according to any of the preceding claims, characterized in that two magnetic field sensors (13,14) are arranged opposite each other on both sides of the corresponding receiving recess (100).

8. A current meter (1) according to any of the preceding claims, characterized in that at least some of the components of the magnetic field sensors (13,14) are formed by magneto-resistive sensors.

9. A current meter (1) according to any of the preceding claims, characterized in that the current meter has an electronic assembly (12) enclosed in a housing (10), which has a control device (16) for evaluating sensor signals obtained via components of the magnetic field sensors (13, 14).

10. A current meter (1) according to any of the preceding claims, characterized in that the current meter has a calibration assembly (17) with a test conductor (170,172) to which a test current can be applied, which test conductor is arranged relative to the assembly of the magnetic field sensors (13,14) in the housing (10) such that an evaluation of the detected magnetic field can be calibrated by means of the test current.

11. Ammeter (1) according to any of the preceding claims, characterized in that it has a first connection for connecting a wire (2) for providing power and/or for transmitting data signals.

12. A current meter (1) according to any of the preceding claims, characterized in that the current meter has a second connection for connecting the current meter (1) to another current meter (1') for detecting a current on a further electrical conductor (30).

Technical Field

The present invention relates to a current meter for detecting current in an electrical conductor as described in the preamble of claim 1.

Background

A current meter of this type comprises a housing and a magnetic field sensor assembly enclosed in the housing.

A current meter of this type can be used in particular for monitoring so-called string currents on solar installations. The solar panels are usually connected to each other in series, for example, by wires, so that a current, a so-called string current, flows between the solar panels. For the purpose of monitoring the string current, it is desirable to detect the current on this type of wire.

In order to monitor the string current, known current meters typically require that the electrical conductor that is to detect the current be disconnected. This is cumbersome and otherwise causes significant intervention in the system.

In the current meter disclosed in DE 102014119276 a1, an electrical conductor can be placed between the half shells in order to detect the magnetic field on the electrical conductor and to deduce the current in the electrical conductor by means of a magnetic field sensor. In order to connect the current meter to the electrical leads to be monitored, the housing halves must be separated. At the connection location, the electrical leads extend through the housing of the current meter, which may make it difficult to seal the housing against the outside in a moisture-tight manner for outdoor use.

Disclosure of Invention

The object of the invention is to provide a current meter which can detect the current on a plurality of conductors in a simple manner, can be used outdoors and can be retrofitted, if appropriate, to existing installations, in particular solar installations.

This object is solved by a body having the features of claim 1.

The housing thus has a plurality of receiving recesses formed in the housing wall, into which the electrical lines can be inserted from the outside in each case. The housing encloses an interior space delimited by the housing wall, in which interior space magnetic field sensor means are arranged for detecting the magnetic field at the electrical line inserted into the receiving recess.

Therefore, a receiving recess into which a plurality of electrical leads can be inserted is formed in a housing wall of a housing of the current meter. The receiving recess is open to the outside so that the electrical lines can be inserted into the receiving recess from the outside without the housing having to be opened in this case. This makes it simple and convenient to connect the wires to the current meter and, in particular, also makes it possible to retrofit current meters on existing devices in a simple manner without having to make complex modifications to the device, in particular, disconnecting the wires.

The components of the magnetic field sensor are enclosed inside a housing. In particular, provision can be made in this case for a receiving recess to be formed on a first side of the housing wall and for electrical lines to be inserted into the receiving recess on the first side, while the components of the magnetic field sensor are arranged on a second side of the housing wall facing away from the first side. Thus, the housing wall separates the exterior of the housing from the interior of the housing. The first side corresponds to an exterior of the housing wall, while the second side faces the interior. The magnetic field sensor is therefore enclosed inside the housing, separated from the electrical lines inserted into the receiving recess by the housing wall, and can be encapsulated with respect to the outside in such a way that moisture and dirt do not enter the housing and do not reach the region of the magnetic field sensor.

In one configuration, the receiving grooves extend parallel to one another on the housing. Therefore, a plurality of electrical leads may be attached to the housing in parallel with each other and accommodated in the accommodation groove. In this case, the receiving groove is formed as a recess in the housing wall of the housing and has an inner clear width adapted to the electrical line to be attached to the housing.

In one configuration, the housing is sealed against the outside in a moisture-tight manner. The housing can in particular meet the desired protection class, for example IP67 (according to EN 60529) or the like, and is therefore weather-resistant, so that the current meter can be used in outdoor areas.

In one configuration, there is at least one magnetic field sensor associated with each receiving recess. For example, two or more magnetic field sensors can be arranged in the region of each receiving recess, which magnetic field sensors are used to detect the magnetic field generated in the region of the receiving recess by an electrical conductor inserted into the receiving recess in order to output a sensor signal, by means of which the current in the electrical conductor can be inferred. Magnetic field sensors of this type can therefore be used for indirect current measurement by inferring a measure of the current strength in the electrical conductor from the magnetic field, possibly using appropriate calibration.

For example, two magnetic field sensors may be arranged opposite to each other on both sides of the corresponding receiving recess. The magnetic field sensors receive the receiving grooves therebetween such that the electrical leads inserted into the receiving grooves are located between the magnetic field sensors. The magnetic field sensor is therefore arranged in the vicinity of the electrical line inserted into the receiving recess in order to detect the magnetic field generated by the current flowing through the electrical line and to generate a sensor signal dependent on the magnetic field.

In one configuration, at least some or all of the magnetic field sensors are formed from magnetoresistive sensors. This type of magnetoresistive sensor utilizes the so-called magnetoresistive effect, as a result of which the resistance of the material changes in accordance with an external magnetic field. This type of resistance change can be detected and evaluated in order to deduce the magnetic field strength and thus the current strength flowing in the electrical conductor on the basis of the resistance change.

With a magnetoresistive sensor of this type, a time-varying alternating magnetic field in alternating current can be detected in the same way as a time-invariant magnetic field in direct current in an electrical line, so that both alternating current and direct current can be detected on the electrical line inserted into the receiving recess.

In one embodiment, the current meter has an electronic assembly enclosed in a housing, which has a control device for evaluating a sensor signal obtained via the magnetic field sensor assembly. The electronic component can have, for example, a printed circuit board on which the magnetic field sensor and an electronic chip for implementing the control device are arranged. The magnetic field sensor is connected to the control device and its sensor signal is fed to the control device which evaluates the sensor signal in order to deduce the current in the electrical line attached to the current meter from the sensor signal.

In one embodiment, the current meter has a calibration assembly with a test conductor to which a test current can be applied, which is arranged relative to the assembly of the magnetic field sensor in the housing such that an evaluation of the detected magnetic field can be calibrated by means of the test current. For example, under the control of the control device, a test current may be generated by a controllable current source in order to conduct a defined current through the test conductor. In this case, the test conductor is arranged in a defined positional relationship with respect to at least one magnetic field sensor in the magnetic field sensor assembly, so that a magnetic field is detected at the one or more magnetic field sensors on the basis of the test current. Due to the known test current and the known positional relationship of the test conductor relative to the magnetic field sensor, a calibration can be carried out with the magnetic field detected in this way in order to determine the current flowing in the electrical line from the sensor signal detected by the magnetic field sensor.

In this case, each magnetic field sensor in the magnetic field sensor assembly can be assigned to a test conductor, so that the magnetic field sensor can be calibrated and tested for its function, respectively. However, it is also conceivable to have only one magnetic field sensor assigned to a test conductor in order to calibrate the current meter overall by means of one test conductor.

The test conductors can be designed, for example, as individual, for example electrically insulated, conductors which are arranged in a defined positional relationship with respect to the corresponding magnetic field sensor. It is also conceivable and possible to form the test conductors, for example, by conductor circuits on a printed circuit board.

In one embodiment, the current meter has a first connection for connecting a line for supplying power and/or for transmitting data signals. For example, the current meter can be supplied with power via the first connection in order to supply the electronic components enclosed in the housing. In this case, data signals, for example measured values of the current flowing through the electrical lines, or analog standard signals, for example in the range from 0/4 to 20mA or-20 mA to 20mA, or voltage signals, for example in the range from 0 to 10V, 0 to 5V, -10V to +10V, etc., can also be transmitted to the superordinate assembly via the first connection.

If the first connection portion is designed as a data connection portion, the first connection portion may be designed as a USB interface, an RS485 connection portion, an ethernet connection portion, or other serial interfaces. In an advantageous embodiment, it is conceivable and possible to use both the power supply and the data transmission via the first connection.

Furthermore, the current meter may have a second connection for connecting the current meter to another current meter for detecting a current on a further electrical conductor. Thus, the current meter may have, for example, two connections, which enable the current meters to be connected in cascade with each other, so that a large number (substantially any number) of electrical wires may be monitored via a cascade arrangement of current meters.

Each current meter may have, for example, four or eight receiving recesses for inserting four or eight electrical conductors. However, a different number of receiving recesses can also be considered on each current meter.

Drawings

In the following, the basic concept of the invention will be explained in more detail with the aid of embodiments shown in the drawings. In the figure:

fig. 1 shows a view of an electrical device together with a current meter;

FIG. 2 shows another view of a current meter;

FIG. 3 shows components of a magnetic field sensor of a current meter;

FIG. 4 shows a view of a cascade connection of a plurality of current meters;

FIG. 5 shows a schematic diagram of a schematic circuit diagram of a current meter;

FIG. 6 shows a schematic view of electrical leads on a receiving recess of a housing of a current meter; and

fig. 7 shows a view of the arrangement of the test conductors of the calibration assembly with respect to the magnetic field sensor.

Detailed Description

Fig. 1 shows a view of a current meter 1 for monitoring a current on an electrical line 30 of an electrical device 3, for example a solar device.

In the context of a solar installation, a plurality of solar modules for generating electric current from solar energy are connected in series with one another, for example, via electrical lines 30. In this case, the current flowing between the solar modules is to be monitored (qualitatively and quantitatively), for which purpose the current meter 1 is used.

An embodiment of such a current meter 1 is shown in fig. 2. The current meter 1 has a housing 10 which has a plurality of receiving recesses 100 extending parallel to one another on a housing wall 101 for receiving electrical lines 30. The (exactly) one electrical conductor 100 can be inserted into each receiving recess 100, so that the electrical conductor 30 is received in the corresponding receiving recess 100, for example in the inserted state, and is held in the receiving recess 100 in a clamping manner.

The receiving recess 100 is molded into the housing wall 101 on the outside, so that the electrical lead 30 can be inserted into the receiving recess 100 from the outside. Therefore, it is not necessary to open the housing 10 of the ammeter 1 to connect the electrical lead 30 to the ammeter 1. Furthermore, the electrical device does not have to be modified in any other way by disconnecting the electrical lead 30, which makes it possible to retrofit one or more current meters 1 on the electrical device in a simple manner.

As shown in fig. 3, in the exemplary embodiment shown, each receiving recess 100 corresponds to two magnetic field sensors 13,14 in the form of magnetoresistive sensors for detecting a magnetic field in the region of the receiving recess 100. The magnetic field sensors 13,14 corresponding to the respective accommodation recesses 100 are opposite to each other and accommodate the electrical lead 30 therebetween with the electrical lead 30 attached to the accommodation recess 100, wherein the magnetic field sensors 13,14 are enclosed within the housing 10 and separated from the electrical lead 30 externally attached to the housing 10 via the housing wall 101, as schematically shown in fig. 6.

The magnetic field sensors 13,14 in the form of magnetoresistive sensors have a resistance that varies in dependence on the magnetic field generated by the electrical leads 30. The magnetic field sensors 13,14 are connected to the electronic component 12, in particular a printed circuit board, via connecting lines 130, 140, so that a sensor signal dependent on the magnetic field present on the electrical line 30 can be obtained and evaluated via the magnetic field sensors 13,14 in order to draw conclusions about the current flowing through the electrical line 30 by means of the sensor signal.

The electrical line 30 has a conductor core 300, which is surrounded by an electrically insulating sheath 301, through which a current flows during operation of the upper-stage electrical device 3. Due to the current flow, a magnetic field is generated on the electrical line 30, which magnetic field surrounds the electrical line 30 in a circular manner and also penetrates the magnetic field sensors 13,14 and, due to the magnetoresistive effect, influences the electrical resistance on the magnetic field sensors 13, 14. Thus, for example, the field strength of the magnetic field around the electrical line 30 can be inferred by means of the voltage drop at the magnetic field sensors 13,14 in order to draw conclusions about the current flowing from the electrical line 30.

As can be seen in the schematic circuit diagram according to fig. 5, in an exemplary embodiment the current meter 1 has a control device 16, for example in the form of a processor arranged on a printed circuit board, to which the magnetic field sensors 13,14 corresponding to the different receiving recesses 100 are connected (only two receiving recesses 100 are schematically shown in fig. 5). The control device 16 serves to evaluate the sensor signals obtained by the magnetic field sensors 13,14 in order to draw conclusions about the current on the electrical line 30 received in the receiving recess 100.

By means of the obtained sensor signals, the current intensity in the electrical conductor 30 can be determined, for example, on the basis of a calibration. For calibration purposes, as shown in the embodiment according to fig. 5, the current meter 1 may have, for example, a calibration component 17 which makes self-calibration of the current meter 1 possible. This type of self-calibration can be performed before start-up and during ongoing operation to calibrate the current meter 1 before start-up and during operation.

The calibration assembly 17 has a test conductor 170 which is arranged in a defined positional relationship with respect to the associated magnetic field sensor 14, so that a calibration can be carried out by means of the current flowing through the test conductor 170, which calibration can lead to conclusions about the current strength in the electrical line 30 in the receiving recess 100.

The test conductor 170 is connected to a current source 171 which can be controlled by the control device 16 and by means of which a defined current can be conducted through the test conductor 170. By means of the defined currents and the sensor signals received via the corresponding magnetic field sensors 13,14 in combination with the positional relationship of the test conductor 170 relative to the corresponding magnetic field sensors 13,14, a calibration can be carried out which correlates the current values with the detected sensor signals which are dependent on the magnetic field, so that, for example, a calibration table can be created from which the current intensity of the current flowing in the electrical line 30 can be determined during actual operation by means of the sensor signals detected by the magnetic field sensors 13, 14.

As shown in fig. 7, the test conductor 170 may be designed as an insulated electrical conductor having a conductor core encapsulated in a cable sheath, which extends in a longitudinal direction along which the electrical conductor 30 is placed in the receiving recess 100 and which is arranged in a defined positional relationship with respect to the associated magnetic field sensor 13, 14.

In addition or alternatively, the test conductor 172 can also be formed by a conductor circuit on the printed circuit board 18, on which further electrical and electronic components of the current meter 1 (in particular the magnetic field sensors 13,14 and the control device 16) are arranged.

The test conductors 170,172 are each connected to a current source 171 for introducing a test current.

As shown in fig. 6, the magnetic field sensors 13,14 corresponding to the accommodation grooves 100 are arranged inside an inner space 102 surrounded by the housing 10. Instead, the electrical line 30 can be inserted from the outside into a receiving recess 100 formed on the housing wall 101, so that the electrical line 30 is located in the receiving recess 100 in the inserted state, but outside the housing 10, and the magnetic field sensors 13,14 are separated from the electrical line 30 by the housing wall 101. The magnetic field sensors 13,14 are connected to the printed circuit board of the electronic assembly 12 by connection lines 130, 140 and to the control device 16 (see fig. 5).

As shown in fig. 2, the current meter 1 has a first connection 11, by means of which a wire 2 can be connected to the current meter 1 in order to provide power at the current meter 1 and/or to transmit data to the current meter 1 or from the current meter 1 to a higher-level component.

If the connection 11 is designed for data transmission, the connection 11 can be realized, for example, by a USB interface, an RS485 interface or an ethernet interface.

In an advantageous embodiment, the connection 11 is designed to supply the current meter 1 with electrical power and additionally for data transmission. For this purpose, as is schematically shown in fig. 5, the connection 11 can have different contact elements 110, 111, by means of which, on the one hand, a supply current (contact element 110) and, on the other hand, data (contact element 111) can be transmitted, so that both a supply of power and data can be transmitted via the connection 11, for example for transmitting measured values from the current meter 1 to a superordinate component.

In one embodiment, the current meter 1 additionally has a second connection 15, as shown in fig. 4 and 5, by means of which an additional current meter 1 'can be connected to the current meter 1 in order to create a cascade arrangement of current meters 1, 1'. Via the connection 15, the current meter 1 can be connected to a further current meter 1 'via a line 2', wherein the contact elements 150, 151 of the connection 15 still supply power on the one hand and transmit data on the other hand.

An ammeter arrangement for measuring the current intensity over substantially any number of electrical leads 30 can be created by cascading a plurality of ammeters 1, 1'. In this case, each current meter 1, 1 'can be designed, for example, to receive eight lines 30, so that currents can be measured on multiples of the eight lines 30 by connecting a plurality of current meters 1, 1'.

In another configuration, four electrical leads 30, for example, may be attached to each ammeter 1, and accordingly, each ammeter 1 may have four receiving grooves 100, for example. However, a different number of receiving recesses 100 is also conceivable and possible on the current meter 1.

The housing 10 in which the electronic assembly 12 with the magnetic field sensors 13,14 and the control device 16 is enclosed is preferably encapsulated in a moisture-tight manner and may correspond to a desired level of protection, for example IP 67. This allows the ammeter 1 to be used outdoors.

A current meter 1 of the kind described may be attached to the electrical device 3. The housing 10 of the current meter 1 can be screwed together with the electrical device for this purpose or otherwise fixed to the electrical device for this purpose. It is also conceivable and possible to design the current meter 1 in such a way that it can be arranged on a support rail and can be combined with other electrical or electronic devices.

The basic concept of the invention is not limited to the exemplary embodiments described previously, but can also be implemented in a completely different way.

In particular, the current meter of the illustrated type is not only suitable for monitoring the string current on solar installations, but can in principle also be used for current measurement on completely different electrical installations.

Description of the reference numerals

1, 1' amperemeter

10 casing

100 receiving groove

101 casing wall

102 inner space

11 connecting part

110. 111 contact assembly

12 electronic component (printed circuit board)

13. 14 magnetic field sensor

130. 140 connecting wire

15 connecting part

150. 151 contact assembly

16 control device

17 calibration assembly

170 test conductor

171 current source

172 test conductor

18 printed circuit board

2, 2' conductor

20 connecting part

3 electric component (solar energy module)

30 wire

300 wire core

301 wire sheath