GB2640444A - Hardware enablement kit for oil-immersed transformers - Google Patents

Abstract

A kit for monitoring an oil-immersed or oil-filled transformer 4 comprises: a communication device 1 and at least three sensors 3 to determine different characteristics of the transformer. The sensors are connected to the communication device using cables and the communication device forwards measured sensor data to a remote database 5. The sensors may measure temperature, humidity, gas content, partial discharge, pressure, liquid level, power, frequency, phase angle, harmonics, impedance, insulation or grounding resistance, earth fault current, arcs, overload or short circuit. Top oil temperature, bottom oil temperature, ambient temperature and winding current may particularly be measured. The kit may be installed to upgrade or service an existing transformer. The measured data may be encrypted before transmission or a certificate may be used to authorize communication. The kits may be used to monitor a fleet of installed transformers remotely.

Description

Description

Hardware enablement kit for oil-immersed transformers The present method refers to a kit for monitoring an oil-immersed transformer. Additionally, the presented invention refers to a method of monitoring a fleet of oil-immersed transformers utilizing such kits. Furthermore, the presented invention refers to a use of the inventive kits for upgrading and servicing oil-immersed transformers. Additionally, the present invention refers to a computer program product to execute such method. Furthermore, the present invention refers to a communication device containing at least one processor and at least one data storage, wherein the data storage con-tains such computer program product.

Oil-immersed transformers are a type of electrical transformer where the core and the windings are immersed in oil. The primary purpose of the oil is to cool the transformer, as it serves as an excellent heat conductor. Additionally, the oil provides electrical insulation between the windings and prevents oxidation of the core.

Monitoring the condition of these transformers is crucial for several reasons. Firstly, transformers are typically high-value assets with a long lifespan, often several decades. Therefore, ensuring their proper operation and maintenance is key to getting the most out of the investment. Secondly, a failure in a transformer can lead to significant disruptions in power supply. Not solely being costly to repair or replace. Such disruptions in power supply can easily provide grave dangers for the modern life strongly relying on continuous and reliable power supply.

For example, important parameters monitored in oil-immersed transformers include oil temperature, oil level, and oil quality. Changes in these parameters originating itself from a significant number of reasons like gas content of the oil, water content of the oil, degradation of the oil, and so on, can indicate issues such as overheating, oil leakage, or insulation breakdown.

Traditionally, monitoring these parameters required manual measurements taken at regular intervals. However, it was noted that taking into account the increasing demands relating to, for example the reliability of respective oil-immersed transformers and the tremendous number of oil-immersed trans- formers currently in use it is expected that the monitoring being able to be provided by such manual monitoring will not be sufficient to meet the demands arising. Especially, as, for example, the reliability increases even faster at a higher pace taking into account the past developments and signif-icantly increased use of electricity. For example, originating from the change from chemical energy sources for heating private and industrial assets to electrical assets based on recent changes and developments. The normal approach would be to continuously upgrade existing oil-immersed transformer by replacing respective parts during overhaul or replace the complete oil-immersed transformers. However, taking into account the expected demand and requirements and the possibilities available to execute such process it was noted that this should not be able to meet the expected sharp increase to solve the upcoming needs.

Thus, it is the belief of the inventors that there will be need to improve the insight even in such basic oil-immersed transformer widely spread throughout the world. To provide such insight on short term for the tremendous number of oil-immersed transformers in the field. Being expected to be required providing a significantly increased insight in their operation in the near future.

This and further problems are solved by the products and methods as disclosed hereafter and in the claims. Further beneficial embodiments are disclosed in the dependent claims and the further description and figures. These benefits can be used to adapt the corresponding solution to specific needs or to solve additional problems.

According to one aspect the present invention refers to a kit 5 for monitoring an oil-immersed transformer, wherein the kit contains a communication device and at least three sensors, wherein the communication device contains a processing unit, wherein the at least three sensors adapted to determine dif-ferent characteristics of the oil-immersed transformer, wherein the sensors are adapted to be connected to the communication device using cables, wherein the communication device is adapted to receive measured sensor data from the at least three sensors, wherein the communication device is adapted forward the measured sensor data to a remotely located database. Herein, the phrase "different characteristics" as herein does not necessarily refer to different physical properties. It can also be, for example, the same physical property for different parts of the oil-immersed transformer. Like the top oil temperature and the bottom oil temperature. The term "remotely located database" refers to a database being remotely located from the oil-immersed transformer. For example, such remotely located database is located outside an industrial facility like a transformer station the oil-immersed transformer is located in. Herein, such remotely located database is typically distanced many kilometers distanced from the oil-immersed transformer. For example, at least 5km in case it is distanced not that far. An example is a cloud database typi-cally containing many servers that might also be located at various locations distanced from the oil-immersed transformer.

It was noted that providing such kit for oil-immersed trans-formers is surprisingly beneficial. Being designed with user convenience in mind. Its easy-to-install format provided with respective sensors for the specific need that can be simply connected to the oil-immersed transformer makes the setup process straightforward and hassle-free. Providing such kit based system allows to easily upgrade a huge number of oil-immersed transformers with low costs and especially low effort. While upgrading such oil-immersed transformers using standard means or replacing such oil-immersed transformers is surprisingly not feasible. On the one hand the oil-immersed transformers represent relatively low value units completely contrary to their real value being essential parts of the modern society energy infrastructure. Furthermore, downtimes resulting from normal upgrade actions would not be acceptable as the time consumption and effort required would not be possible. Especially taking into account organizing the respective shut-downs and/or provision of replacements to be provided and moved to the respective locations. Thus, the simply kits as disclosed herein enable to realize such upgrades under real life conditions for oil-immersed transformers being otherwise only possible in theory in a satisfying time frame to solve the present needs.

Respective tests and simulations showed that only providing a single sensor data source is typically not enough to meet the expected demand of insight. Utilizing at least three sensors allows to provide kits suitable for many different application cases. Wherein less than three sensors typically do not provide enough insight to ensure that the monitoring estimated to be required can be achieved.

This innovative kit for monitoring an oil-immersed transformer offers several key benefits. For example, it enables real-time monitoring of the transformer's condition, providing immediate insights into any potential issues. Such early detection system, for example, allows for preventive maintenance, reducing the risk of transformer failure and extending its lifespan. Moreover, the kit not only monitors but also logs the data, forwarding it to a remote storage location. This feature allows for easy access to historical data, which can be invaluable for trend analysis and predicting future issues.

According to a further aspect the presented invention refers to a use of an inventive kit to upgrade or service an oil-immersed transformer.

According to a further aspect the presented invention refers to a method of monitoring a plurality of oil-immersed transformers, preferably a fleet of oil-immersed transformers, wherein the method contains the step of acquiring and pro-cessing measured sensor data to create an output for the fleet of oil-immersed transformers, wherein each oil-immersed transformer contains an inventive kit creating an output, wherein the outputs are forwarded to a database and/or a user interface.

According to a further aspect the presented invention refers to a computer program product, tangibly embodied in a machine-readable storage medium, including instructions operable to cause a computing entity to execute an inventive meth-od. The tangible embodiment of a computer program product in a machine-readable storage medium provides a convenient and efficient way to implement the monitoring method. It allows for easy installation and execution of the method on a computing entity.

According to a further aspect the presented invention refers to a storage device for providing an inventive computer program product, wherein the device stores the computer program product and/or provides the computer program product for fur-ther use.

According to a further aspect the presented invention refers to a communication device containing at least one processor and at least one data storage, wherein the at least one data storage contains an inventive computer program product, wherein the at least one processor is adapted to execute an inventive method. The communication device that contains at least one processor and data storage with the computer pro-gram product provides a complete solution for transformer monitoring. It allows for efficient execution of the monitoring method, ensuring effective and reliable management of the oil-immersed transformer.

To simplify understanding of the presented invention it is referred to the detailed description hereafter and the figures attached as well as their description. Herein, the figures are to be understood being not limiting the scope of the present invention as they merely disclosing preferred embodiments explaining the invention further.

Fig. 1 shows a scheme of a kit as utilized.

Fig. 2 shows a scheme of such kit including pictures of exemplary components.

Fig. 3 shows a connection element of the exemplary inventive embodiment as shown in figure 1.

Fig. 4 shows a communication element of the exemplary inventive embodiment as shown in figure 1, wherein the front side is visible.

Fig. 5 shows a communication element of the exemplary in-ventive embodiment as shown in figure 1, wherein the back side is visible.

Preferably, the embodiments hereafter contain, unless speci30 fied otherwise, at least one processor and/or data storage unit to implement the inventive method.

Unless specified otherwise terms like "calculate", "process", "determine", "generate", "configure", "reconstruct" and com-parable terms refer to actions and/or processes and/or steps modifying data and/or creating data and/or converting data, wherein the data are presented as physical variables or are available as such.

The term "data storage" or comparable terms as used herein, for example, refer to a temporary data storage like RAM (Random Access Memory) or long-term data storage like hard drives or data storage units like CDs, DVDs, USB sticks and the like. Such data storage can additionally include or be connected to a processing unit to allow a processing of the data stored on the data storage.

According to one aspect the presented invention refers to a kit as described above.

According to further embodiments it is preferred that the kit contains at least four sensors, even more preferred at least five sensors. While a three sensor based kit already provides a very detailed insight increasing the number of sensors, especially utilizing different sensor types to measure different characteristics of the oil-immersed transformer is typically very beneficial. More measured sensor data provides a more comprehensive and accurate understanding of the condition of the oil-immersed transformer. Easily compensating for the increasing costs of such kit and the additional effort required to install such kit. Providing an even improved possibility to provide preventive maintenance and overall im-proved transformer performance.

According to further embodiments it is preferred that the at least three sensor are each adapted to determine one of the parameters as contained in the list consisting of tempera-ture, humidity, gas content, partial discharge activity, pressure, liquid level, noise, vibration, current, voltage, power factor, active power, reactive power, apparent power, frequency, phase angle, harmonics, impedance, insulation resistance, grounding resistance, earth fault current, arc flash, arc fault, overheating, overloading, and short circuit of the oil-immersed transformer. Preferably, the at least three sensors are each adapted to determine one of the parameters as contained in the list consisting of temperature, hu-midity, gas content, partial discharge activity, pressure, liquid level, noise, and vibration of the oil-immersed transformer. The ability of the sensors to determine a wide range of parameters -from temperature, humidity, and gas content to power factor, active power, and even arc flash or short circuit -offers a holistic view of the transformer's health. This comprehensive monitoring can help detect a variety of potential issues, ensuring optimal transformer operation and longevity.

According to further embodiments it is preferred that the communication device is adapted to be connected to a data cable to forward the measured sensor data to the remotely located database. The adaptation of the communication device to be connected to a data cable for forwarding sensor data to remote storage ensures reliable and secure data transmission. This can provide consistent real-time monitoring and quick response to any potential issues, enhancing the overall efficiency of the transformer management system.

According to further embodiments it is preferred that the communication device contains a wireless communication interface, wherein the wireless communication interface is adapted to forward the measured sensor data to the remotely located database. The inclusion of a wireless communication interface in the communication device offers flexibility and further ease of installation. It eliminates the need for physical cabling, making the system more adaptable to different site conditions. Additionally, wireless communication can facili-tate seamless data forwarding to remote storage, ensuring uninterrupted monitoring.

According to further embodiments it is preferred that the communication device is adapted to forward only selected data to the remotely located database. The ability of the communication device to forward only selected data to the remote storage can optimize data management. By filtering and forwarding only relevant sensor data, such as values above or below a certain threshold, the system can reduce data clutter and focus on potentially critical issues. This can lead to more efficient data analysis and quicker identification of potential problems. Surprisingly, it was noted that, for ex-ample, some effective filtering using threshold values can be easily realized significantly improving the overall communications and already addresses challenges of specific application sites providing lower data communication rates or data connection problems otherwise requiring additional effort to improve the data connection along with the installation of the inventive kits. For example, such selection can be realized by means of a filter reducing the measured sensor data, for example, to sensor data values above and/or below a threshold value.

According to further embodiments it is preferred that the communication device is waterproof. Typically, it is preferred that the kit contains at least one connection element to connect the at least three sensors to the communication device, wherein the at least one connection element are waterproof or the at least one connection element is located inside a connection element box being waterproof. A waterproof communication device and connection elements offer enhanced durability and reliability, especially in environments with high humidity or potential exposure to liquids. This feature ensures that the monitoring system continues to function effectively under various conditions, reducing the risk of data loss or system failure due to water damage. Being surprisingly beneficial for oil-immersed transformer being often utilized in difficult environments and benefitting significantly from such improvement.

According to further embodiments it is preferred that the communication device contains a wireless charging element, wherein the wireless charging element is adapted to receive electromagnetic waves from the oil-immersed transformer, wherein energy of the electromagnetic waves is utilized to power the communication device. The inclusion of a wireless charging element that utilizes the energy of electromagnetic waves from the transformer to power the communication device offers a self-sustaining power solution. Eliminating the need for external power sources or frequent battery replacements being a surprisingly significant additional challenge when rolling out such upgrades. As the subsequent additional service actions otherwise might even render the overall benefit null as the constant replacements might easily bind all capacities for such tasks.

According to further embodiments it is preferred that the communication device contains a power input adapted to receive a cable supplying electrical power to the communication device to power the communication device. Such solution re- quires a respective power connection being available at the specific location the kit is located. However, for typical applications such solution is very beneficial as the required effort to provide such power supply is typically limited and the power supply is very reliable and very safe to misplace-ments of the kit.

According to further embodiments it is preferred that the kit contains at least one connection element to connect the at least three sensors to the communication device, wherein the at least one connection element provides different connections for the at least three sensors, wherein the different connections are adapted to prevent an incorrect connection of the at least three sensors to the communication device. The provision of different connections for the sensors to prevent incorrect connection enhances the ease of installation and reduces the risk of errors. This feature can save time during setup and ensure accurate data collection from each sensor.

According to further embodiments it is preferred that the re-motely located database is a cloud database. Using cloud database storage for the remotely located database offers several benefits. It provides virtually unlimited storage space, allows for easy access to data from anywhere, and facilitates seamless integration with other cloud database-based systems or services. Enabling to significantly further applications and utilizations of the data collected. Even the first collected low amount of data allowed to identify trends within the fleets of oil-immersed transformers and indicates that a huge number of additional benefits and improvements can be acquired when collecting and analyzing such data collection.

According to further embodiments it is preferred that the cloud database is adapted to process the measured sensor data, wherein processing of the measured sensor data contains de-termining the status of the oil-immersed transformer. The ability of the cloud database to process the measured sensor data and determine the status of the transformer provides a powerful tool for predictive maintenance. This feature can help identify potential issues early, optimize maintenance schedules, and improve the overall efficiency and lifespan of the transformer.

According to further embodiments it is preferred that the communication device is adapted to encrypt the measured sensor data forwarded to the remotely located database. The ability of the communication device to encrypt the sensor da-to forwarded to the remote storage enhances the security of the system. This feature protects sensitive data from unauthorized access or potential cyber threats, ensuring the integrity and confidentiality of the oil-immersed transformer's operational data.

According to further embodiments it is preferred that the communication device contains a certificate, wherein the certificate is adapted to authorize a communication with and/or access to the remotely located database. The inclusion of a certificate in the communication device to authorize communication with or access to the remotely located database enhances the security of the system. Herein, for example, the remotely located database can check the certifi- cate provided by the respective communication device to acquire insight whether this respective communication device is to be allowed to provide sensor data to be stored. In turn the communication device can also be adapted to check feed-back received from the remotely located database to check whether the data will be sent to the correct database. This feature ensures, for example, that only authorized devices can access the data, protecting the integrity and confidentiality of the transformer's operational data.

According to further embodiments it is preferred that the at least three sensors are adapted to acquire measured sensor data related to at least three characteristics of the oil-immersed transformer selected from the group consisting of top oil temperature, bottom oil temperature, winding current, and ambient temperature. The adaptation of the sensors to acquire specific data related to top oil temperature, bottom oil temperature, winding current, and ambient temperature offers precise and targeted monitoring. This can help detect specific issues related to these parameters, ensuring optimal transformer operation and longevity.

According to further embodiments it is preferred that kit contains a connection element box and a connection element, wherein the connection element box contains the connection element, wherein the communication device and the connection element box are mounted on a base plate. Such separation of the connection element is typically beneficial to increase the reli-ability of the communication element. Such separation is already very beneficial to prevent dirt being introduced into the more sensible part contained in the communication device. However, it was, for example, noted that it is especially beneficial when being combined with waterproof communication devices and waterproof connection element boxes. Increasing the overall reliability while even enabling mounting the kit at a location of the oil-immersed transformer being easily confronted with humidity.

According to further embodiments it is preferred that the connection element box and the communication device are mounted on a plate. This allows to significantly simplify the mounting of such kit under real life application cases. Not only saving time to attach the respective kit. But also to reduce the number of attachment points required to mount such kit. Being a surprisingly challenging task to attach such kit to the huge number of available oil-immersed often differing slightly. Requiring to carefully consider where a respective fixation can be utilized.

According to further embodiments it is preferred that the plate contains at least 3, more preferred at least 5, even more preferred at least 7 holes, wherein the holes are adapted to enable a fixation of the communication device and the connection element box. Providing a higher number of holes even in case a single hole for a screw would be satisfying is surprisingly beneficial to more flexibly adapt the location of fixation of the plate. Requiring not only to take into account the periphery like cables and pipe narrowing down the location of fixation, but also the possible fixation point used by the holes to fixate the plate to an oil-immersed transformer, for example, using a screw that cannot be screwed into the counterpart at the respective location, for example, based on underlying electronics or the oil tank being possible damages in case a counterpart is drilled into the oil-immersed transformer at this location.

According to further embodiments it is preferred that the plate contains at least one magnetic fixation element. Utilizing such magnetic fixation element allows to attach the plate and the attached communication device and connection element box to the oil-immersed transformer very fast and easily. A very reliable fixation can furthermore be acquired by combining such at least one magnetic fixation element with a fixation element making use of holes. Like using a screw or bolt through one of the holes together with at least one mag-netic fixation elements. Such combination is especially beneficial to provide an optimum of swift and firm attachment allowing to, for example, easily detach cables or the like as the plate and the other elements are firmly attached.

For many application cases it was especially beneficial to utilize kits, wherein the remotely located database is a cloud database, wherein the communication device is adapted to encrypt the measured sensor data forwarded to the remotely located database, wherein the kit contains a connection element box and a connection element, wherein the connection element box contains the connection element, wherein the communication device and the connection element box are mounted on a base plate, wherein the communication device and the con-nection element box are waterproof. Such solution is especially beneficial for many application cases. Herein, the features are especially suitable to work together to provide a solution being easily and swiftly attached to a desired location, wherein the separation of the connection element from the communication device further increases the protection against damages and tampering with the communication device. Wherein the communication device provides an encrypted communication to secure the communication with the remotely located database. All the features very efficiently work together to provide an overall improved solution addressing a plurality of needs and problems arising for real life application cases.

According to further embodiments it is preferred that the at least one sensor contains at least one detachably connected sensor, more preferred at least two detachably connected sensors, wherein such detachably connected sensor is adapted to be detachably connected to the communication device, preferably by means of a connection element. The ability to detachably connect the sensors to the communication device offers flexibility and convenience. This "plug and play" feature allows for easy installation, replacement, or removal of sensors, making the system adaptable and easy to maintain. It was noted that despite the long-term application and high lifetime of the kit such solution is often to be preferred for typical application cases. For example, benefits like the possibility to simply exchange sensor to check, for example, a possible reason for problems and the saved downtime and the like provides a significant benefit easily outweighing additional effort required.

The term "detachably connected" as used herein refers to a connection like a plug and play connection allowing, for example, to connect or disconnect the respective units or a connection being attached by a screw.

According to further embodiments it is preferred that the at least one sensor contains at least one non-detachably connected sensor, more preferred at least two non-detachably connected sensors, wherein such non-detachably connected sensor is adapted to be non-detachably connected to the communication device. The non-detachable connection of the sensors to the communication device ensures a secure and stable connection. This can prevent accidental disconnection of the sensors, ensuring consistent and reliable data collection. For example, such non-detachable connection can be provided by soldering a cable to the sensor and the communication device or to the sensor and a connection element being non detachably connected to the communication device. The term "non detachably connected" as used herein refers to a connection like a cable being welded a sensor and a main board of the communication device. Detaching such connection requires to at least partially destroy the connection like using a pair of pliers.

According to further embodiments it is preferred that the contains quick connectors to attach the at least three sensors to the communication device by means of such quick connector, wherein the quick connectors are adapted to enable connecting the at least three sensors to the communication device without the need of tools. The inclusion of quick connectors to attach the sensors to the communication device without the need for tools simplifies the installation process. This fea-ture can save time and effort during setup and maintenance.

According to a further aspect the present invention refers to a use of an inventive kit to upgrade or service an oil-immersed transformer.

The use of the kit to upgrade or service an oil-immersed transformer provides a cost-effective and efficient solution. It can enhance the transformer's monitoring capabilities and overall performance without the need for a complete replace-ment.

According to a further aspect the present invention refers to a method of monitoring a fleet of oil-immersed transformers, wherein the method contains the step of acquiring and pro-cessing measured sensor data to create an output for the fleet of oil-immersed transformers, wherein each oil-immersed transformer contains an inventive kit creating an output, wherein the outputs are forwarded to a database and/or a user interface.

The method of monitoring a plurality of oil-immersed transformers, preferably a fleet of oil-immersed transformers, using the kit provides a comprehensive solution for large-scale transformer management. It allows for efficient data collec-tion and analysis across multiple transformers, facilitating effective fleet management and maintenance.

The term "plurality" as used herein refers to as least 5 assets, more preferred at least 7 assets.

The term "fleet" as used herein refers to at least at least 10 assets, more preferred at least 20 assets.

According to further embodiments it is preferred that method contains the step of monitoring a fleet of oil-immersed transformers, wherein the kits of at least 10, more preferred at least 20, of the oil-immersed transformers of the fleet of oil-immersed transformers contain different certificates being adapted to authorize a communication with and/or access to the remotely located database. The use of different certificates to authorize communication with the remote storage in a fleet of transformers enhances the security of the sys-tem. It ensures that only authorized transformers can access the data, protecting the integrity and confidentiality of the fleet's operational data.

According to further embodiments it is preferred that the method contains the step of simulating a current state of the fleet of oil-immersed transformers using the measured sensor data. The method of simulating the current state of the fleet of transformers using the measured sensor data provides a powerful tool for predictive maintenance. This feature can help identify potential issues across the fleet early, optimize maintenance schedules, and improve the overall efficiency and lifespan of the transformers.

According to further embodiments it is preferred that the method contains the step of simulating the load of the oil-immersed transformer using the measured sensor data. This, for example, allows to optimize loads of the oil-immersed transformer to improve productivity.

According to further embodiments it is preferred that the method contains the step of simulating the relative aging of the oil-immersed transformer. Herein the measured sensor data is utilized to calculate the relative aging of the oil-immersed transformer. Providing a very good insight into the remaining life as well as current strain put onto the oil-immersed transformer.

According to further embodiments it is preferred that the method contains the step of determining virtual sensor data based on the measured sensor data. For example, based on the proprietary understanding of the design, such as top oil tem-perature and hotspot winding temperatures, it becomes possible to also determine the values of virtual sensors that can be beneficially utilized, for example, to support an expert desiring to monitor such oil-immersed transformer or gain insight into its current state.

According to further embodiments it is preferred that the simulation of the current state of the fleet of oil-immersed transformers utilizes virtual sensor data based on the measured sensor data. The use of virtual sensor data based on the measured sensor data in the simulation of the fleet's current state provides a more comprehensive view of the fleet's condition. This can enhance the accuracy of the simulation and improve the effectiveness of the predictive maintenance strategy.

Making use of the inventive kits and the data obtained herewith allows to utilize further data analysis software. Such data analysis software can, for example, be integrated in a cloud database. Such data analysis software can, for example, be utilized to help users understand the sensor data and make informed decisions. The software could include features like trend analysis, predictive maintenance algorithms, and visualization tools. Combining such data analysis software with a cloud database especially allows to provide an easy access to such data.

According to a further aspect the presented invention refers to a computer program product, tangibly embodied in a machine-readable storage medium, including instructions opera-35 ble to cause a computing entity to execute an inventive meth-od.

According to a further aspect the presented invention refers to a storage device for providing an inventive computer program product, wherein the device stores the computer program product and/or provides the computer program product for fur-ther use.

According to a further aspect the presented invention refers to a communication device containing at least one processor and at least one data storage, wherein the at least one data storage contains an inventive computer program product, wherein the at least one processor is adapted to execute an inventive method.

The following detailed description of the figure uses the figure to discuss illustrative embodiments, which are not to be construed as restrictive, along with the features and further advantages thereof.

Figure 1 shows a scheme of an inventive kit for monitoring an oil-immersed transformer 4. Herein, the kit contains a communication device 1 and at three sensors 3 being connected to the communication unit by means of three contacts of a connection element 2 being part of the communication device 1. In alternative embodiments the sensors 3 can be directly con- nected to the communication device 1 by means of a non detachable connection being soldered to the respective contacts of the communication device 1. However, for typical application cases the possibility to easily switch the sensor 3 allows to easily adapt the kit to specific needs of the respec- tive oil-immersed transformer 4 to be monitored. The connection element 2 connects to the three sensors 3, wherein one sensor 3 is introduced into the oil-immersed transformer 4. One sensor 3 is attached to the surface of the oil-immersed transformer 4. And one sensor 3 is connected to the oil-immersed transformer 4 by a cable.

The connection between the communication device 1, the connection element 2 and the sensors 3 is established by means of cables. In alternative embodiments not shown in the figure at least a part of the connection element 2 are not integrated in the communication device 1, but are connected to the communication device 1 by cables.

The communication device 1 contains a processing unit to enable a communication with the remotely located database 5 being a cloud database in this embodiment. The communication device 1 further contains a multi-purpose interface being in- tegrated into the communication device 1 to allow further sensors 3 and external devices to the attached to the communication device 1. For example, such multipurpose interface 11 can be a standard interface allowing to attach a corresponding data hub allowing to permanently or temporarily con-nect multiple additional sensors 3 to the communication device 1. The connection element 2 provide different connections for the three sensors 3. For example, preventing any incorrect connection of the sensors 3 with the communication device 1. A further benefit noted was that it is surprisingly beneficial during later overhaul and service actions. As it allows to easily identify the connecting cable of a respective sensor 3 without being required to follow the respective cable connection. Being surprisingly beneficial under real conditions applicable in this context.

The three sensors 3 shown in figure 1 are selected to determine different characteristics of the oil-immersed transformer 4 being in the example as shown the top oil temperature the winding current, and ambient temperature. Said sensors 3 provide measured sensor 3 data being consistently sent to the communication device 1. The communication device 1 forwards the measured sensor 3 data to the remotely located database being a cloud database through a data cable connection being attached to the communication device 1 and connecting the communication device 1 to a router allowing to access the Internet. Alternatively, the communication device 1 can contain a wireless interface allowing to forward the measured sensor 3 data without such cable connection.

To ensure that the measured sensor 3 data is not changed or illegally utilized by a third party the measured sensor 3 data is encrypted by the communication device 1 utilizing an encryption protocol stored on a data storage of the communication device 1. Alternatively, an encryption chip like a hardware oracle could be implemented in the communication device 1 to provide a corresponding encryption.

Additionally, the data storage containing the encryption protocol contains a certificate utilized by the communication device 1 to authorize itself when communicating with the remotely located database 5 being a cloud database.

The communication device 1 itself is provided being waterproof. Allowing to reduce the care to be taken to ensure that a long-term operation can be ensured under the very differing conditions available for the fleet of oil-immersed transformer 4s to be upgraded accordingly.

Furthermore, the communication device 1 contains a wireless charging element being adapted to receive electromagnetic waves from the oil-immersed transformer 4 based in the electricity running through the oil-immersed transformer 4. The energy of the electromagnetic waves received is utilized to power the communication device 1. Allowing to avoid providing power cables that might be required to laid down first or to utilize batteries being required to be replaced. It is especially beneficial to utilize the combination of a waterproof solution of the communication device 1 and such wireless charging element as it was noted that the placement of the communication device 1 is in such case restricted and the insurance that small amounts of water possibly being present based on condensation process or the like will not impair the functionality is a surprisingly beneficial improvement under real life conditions.

Such kit as exemplarily shown in figure 1 can easily be utilized to upgrade existing oil-immersed transformer 4 not providing any continuous monitoring at all. Taking into account the detachable connections utilized for the kit it is also easily possible to replace such communication device 1 during service actions.

Not shown in figure 1 are the further oil-immersed transformers 4 also containing the inventive kits. Wherein the kits allow to upgrade available oil-immersed transformers 4 in a very big scale to provide within a very short time period a fleet of oil-immersed transformer 4s providing the described monitoring possibilities.

Figure 2 shows a scheme of such kit including pictures of exemplary components of an alternative inventive embodiment. Herein the communication device is connected to a connection element providing a quick connectivity functionality. Said quick connectivity allows to easily connect the cables of the sensors without the need to tools. Only two of the four sensors of the exemplary inventive example are shown. Herein, the figure shows a are shown to illustrate the embodiment an oil-temperature sensor as well as a current transducer. The sensors are connected to the oil-immersed transformer like in figure 1.

Figure 3 shows a connection element of the exemplary inventive embodiment as shown in figure 1. Herein, the connection element allows to connect cables by simply inserting re-spective cables into it. The cables are automatically fixated. However, pressing the button below the respective opening, for example, with a pen allows to unfasten the respective cable. The numbering provided additionally simplifies the correct connection, for example, based on connection schemes provided along.

Figure 4 shows a communication element 1 of the exemplary inventive embodiment as shown in figure 1, wherein the front side is visible. Herein, the communication device provides a data processing and transmission unit 12 and a connection element box 14 being separated from each other and both being attached to a base plate 16. This apparently simple arrange-ment is surprisingly beneficial to address many needs herein.

Separating the data processing and transmission unit 12 and the connection element box 14 provides the possibility to further increase the reliability of the communication element 1. Increasing the encapsulation of the data processing and transmission unit 12 making it especially waterproof, for example, provides a significant improvement of the reliability. The fixed connections to the connection element box 14 allows to prevent any subsequent interaction of, for example, a field operator with the data processing and transmission unit 12 being significantly more prone to damages from humidity and the like.

The connection element box 14 contains the connection element 2 as shown in figure 3. A field operator only needs to open the connection element box 14 and execute all required interactions in this box. From the connection element box 14 a cable is connected to a sensor 3 measuring the ambient temperature at the oil-immersed transformer as the communication de-vice 1 is adapted to be directly attached to the oil-immersed transformer.

The fixation of the communication device 1 is realized by screws through the holes 13. Herein, not all holes 13 need to be utilized even a single screw is enough, but the multiple holes 13 allow to select a hole being beneficial for the specific application case. Also being surprisingly beneficial, as it was noted that in real application cases the location of fixating such communication element 1 can be limited and the flexibility provided hereby is especially useful.

Figure 5 shows a communication element of the exemplary in-ventive embodiment as shown in figure 1, wherein the back side is visible. Herein, the data processing and transmission unit 12 and the connection element box 14 are only visible in a limited way. Also, visible are the holes 13 to fixate the communication device 1 to the oil-immersed transformer. Addi-tionally, the magnetic fixation elements 15 are visible enabling to further stabilize and fixate the communication device 1. Herein, said magnetic fixation elements 15 enable that the communication device 1 as exemplarily shown in figure 1 can be fixated to the oil-immersed transformer by a single screw through any of the holes 13. Allowing to significantly simplify the attachment of the communication device 1 during upgrades or its replacement during servicing actions.

The present invention was only described in further detail for explanatory purposes. However, the invention is not to be understood being limited to these embodiments as they represent embodiments providing benefits to solve specific problems or fulfilling specific needs. The scope of the protection should be understood to be only limited by the claims attached.

Claims (15)

1. Patent claims 1. Kit for monitoring an oil-immersed transformer (4), 5 wherein the kit contains a communication device (1) and at least three sensors (3), wherein the communication device (1) contains a processing unit, wherein the at least three sensors (3) adapted to determine 10 different characteristics of the oil-immersed transformer (4), wherein the sensors (3) are adapted to be connected to the communication device (1) using cables, wherein the communication device (1) is adapted to receive measured sensor data from the at least three sensors (3), wherein the communication device (1) is adapted forward the measured sensor data to a remotely located database (5).
2. 2. Kit according to claim 1, wherein the at least three sensor (3) are each adapted to determine one of the parameters as contained in the list consisting of temperature, humidity, gas content, partial discharge activity, pressure, liquid level, noise, vibration, current, voltage, power factor, active power, reactive power, apparent power, frequency, phase angle, harmonics, impedance, insulation resistance, grounding resistance, earth fault current, arc flash, arc fault, overheating, overloading, and short circuit of the oil-immersed transformer (4).
3. 3. Kit according to any of claims 1 to 2, wherein the com-munication device (1) is waterproof.
4. 4. Kit according to any of claims 1 to 3, wherein the kit contains at least one connection element (2) to connect the at least three sensors (3) to the communication device (1), wherein the at least one connection element (2) provides different connections for the at least three sensors (3), wherein the different connections are adapted to prevent an incorrect connection of the at least three sensors (3) to the communication device (1).
5. 5. Kit according to any of claims 1 to 4, wherein the re-5 motely located database (5) is a cloud database.
6. 6. Kit according to any of claims 1 to 5, wherein the communication device (1) is adapted to encrypt the measured sensor data forwarded to the remotely located database (5).
7. 7. Kit according to any of claims 1 to 6, wherein the communication device (1) contains a certificate, wherein the certificate is adapted to authorize a communication with and/or access to the remotely located database (5).
8. 8. Kit according to any of claims 1 to 7, wherein the at least three sensors (3) are adapted to acquire measured sensor data related to at least three characteristics of the oil-immersed transformer (4) selected from the group consist-ing of top oil temperature, bottom oil temperature, winding current, and ambient temperature.
9. 9. Kit according to any of claims 1 to 8, wherein the kit contains a connection element box (14) and a connection ele25 ment (2), wherein the connection element box (14) contains the connection element (2), wherein the communication device (1) and the connection element box (14) are mounted on a base plate.
10. 10. Use of a kit according to any of claims 1 to 9 to upgrade or service an oil-immersed transformer (4).
11. 11. Method of monitoring a plurality of oil-immersed trans-35 formers (4), wherein the method contains the step of acquiring and pro- cessing measured sensor data to create an output for the fleet of oil-immersed transformers (4), wherein each oil-immersed transformer (4) contains a kit according to any of claims 1 to 9 creating an output, wherein the outputs are forwarded to a database and/or a user interface.
12. 12. Method according to claim 11, wherein the method contains the step of monitoring a fleet of oil-immersed transformers (4), wherein the kits of at least 10 of the oil-immersed transformers (4) of the fleet of oil-immersed trans-formers (4) contain different certificates being adapted to authorize a communication with and/or access to the remotely located database (5).
13. 13. Method according to any of claims 11 to 12, wherein the 15 method contains the step of simulating a current state of the fleet of oil-immersed transformers (4) using the measured sensor data.
14. 14. Computer program product, tangibly embodied in a ma-20 chine-readable storage medium, including instructions operable to cause a computing entity to execute a method according to any of claims 11 to 13.
15. 15. Communication device (1) containing at least one proces-sor and at least one data storage, wherein the at least one data storage contains a computer program product according to claim 14, wherein the at least one processor is adapted to execute a method according to any of claims 11 to 12.