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EP-4419929-B1 - ELECTRICAL SWITCHING DEVICE FOR HIGH VOLTAGE WITH INTEGRATED FAULT DETECTOR, METHOD FOR DETECTING A FAULT IN THE HIGH VOLTAGE SWITCHING DEVICE AND USE OF THE HIGH VOLTAGE SWITCHING DEVICE

EP4419929B1EP 4419929 B1EP4419929 B1EP 4419929B1EP-4419929-B1

Inventors

  • AUMANN, ERHARD
  • MLADENOVIC, IVANA

Dates

Publication Date
20260513
Application Date
20221124

Claims (15)

  1. Electrical switching device (1) for high voltage, having - at least one field control electrode (11) for controlling the field of at least one high-voltage-carrying component (10) of the electrical switching device (1) and - having at least one fault detector (12) for detecting a fault in the electrical switching device (1), said fault detector being integrated in the electrical switching device (1), wherein - the fault detector (12) comprises the field control electrode (11), - the fault detector (12) comprises a temperature sensor (120) for measuring a temperature of the electrical switching device (1) and for the temperature sensor (120) - the field control electrode (11) comprises at least one capacitance electrode (1210) of a high-voltage capacitor (121) of the electrical switching device (1), - the high-voltage component (10) comprises a capacitance dielectric (1211) which is electrically coupled to the field control electrode (11) and - the capacitance dielectric (1211) has at least one dielectric parameter (1212) having a temperature dependency.
  2. Electrical switching device (1) according to Claim 1, wherein the capacitance dielectric (1211) is formed with the aid of a castable dielectric starting material.
  3. Electrical switching device (1) according to Claim 1 or 2, wherein the capacitance dielectric (1211) comprises at least one capacitance material (1213) selected from the group of epoxy casting resin and ceramic.
  4. Electrical switching device (1) according to one of Claims 1 to 3, wherein the high-voltage capacitor (121) is formed of a connection socket (122) of the electrical switching device (1).
  5. Electrical switching device according to one of Claims 1 to 4 having an interface for sensing a capacitive output signal in accordance with IEC61243-5/ 62271-213/ 62271-206.
  6. Method for detecting a fault in an electrical switching device (1) according to one of Claims 1 to 5, wherein, as fault detector (12), a temperature sensor (120) is used to determine a temperature of the electrical switching device (1).
  7. Method according to Claim 6, wherein, in order to determine the temperature of the electrical switching device (1), the following method steps are carried out: a) providing (2001) capacitance data of the high-voltage capacitor (121) on the basis of a temperature of the capacitance dielectric (1211), b) determining (2002) an actual value of the capacitance of the high-voltage capacitor (121) by measuring an electrical voltage present at the field control electrode (11) and determining an actual value of an electrical reference voltage of the electrical switching device (1) and c) ascertaining (2003) the temperature of the electrical switching device (1) with the aid of an evaluation unit (140) taking into account the provided capacitance data of the high-voltage capacitor (121), the actual value of the capacitance of the high-voltage capacitor (121) and the actual value of the electrical reference voltage (131) of the electrical switching device (1).
  8. Method according to Claim 7, wherein, in order to provide the capacitance data, a known temperature dependency of at least one dielectric parameter (1212) of the high-voltage capacitor (121) is used.
  9. Method according to Claim 8, wherein at least one temperature-dependent material variable of the capacitance dielectric selected from the group of loss factor and relative permittivity is used as the dielectric parameter (1212) of the capacitance dielectric (1211).
  10. Method according to one of Claims 7 to 9, wherein the actual value of the capacitance of the high-voltage capacitor (121) and the actual value of the electrical reference voltage (131) are determined at an essentially identical temperature.
  11. Method according to one of Claims 7 to 10, wherein the actual value of the capacitance of the high-voltage capacitor (121) and the actual value of the electrical reference voltage (131) are determined at an essentially identical frequency (1311, 1312).
  12. Method according to one of Claims 7 to 11, wherein the temperature of the electrical switching device (1) depends essentially on a temperature of a screw connection (110) to a high-voltage cable (123).
  13. Method according to one of Claims 7 to 12, wherein an epoxy resin is used as the capacitance dielectric (1211) and the capacitance of the high-voltage capacitor (121) and the reference voltage (131) are determined at a glass transition temperature of the epoxy resin.
  14. Method according to one of Claims 7 to 13, wherein a comparison with a reference value in the form of a signal of an adjacent phase and/or an identical phase of a further electrical switching device for high voltage having a sufficiently similar geometry and sufficiently similar material properties is carried out.
  15. Use of an electrical switching device (1) according to one of Claims 1 to 5 for a switching installation (2) for switching an electrical AC current with high voltage of over 1 kV.

Description

The invention relates to an electrical switching device for high voltage with an integrated fault detector. In addition, a method for detecting a fault in the electrical switching device for high voltage and a use of the electrical switching device for high voltage are described. A high-voltage electrical switching device is a switch for switching an electric current with an alternating voltage exceeding 1 kV. One of the most frequent sources of failure in a switchgear assembly containing such a device is the high-voltage components of the switching device located within the assembly, in the form of screw connections. A screw connection that is only installed at a specific location within the switchgear assembly carries a particularly high risk of failure. A screw connection on the electrical switching device, which connects a busbar to a high-voltage cable, plays a crucial role. Such a screw connection can deteriorate during operation, especially if improperly installed, causing additional local heating at the connection. This can lead to a deviation from the switching device's normal operating temperature and ultimately to its failure. To assess the failure risk of the electrical switching device with the screw connection due to heating of the screw connection, measuring the temperature at the screw connection is important. A temperature sensor is used for this purpose. required. The temperature sensor acts as a fault detector, which can detect an anomaly with regard to temperature at the screw connection. From the DE 10 2014 102509 A1 A method for determining the temperature in the area of a high-voltage conductor of such a switching device using a temperature sensor is known. The temperature of the high-voltage conductor is then deduced from the determined (measured) temperature. However, measuring the temperature at the screw connection is difficult because the electrical switching device is difficult to retrofit in order to advantageously position a suitable temperature sensor (e.g. SAW (Surface Acoustic Wafe) sensor or PT1000 (resistance thermometer)) near the screw connection. The object of the present invention is to demonstrate how an electrical switching device for high voltage can be equipped with a fault detector without having to attach a separate component for a fault detector. To solve the problem, an electrical switching device for high voltage is specified, comprising at least one field control electrode for field control of at least one high-voltage component of the electrical switching device and at least one fault detector integrated into the electrical switching device for detecting a fault in the electrical switching device. The fault detector includes the field control electrode. Furthermore, the fault detector includes a temperature sensor for measuring the temperature of the electrical switching device. For the temperature sensor, the field control electrode includes at least one capacitance electrode of a high-voltage capacitance of the electrical switching device. The high-voltage component has a capacitance dielectric electrically coupled to the field control electrode. The capacitance dielectric has at least one dielectric parameter exhibiting a temperature dependence. A fault in the switching device represents a deviation of the actual temperature of the switching device from its setpoint temperature or from a range within that setpoint. The fault detector is a monitoring unit for monitoring the temperature of the electrical switching device. To assess the risk of failure of the electrical switching device, it can be used to determine whether a deviation of the measured actual temperature from the setpoint temperature is tolerable or whether a failure of the electrical switching device must be expected, thus necessitating measures to prevent such a failure. To assess the failure risk of the electrical switching device, its temperature is monitored. The temperature dependence of the dielectric parameter allows conclusions to be drawn about the actual temperature of the capacitive dielectric and thus the actual temperature of the electrical switching device itself. To solve the problem, a method for detecting a fault in the electrical switching device is also described. A temperature sensor is used as the fault detector to determine the temperature of the electrical switching device. Preferably, the following method steps are performed: a) providing capacitance data of the high-voltage capacitor as a function of the temperature of the capacitance dielectric, b) determining the actual value of the high-voltage capacitor's capacitance by measuring an electrical voltage applied to the field control electrode and determining the actual value of an electrical reference voltage of the electrical switching device, and c) determining the temperature of the electrical switching device using an evaluation unit, taking into account the provided capacitance data. The high-voltage capacit