Method for improved condition monitoring of a power circuit breaker, power circuit breaker and switch panel having such a power circuit breaker

Abstract

The invention relates to a method for improved condition monitoring of a power circuit breaker (2), which is used in a switch panel (1.4) of a medium-voltage switchgear (100) as an overcurrent protection device, wherein a current value of a parameter, which is a measurement for the wear of switch contacts of the power circuit breaker (2), is transferred from a data store (3b) of the switch panel (1.4) to a data store (10c) of the power circuit breaker (2) when the power circuit breaker (2) is removed from the switch panel (1.4).

Description

[0001] Description

[0002] Method for improved condition monitoring of a circuit breaker, circuit breaker and switchgear panel with such a circuit breaker

[0003] The present invention relates to a method for improved condition monitoring, a circuit breaker and a switchgear panel of a medium-voltage switchgear.

[0004] Medium-voltage switchgear is divided into switchgear panels, which are also simply referred to as "panels". As shown, for example, in EP 0 737 377 Al • (Siemens AG) 16.10.1996, a panel usually comprises a busbar compartment, a switch compartment, a cable connection compartment and a low-voltage compartment. The switch compartment contains an overcurrent protection device, e.g. a circuit breaker. The circuit breaker, e.g. a vacuum circuit breaker, can be movable on travel rails and can be withdrawn from the switch compartment for replacement, repair and maintenance, as in

[0005] DE 101 04 890 Al (Siemens AG) 08.08.2002. The low-voltage compartment, which can be located above the switchgear compartment and is completely separated from the other rooms by walls, contains control, protection, and display devices for the circuit breaker.

[0006] The switching contacts of the circuit breaker are designed for a maximum number of switching cycles – i.e. the number of possible opening operations. For example, in

[0007] As described in DE 10 2004 020 045 Al (Siemens AG) 10.11.2005, circuit breaker manufacturers often specify in technical specifications, data sheets, and manuals how many switching cycles a switching device is designed for, depending on the switched current (maximum number of switching cycles). Typical values ​​are 10,000, 25,000, or 50,000 switching cycles. Based on the history (how many switching operations have already been performed at which current), the number of remaining switching cycles can be estimated depending on the current.

[0008] Another approach is to determine the energy acting on a switching device during switching operations. When current-carrying switching contacts of the circuit breaker open, an arc can occur, which leads to the switching contacts being burned away. It is known (see, for example, DE 103 12 504 Al (Siemens AG) September 30, 2004) to determine the current status of contact wear resulting from such arcs on the basis of a current-time integral. The current-time integral is usually the value i 2 t is calculated, where i is the plasma current flowing through the arc and t is the arc duration. The value of the current-time integral is summed for the switching operations already performed. Depending on the switch type, there is a certain limit for the maximum total energy.

[0009] For a circuit breaker in a medium-voltage switchgear, the current value of the circuit breaker's operating cycles is recorded by a mechanical operating cycle counter mounted on the circuit breaker. In contrast, the current value of the circuit breaker's current-time integral is stored in a data memory, also referred to simply as a "memory," in the low-voltage compartment of the bay.

[0010] When a circuit breaker is removed from the bay for maintenance or repair, the current value of the removed circuit breaker's current-time integral remains stored in the low-voltage compartment but is not transferred to the removed circuit breaker. Thus, an operator who wishes to reuse the removed circuit breaker after maintenance or repair is missing important information about the circuit breaker's contact state. Therefore, there is a need for a method that can preserve information about the contact state of a circuit breaker.

[0011] This object is achieved according to the invention by a method having the features specified in claim 1. This object is also achieved according to the invention by a circuit breaker having the features specified in claim 6. This object is also achieved according to the invention by a switchgear panel having the features specified in claim 7.

[0012] The method is used for improved condition monitoring of a circuit breaker that is used as an overcurrent protection device in a switchgear panel of a medium-voltage switchgear. The term "circuit breaker" is not to be interpreted narrowly; rather, it includes all electrical switching devices that can be used in a medium-voltage switchgear to interrupt a current path, i.e. both protection devices and switching devices. The circuit breaker can be based on different technologies; e.g., a vacuum circuit breaker is just as possible as an air- or gas-based circuit breaker. The circuit breaker has at least two switching contacts that are brought out of contact to interrupt the current path and brought into contact with each other to (re-)establish the current path.According to the method, a current value of a parameter which is a measure of wear of switching contacts of the circuit breaker is transferred from a data memory of the switchgear panel to a data memory of the circuit breaker when the circuit breaker is removed from the switchgear panel.

[0013] A circuit breaker according to the invention can be used in a switchgear panel of a medium-voltage switchgear assembly as an overcurrent protection device. It has a transceiver which is designed to receive a parameter from a communication device in the switchgear panel and to store it in a data memory. The transceiver and the data memory can be components of a transceiver and memory unit (chip for short) of the circuit breaker. The chip arranged on the circuit breaker has an electrical circuit for receiving and transmitting, i.e. a transceiver, as well as a digital circuit which has a data memory. The transceiver has an antenna with a resonant circuit. The entire electronics of the chip can be integrated in a single microchip. The chip can be a transponder or an RFID chip.A serial number (S / N) for identifying the assigned circuit breaker, a current value of the switching cycles of the circuit breaker and a current value of the current-time integral of the circuit breaker can be stored on the chip.

[0014] A switchgear panel of a medium-voltage switchgear assembly according to the invention is a switchgear panel in which a circuit breaker can be used as an overcurrent protection device. The switchgear panel has a communication device that is designed to send a parameter that is stored in a data memory of the switchgear panel to a transceiver of the circuit breaker. The communication device can have a read / write device and a detector, wherein the read / write device can send data to the chip of the circuit breaker and read data from the chip of the circuit breaker. The communication device is preferably located on an installation door that covers the circuit breaker, so that an IoT system can detect that the circuit breaker is being replaced (IoT = Internet of Things).

[0015] The invention therefore relates to a preferably IoT and RFID-based monitoring of components in a medium-voltage switchgear system, and to automated detection of the replacement and automatic adoption of parameters and new measured values ​​when components (switching devices) are replaced. In particular, the invention relates to a method with which information about the contact state of a circuit breaker can be saved. The invention is based on the idea that the current-time integral represents essential information about the wear and tear of the circuit breaker, which must be available on the circuit breaker. If it is detected in the medium-voltage switchgear system that the current-time integral of a circuit breaker exceeds a defined threshold value, this exceedance can be communicated to an operator and countermeasures can be suggested to the operator.

[0016] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0017] According to a preferred embodiment of the invention, a current value of a parameter, which is a measure of the wear of the circuit breaker's switching contacts, is transferred from a data memory of the circuit breaker to a data memory of the switchgear panel when the circuit breaker is inserted into the switchgear panel. This has the advantage that the condition monitoring, which is performed by a control unit of the switchgear panel, can be continued with the current wear status of the circuit breaker used.

[0018] According to a preferred embodiment of the invention, the parameter is a current-time integral. Advantageously, a current-time integral is a criterion for the short-term pulse overload capacity of various electrical or electronic components.

[0019] According to a preferred embodiment of the invention, the value is transmitted based on REID. The advantage here is that RFID technology is relatively inexpensive and reliable.

[0020] According to a preferred embodiment of the invention, the circuit breaker's data memory is part of an RFID chip arranged on the circuit breaker. The advantage here is that RFID technology is relatively inexpensive and reliable.

[0021] In the following, the invention is explained using several embodiments with the aid of the accompanying drawings. Each drawing is schematic and not to scale.

[0022] Fig. 1 a medium-voltage switchgear;

[0023] Fig. 2 shows a section of a switch panel;

[0024] Fig. 3 Process steps when a circuit breaker is pulled out of the switch compartment;

[0025] Fig. 4 Process steps when a circuit breaker is pushed into the switch compartment; and

[0026] Fig. 5 a transceiver and memory unit (short: chip) of the circuit breaker.

[0027] Fig. 1 shows a front panel 12 of a medium-voltage switchgear 100 comprising four switch panels 1.1, 1.2, 1.3, 1.4. Each of the switch panels 1.1, 1.2, 1.3, 1.4 has a switch compartment 4, a cable connection compartment 5, a busbar compartment 6, and a low-voltage compartment 7. A circuit breaker 2 is arranged in the switch compartment 4.

[0028] Fig. 2 shows a section of the right-hand switchgear panel 1.4. The circuit breaker 2 is mounted on rails 9, with which it can be pulled out 11A forwards to the front 12 of the switchgear compartment 4 for replacement, repair, and maintenance. The circuit breaker 2 carries a transceiver and memory unit 10 that can receive, store, and send data. The transceiver and memory unit 10 is also referred to hereinafter simply as a "chip." A detector 8 is arranged in the switchgear compartment 4 on the front 12, which detects movement of the chip 10 when a circuit breaker 2 is pulled out 11A from the switchgear compartment 4 or when a circuit breaker 2 is pushed into the switchgear compartment 4 11B.

[0029] In the switch room 4 on the front side 12 there is also a read and write device 13 which can send data to the chip 10 and read data from the chip 10.

[0030] The detector 8 and the read / write device 13 can also be combined in a single communication device 14. For example, the following configuration can be used:

[0031] The chip 10 arranged on the power switch 2 has an electrical circuit for receiving and transmitting, i.e., a transceiver 10a, as well as a digital circuit 10b with a memory 10c. The transceiver 10a has an antenna with a resonant circuit. The entire electronics of the chip 10 can be integrated into a single microchip.

[0032] The detector 8 and the read / write device 13 are integrated into a communication device 14, which generates a high-frequency (HF) alternating electromagnetic field to which the chip 10 is exposed. Thus, the chip 10 itself does not generate a field, but rather influences the electromagnetic transmission field of the communication device 14.

[0033] The resonant circuit of chip 10 supplies the digital circuit of chip 10 with energy via the RF radiation of communication device 14. At the same time, data is transmitted between chip 10 and communication device 14 by chip 10 modulating the attenuation of the resonant circuit of communication device 14. Chip 10 also stores data in its memory 10c. As long as chip 10 is in the electromagnetic field of communication device 14, chip 10 is supplied with energy, and data can be exchanged between communication device 14 and chip 10. Information can be read from chip 10, but new data can also be stored on chip 10.

[0034] A control unit 3 is arranged in the low-voltage compartment 7. Based on current values ​​and time values ​​that the control unit 3 receives from corresponding sensors of the circuit breaker 2, the control unit 3 can calculate a current-time integral of the circuit breaker 2 and store one or more values ​​of the current-time integral. For this purpose, the control unit 3 can have a processor 3a and a memory 3b.

[0035] If the circuit breaker 2 is to be withdrawn from the switchgear compartment 4 for maintenance or repair, the panel 1 . 4 is disconnected from the network . After the circuit breaker 2 has been removed from the switchgear compartment 4 , a reserve breaker can be used in the panel 1 . 4 until the maintenance or repair of the removed circuit breaker 2 is completed . In this way, the downtime of the panel 1 . 4 can be shortened . After the maintenance or repair of the removed circuit breaker 2 is completed, the circuit breaker 2 can be reinserted in its original panel 1 . 4 or in another panel if its characteristics, e.g. current intensity, allow it . For example, the medium-voltage switchgear 100 can have four switchgear panels 1 . 1 , 1 . 2 , 1 . 3 , 1 . 4 , with a 1250 A circuit breaker installed in each panel.If a reserve breaker of 1250 A is also available, the reserve breaker can be used after a circuit breaker has been removed from one of the panels. The removed circuit breaker, after it has been serviced or repaired, can be kept as a reserve breaker until it is used the next time a circuit breaker in the medium-voltage switchgear is replaced. Fig. 3 shows method steps when a circuit breaker 2 is pulled out of the switch compartment 4, 11A. The detector 8 receives a signal 31 from the chip 10 arranged on the circuit breaker 2. For example, the detector 8 detects when the chip 10 comes into its transmission field. The detector 8 sends a signal 32 to the control unit, which signals to the control unit 3 that the circuit breaker 2 is being pulled out of the switch compartment 4. In response, the control unit 3 sends a current value 33 of the current-time integral to the read / write device 13.The read / write device 13 sends the current value 33 of the current-time integral to the chip 10, where it is stored.

[0036] Fig. 4 shows method steps when a circuit breaker 2 is pushed into the switch compartment 4. The detector 8 receives a signal 41 from the chip 10 arranged on the circuit breaker 2. For example, the detector 8 detects when the chip 10 comes into its transmission field. The detector 8 sends a signal 42 to the control unit, which signals to the control unit 3 that the circuit breaker 2 is being pushed into the switch compartment 4. In response, the control unit 3 sends an activation signal 43 to the read and write device 13. The read and write device 13 sends a request signal 44 to the chip 10. The request signal 44 can also consist of the chip 10 being supplied with energy by an electromagnetic field of the read and write device 13, which allows the chip 10 to send one or more pieces of data from its memory to the read and write device 13.In response to the request signal 44, the chip 10 sends the value 45 of the current-time integral stored on the chip to the read / write device 13. The read / write device 13 sends the current value of the current-time integral in a signal 46 to the control unit 3, where it is stored.

[0037] Fig. 5 shows a transceiver and memory unit 10 (chip for short) of the power switch 2. The chip 10 arranged on the power switch 2 has an electrical circuit for receiving and transmitting, i.e., a transceiver 10a, as well as a digital circuit 10b having a memory 10c. The transceiver 10a has an antenna with a resonant circuit. The entire electronics of the chip 10 can be integrated into a single microchip.

Claims

Patent claims 1. Method for improved condition monitoring of a circuit breaker (2) which is used as an overcurrent protection device in a switchgear panel (1.4) of a medium-voltage switchgear assembly (100), wherein a current value of a parameter which is a measure of wear of switching contacts of the circuit breaker (2) is transmitted from a data memory (3b) of the switchgear panel (1.4) to a data memory (10c) of the circuit breaker (2) when the circuit breaker (2) is removed from the switchgear panel (1.4).

2. Method according to claim 1, wherein a current value of a parameter which is a measure of wear of switching contacts of the circuit breaker (2) is transferred from a data memory (10c) of the circuit breaker (2) to a data memory (3b) of the switchgear panel (1.4) when the circuit breaker (2) is inserted into the switchgear panel (1.4).

3. Method according to one of the preceding claims, wherein the parameter is a current-time integral.

4. Method according to one of the preceding claims, wherein the transfer of the value is based on RFID.

5. The method according to claim 4, wherein the data memory (10c) of the circuit breaker (2) is part of an RFID chip (10) arranged on the circuit breaker (2).

6. Circuit breaker (2) which can be used as an overcurrent protection device in a switchgear panel (1.4) of a medium-voltage switchgear assembly (100), comprising a transceiver (10a) which is designed to receive a parameter from a communication device (14) of the switchgear panel (1.4) and to store it in a data memory (10c).

1. Switchgear panel (1.4) of a medium-voltage switchgear assembly (100), in which a circuit breaker (2) can be used as an overcurrent protection device, comprising a communication device (14) which is designed to send a parameter stored in a data memory (3b) of the switchgear panel (1.4) to a transceiver (10a) of the circuit breaker (2).

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