ELECTRICAL DEVICE FOR CONNECTION TO A HIGH-VOLTAGE SUPPLY SYSTEM, AND METHOD FOR DETECTING A FAULT OF A COMPONENT OF THE ELECTRICAL DEVICE

Abstract

An electrical device for connection to a high-voltage supply system includes a fluid-tight tank which is filled with an insulating fluid and in which a core is surrounded by a winding at least in sections. A cooling unit is connected to the tank and a pump circulates the insulating fluid of the tank through the cooling unit. A measuring sensor is provided for detecting vibrations of the pump while providing time-triggered vibration measurement values. A protection unit is connected to the measuring sensor and is configured to receive and convert the time-triggered vibration measurement values into frequency-triggered vibration values. The protection unit analyzes the frequency-triggered vibration values with the aid of a previously determined logic for the existence of a fault criterion and is configured to generate a warning signal in the event that a fault criterion is determined.

Claims

1-13. (canceled)

14. An electrical device for connection to a high-voltage supply system, the electrical device comprising: a fluid-tight tank to be filled with an insulating fluid; a core disposed in said tank and a winding partially enclosing said core; a cooling unit connected to said tank; a pump for circulating the insulating fluid of said tank through said cooling unit; a measuring sensor for detecting vibrations of said pump and providing time-triggered vibration measured values; and a protection unit connected to said measuring sensor and configured for receiving and converting the time-triggered vibration measured values into frequency-triggered vibration values, said protection unit analyzing the frequency-triggered vibration values for an existence of a fault criterion by using previously determined logic, and said protection unit configured to generate a warning signal upon determining a fault criterion.

15. The electrical device according to claim 14, which further comprises a display unit connected to said protection unit.

16. The electrical device according to claim 14, wherein said measuring sensor is an acceleration sensor attached to said pump.

17. The electrical device according to claim 16, wherein said measuring sensor is a piezo element.

18. The electrical device according to claim 14, wherein the electrical device is a railway transformer.

19. A method for detecting a fault of a component of an electrical device, the method comprising the following steps: detecting vibrations of the component to be monitored while obtaining time-triggered vibration measured values; transmitting the time-triggered vibration measured values to a protection unit of the electrical device; using the protection unit to convert the time-triggered vibration measured values into frequency-triggered vibration values; using the protection unit to analyze the frequency-triggered vibration values for an existence of a fault criterion by using logic; and using the protection unit to trigger a warning signal upon an existence of a fault criterion.

20. The method according to claim 19, which further comprises: transmitting the time-triggered vibration measured values or the frequency-triggered vibration values over a wireless connection to a cloud server; using the cloud server, in addition to an evaluation unit, to check received data for an existence of a fault criterion by using a previously known logic; and generating a cloud warning signal upon an existence of a fault criterion.

21. The method according to claim 20, which further comprises transmitting the cloud warning signal back to the protection unit.

22. The method according to claim 19, which further comprises analyzing the frequency-triggered vibration values for an existence of a plurality of fault criteria being respectively associated with a particular hazard level.

23. The method according to claim 19, which further comprises transmitting the warning signal to a display unit configured for an optical depiction of a respective fault.

24. The method according to claim 19, which further comprises using a filter unit to filter the frequency-triggered vibration values and to suppress vibration values of predetermined frequency ranges.

25. The method according to claim 19, which further comprises providing a pump as the component.

26. The method according to claim 19, which further comprises providing a railway transformer as the electrical device.

Description

[0020] Further advantageous embodiments and advantages of the present invention form the subject matter of the following description of exemplary embodiments of the present invention, with reference to the figures of the drawing, wherein identical reference signs refer to identical components, and wherein

[0021] FIG. 1 illustrates a schematic representation of an exemplary embodiment of the electrical device according to the present invention,

[0022] FIG. 2 illustrates a schematic representation of the method according to the present invention, and

[0023] FIG. 3 illustrates characteristic vibration spectra which are received according to the method according to the present invention and the electrical device according to the present invention.

[0024] FIG. 1 depicts an exemplary embodiment of the electrical device 1 according to the present invention, which is designed as a railway transformer 1 in the depicted exemplary embodiment. The railway transformer 1 comprises a tank 2 which is designed to be fluid-tight and in which an active portion is arranged which is not visible in the figure. The active portion comprises a core having a leg which is enclosed by two windings which are concentrically arranged with respect to one other. The radially exterior upper-voltage winding is electrically connected to input feedthroughs 3, while the interior winding is connected to two output feedthroughs 4. For insulating the active portion, which is at a high-voltage potential during the operation of the transformer 1 with respect to the tank 2, which is at ground potential, the tank 2 is filled with an insulating fluid, here, an insulating liquid such as ester oil. A cooling unit 5 which is connected to the tank via tubing 6 and 7 is used for cooling. A pump 8 is used for circulating the insulating fluid via the cooling unit 5.

[0025] For monitoring the state of the pump 8, said pump is equipped with a measuring sensor 9 which, in the depicted exemplary embodiment, is designed as a piezo element. The piezo element 9 is directly affixed to the housing of the pump 8 and is configured to detect the structure-borne sound of the pump 8. Via a signal line which is not depicted, the piezo element 9 is connected on the output side to a protection unit 10 which is equipped with a display element 11 in the form of a yellow and red illumination unit.

[0026] In this case, the piezo element 9 provides time-triggered vibration measured values on the output side which are transmitted to the protection unit 10. The protection unit 10 carries out a Fourier transform of the received data, wherein frequency-triggered vibration values are generated. The depiction of the intensity of the vibrations as a function of the frequencies is referred to here as the vibration spectrum. The detected vibration spectrum is a function of the respective state of the pump 8. In other words, each state of the pump 8 has a resulting so-called fingerprint in the form of a characteristic vibration spectrum. Logic which is stored in the protection unit, for example, software, has access to a data area in which spectra of pumps having previously known faults are stored. The logic compares the measured vibration spectrum with the previously known spectra. If the measured spectrum matches the previously determined comparison spectrum, a comparison spectrum which is based this state of the pump 8 is deduced. In the comparison, typical tolerances are applied.

[0027] FIG. 2 shows a schematic sequence of the method according to the present invention; in particular in a first step, a measured value detection 11 by means of the measuring sensor 9 is illustrated. Subsequently, in a step 13, a bandpass filter is used which filters out vibrations which are generated by a fault-free pump 8. In the work step 14, the vibration spectra are monitored for the existence of a fault criterion with the aid of the previously mentioned logic, wherein a hazard level is assigned to the fault. In the case of a less serious fault which does not yet make the immediate replacement necessary, a corresponding warning signal 15 is generated which triggers the illumination of a yellow illumination unit 16 at the display 11. In the case of a serious fault, a warning signal 17 is generated which generates a red signal light 18, whereupon the conductor or the maintenance personnel may effectuate an immediate replacement of the pump.

[0028] FIG. 3 depicts typical vibration spectra, wherein on the respective X-axis, the frequency is plotted in kHz, and on the respective Y-axis, the intensity is plotted in arbitrary units (a.u.). In the diagram of FIG. 3 which is depicted on the top left, a vibration spectrum of a fault-free pump is depicted. The dashed line 19 illustrates the action line of the bandpass filter, which suppresses the lower frequencies for the subsequent evaluation unit. In the diagram on the top right, a vibration spectrum is depicted which corresponds to a pump having the faulty balls of its bearing. Therefore, additional oscillations are identifiable to the right of the aforementioned characteristic curve, in comparison to the spectrum on the top left.

[0029] The vibration spectrum depicted on the bottom left corresponds to a fault of the inner bearing ring, wherein the vibration spectrum depicted on the bottom right corresponds to a fault of the outer bearing ring. A higher hazard level is assigned to the two spectra depicted on the bottom than to a fault which results in the spectrum on the top right.