Sensor system for measuring arc discharge combustion time and load tap changer

Abstract

A sensor system 20 for measuring the arc discharge combustion time in a vacuum switch tube 4, comprising a measuring device 5 equipped with a receiver 16 and a measuring instrument 18, and a sensor unit 10 equipped with a voltage divider 11, an energy generator 12, an energy conversion unit 13, an evaluation unit 14 and a transmitter 15. The sensor unit 10 can be connected to a first contact 4.1 and a second contact 4.2 of the vacuum switch tube 4, and the sensor unit 10 is connected to the measuring device 5 via a signal transmission path 17.

Description

Technical Field

[0001] The present invention relates to a sensor system for measuring the arc discharge burning time and a load tap changer.

Background Art

[0002] A load tap changer serves to switch seamlessly between different winding taps of electrical operating means such as, for example, power transformers or adjustable chokes. Due to the fact that components to be switched, such as vacuum switching tubes and selector arms, are always applied with a high voltage potential, monitoring of these components is generally not carried out. However, means and methods for monitoring these components are desired.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Accordingly, an object of the present invention is to provide a sensor system capable of realizing accurate and inexpensive monitoring of a vacuum switching tube.

Means for Solving the Problems

[0004] This problem is solved by the subject matters of the independent claims. Further implementation configurations are the subject matters of the dependent claims.

[0005] The present invention is a sensor system for measuring the arc discharge burning time in a vacuum switching tube, comprising a measuring device having a receiver and a measuring instrument, and a sensor unit having a voltage divider, an energy generator, an energy conversion unit, an evaluation unit and a transmitter, and having, wherein this sensor unit is connectable to a first contact and a second contact of the vacuum switching tube, and this sensor unit is connected to the measuring device via a signal transmission path, a sensor system is proposed.

[0006] By directly connecting this sensor unit to the vacuum switch tube, it is possible to measure the arc discharge combustion time. In this case, the voltage divider of the sensor unit detects or taps the voltage applied to the vacuum switch tube when an arc discharge occurs in the vacuum switch tube. The detected arc discharge is transmitted as an output signal to the measuring device via the evaluation unit and the transmitter, and is evaluated by the measuring device. The arc discharge combustion time can be estimated according to the duration of the output signal. The sensor unit is autonomously supplied with energy by an energy generator. This is particularly advantageous because the sensor unit is applied with a high-voltage potential, eliminating the need for burdensome wiring for energy supply.

[0007] The transmitter and the receiver can be configured in any form. For example, the transmitter can be configured as a diode and the receiver can be configured as a photodiode. In such an implementation configuration, the signal transmission path is configured as an optical waveguide tube. Furthermore, the signal can be transmitted in any form, such as wirelessly, via Bluetooth, WLAN, etc., depending on the configurations of the transmitter, the receiver, and the signal transmission path.

[0008] The energy generator can be, for example, a current converter, a voltage converter, or a converter based on an energy harvesting method. This is advantageously applied with a high-voltage potential and is advantageously arranged in a tapped transformer.

[0009] Furthermore, the evaluation unit can be configured as a rectifier network. The evaluation unit is advantageously connected to the energy generator via an energy conversion unit to supply energy to the sensor unit. The voltage divider of the sensor unit is connected to the first and second contacts of the vacuum switch tube to detect the arc discharge combustion time.

[0010] The sensor unit is configured and equipped to be connected to the vacuum switch tube of the on-load tap changer. In particular, the sensor unit is configured and equipped to be connected to the first and second contacts of the vacuum switch tube.

[0011] The vacuum switch tube can be configured in any form and has a first contact and a second contact. These contacts extend from the inside to the outside of the vacuum switch tube. In this case, the sensor unit can be directly connected to the contacts of the vacuum switch tube or is connected to conductive components such as cables connected to those contacts.

[0012] Furthermore, the present invention is an on-load tap changer device, an on-load tap changer equipped with a vacuum switch tube, a sensor system including a measuring device for measuring the arc discharge combustion time in this vacuum switch tube and a sensor unit, and has, this sensor unit is connected to the first and second contacts of the vacuum switch tube, this measuring device is connected to the sensor unit via a signal transmission path, and proposes an on-load tap changer device.

[0013] This on-load tap changer device can measure the arc discharge combustion time in the vacuum switch tube of the on-load tap changer. In this way, the arc discharge in the operating on-load tap changer can be reliably eliminated. Furthermore, based on this information, the operation of the on-load tap changer can be adjusted by the drive mechanism, and as a result, the arc discharge combustion time can be made as short as possible. By arranging the sensor unit in the immediate vicinity of the vacuum switch tube, the on-load tap changer device is particularly compactly configured. Furthermore, the energy supply to the sensor unit is autonomously performed by a dedicated energy generator.

[0014] The on-load tap changer device further includes a drive for operating the on-load tap changer, and this drive is controlled by the measuring device of the sensor system. This drive is arranged outside the tapped transformer. This measuring device can be arranged outside the tapped transformer or inside the tapped transformer. Further, this measuring device can be arranged at the head of the on-load tap changer. However, the measuring device and the drive are always applied with the ground potential. The sensor unit is arranged near the vacuum switch in the tapped transformer or in the on-load tap changer. "Inside the tapped transformer or in the on-load tap changer" means inside the housing of the tapped transformer or in or on the housing of the on-load tap changer. In particular, the sensor unit is arranged in the oil tank of the on-load tap changer. The load switching switch is a part of the on-load tap changer and is also arranged inside the tapped transformer, that is, inside its housing. The sensor unit and the vacuum switch are always applied with a high voltage potential. This also applies to the load switching switch.

[0015] In the following, with reference to the drawings, the present invention will be described in detail based on embodiments.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0017] Figure 1 shows a tapped transformer 1 equipped with a load tap changer 30. The load tap changer 30 includes a load tap changer 2 and a sensor system 20. The load tap changer 2 is connected to a drive mechanism 3 and is operated thereby. The load tap changer 2 includes a load switching disconnector and a selector (not shown). Further, the load switching disconnector, and thus the load tap changer 2 as well, includes at least one vacuum switch tube 4 used for switching during load. A sensor unit 10 is connected to this vacuum switch tube 4. The sensor unit 10 serves to detect or measure the arc discharge burning time, particularly when opening, during the operation of the vacuum switch tube 4. The sensor unit 10 is preferably arranged inside the load tap changer 4, particularly inside the load switching disconnector, or in the immediate vicinity of the vacuum switch tube 4. Further, the sensor unit 10 is connected to a measuring device 5. The sensor unit 10 and the measuring device 5 constitute a sensor system 20 for detecting or measuring the arc discharge burning time.

[0018] Figure 2 shows a detailed drawing of the sensor unit 10. The sensor unit 10 is connected to the first contact 4.1 and the second contact 4.2 of the vacuum switch tube 4 of the load tap changer 2. The sensor unit 10 includes a voltage divider 11 equipped and configured to step down the high voltage applied through the vacuum switch tube 10 to a low voltage. In particular, the voltage divider 11 of the sensor unit is connected to the first contact 4.1 and the second contact 4.2 of the vacuum switch tube 4.

[0019] Further, an energy generator 12 is provided. This supplies the energy required for the operation of the sensor unit 10. The energy generator 12 can be configured, for example, as a current converter, a voltage converter, or other converters that function based on an energy harvesting method (such as tapping temperature, mechanical vibration, electric field, or magnetic field). The energy generator 12 is a fixed component of the sensor unit 10, i.e., it is integrated or is electrically connected thereto.

[0020] Furthermore, an energy conversion unit 13 is provided. This adapts the energy received from the energy generator 12 to the requirements and specifications of the evaluation unit 14 and the transmitter 15 according to the specifications of other components, namely voltage and current. Furthermore, the energy conversion unit 13 generates a reference voltage. The energy conversion unit 13 can be configured, for example, as a rectifier network and can also be equipped with a capacitor or coil for intermediate energy storage.

[0021] For example, the evaluation unit 14 configured as a comparator network is connected to the voltage divider 11 and the energy conversion unit 13. The evaluation unit 14 is configured and equipped to evaluate the voltage detected or tapped by the voltage divider 11. Here, based on the voltage tapped by the voltage divider 11, it is determined whether an arc discharge is occurring in the vacuum switch tube 4 during switching. Thus, for example, when the tapped voltage is between 15 mV and 25 mV, an arc discharge is occurring in the vacuum switch tube. This voltage range is shown here as an example. The range of the tapped voltage depends in particular on the characteristics of the individual components of the vacuum switch tube 4. The evaluation unit 14 is equipped and configured to detect a predetermined voltage value or voltage range, process or compare it using the reference voltage, and then generate an output signal.

[0022] Furthermore, the evaluation unit 14 is connected to the transmitter 15. This transmits the output signal generated by the evaluation unit 14 to the measuring device 5. The transmitter 15 is preferably configured as a diode. The measuring device 5 at ground potential comprises a receiver 16 configured as a diode or a photodiode. In the example illustrated here, the transmitter 15 and the receiver 16 are connected to each other via an optical waveguide serving as a signal transmission path 17. Depending on the embodiments of the transmitter 15, the receiver 16 and the signal transmission path 17, the signal can be transmitted in any form, for example, wirelessly, via Bluetooth, WLAN, etc. The measuring device 5 can be arranged under the lid of the on-load tap changer in the tapped transformer 1 or outside the tapped transformer 1, for example, in a motor drive or a voltage regulator.

[0023] The measuring device 5 further comprises a measuring instrument 18 capable of evaluating the received output signal. This measuring instrument 18 is configured and equipped to process and evaluate the output signal and can, for example, comprise a corresponding processor and memory.

[0024] When operating the on-load tap changer 2, the drive 3 is used to open the vacuum switch 4 of the on-load tap changer 2. Normally, a sinusoidal current flows through the on-load tap changer 2 and thus through the vacuum switch 4, so when opening the vacuum switch 4, an arc discharge may occur between the contacts. These usually disappear at the next current zero crossing or when the contacts of the vacuum switch are sufficiently far apart from each other. If the current is exactly at the zero point when opening, no arc discharge will occur. The sensor unit 10 serves to detect the arc discharge burning time. In this case, the voltage value or voltage range from the voltage divider 11 is converted into an output signal in the evaluation unit 14 and transmitted to the measuring device 5 via the transmitter 15. The measuring instrument 18 in the control device 5 measures the duration of the output signal and then measures the arc discharge burning time. The duration of the output signal depends on the arc discharge burning time or is indicated by that burning time. The measuring device 18 is configured and equipped to measure the arc discharge burning time from the output signal of the sensor unit 10.

Explanation of Symbols

[0025] 1 Transformer with Tap 2 On-Load Tap Changer 3 Driving Machine 4 Vacuum Switching Tube 4.1 First Contact 4.2 Second Contact 5 Measuring Device 10 Sensor Unit 11 Voltage Divider 12 Energy Generator 13 Energy Conversion Unit 14 Evaluation Unit 15 Transmitter 16 Receiver 17 Signal Transmission Line 18 Measuring Instrument 20 Sensor System 30 On-Load Tap Changer Device

Claims

1. A sensor system (20) for measuring the arc discharge combustion time in a vacuum switch tube (4), comprising: A measuring device (5) equipped with a receiver (16) and a measuring instrument (18); A sensor unit (10) equipped with a voltage divider (11), an energy generator (12), an energy conversion unit (13), an evaluation unit (14) and a transmitter (15); And having This sensor unit (10) can be connected to the first contact (4.1) and the second contact (4.2) of the vacuum switch tube (4); This sensor system, wherein this sensor unit (10) is connected to the measuring device (5) via a signal transmission path (17).

2. In the sensor system (20) according to Claim 1, The said transmitter (15) is configured as a diode; The said signal transmission path (17) is configured as an optical waveguide tube; This sensor system, wherein the said receiver (16) is configured as a photodiode.

3. In the sensor system (20) according to Claim 1 or 2, This sensor system, wherein the said energy generator (12) is a current converter, a voltage converter or a converter based on an energy harvesting method.

4. In the sensor system (20) according to any one of Claims 1 to 3, This sensor system, wherein the said evaluation unit (14) is configured as a rectifier network.

5. In the sensor system (20) according to any one of Claims 1 to 4, This sensor system, wherein the said evaluation unit (14) supplies energy to the sensor unit (10) and is connected to the energy generator (12) via the energy conversion unit (13) to generate a reference voltage.

6. In the sensor system (20) according to any one of Claims 1 to 5, This sensor system, wherein the voltage divider (11) of the said sensor unit (10) can be connected to the first contact (4.1) and the second contact (4.2) of the vacuum switch tube (4).

7. In the sensor system (20) according to any one of Claims 1 to 6, This sensor system, wherein the said voltage divider (11) taps the voltage applied to the vacuum switch tube (4).

8. In the sensor system (20) according to any one of Claims 1 to 7, The evaluation unit (14) generates an output signal based on the reference voltage from the energy conversion unit (13) and the voltage tapped by the voltage divider (11), The sensor system in which the evaluation unit (14) transmits the output signal to the measuring device (5) using the transmitter (15). **Claim 9** A load tap changer (2) provided with a vacuum interrupter (4), A load tap changing device (30) having a sensor system (20) for measuring the arc discharge burning time in the vacuum interrupter (4), the sensor system (20) including a measuring device (5) and a sensor unit (10), This sensor unit (10) is connected to the first contact (4.1) and the second contact (4.2) of the vacuum interrupter (4), This load tap changing device in which the measuring device (5) is connected to the sensor unit (10) via a signal transmission path (10). **Claim 10** In the load tap changing device (30) according to claim 7, A drive machine (3) for operating the load tap changer (2), the drive machine (3) being controlled via the measuring device (5) of the sensor system (20).

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