EP3959731A1

EP3959731A1 - Monitoring arrangement for electrical equipment, and monitoring system

Info

Publication number: EP3959731A1
Application number: EP20732741.2A
Authority: EP
Inventors: Thomas Koch; Bastian Robben; Matthias Schubert
Original assignee: Siemens Energy Global GmbH and Co KG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2019-06-12
Filing date: 2020-05-25
Publication date: 2022-03-02
Also published as: US20220357388A1; WO2020249379A1; DE102019208520A1; US11906568B2

Abstract

The invention relates to a monitoring arrangement for electrical equipment, having a first sensor for sensing a surface creeping current on a creeping path-lengthening electrically insulating housing of the equipment, and to a monitoring system comprising the monitoring arrangement.

Description

description

Monitoring arrangement for an electrical equipment and monitoring system

The invention relates to a monitoring arrangement for electrical equipment according to the preamble of claim 1 and a monitoring system according to the preamble of claim 20.

Surge arresters are used in the medium-voltage and high-voltage range in order to safely divert so-called overvoltages, i.e. voltages far above the nominal voltages intended during operation, to earth. This causes damage to equipment such as Transformers avoided. For example, a surge arrester for high voltage can be placed on an overhead line and in the event of a lightning strike or short circuit, it can discharge impermissibly high currents to earth.

Surge arresters usually contain so-called varistors ("variable resistors"), i.e. electrical resistors whose electrical resistance value is very high up to a design-related threshold voltage and greatly reduced above the threshold voltage, so that the surge arrester becomes a good electrical conductor. E.g. Metal oxide resistors in disc form arranged one above the other in a housing and connected to the high voltage potential and the ground potential at the respective ends of the housing. The surge arrester is hardly conductive during normal operation, so that only a small leakage current flows to earth. In the event of an overvoltage, however, a high leakage current flows.

From the product brochure "A full ranges of monitoring solutions for surge arresters", Siemens AG 2012, Order No. E50001-G630-A141-V2-4A00, it is known from pages 4-6 and 10 that the monitoring device "ACM advanced - Arrester Condition Monitoring "for monitoring surge arresters. It is connected to the underground cable of an arrester and has solar cells for power supply. The device has a digital display device and a communication device that is designed for radio transmission of measurement data in the immediate vicinity Overvoltage impulses are recorded by sensors with regard to a maximum amplitude, pulse width and energy input and provided with a time stamp. Furthermore, the total leakage current is recorded (3rd harmonic) and the total energy absorption of the arrester is determined. The device saves the measured values internally in a data memory so that later information can be obtained from the history of the derivation processes.

In the course of the increasing networking of devices on the Internet, the so-called "Internet of Things", more and more devices are currently being directly interconnected by machine-to-machine

Interfaces connected. In the field of industrial automation, for example, production lines are simulated as so-called "cyber-physical systems" under the catchphrase "Industry 4.0" in order to be able to monitor and optimize the production of goods in real time.

In the field of energy technology, too, it is desirable to be able to monitor devices that were previously not remotely monitored, such as high-voltage transformers, via data communication from the outside. For the transmission and bundling of sensor signals of the respective equipment detected by sensors, a device is typically used that transfers the sensor signals to an Internet environment ("IoT Device"). From the data sheets "Sensformer ™ Connectivity Device" and "Sensformer ™ Connectivity Device, outdoor version, "such devices are known. Both models have a limited number of inputs or interfaces (eg three analog and two digital inputs) and a number of Communication options such as Ethernet, USB, or radio (GSM).

On the basis of the known "ACM advanced", the object of the invention is to specify a monitoring arrangement with which an accurate remote monitoring of electrical equipment is made possible in a comparatively comprehensive and efficient manner.

The invention solves this problem by means of a monitoring arrangement according to claim 1.

Electrical equipment within the meaning of the invention is, for example, a surge arrester or an electrical insulator, e.g. a long rod insulator. Even equipment that has insulators and surge arresters, such as an EGLA ("externally gapped line arrester") are suitable.

In a preferred embodiment of the invention, the monitoring arrangement has a computer device. The computer device has, for example, processor means and / or data storage means in order to summarize the acquired sensor measurement data in digital form and to prepare them for transmission.

In a preferred embodiment of the invention, the first sensor has an electrically conductive electrode. This can for example have a metal, so for example at least partially made of aluminum, copper, brass, stainless steel. Since arresters are also used outdoors, weather-resistant, ie corrosion-resistant metals such as brass are preferred. The electrode can be guided around the housing, for example, as a clamp or cuff or as a band, that is to say encompass the housing completely on its circumference. Alternatively, a solution can be chosen in which the electrode overlaps only part of the circumference of the housing.

It is also preferred if the electrode is arranged on the earth side and has a predetermined minimum distance from the metallic end fitting. The electrode should rest completely on the insulated housing and can, for example, be placed between two screens, i.e. in cross-section ge, so to speak, in the valley between two mountains, be arranged.

The first sensor and also all further sensors that may be used according to the invention provide sensor measurement data. These can be available in different data formats depending on the type of sensor used. In a preferred variant, all of the sensor measurement data can be combined by means of the computer device and prepared for transmission in a uniform data format. A computer device can also be used for this purpose, which is provided in a communication device of a monitoring system.

In a further preferred embodiment of the monitoring arrangement according to the invention, a second sensor for detecting a voltage applied to the equipment is formed, the second sensor evaluating the electrical and / or magnetic field in the vicinity of the equipment. This is an advantage because overvoltages can be detected and counted in order to determine the thermal load on the equipment over its lifetime. For example, a sensor for the electrical field can be used, which is preferably net angeord in the vicinity of the earth potential.

If the second sensor is used in the vicinity of the high-voltage potentiometer, it can be supplied with electrical energy from surrounding electromagnetic radiation, for example by means of so-called "energy harvesting", which is possibly temporarily stored in an energy store be transmitted by radio link to other components of the monitoring arrangement so that isolation distances can be maintained.

Alternatively or additionally, a sensor for voltage measurement can be provided, which is galvanically connected to the current path.

The use of the second sensor enables, in particular, an evaluation of the harmonics (e.g. 3rd, 5th, 7th harmonic). Harmonics are caused by equipment with a non-linear characteristic, such as transformers. The non-sinusoidal currents of these loads cause a voltage drop in the network impedance that distorts the nominal network voltage. The 3rd harmonics are proportional to the resistive components of the currents (at a mains frequency of 50 Hz there are 3rd harmonic harmonics at 150 Hz). This allows conclusions to be drawn about the aging of the at least one varistor. In other words, the more the varistor has aged, the stronger 3rd harmonics are detected.

By comparison with a previously determined characteristic curve or calibration measurement, conclusions can be drawn about the degree of aging of the at least one varistor from the measurement data from the second sensor. This enables a particularly accurate service life prediction for the surge arrester equipment.

In a further preferred embodiment of the monitoring arrangement according to the invention, a service life detection device is provided which detects the service life of the equipment from the time it is put into operation and emits a maintenance signal at predetermined ages of the equipment. This is an advantage because such maintenance signals can be transmitted to a remote server device within the scope of a monitoring system according to the invention in order to routinely and automatically process a whole Manage a fleet of equipment. Maintenance can include, for example, a visual inspection by a technician or by an autonomous drone in order to detect errors. If, for example, damage to a housing or insulator jacket is recognizable, the operating means can be replaced. Such maintenance can, for example, be scheduled every second year after the equipment has been installed.

In a further preferred embodiment of the monitoring arrangement according to the Invention, a third sensor for detecting acoustic signals in the vicinity of the operating means is designed. This is an advantage because vibrations in the equipment can be detected. It can be a microphone or a piezoelectric component, for example. The microphone is, for example, suitable for monitoring frequency ranges in the frequency range audible to humans of between 20 and 20,000 Hertz, so that e.g. Arcs, rattling or mechanical vibrations can be detected at the nominal frequency of the network.

In a further preferred embodiment of the monitoring arrangement according to the invention, the operating means has an electrical insulator. It can e.g. about one

Act long rod insulator.

In a further preferred embodiment of the monitoring arrangement according to the invention, the operating means has a bushing. It can e.g. be a bushing or bushing for a transformer.

In a further preferred embodiment of the monitoring arrangement according to the invention, the operating means has a surge arrester with at least one varistor. In a further preferred embodiment of the monitoring arrangement according to the Invention, a fourth sensor is provided for detecting an operating temperature of a varistor.

It can e.g. a surge arrester can be used, which has a housing with a viewing window. The viewing window is provided with a transparent and infrared light-permeable material and the fourth sensor has a measuring device for infrared light. The fourth sensor can automatically deduce a temperature of the varistor from a measurement of a light intensity by means of a previously established calibration curve and provide this determined temperature. Alternatively, the fourth sensor can fall back on the computer device mentioned at the beginning in order to undertake this conversion. The viewing window can, for example, be a round or rectangular recess in a tube made of glass fiber reinforced plastic that surrounds a column of varistor disks. The viewing window can e.g. be sealed fluid-tight by a glass that is permeable to infrared light.

It can e.g. a photodiode or a thermal imaging camera can be used. A so-called "thermopile" is particularly suitable for temperature measurement, as described for example on Wikipedia (permanent link: "https: // en. Wikipe dia. Org / w / index. Php? Title = Thermopile & oldid = 890447398).

Alternatively or additionally, a sensor for the temperature can be used, which is arranged directly on a varistor disk or between two varistors of the arrester column. For example, a disk-shaped device with the same diameter as the Varis torenscheiben used can be used. Such a device with what is known as a surface wave sensor is known from the publication EP 0 996 956 B1.

The temperature measured directly at the varistor can preferably be sent to a control center (for example a supervisory control and data acquisition (SCADA) system) of the energy supply network be transmitted. For example, the monitoring arrangement can be connected to the control technology of a substation via Modbus or Ethernet, which forwards the temperature measurement data to the control center. Alternatively or additionally, the temperature measured directly on the varistor can first be transmitted to the server device and from there to the control center.

The measured temperature of the varistor is preferably evaluated so that when a first threshold value of e.g. 200 ° C to give an advance warning that a so-called "thermal runaway" threatens (ie a thermal overload of the arrester with failure of the device) Furthermore, if a second threshold value of 230 ° C, for example, is exceeded, the network section on which the arrester is located can be switched off immediately.

In a preferred development of the aforementioned embodiment of the monitoring arrangement according to the invention, the fourth sensor is designed to detect an ambient temperature of the operating means. This is an advantage because the temperature difference between the varistor and the environment can be determined.

In a further preferred embodiment of the monitoring arrangement according to the invention, a fifth sensor for detecting a leakage current of the surge arrester is provided. The fifth sensor can for example be arranged on the underground cable or e.g. on the earth-side end fitting.

In a further preferred embodiment of the monitoring arrangement according to the invention, the fifth sensor is ausgebil det to detect a total leakage current, which consists of a Leakage current through the at least one varistor and one

Leakage current composed through the insulating housing.

In a further preferred embodiment of the monitoring arrangement according to the Invention, the fifth sensor is designed to detect direct currents and alternating currents.

This is an advantage because previous leakage current measuring devices are provided for measuring alternating currents. Leakage current meters for alternating current are for example formed with an iron rod that is surrounded by a coil. However, such an inductive measuring device is unsuitable for measuring direct currents. A uniform monitoring arrangement for equipment such as surge arresters can be used to advantage, particularly on overhead power towers for so-called hybrid lines with DC voltage lines and AC voltage lines on a common pole.

In a further preferred embodiment of the monitoring arrangement according to the invention, the fifth sensor has an ohmic resistor and a spark gap, a rectifier being provided for rectifying alternating currents. For example, a bridge rectifier can be used. This embodiment has the advantage that alternating currents can also be measured by means of the rectifier.

In a further preferred embodiment of the monitoring arrangement according to the invention, the fifth sensor has a Hall probe. For example, a metal bolt or the like can be used on which the Hall probe for detecting magnetic fields is arranged. Such a never-ohmic design (the metal bolt has almost no electrical resistance in a first approximation) is advantageous because previous versions with electrical resistances often fail over longer periods of time. In a further preferred embodiment of the monitoring arrangement according to the invention, a sixth sensor for detecting a density of an electrically insulating protective gas is designed. In this case, a high-voltage arrester is typically monitored as equipment. The arrester has a fluid-tight housing, for example made of metal, which is provided on the inside with one or more columns of varistor disks. The columns are often braced using GRP rods. The columns are electrically insulated from each other and from the housing by electrically isolating the protective gas. Sulfur hexafluoride (SF6) is often used under pressure or alternatively, purified and dehumidified air (so-called "clean air" systems, such as those offered by Siemens AG). The gas density can, for example, be determined by means of pressure and temperature sensors using a gas equation of an ideal gas or the like. Particularly suitable are sensor types that can be operated without their own energy supply by means of so-called "energy harvesting" from the electromagnetic field and transmit their measured values by radio from inside the housing to the outside . If the gas density falls below a specified threshold value, the arrester can no longer be operated safely and must be switched off and replaced.

In a further preferred embodiment of the monitoring arrangement according to the Invention, a seventh sensor is provided for detecting surge currents. Surge currents are brief current surges with currents of e.g. 100 A to 100 kA. The seventh sensor can, for example, carry out an inductive current measurement; a so-called Ro gowskispule can preferably be used, which is arranged around the underground cable.

In a further preferred embodiment of the monitoring arrangement according to the invention, a data memory is provided for storing the measured values recorded by the sensors. The data memory can be designed to be recorded To temporarily store sensor measurement data prior to transmission by means of a communication device. For example, an HDD or RAM memory can be used. This embodiment has the advantage that in the event of an interruption in the connection between the monitoring arrangement and a remote server device, the raw data collected can be cached and sent later after a connection has been re-established.

In a further preferred embodiment of the monitoring arrangement according to the invention, an energy supply is provided which is designed to generate energy via an Ethernet connection. An energy supply can alternatively or additionally take place by so-called "energy harvesting" from surrounding electromagnetic radiation by means of an energy recovery device. A solar power supply can also be provided in the outside area.

In a preferred embodiment of the monitoring arrangement according to the invention, a time stamp device is provided which is designed to assign a time stamp to each of the sensor measurement data. The time stamp indicates the point in time at which the respective measured values or sensor measurement data are recorded in the monitoring arrangement. A single time stamp device can preferably be provided in order to provide all of the sensor measurement data that arise at the various sensors with time stamps. Alternatively, several time stamping devices can be provided, e.g. a time stamp facility for each sensor. The time stamps can, for example, be recorded to the millisecond. Acquisition in hundredths of a second or in tenth of a second range can also be carried out.

It is particularly preferred if the time stamp device is synchronized with an external timer. For example, this can be done by receiving satellite time data, for example via a receiving device for global positioning System (GPS) can be achieved, which, for example, are in turn synchronized with an atomic clock. This has the advantage that all sensor measurement data are recorded at the same time, regardless of where the monitoring arrangements are located. Furthermore, measurement data from various monitoring arrangements can be brought into a chronological order, which enables more precise calculations, for example of network stability in a control center.

Because the sensor measurement data according to the invention usually

not evaluated locally in a hard-wired system, but remotely and centrally in a server device, slow data transport or an interruption of the respective connection can occur, especially when using radio links and / or Internet connections. Scenarios for an interruption of the connection are, for example, a power failure in the low and / or medium voltage network and thus failure of a GSM connection and / or failure of a LAN connection. Alternatively, the Internet service provider has a system error and the Internet connection is disrupted by the service provider.

In such a case, after the connection has been re-established, it is possible without any problems to bring the sensor measurement data into a chronological order with respect to newer sensor measurement data based on their time stamp and to resume evaluations provided on the part of the server device.

On the basis of the known "ACM advanced", the object of the invention is to provide a monitoring system with which an accurate remote monitoring of electrical equipment is enabled in a comparatively comprehensive and efficient manner.

The invention solves this problem by a monitoring system according to claim 20. A preferred embodiment is given in claim 21. The same advantages result analogously as at the beginning for the inventive Monitoring arrangement specified. It is clear to a person skilled in the art that all of the embodiments of the invention described in connection with the monitoring arrangement can also be used in the monitoring system.

The server device can e.g. be a central server facility such as a data center or a cloud application. In the context of the invention, a cloud application is to be understood as a computer program that uses networked resources (processors, data storage, etc.) via a data network such as the Internet. Examples are Microsoft Azure, Amazon Web Services or Siemens Mindsphere.

Alternatively or in parallel, the server device can also be a decentralized server device;

this can be understood, for example, as a computer device locally available in a substation.

In addition or as an alternative to the aforementioned embodiment, data exchange can also be provided between the server device and a control center in order to improve the network control in the control center.

In a preferred embodiment of the monitoring system according to the invention, the communication device is designed for data communication with a network control center. For example, data communication according to the IEC 61850 standard can be provided. This embodiment has the advantage that a direct connection and transmission of the sensor measurement data to a network control center or a control device for a substation is made possible. In this way, it is possible to feed directly into a "Supervisory Control and Data Acquisition" (SCADA) system, for example, without detour via the aforementioned server facility. This allows the sensor measurement data to be used to control network operation Sensor measurement data in the control center Faults in electrical equipment such as surge arresters, which affect network operation, can be quickly detected. In particular, the severity of faults and thus the probability of failure of the electrical systems can be estimated on the basis of the measurement data. Without the sensor measurement data evaluation, the control center could only recognize the failure of an electrical system as soon as it happened. A slow deterioration, etc., would go undetected.

In another example, data communication according to the Modbus protocol can also be provided. This is particularly important within an electrical system such as a substation advantageous.

The server device can bring together the sensor measurement data from a large number of data processing arrangements centrally and thus provide cross-fleet monitoring of the operating status of the electrical equipment. On the part of the server device, an app with a user interface can be provided which, in addition to the information obtained from the sensor measurement data, also displays the time of the data acquisition in a so-called dashboard. It is also e.g. a general overview of all electrical equipment of a network and / or customer is provided, which, in addition to a description of any abnormality (s) discovered, also shows the current live status (online / offline) of the respective monitoring arrangements.

In a preferred embodiment of the monitoring system according to the invention, a mobile device is provided which is designed for data communication with the server device. It can be, for example, a tablet, a cell phone or a laptop, with e.g. an LTE network is used for data communication. The mobile device is used to present information about an operating state of the

electrical systems trained. Can be used for example a touch screen. This approach represents a decisive advantage in comparison to the classic control technology systems. Electrical equipment can be monitored conveniently, easily and from anywhere. It can also easily be compared between two or more electrical equipment in order to detect deviations from permissible operating parameters. Control and maintenance personnel have the option of monitoring the entire system status directly on site, for example in a substation, for example using tablets or notebooks. Immediately before an activity, such as a repair measure, it can check the status of the system again.

For example, a “Sensformer ™ Connectivity Device” or a “Sensformer ™ Connectivity Device, outdoor version” described above can serve as the communication device.

In a preferred embodiment of the monitoring system according to the invention, the communication device is designed to transmit the sensor measurement data to a further communication device of a further monitoring arrangement. Correspondingly, the monitoring arrangements involved are designed to receive data from other monitoring arrangements.

This procedure makes it possible, in cases where no connection to the server facility or the network control center is possible (weak infrastructure), to pass on data within the spatial distribution of the electrical systems. For example, this can be done in a substation via W-LAN, WAN, radio or Ethernet. The transmission of the sensor measurement data takes place until a monitoring arrangement is reached that can establish a connection to the server device and / or to the network control center. This creates a dynamic transmission path. With this method you can also reduce the effective transfer points in the data cloud. It is also possible to build monitoring arrangements that are not planned to be able to establish a connection to the server device and / or to the network control center. In such a case, all monitoring arrangements can use a common router in order to establish contact with the outside world. In the extreme case, the connection points are so limited that a mesh network must be set up. This means that larger distances can be overcome before a connection to the server device and / or to the network control center can be established.

In a preferred embodiment of the monitoring system according to the invention, the central server device is designed to determine a degree of pollution of the housing on the basis of a detected leakage current. A next maintenance date can also be set based on the degree of soiling. This embodiment is of particular advantage because in many regions of the world the insulating equipment housings are heavily burdened with electrically conductive foreign layers due to particularly harsh environmental conditions. For this reason, customers in Egypt, for example, have the housings of equipment with a porcelain jacket regularly cleaned by maintenance teams to remove sand deposits, salts and the like. It is also known from the Canary Islands that customers regularly clean or wash polymer housings. This serves to ensure the safety of the equipment, since foreign layer discharges can be avoided when the housings are dirty. However, such missions are very labor, time and cost intensive. Furthermore, for reasons of occupational safety, the equipment in question must be de-energized, which reduces the availability and security of the energy network. It is therefore a great advantage of the invention that a cleaning interval that is minimal for safety does not have to be specified for all of a customer's equipment.

Rather, based on the leakage current measurement, a Conclusions can be drawn about the degree of contamination, ie, for example, the type and thickness of the foreign layer by comparison with calibration measurements and a prediction of the further course of the contamination over time can be calculated. This makes it possible to set a maintenance time individually for each item of equipment because, for example, the degree of contamination has exceeded a permissible threshold value. This saves time and money.

In a preferred embodiment of the monitoring system according to the invention, the central server device is designed to determine an influence of direct sunlight on the housing temperature on the basis of a correlation of the measured leakage current through the at least one varistor with a measured housing temperature. This is an advantage, because in this way a noticeable warming of the operation by means of the outside (even without knowledge of a directly measured varistor temperature) can be recognized as uncritical for safety, since the leakage current essentially remains in an expected range and does not increase. This is an advantage because false alarms relating to the temperature of the trap can be avoided. A so-called “thermal runaway” of the varistor can also be excluded without direct measurement of the temperature of the varistor.

To better explain the invention, FIG. 1 shows a schematic representation of an embodiment of the invention.

A surge arrester 2 has a large number of varistor disks 8, 10 or voltage-dependent disks in its interior

Resistances that are stacked on top of one another to form a deflection column and clamped between two end fittings 28. The bracing is produced in a so-called cage construction by means of tension elements 24. The tension elements 24 are, for example, rods made of glass fiber reinforced plastic (GRP). That tensed up in this way Down conductor column is net angeord in a tubular housing 25, which is surrounded by an electrically insulating housing 4 with creep path lengthening shield. The creep path-extending shield can be made of silicone rubber or porcelain, for example. On the high voltage side, the surge arrester 2 has a first connection bolt 26. On the earth side, a second connection bolt 27 is connected to an earth cable 36. The tube 25 and the insulating housing 4 have at one point a recess 11 in which a viewing window 12 is provided. The viewing window 12 is closed in a fluid-tight manner with a transparent pane permeable to infrared light, for example made of a suitable glass or plastic.

The surge arrester is monitored for a wide variety of operating parameters by means of a monitoring arrangement 1.

This has a first sensor 3, which is arranged on the screen that extends the creepage path for detecting a superficial leakage current. This first sensor 3 is connected to an input 31 of a housing 35. A second sensor 5 is designed to detect a voltage applied to the surge arrester 2 and detects the electric and / or magnetic field in the vicinity of the surge arrester 2. This second sensor 5 is connected to an input 34. A fourth sensor 9 is provided for detecting an operating temperature of a varistor 10 loading. For this purpose, the sensor 9 has a measuring device for infrared light and is arranged on the viewing window 11. The fourth sensor 9 is connected to an input 33. A third sensor 7 is arranged in the vicinity of the surge arrester 2 and is designed to detect acoustic signals. This sensor 7 is connected to an input 32.

In the housing 35 of the monitoring arrangement 1, the inputs 30 - 34 are connected to a computer device 17 via data communication lines 37. This has a data memory 14. The ones arriving at entrances 30 - 34 Sensor measurement data are transmitted to the computer device 17 and summarized there and preprocessed for transmission. The computer device 17 is connected to a communication device 18 via a further data communication line 37. The communication device 18 is designed for data transmission 20 by radio to a cloud application 19. In the housing 35, an energy supply 15, which is formed for generating energy via an Ethernet connection 16, and an energy store 16 are also provided. A service life detection device 6 is provided in order to detect the service life of the surge arrester 2 from the time of commissioning and to transmit a maintenance signal to the communication device 18 via a further data communication line at the predetermined age of the surge arrester. In the cloud application 19, which can be understood as a server device with decentralized resources, the sensor measurement data are further processed and, for example, displayed in a structured manner within the framework of a fleet management for a large number of operating resources to be monitored. This information can be transferred to a mobile device 22 by means of a data communication 21. The mobile device is, for example, a cell phone or tablet. This has a display device 23, for example a touch screen. In this way, a maintenance technician can easily determine the operating state of the surge arrester 2 at any time and regardless of location and, if necessary, initiate maintenance or repair measures.

Previous monitoring arrangements such as the well-known "ACM advanced" do not have a plurality of inputs in order to be able to record a wide variety of sensor measurement data at the same time. This is a great advantage over previous devices.

Claims

1. Monitoring arrangement (1) for electrical equipment (2),

having, characterized by

a first sensor (3) for detecting a superficial leakage current on an electrically insulating housing (4) of the equipment (2) which extends the creep path.

2. Monitoring arrangement (1) according to claim 1, characterized in that the first sensor (3) has an electrically conductive electrode.

3. Monitoring arrangement (1) according to claim 1 or 2, characterized in that a second sensor (5) is designed to detect a voltage applied to the operating means (2), the second sensor (5) being the electrical and / or the magnetic Evaluates field in the vicinity of the equipment (2).

4. Monitoring arrangement (1) according to one of the preceding claims, characterized in that a service life detection device (6) is provided, which from the time of commissioning to the service life of the equipment (2) it records and a maintenance signal at predetermined ages of the equipment (2) gives.

5. Monitoring arrangement (1) according to one of the preceding claims, characterized in that a third sensor

(7) is designed to detect acoustic signals in the vicinity of the equipment (2).

6. Monitoring arrangement (1) according to one of the preceding claims, characterized in that the operating means has an electrical insulator.

7. Monitoring arrangement (1) according to one of the preceding claims, characterized in that the operating means has a surge arrester (2) with at least one varistor (8, 10).

8. Monitoring arrangement (1) according to one of claims 2 to 7, characterized in that third harmonic harmonics are determined from measurement data of the second sensor, based on which a degree of aging of the at least one varistor is determined.

9. Monitoring arrangement (1) according to claim 7 or 8, characterized in that a fourth sensor (9) for detecting egg ner operating temperature of a varistor (10) is provided.

10. Monitoring arrangement (1) according to claim 9, characterized in that

the surge arrester (2) has a housing (4) with a

Has viewing window (11) which is provided with a transparent and infrared light-permeable material (12), and that

the fourth sensor has a measuring device (8) for infrared light.

11. Monitoring arrangement (1) according to one of claims 7 to 10, characterized in that a fifth sensor (13) is provided for detecting a leakage current of the surge arrester (2).

12. Monitoring arrangement (1) according to claim 11, characterized in that the fifth sensor is designed to detect a total leakage current, which is composed of a leakage current through the at least one varistor and a leakage current through the insulating housing.

13. Monitoring arrangement (1) according to claim 11 or 12, characterized in that the fifth sensor is designed to detect direct currents and alternating currents.

14. Monitoring arrangement (1) according to claim 13, characterized in that the fifth sensor was an ohmic resistor and has a spark gap, a rectifier being provided for rectifying alternating currents.

15. Monitoring arrangement (1) according to claim 13 or 14, characterized in that the fifth sensor has a Hall probe.

16. Monitoring arrangement (1) according to one of claims 7 to 12, characterized in that a sixth sensor for detecting a density of an electrically insulating protective gas is designed.

17. Monitoring arrangement (1) according to one of the preceding claims, characterized in that a data memory

(14) is provided for storing the measured values recorded by the sensors.

18. Monitoring arrangement (1) according to one of the preceding claims, characterized in that a Energieversor supply (15) is provided, which is designed for energy generation via an Ethernet connection (16).

19. Monitoring arrangement (1) according to one of the preceding claims, characterized in that an energy store

(16) is provided for energy supply.

20. Monitoring system, characterized by

- an electrical device (2), and

- A monitoring arrangement (1) according to one of the preceding claims, and - A communication device (18) for transmitting data to a central server device (19), and

- A central server device (19) which is designed to receive and evaluate the data.

21. Monitoring system according to claim 20, characterized in that the communication device (18) is designed to transmit the data in at least one of the following ways: via Ethernet, USB, serial interface lx RS485, IEC 61850 standard, radio, GSM, 2G , 3G, 4G, 5G, long range radio, NFC, Bluetooth, W-LAN, fiber optic cables, powerline communication, Modbus, Modbus RTU, Modbus ASCII, Modbus TCP.

22. Monitoring system according to claim 21, characterized in that the central server device (19) is designed to determine a degree of soiling of the housing on the basis of a determined leakage current.