METHOD FOR DETERMINING THE OVERLOAD CAPACITY OF A HIGH-VOLTAGE DEVICE

Abstract

A method determines an overload capacity of at least one high-voltage device. In which method, measurement values are continuously recorded by sensors located in or on the high-voltage device. The measurement values and/or values derived therefrom are transmitted via a near field communication connection from the sensors to a communication unit of the high-voltage device. The communication unit is connected to a data processing cloud. For high-voltage devices, a load forecast request is created for a predetermined time-period and is transmitted to a data processing cloud. For each high-voltage device, a state parameter is determined in part based on the measurement values. The load forecast request and each state parameter are transmitted at a request time to a load forecasting model; and the load forecasting model determines the maximum load in the predetermined time period.

Claims

1-15. (canceled)

16. A method for determining an overload capacity of at least one high-voltage device, which comprises the steps of: continuously capturing measured values by sensors which are disposed in or on the at least one high-voltage device; transmitting the measured values and/or values derived therefrom via a short-range communication connection from the sensors to a communication unit of the at least one high-voltage device, the communication unit being connectable via a long-range communication connection to a data processing cloud; creating, for the at least one high-voltage device, a load forecast request for a predefined time period and transmitting the load forecast request to the data processing cloud; determining, for each said at least one high-voltage device, at least one state parameter at least partially on a basis of the measured values and/or the values derived therefrom; transmitting the load forecast request and each said at least one state parameter at a request time to a load-forecasting model, the load-forecasting model determining a maximum utilization in the predefined time period; and deriving a lifetime of each said at least one high-voltage device consumed before the request time from stored measured values by obtaining an actually consumed lifetime and by feeding the actually consumed lifetime to the load-forecasting model as a further state parameter, wherein the load-forecasting model determines a maximum overload capacity depending on the actually consumed lifetime for each said at least high-voltage device.

17. The method according to claim 16, wherein the at least one state parameter is one of a plurality of state parameters which include a parameter which maps available cooling power.

18. The method according to claim 16, wherein the at least one state parameter is one of a plurality of state parameters which include a parameter which maps weather conditions to which the at least one high-voltage device is exposed.

19. The method according to claim 16, wherein the at least one high-voltage device is a transformer, and the at least one state parameter is one of a plurality of state parameters which include a parameter which was determined on a basis of a temperature of a coolant of the transformer.

20. The method according to claim 16, wherein the at least one high-voltage device is a transformer having windings, and the at least one state parameter is one of a plurality of state parameters which include a parameter which was determined on a basis of a current flowing through one of the windings of the transformer.

21. The method according to claim 16, wherein the actually consumed lifetime of the at least one high-voltage device is continuously calculated and stored on a storage unit.

22. The method according to claim 16, wherein the load forecast request includes a forecast of weather conditions.

23. The method according to claim 16, wherein the load forecast request contains an indication of a desired lifetime consumption.

24. The method according to claim 16, wherein the load-forecasting model indicates an expected lifetime consumption.

25. The method according to claim 16, which further comprises using the measured values and/or the values derived from the measured values which have been captured or derived before the request time.

26. The method according to claim 16, which further comprises continuously repeating the method at predefined intervals of time and an overload capacity obtained in a process is made available to a user.

27. The method according to claim 16, which further comprises storing the measured values and/or the values derived therefrom captured before the request time on a storage device of the communication unit or of the data processing cloud.

28. The method according to claim 16, which further comprises determining a geographical location of the communication unit and the at least one high-voltage device connected to it by means of an antenna for position determination which is disposed in the communication unit, and weather data are then captured by a weather-reporting service, the weather data being provided by a service provider for the geographical location of the at least one high-voltage device.

29. A computer program for a computing device, the computer program comprising: computer executable instructions for carrying out the method according to claim 16.

30. A transitory storage medium, comprising: a computer program for carrying out the method according to claim 16.

Description

[0037] Further appropriate designs and advantages of the invention form the subject-matter of the following description of example embodiments of the invention with reference to the figures in the drawing, wherein the same reference numbers refer to identically acting components, and wherein

[0038] FIG. 1 shows an overload curve of a transformer according to the prior art,

[0039] FIG. 2 shows a schematic view of an example embodiment of the method according to the invention, and

[0040] FIG. 3 shows schematically a transformer with a communication unit and a data processing cloud.

[0041] FIG. 1 shows an example embodiment of an overload curve, already introduced above, of a transformer, wherein the time in hours is plotted on the x-axis and the utilization capacity of said transformer in relation to the nominal power is plotted on the y-axis. The overload curve shown was created following the manufacture of the transformer assigned to it on the basis of test measurements on said transformer and was made available to the customer.

[0042] In the example embodiment shown in FIG. 1, said transformer can be operated for 2 hours with an overload of 120% in relation to the nominal power (100%). Operation with an overload of 110% is then possible for 3 hours.

[0043] It is assumed that the overload operation takes place constantly in each case, i.e. 2 hours with 120% of the nominal power and 3 hours with 11% of the power. However, this is not the case in reality. Instead, the transformer is not operated continuously with 120% overload during said 2 hours. Fluctuations instead occur in said 2 hours. Operation is thus possible, for example, for 20 minutes at nominal power, for 10 minutes at 80% of the nominal power, for 30 minutes at 70% of the nominal power and for 60 minutes with an overload of 120% of the nominal power. This different loading obviously impacts on the lifetime or aging of the transformer. In other words, the potential of the transformer is not fully exploited.

[0044] Transformers as electrical device according to the invention are key components of electrical supply networks. The failure of a transformer can result in extreme losses and even network outages. Transformers are therefore carefully monitored. In order to establish the aging of a transformer, a “temperature curve”, for example, of the transformer is recorded in order to thus obtain information relating to the present load and lifetime.

[0045] It is known from the ICE 60076-7 standard for an aging rate of an electrical transformer to be calculated depending on the hotspot temperature. Particularly the insulating paper of the windings is taken into account in the calculation. It is assumed by way of approximation that the insulating properties of the insulating paper are dependent on the degree of polymerization of the insulating paper, along with other influencing variables. However, the loads occurring during the operation of the transformer modify the degree of polymerization of the insulating paper such that the insulation capability of the winding paper decreases as the lifetime increases and finally becomes insufficient, so that the transformer reaches the end of its lifetime.

[0046] The hotspot temperature can be determined from measurements of the temperature of the insulating fluid and from the measurement of the winding current. As already explained above, the lifetime of the transformer can be determined from the hotspot temperature.

[0047] The invention is based on the idea that the temperature of the coolant, or in other words of the insulating fluid, and the winding current are in any case continuously observed. With regard to digitization, it is additionally probable that these measurement variables or data derived therefrom are transmitted from the respective high-voltage device to a data processing cloud, wherein the data processing cloud continuously determines the lifetime of said transformer from the data made available to it and can make this variable available, for example to a load-forecasting model.

[0048] FIG. 2 shows an example embodiment of the method 1 according to the invention which is shown schematically in FIG. 2. A load-forecasting model 2 is shown which receives a load forecast request 2 at a request time. The load forecast request 2 contains the query concerning the amount of overload with which the transformer can be operated in 2 hours for 8 hours if the lifetime consumption is intended to be 110%. Reference is made to the lifetime consumption (100%) which occurs during an operation of the transformer at nominal power.

[0049] In addition, state parameters are transmitted to the load-forecasting model 2, wherein, in the example embodiment shown, the state parameters 4 comprise the temperature of the insulating fluid in the upper area of the transformer and the winding current. Further state parameters relate to the available cooling power and the forecast weather conditions at the location of the transformer. In addition, the hitherto consumed lifetime 5 is fed to the load-forecasting model 2 as a state parameter.

[0050] According to the invention, the already consumed lifetime is in no way roughly estimated. Instead, the consumed lifetime is determined continuously on the basis of measured values and is stored on a storage unit 6. This consumed lifetime is referred to here as actually consumed lifetime. According to the invention, it is possible for the load-forecasting model 2 to determine the overload capacity of the transformer more precisely on the basis of the actually consumed lifetime determined in this way or, in other words, the lifetime consumption measured in this way.

[0051] On the output side, the load-forecasting model generates, on the one hand, the statement 7 indicating the level of the maximum possible overload operation in the desired time period. The load-forecasting model furthermore indicates the expected lifetime consumption 8 in the desired time period.

[0052] FIG. 3 shows a schematically illustrated transformer 9 with its three bushings 10 which are supported on a tank of the transformer 11. On their end facing away from the tank 11, the bushings 10 have an outdoor connection to connect an air-insulated high-voltage line of an energy supply network. Each bushing 10 has an inner high-voltage conductor which extends through a hollow insulator. The insulator and the high-voltage conductor pass through the upper wall of the tank 11 of the transformer 9 and extend with their free end into the oil chamber of the tank 11. The high-voltage conductor of each bushing 10 can thus be connected to the respective high-voltage winding of the transformer 9. Each high-voltage winding is disposed concentrically with a low-voltage winding through which a leg of a magnetizable core extends. The high-voltage and low-voltage windings are thus inductively coupled with one another.

[0053] The tank 11 of the transformer 9 is filled with an insulating fluid which serves to insulate and cool the high-voltage-connected windings and the core. The transformer further has a cooling unit, but this is not shown in the figure.

[0054] The transformer 9 is equipped with temperature sensors which are disposed inside the tank 11 to measure the temperature of the insulating fluid and are therefore not shown in the figure. Each temperature sensor is connected via a short-range communication connection 12 to a communication unit 13 attached to the transformer 9, wherein the short-range communication connection 12 is designed in this case as a cable. The communication unit 13 is in turn connected via a long-range communication connection 14 to a data processing cloud 15.

[0055] The temperature measured values captured by the temperature sensors are transmitted via the short-range communication connection 12 to the communication unit 13. Said communication unit transmits the temperature measured values via the long-range communication connection 14 to the data processing cloud 15. The data processing cloud 15 has the storage device shown in FIG. 2 and calculates the consumed lifetime on the basis of the captured temperature measured values and the captured winding currents according to the aforementioned standard. The lifetime consumption of the transformer 9 is determined continuously in this way and is available on demand to the load-forecasting model 2 according to FIG. 2.