Monitoring a switchgear assembly
Patent Information
- Application Number
- EP2023813582
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-02
- Filing Date
- 2023-11-17
- Publication Date
- 2025-08-20
AI Technical Summary
The high cost and complexity of monitoring switchgear components due to the use of analog sensors, which require extensive wiring and are limited in accessibility and data transmission range, making them impractical for many applications.
Implementing a network of digital temperature sensors connected via a bus line to form a sensor network, allowing for efficient data transmission and self-monitoring, reducing installation effort and costs, and enabling flexible integration in difficult-to-access locations.
This approach significantly reduces measuring point costs, increases coverage, and facilitates comprehensive data-based condition analysis while enabling self-diagnosis of faulty sensors and connections, improving the reliability of switchgear monitoring.
Smart Images
Figure 1.1
Abstract
Description
[0001] Description
[0002] Monitoring a switchgear
[0003] The invention relates to a switchgear and a method for monitoring a switchgear.
[0004] In switchgear, information acquisition is becoming increasingly important as a basis for data-based monitoring and condition assessment of switchgear components. A large proportion of the information is acquired using sensors, which is leading to an increase in the number of sensors installed in the switchgear. Conventionally, analog sensors are used, but these have a number of disadvantages. Firstly, analog solutions are very cost-intensive, as each sensor value has to be digitized by an external electronic module. Only a small number of sensors, for example fewer than ten sensors, can be connected to a measured value processing unit. This increases the cost per measuring point by the cost of the measured value processing unit module and the total cost by the number of connected sensors.In addition to the actual sensors, many of these modules are required to achieve comprehensive information acquisition. Sensors are wired in parallel to a module, resulting in extensive wiring and a complex topology. The complexity is further increased because the cabling may not be fully adaptable to the integration requirements.
[0005] To avoid wiring, wireless temperature sensors are occasionally used. In addition to the actual temperature measuring unit, these also have integrated devices for transmitting the measured values to a central node or to the next sensor. This usually requires a power supply. This can be achieved either by integrated energy storage, by energy harvesting from current-carrying rails, by wireless power transmission from a central node or by other methods. What all of these sensors have in common is that they are relatively large due to the additional components and can therefore only be used at measuring points with sufficient space. Furthermore, in heavily encapsulated or sealed rooms the range of the data transmission is usually very limited, so that, for example, a large number of antennas are required.This results in the problem that the costs per measuring point are very high and therefore the use only makes sense in positions where no wired sensors can be used, for example at connection points in medium-voltage switchgear.
[0006] The invention is based on the object of specifying an improved method for monitoring a switchgear and a switchgear which is improved with regard to its monitoring.
[0007] The object is achieved according to the invention by a method having the features of claim 1 and by a switchgear having the features of claim 7.
[0008] Advantageous embodiments of the invention are the subject of the dependent claims.
[0009] In the method according to the invention for monitoring a switchgear, in particular a low-voltage system,
[0010] - several digital temperature sensors are arranged in the switchgear and networked by a bus to form a sensor network, wherein the bus has a bus line running between a first bus end of the bus and a second bus end of the bus, from which several bus branches branch off in a branch sequence related to the first bus end, in each of which at least one temperature sensor is arranged,
[0011] - measured values recorded by the temperature sensors are transmitted to the bus line via the respective bus branch,
[0012] - it is checked whether measured values received at the first bus end are complete and plausible, and
[0013] - if no measured values are received at the first bus end from any bus branch of a partial bus of the bus, which comprises at least one bus branch and all bus branches of the bus following this bus branch according to the branch sequence, measured values received from the partial bus at the second bus end are checked for completeness and plausibility.
[0014] For example, a measured value is classified as implausible if it shows an unrealistically high or low temperature. When checking the completeness of measured values received from the bus or a sub-bus, a check is made to see whether measured values have been received from all temperature sensors connected to the bus or sub-bus. A branch sequence of successive bus branches related to the first bus end refers to a sequence of bus branches that orders the bus branches in ascending order, starting from the first bus end along the connection of the bus branches to the bus line.
[0015] According to the invention, digital temperature sensors are used to monitor a switchgear assembly and are networked by a bus to form a sensor network. Compared to the use of analogue temperature sensors, this makes it possible to eliminate parallel wiring of the temperature sensors and replace it with a bus line. Furthermore, the number of temperature sensors connected to a central evaluation unit can be greatly increased compared to the use of analogue temperature sensors, which in turn considerably reduces the measuring point costs because the cost of the evaluation unit hardly depends on the number of measuring points. In addition, the installation effort for the temperature sensors is reduced and the temperature sensors can be integrated more flexibly, allowing measurements to be taken in places that are difficult to access. Due to the significant cost reduction, the measuring point coverage can be increased, which leads to an improved basis for data-based condition analysis.
[0016] In addition, the method according to the invention enables self-monitoring of the sensor network with regard to faulty sensors or connections. Knowledge of the bus structure, in particular the topology of the bus, makes it possible to detect and locate faulty temperature sensors and bus components such as hubs, nodes or line segments. To improve the self-monitoring of the sensor network, the method according to the invention further provides for the ability to check the measured values of the temperature sensors sent via the bus at both ends of the bus for completeness and plausibility. This creates a simple "system redundancy" on the one hand. On the other hand, it makes it possible to reach the temperature sensors that are no longer reachable from one end of the bus from the other end of the bus in the event of an interruption in the bus line (main line).Accordingly, the method provides that if no more measured values are received at the first bus end from a "rear" sub-bus of the bus connected to the second bus end, the measured values received at the second bus end from this sub-bus are to be checked for completeness and plausibility.
[0017] In one embodiment of the method according to the invention, the result of the test of the measured values received at the first bus end and / or the second bus end is used to diagnose errors in the sensor network. For example, if measured values are missing from parts of the sensor network, knowledge of the bus topology is used to locate possible fault locations in the sensor network.
[0018] In a further embodiment of the method according to the invention, if measured values are received at the second bus end from a bus branch of the partial bus, it is concluded that the bus line upstream of this bus branch is interrupted. This embodiment takes advantage of the fact that measured values received at the second bus end are only analyzed if no more measured values are received at the first bus end from a subsequent partial bus. If measured values are then received from a bus branch of the partial bus at the second bus end, it can be concluded that the bus line upstream of this bus branch is interrupted, because otherwise measured values from this bus branch would also be received at the first bus end.Although it is generally not possible to determine exactly where the bus line is interrupted, the location of the interruption can at least be reduced to the area between the bus branch from which measured values are received at the second bus end and the section of the bus line immediately before the rear sub-bus. In particular, it can be concluded that the bus line is interrupted in the section immediately before the rear sub-bus if measured values from the first bus branch of the rear sub-bus are received at the second bus end.
[0019] In a further embodiment of the method according to the invention, if no measured values are received at one end of the bus from a first temperature sensor arranged in a bus branch, but measured values are received at the end of the bus from a second temperature sensor arranged in the same bus branch, it is concluded that the first temperature sensor has failed or is faulty or that a connection in the bus branch to the first temperature sensor is interrupted.
[0020] In a further embodiment of the method according to the invention, if no measured values are received at the first bus end from a temperature sensor arranged in a first bus branch, but measured values are received from a second bus branch arranged downstream of the first bus branch, it is concluded that the temperature sensor has failed or is faulty, or that a connection in the first bus branch to the first temperature sensor is interrupted. Here, the second bus branch is referred to as being arranged downstream of the first bus branch if it is subordinate to the first bus branch according to the branch sequence.
[0021] In a further embodiment of the method according to the invention, if no measured values are received at the second bus end from a temperature sensor arranged in a first bus branch, but measured values are received from a second bus branch arranged upstream of the first bus branch, it is concluded that the temperature sensor has failed or is faulty or that a connection in the first bus branch to the first temperature sensor is interrupted. Here, the second bus branch is referred to as being arranged upstream of the first bus branch if the first bus branch is subordinate to the second bus branch according to the branch sequence.
[0022] The three aforementioned embodiments of the method according to the invention utilize the topology of the bus, namely that the bus essentially has a line topology or the topology of an open ring with bus branches branching off from the bus line.
[0023] A switchgear according to the invention, in particular a low-voltage system, comprises
[0024] - a plurality of digital temperature sensors which are networked by a bus to form a sensor network, wherein the bus has a bus line running between a first bus end of the bus and a second bus end of the bus, from which a plurality of bus branches branch off in a branch sequence related to the first bus end, in each of which at least one temperature sensor is arranged, wherein the temperature sensors are configured to transmit measured values acquired by them to the bus line via the respective bus branch, and
[0025] - a processing unit which is aware of the topology of the bus and which is set up to check whether measured values received at the first bus end are complete and plausible, and if no measured values are received at the first bus end from any bus branch of a sub-bus of the bus which comprises at least one bus branch and all bus branches following this bus branch according to the branch sequence, to check whether measured values received at the second bus end of the bus from the sub-bus are complete and plausible.
[0026] A switchgear assembly according to the invention enables the method according to the invention to be implemented. Therefore, the advantages of such a switchgear assembly correspond to the above-mentioned advantages of the method according to the invention. This also applies to the following embodiments of a switchgear assembly according to the invention.
[0027] In one embodiment of the switchgear assembly according to the invention, the processing unit has a first bus master connected to the first bus end and a second bus master connected to the second bus end, wherein the first bus master is configured to check measured values received at the first bus end for completeness, and the second bus master is configured to check measured values received at the second bus end for completeness.
[0028] In a further embodiment of the switchgear according to the invention, the processing unit is configured to use the result of the test of the measured values received at the first bus end and / or the second bus end to diagnose errors in the sensor network.
[0029] In a further embodiment of the switchgear according to the invention, the processing unit is configured to output an error message that the bus line is interrupted before a bus branch when measured values are received at the second bus end from this bus branch of the partial bus.
[0030] In a further embodiment of the switchgear according to the invention, the processing unit is set up to output an error message that a specific temperature sensor has failed or is faulty or that a connection to this temperature sensor is interrupted in the bus branch in which the temperature sensor is arranged, if no measured values are received from this temperature sensor at one end of the bus, but measured values are received at the end of the bus from another temperature sensor which is arranged in the same bus branch.
[0031] In a further embodiment of the switchgear according to the invention, the processing unit is set up to output an error message that a specific temperature sensor has failed or is faulty or that a connection to this temperature sensor is interrupted in the bus branch in which the temperature sensor is arranged, if no measured values are received from this temperature sensor at the first bus end, but measured values are received from a bus branch arranged behind the bus branch in which the temperature sensor is arranged.
[0032] In a further embodiment of the switchgear according to the invention, the processing unit is set up to output an error message that a specific temperature sensor has failed or is faulty or that a connection to this temperature sensor is interrupted in the bus branch in which the temperature sensor is arranged, if no measured values are received from this temperature sensor at the second bus end, but measured values are received from a bus branch arranged upstream of the bus branch in which the temperature sensor is arranged.
[0033] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of exemplary embodiments, which are explained in more detail in connection with the drawings. Therein: FIG. 1 shows an exemplary embodiment of a switchgear with several digital temperature sensors that are networked by a bus to form a sensor network,
[0034] FIG 2 shows a flow diagram of an embodiment of the method according to the invention,
[0035] FIG 3 the sensor network shown in Figure 1 in a first fault case,
[0036] FIG 4 the sensor network shown in Figure 1 in a second fault case,
[0037] FIG 5 the sensor network shown in Figure 1 in a third fault case,
[0038] FIG 6 the sensor network shown in Figure 1 in a fourth error case with the first bus master activated,
[0039] FIG 7 the sensor network shown in Figure 1 in the fourth error case with the second bus master activated,
[0040] FIG 8 the sensor network shown in Figure 1 in a fifth fault case.
[0041] Corresponding parts in the figures are provided with the same reference symbols.
[0042] Figure 1 (FIG 1) shows schematically an exemplary embodiment of a switchgear 1 with a plurality of digital temperature sensors S 1 to S 6 . The switchgear 1 is, for example, a low-voltage switchgear. Apart from the networking of the temperature sensors S 1 to S 6, the design of the switchgear 1 is irrelevant for the invention and is therefore not shown or described in more detail here. The temperature sensors S 1 to S 6 are networked by a bus 2 to form a sensor network. The bus 2 has a bus line 3 (main line) running between a first bus end and a second bus end of the bus 2. In the bus line 3, a plurality of nodes K1 to K3 are arranged one after the other along the bus line 3, at each of which a bus branch B1 to B3 branches off from the bus line 3.
[0043] In each bus branch Bl to B3 at least one temperature sensor S1 to S6 is arranged, which is connected to the bus line 3 via the respective bus branch Bl to B3 and the node Kl to K3, via which the bus branch Bl to B3 is connected to the bus line 3.
[0044] Furthermore, the bus 2 has a processing unit 4, which comprises a first bus master M1 and a second bus master M2. The first bus master M1 is connected to a first end of the bus line 3, the second bus master M2 is connected to a second end of the bus line 3. The nodes K1 to K3 and bus branches B1 to B3 are each assigned a bus or branch sequence along the bus line 3, starting from the first end of the bus line 3 or from the first bus master M1. According to the branch sequence, in the example shown, B1 is the first bus branch of bus 2, B2 is the second bus branch of bus 2, and B3 is the third bus branch of bus 2. Accordingly, in the node sequence, K1 is the first node, K2 is the second node, and K3 is the third node in the bus line 3.In the example shown, the first bus branch B1 has a temperature sensor S1, the second bus branch B2 has two temperature sensors S2, S3 and a branch node K4, and the third bus branch B3 has three temperature sensors S4, S5, S6 and two branch nodes K5, K6.
[0045] The bus 2 thus essentially has a line topology or the topology of an open ring with bus branches B1 to B3, which branch off from the bus line 3 at a node K1 to K3, respectively, and in which the temperature sensors S1 to S6 are arranged. The topology of the bus 2 and the relationships between the nodes K1 to K3 are known to the processing unit 4 or are stored in the processing unit 4.
[0046] For example, a hub is arranged at each of the nodes Kl to K3 and is set up to forward data that it receives, both from the bus branch Bl to B3 connected to it into the bus line 3 and from the bus line 3 into the bus branch Bl to B3 connected to it and via the bus line 3 on to a neighboring node Kl to K3. Measured values recorded by a temperature sensor S 1 to S 6 are transmitted in the bus branch Bl to B3, in which the temperature sensor S 1 to S 6 is arranged, to the node Kl to K3 connected to the bus branch Bl to B3 and are forwarded from the node Kl to K3 to the bus line 3. The measured values are checked for completeness and plausibility by the processing unit 4 according to the method described with reference to Figures 2 to 8.
[0047] Figure 2 (FIG 2) shows a flow diagram of an embodiment of the method according to the invention with method steps 101 to 110.
[0048] In a first method step 101, with the first bus master M1 activated, the processing unit 4 checks the measured values of the temperature sensors S1 to S6 received from the first bus master M1 for completeness and plausibility within a defined test time interval. Following the first method step 101, a second method step 102 is executed.
[0049] In the second method step 102, the processing unit 4 checks whether the first bus master M1 has received at least one plausible measured value from each temperature sensor S1 to S6 within the test time interval. If this is the case, the first method step 101 is executed again. Otherwise, a third method step 103 is executed.
[0050] In the third method step 103, the processing unit 4 checks whether the first bus master M1 did not receive a plausible measured value from several temperature sensors S1 to S6 in the first method step 101. If this is not the case, a fourth method step 104 is executed. Otherwise, a fifth method step 105 is executed.
[0051] In the fourth method step 104, the processing unit 4 identifies the temperature sensor S1 to S6 from which the first bus master M1 did not receive a plausible measured value in the first method step 101, and generates an error message that this temperature sensor S1 to S6 has failed, is faulty or is not accessible.
[0052] Figure 3 (FIG 3) shows an example of such a fault. The arrows indicate that the first bus master M1 is active. In this example, the bus branch B2 between the temperature sensor S3 and the branch node K4 is interrupted. Therefore, the first bus master M1 receives no measured values from the temperature sensor S3. This is indicated by a symbol x in the representation of the temperature sensor S3. The first bus master M1 receives measured values from all other temperature sensors S1, S2, S4, S5 and S6. This is indicated by a check mark symbol. These temperature sensors are indicated in the diagram. Processing unit 4 identifies a fault location F based on the bus topology and issues an error message indicating that temperature sensor S3 is faulty, has failed, or is not accessible.
[0053] In the fifth method step 105, the
[0054] Using the bus topology, processing unit 4 identifies those temperature sensors S1 to S6 from which the first bus master M1 did not receive a plausible measured value in the first method step 101. After the fifth method step 105, a sixth method step 106 is executed.
[0055] In the sixth method step 106, the processing unit 4 checks whether several temperature sensors S1 to S6, from which the first bus master M1 did not receive a plausible measured value in the first method step 101, are arranged in the same bus branch B1 to B3. If this is not the case, a seventh method step 107 is executed. Otherwise, an eighth method step 108 is executed.
[0056] In the seventh method step 107, the processing unit 4 generates an error message that the temperature sensors S1 to S6 identified in the fifth method step 105 have failed, are faulty or are not accessible.
[0057] Figure 4 (FIG 4) shows such a fault scenario. In this example, bus branch B2 between temperature sensor S3 and branch node K4 is interrupted, and bus branch B3 between temperature sensor S6 and branch node K6 is interrupted. Therefore, the first bus master M1 receives no measured values from temperature sensors S3 and S6. The first bus master M1 receives measured values from all other temperature sensors S1, S2, S4, and S5. Based on the bus topology, processing unit 4 identifies two fault locations F1 and F2 and outputs an error message indicating that temperature sensors S3 and S6 are faulty, failed, or unreachable.
[0058] In the eighth method step 108, the processing unit 4 checks whether the first bus master M1 is not receiving any measured values from any bus branch B1 to B3 of a sub-bus 5 (see Figure 6) of the bus 2, which comprises at least one bus branch B1 to B3 and all bus branches B1 to B3 following this bus branch B1 to B3 according to the branch sequence. If this is not the case, a ninth method step 109 is executed. Otherwise, a tenth method step 110 is executed.
[0059] In the ninth method step 109, an error message is generated that the temperature sensors S1 to S6 identified in the fifth method step 105 have failed, are faulty or are not accessible.
[0060] Figure 5 (FIG 5) shows an example of such a fault scenario. In this example, bus branch B2 between temperature sensor S2 and node K2 is interrupted. Therefore, the first bus master M1 receives no measured values from temperature sensors S2 and S3. The first bus master M1 receives measured values from all other temperature sensors S1, S4, S5, and S6. Based on the bus topology, processing unit 4 identifies a fault location F, which in this example encompasses the entire bus branch B2, and outputs an error message indicating that temperature sensors S2 and S3 are faulty, have failed, or are unreachable.
[0061] Figure 6 (FIG 6) shows an example of a fault scenario in which the tenth method step 110 is executed. In this example, the bus line 3 between the nodes K1 and K2 is interrupted. Therefore, the first bus master M1 receives no measured values from the bus branches B2 and B3. The bus branches B2 and B3 form a sub-bus 5 of the type mentioned above.
[0062] In the tenth method step 110, the second bus master M2 is activated.
[0063] After the tenth method step 110, method steps 101 to 109 are carried out for sub-bus 5 when the second bus master M2 is activated, instead of for the entire bus 2 when the first bus master M1 is activated. In method step 108, a check is carried out as to whether sub-bus 5 comprises a sub-bus which has at least one bus branch and all bus branches of the sub-bus which precede this bus branch, and from whose bus branches the second bus master M2 does not receive any measured values. If this is not the case, the checks of the measured values carried out with the first bus master M1 and the second bus master M2 are regarded as complete in the sense that at least all bus branches B1 to B3 have been individually checked for failed, faulty or unreachable temperature sensors S1 to S6, i.e. all bus branches B1 to B3 in which at least one temperature sensor S1 to S6 has failed, is faulty or unreachable have been determined.Otherwise, it cannot be concluded that the tests of the measured values carried out with the first bus master Ml and the second bus master M2 are complete in this sense.
[0064] Figure 7 (FIG 7) shows a fault case in which the tests of the measured values carried out with the first bus master M1 and the second bus master M2 are complete in the above sense. This is the fault case already shown in Figure 6, but after the activation of the second bus master M2, that is to say "from the perspective of the second bus master M2. Due to the interruption of the bus line 3 between the nodes K1 and K2, the second bus master M2 does not receive any measured values from the temperature sensor S1. Due to an interruption of the bus branch B2 between the temperature sensor S3 and the branch node K4, the second bus master M2 also does not receive any measured values from the temperature sensor S3. However, the second bus master M2 does receive measured values from the other temperature sensors S2, S4, S5 and S6. The first bus branch B1 can be tested when the first bus master M1 is activated, the other bus branches B2, B3 can be tested when the second bus master B2 is activated.Since the second bus master M2 receives measured values from the bus branch B2 (namely from the temperature sensor S2), the processing unit 4 can also detect that the bus line 3 between the nodes K1 and K2 is interrupted and identify this as a first fault location F1. Furthermore, in method step 104, which is carried out for the partial bus 5 when the second bus master M2 is activated, a second fault location F2 is identified and it is detected that the temperature sensor S3 in the bus branch B2 has failed, is faulty, or is not accessible.
[0065] Figure 8 (FIG 8), on the other hand, shows a fault case in which the tests of the measured values carried out with the first bus master M1 and the second bus master M2 are not complete in the above sense. In this example, the bus line 3 is interrupted both between the nodes K1 and K2 and also between the nodes K2 and K3. During the test shown in Figure 8 with the second bus master M2, no measured values are therefore received from the bus branch B2. In this case, the processing unit 4 cannot clearly identify the two interruptions in the bus line 3. From the point of view of the processing unit 4, for example, instead of two interruptions in the bus line 3, the two temperature sensors S2 and S3 could have failed and the bus line 3 could be interrupted between the nodes K1 and K2 or between the nodes K2 and K3.However, it can at least be concluded that there is a fault in a partial bus of bus 2, which includes bus branch B2 and bus line 3 between nodes K1 and K3.
[0066] Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.
Claims
Patent claims 1. Method for monitoring a switchgear (1), wherein - a plurality of digital temperature sensors (S1 to S6) are arranged in the switchgear (1) and are networked by a bus (2) to form a sensor network, wherein the bus (2) has a bus line (3) running between a first bus end of the bus (2) and a second bus end of the bus (2), from which a plurality of bus branches (B1 to B3) branch off in a branch sequence related to the first bus end, in each of which at least one temperature sensor (S1 to S6) is arranged, - measured values recorded by the temperature sensors (S1 to S6) are transmitted to the bus line (3) via the respective bus branch (B1 to B3), - it is checked whether measured values received at the first bus end are complete and plausible, and - if no measured values are received at the first bus end from any bus branch (Bl to B3) of a partial bus (5) of the bus (2), which comprises at least one bus branch (Bl to B3) and all bus branches (Bl to B3) of the bus (2) following this bus branch (Bl to B3) according to the branch sequence, measured values received at the second bus end from the partial bus (5) are checked for completeness and plausibility.
2. The method according to claim 1, wherein the result of the test of the measured values received at the first bus end and / or the second bus end is used to diagnose errors in the sensor network.
3. Method according to claim 2, wherein, if measured values are received at the second bus end from a bus branch (Bl to B3) of the partial bus (5), it is concluded that the bus line (3) is interrupted upstream of this bus branch (Bl to B3).
4. Method according to claim 2 or 3, wherein, if at one end of the bus a signal is transmitted from a bus branch (B1 to B3) If no measured values are received from the first temperature sensor (S1 to S6), but measured values are received at the end of the bus from a second temperature sensor (S1 to S6) arranged in the same bus branch (B1 to B3), it is concluded that the first temperature sensor (S1 to S6) has failed or is faulty, or that a connection in the bus branch (B1 to B3) to the first temperature sensor (S1 to S6) is interrupted.
5. Method according to one of claims 2 to 4, wherein, if no measured values are received at the first bus end from a temperature sensor (S1 to S6) arranged in a first bus branch (B1 to B3), but measured values are received from a second bus branch (B1 to B3) arranged behind the first bus branch (B1 to B3), it is concluded that the temperature sensor (S1 to S6) has failed or is faulty or a connection in the first bus branch (B1 to B3) to the first temperature sensor (S1 to S6) is interrupted.
6. Method according to one of claims 2 to 5, wherein, if no measured values are received at the second bus end from a temperature sensor (S1 to S6) arranged in a first bus branch (B1 to B3), but measured values are received from a second bus branch (B1 to B3) arranged upstream of the first bus branch (B1 to B3), it is concluded that the temperature sensor (S1 to S6) has failed or is faulty or that a connection in the first bus branch (B1 to B3) to the first temperature sensor (S1 to S6) is interrupted.
7. Switchgear (1) comprising - several digital temperature sensors (S 1 to S6) which are networked by a bus (2) to form a sensor network, wherein the bus (2) has a bus line (3) running between a first bus end of the bus (2) and a second bus end of the bus (2), from which several bus branches (B1 to B3) branch off in a branch sequence related to the first bus end, in each of which at least one temperature sensor (S1 to S6) is arranged, wherein the temperature sensors (S1 to S6) are arranged to transmit measured values detected by them to the bus line (3) via the respective bus branch (B1 to B3), and - a processing unit (4) which is aware of the topology of the bus (2) and which is set up to check whether measured values received at the first bus end are complete and plausible, and if measured values are not received at the first bus end from any bus branch (Bl to B3) of a sub-bus (5) of the bus (2) which comprises at least one bus branch (Bl to B3) and all bus branches (Bl to B3) following this bus branch (Bl to B3) according to the branch sequence, to check whether measured values received at the second bus end of the bus (2) from the sub-bus (5) are complete and plausible.
8. Switchgear (1) according to claim 7, wherein the processing unit (4) has a first bus master (M1) connected to the first bus end and a second bus master (M2) connected to the second bus end, wherein the first bus master (M1) is configured to check measured values received at the first bus end for completeness, and the second bus master (M2) is configured to check measured values received at the second bus end for completeness.
9. Switchgear (1) according to claim 7 or 8, wherein the processing unit (4) is configured to use the result of the test of the measured values received at the first bus end and / or the second bus end to diagnose faults in the sensor network.
10. Switchgear (1) according to one of claims 7 to 9, wherein the processing unit (4) is configured to output an error message that the bus line (3) is interrupted before a bus branch (B1 to B3) when measured values are received at the second bus end from this bus branch (B1 to B3) of the partial bus (5).
11. Switchgear (1) according to one of claims 7 to 10, wherein the processing unit (4) is set up to output an error message that a specific temperature sensor (S1 to S6) has failed or is faulty or that a connection to this temperature sensor (S1 to S6) is interrupted in the bus branch (B1 to B3) in which the temperature sensor (S1 to S6) is arranged, if no measured values are received from this temperature sensor (S1 to S6) at one end of the bus, but measured values are received at the bus end from another temperature sensor (S1 to S6) which is arranged in the same bus branch (B1 to B3).
12. Switchgear (1) according to one of claims 7 to 11, wherein the processing unit (4) is set up to output an error message that a specific temperature sensor (S1 to S6) has failed or is faulty or that a connection to this temperature sensor (S1 to S6) is interrupted in the bus branch (B1 to B3) in which the temperature sensor (S1 to S6) is arranged, if no measured values are received from this temperature sensor (S1 to S6) at the first bus end, but measured values are received from a bus branch (B1 to B3) arranged behind the bus branch (B1 to B3) in which the temperature sensor (S1 to S6) is arranged.
13. Switchgear (1) according to one of claims 7 to 12, wherein the processing unit (4) is configured to output an error message that a specific temperature sensor (S1 to S6) has failed or is faulty or that a connection to this temperature sensor (S1 to S6) is interrupted in the bus branch (B1 to B3) in which the temperature sensor (S1 to S6) is arranged, if no measured values are received from this temperature sensor (S1 to S6) at the second bus end, from a bus branch (B1 to B3) in which the temperature sensor (S1 to S6) is arranged, but measured values are received on the arranged bus branch (Bl to B3).