Device for measuring pre-breakdown time of high-voltage switch

Abstract

The utility model discloses a device for measuring the pre-breakdown time of a high-voltage switch. The device comprises a low-voltage measuring unit, a high-voltage switch and a high-voltage testing unit which are connected in sequence, the high-voltage switch comprises a no-load pole and a test pole; the high-voltage test unit comprises a first power supply module and an output adjusting module and is used for providing short-circuit current; the low-voltage measuring unit comprises a second power supply module, an isolated digital converter and a transient recorder, the second power supply module is connected with the high-voltage switch, the data output end of the isolated digital converter is connected with the transient recorder, and the data input end of the isolated digital converter is connected with the high-voltage switch. According to the method, errors caused by sensor jitter are avoided, the measurement precision is greatly improved, the measurement result is closer to the real pre-breakdown time, and more reliable data support is provided for performance evaluation and quality control of the high-voltage switch cabinet.

Description

Technical Field

[0001] This utility model relates to the field of high voltage switchgear technology, and in particular to a high voltage switch pre-breakdown time measuring device. Background Technology

[0002] In the research, development, production and quality testing of high-voltage switchgear, accurate evaluation of high-voltage switch performance is crucial. In type test projects of high-voltage switchgear, such as load switch short-circuit closing, grounding switch short-circuit closing, circuit breaker T100s(a) and circuit breaker out-of-step closing tests, pre-breakdown time is a key parameter that needs to be accurately measured.

[0003] Currently, the traditional method for measuring pre-breakdown time mainly uses a travel sensor to record the closing point of the switch. However, this method has many drawbacks. In actual operation, the travel sensor installed on the moving contact of the switch is subjected to the combined effects of electrodynamic force and spring force, resulting in severe jitter. This jitter causes serious distortion of the measured contact mechanical travel curve, thus greatly reducing the accuracy of the travel sensor in measuring pre-breakdown time. Moreover, travel sensors are not only easily affected by jitter, but in some switch structures, it is difficult or even impossible to install travel sensors, which brings great inconvenience and error to the measurement of pre-breakdown time. In addition, due to the presence of high voltage, accurate measurement of arc voltage is also extremely difficult, which also limits the accuracy of existing technologies for measuring pre-breakdown time. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a high-voltage switch pre-breakdown time measuring device. By connecting a low-voltage measuring unit and a high-voltage testing unit to the unloaded pole and the test pole of the high-voltage switch respectively, errors caused by travel sensor jitter are avoided, and accurate measurement of pre-breakdown time is achieved.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-voltage switch pre-breakdown time measuring device includes: a low-voltage measuring unit, a high-voltage switch, and a high-voltage testing unit connected in sequence; the high-voltage switch includes an unloaded electrode and a test electrode.

[0007] The high-voltage test unit includes a first power supply module and an output regulation module for providing short-circuit current; the low-voltage measurement unit includes a second power supply module, an isolated digital converter, and a transient recorder. The second power supply module is connected to the high-voltage switch, and the data output terminal of the isolated digital converter is connected to the transient recorder, while the data input terminal of the isolated digital converter is connected to the high-voltage switch.

[0008] As a further technical solution, the high-voltage switch includes an unloaded pole and a test pole. The data input terminals of the isolated digital converter are respectively connected to the two ends of the unloaded pole for acquiring the voltage signal of the unloaded pole and for photoelectric isolation. The two ends of the second power module are respectively connected to the two ends of the unloaded pole for providing a low-voltage measurement environment. One end of the test pole is connected to the first power module in the high-voltage test unit, and the other end is connected to the output regulation module.

[0009] As a further technical solution, two unloaded poles are provided.

[0010] As a further technical solution, the unloaded electrode and the test electrode are insulated from each other.

[0011] As a further technical solution, one end of the output adjustment module is connected to the first power supply module, and the other end is connected to the test pole. The output adjustment module includes a DC component limiting resistor and a current limiting reactor, wherein the DC component limiting resistor and the current limiting reactor are connected in series.

[0012] As a further technical solution, one end of the test electrode is connected to one end of the current-limiting reactor, the other end of the current-limiting reactor is connected to one end of the DC component limiting resistor, the other end of the DC component limiting resistor is connected to one end of the first power module, and the other end of the first power module is connected to the other end of the test electrode.

[0013] As a further technical solution, the second power module includes a battery and a resistor, wherein the battery and the resistor are connected in series, and the battery is a rechargeable lithium battery and the resistor is an adjustable resistor.

[0014] As a further technical solution, one end of the battery is connected to one end of the resistor, the other end of the resistor is connected to one end of the unloaded terminal, and the other end of the unloaded terminal is connected to the other end of the battery.

[0015] As a further technical solution, the data output terminal of the isolated digital converter is connected to the transient recorder via optical fiber for signal transmission.

[0016] As a further technical solution, the high-voltage switch pre-breakdown time measuring device also includes a host computer, and the transient recorder is connected to the host computer.

[0017] One or more technical solutions of this utility model have the following beneficial effects:

[0018] (1) This invention designs an isolated digital converter and connects its data input terminal to the unloaded electrode of the high-voltage switch to collect the voltage signal (break voltage) of the unloaded electrode and provide opto-isolation. This avoids sensor jitter errors caused by the installation of a travel sensor, ensuring that the measurement signal comes directly from the unloaded electrode voltage throughout the measurement process, unaffected by the mechanical movement of the moving contact. This allows for more accurate capture of the pre-breakdown time, greatly improving measurement accuracy and making the measurement results closer to the actual pre-breakdown time. This provides more reliable data support for the performance evaluation and quality control of high-voltage switchgear.

[0019] (2) This utility model is sequentially connected with a low-voltage measurement unit, a high-voltage switch, and a high-voltage test unit. The connection is simple and easy to wire, solving the technical problem that the travel sensor is difficult to install in many switches, or even impossible to install, in the traditional travel sensor measurement method. This utility model greatly reduces the difficulty and workload of measurement operation, reduces measurement errors caused by installation problems, improves measurement efficiency, and enables operators to perform pre-breakdown time measurement work more conveniently. It is especially suitable for high-voltage switchgear testing in various complex field environments. Attached Figure Description

[0020] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0021] Figure 1 This is a schematic diagram of the high-voltage switch pre-breakdown time measuring device of this utility model. Detailed Implementation

[0022] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] Example 1

[0024] This utility model provides a high-voltage switch pre-breakdown time measuring device, such as... Figure 1 The schematic diagram of the high-voltage switch pre-breakdown time measuring device shows that it includes a low-voltage measuring unit, a high-voltage switch, and a high-voltage testing unit connected in sequence. The high-voltage switch includes, but is not limited to, load switches, circuit breakers, and grounding switches. In this embodiment, the high-voltage switch is equipped with an unloaded electrode and a test electrode, such as... Figure 1As shown, two unloaded poles are set, namely pole A and pole B, and one test pole, pole C. Poles A, B, and C are insulated from each other. The purpose of setting two unloaded poles, poles A and B, in this embodiment is twofold: First, to provide redundant measurement channels. During the measurement process, if one unloaded pole (e.g., pole A) experiences an unexpected situation (such as a line fault or poor contact) that prevents accurate voltage signal measurement, the other unloaded pole (pole B) can serve as a backup measurement channel, ensuring the continuity and reliability of the measurement work and avoiding the failure of the entire measurement test due to a single measurement point failure. Second, to improve the verification of measurement accuracy. By simultaneously measuring the voltage signals at both poles A and B, the measurement results can be mutually verified. If the pre-breakdown time data obtained from the two unloaded poles are similar or within a reasonable error range, the accuracy of the measurement results can be further confirmed; if the two data differ significantly, potential problems during the measurement process (such as interference or equipment failure) can be identified in a timely manner for troubleshooting and correction.

[0025] like Figure 1 As shown, the high-voltage test unit includes a first power supply module and an output regulation module for providing short-circuit current. In the high-voltage test unit, the first power supply module is a power supply Us. One end of the output regulation module is connected to the first power supply module, and the other end is connected to the test pole (C pole). The output regulation module includes a DC component limiting resistor Rs and a current-limiting reactor Ls, which are connected in series. The required short-circuit current is obtained by adjusting the parameters of the DC component limiting resistor Rs and the current-limiting reactor Ls. Specifically: one end of the test pole (C pole) is connected to one end of the current-limiting reactor Ls, the other end of the current-limiting reactor Ls is connected to one end of the DC component limiting resistor Rs, the other end of the DC component limiting resistor Rs is connected to one end of the first power supply module, and the other end of the first power supply module is connected to the other end of the test pole (C pole). The series connection of the DC component limiting resistor Rs and the current-limiting reactor Ls controls the magnitude of the short-circuit current. In high-voltage testing, a suitable short-circuit current is needed to simulate actual operating conditions for accurate measurement. On the other hand, it can suppress the influence of DC components. The short-circuit current generated by the high-voltage test may contain a certain DC component, which may interfere with the measurement results, such as affecting the accuracy of the measuring instrument and causing distortion of the measurement waveform.

[0026] like Figure 1As shown, the low-voltage measurement unit includes a second power module, an isolated digital converter, and a transient recorder. The second power module is connected to the high-voltage switch. The data input terminal of the isolated digital converter is connected to the high-voltage switch, and the data output terminal of the isolated digital converter is connected to the transient recorder. Specifically, the data input terminals of the isolated digital converter are connected to the two ends of the unloaded electrode (A or B) to collect the voltage signal of the unloaded electrode and for opto-isolation. The two ends of the second power module are connected to the two ends of the unloaded electrode (A or B) to provide a low-voltage measurement environment. In this embodiment, the second power module includes a battery and a resistor R. The battery and resistor are connected in series, and the battery is a 12V rechargeable lithium battery. The resistor R is an adjustable resistor. Specifically, one end of the battery is connected to one end of the resistor R, the other end of the resistor R is connected to one end of the unloaded electrode (A or B), and the other end of the unloaded electrode (A or B) is connected to the other end of the battery. The data output terminal of the isolated digital converter is connected to the transient recorder via optical fiber for signal transmission, and as shown... Figure 1 As shown, the high-voltage switch pre-breakdown time measurement device also includes a host computer, and the transient recorder is connected to the host computer. The isolated digital converter can accurately acquire the voltage signal across the unloaded pole (A or B pole). It converts the analog voltage signal into a digital signal for subsequent processing and analysis by equipment such as the transient recorder and the host computer. It should be noted that the processing and analysis by the transient recorder and the host computer are existing technologies; this embodiment does not improve the processing and analysis process and is not within the scope of protection of this embodiment. In the measurement of the pre-breakdown time of high-voltage switchgear, accurately acquiring the changes in the unloaded pole voltage signal is crucial for determining the pre-breakdown time, and the isolated digital converter is a key link in realizing this signal acquisition and conversion. Furthermore, the isolated digital converter achieves high-low voltage isolation and opto-isolation. In a high-voltage test environment, effective isolation measures are needed between the high-voltage test unit and the low-voltage measurement unit to prevent high voltage from damaging the low-voltage equipment. High-low voltage isolation and opto-isolation are achieved, ensuring the safe operation of the low-voltage equipment.

[0027] The high-voltage switch pre-breakdown time measuring device mentioned in this embodiment measures the high-voltage switch pre-breakdown time using the following method: The closing time t of the A, B, and C poles under no-load conditions is measured using a high-voltage switch tester. A t B t C The closing time t′ of the unloaded pole A (or pole B, the principle is explained below using pole A as an example) is measured using a high-voltage pre-breakdown time measuring device. A Then the closing time of the test electrode C is t′. c =t′ A +(t C -t AThe closing time T of the C electrode C This can be read from the oscilloscope. According to the standard GB / T 1984-2014, the pre-breakdown time of the test electrode C is defined as: closing time minus closing time. Therefore, the pre-breakdown time of electrode C is t. pc =t′ c -T C .

[0028] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-voltage switch pre-breakdown time measuring device, characterized in that, include: A low-voltage measurement unit, a high-voltage switch, and a high-voltage test unit are connected in sequence; the high-voltage switch includes an unloaded electrode and a test electrode. The high-voltage test unit includes a first power supply module and an output regulation module for providing short-circuit current; the low-voltage measurement unit includes a second power supply module, an isolated digital converter, and a transient recorder. The second power supply module is connected to the high-voltage switch, and the data output terminal of the isolated digital converter is connected to the transient recorder, while the data input terminal of the isolated digital converter is connected to the high-voltage switch.

2. The high-voltage switch pre-breakdown time measuring device as described in claim 1, characterized in that, The data input terminals of the isolated digital converter are respectively connected to the two ends of the unloaded electrode to collect the voltage signal of the unloaded electrode and for opto-isolation; the two ends of the second power module are respectively connected to the two ends of the unloaded electrode to provide a low-voltage measurement environment; one end of the test electrode is connected to the first power module in the high-voltage test unit, and the other end is connected to the output adjustment module.

3. The high-voltage switch pre-breakdown time measuring device as described in claim 2, characterized in that, Two unloaded poles are provided.

4. The high-voltage switch pre-breakdown time measuring device as described in claim 2, characterized in that, The unloaded electrode and the test electrode are insulated from each other.

5. The high-voltage switch pre-breakdown time measuring device as described in claim 2, characterized in that, One end of the output adjustment module is connected to the first power supply module, and the other end is connected to the test pole. The output adjustment module includes a DC component limiting resistor and a current limiting reactor, wherein the DC component limiting resistor and the current limiting reactor are connected in series.

6. The high-voltage switch pre-breakdown time measuring device as described in claim 5, characterized in that, One end of the test electrode is connected to one end of the current-limiting reactor, the other end of the current-limiting reactor is connected to one end of the DC component limiting resistor, the other end of the DC component limiting resistor is connected to one end of the first power module, and the other end of the first power module is connected to the other end of the test electrode.

7. The high-voltage switch pre-breakdown time measuring device as described in claim 2, characterized in that, The second power module includes a battery and a resistor, wherein the battery is connected in series with the resistor, and the battery is a rechargeable lithium battery and the resistor is an adjustable resistor.

8. The high-voltage switch pre-breakdown time measuring device as described in claim 7, characterized in that, One end of the battery is connected to one end of the resistor, the other end of the resistor is connected to one end of the unloaded terminal, and the other end of the unloaded terminal is connected to the other end of the battery.

9. The high-voltage switch pre-breakdown time measuring device as described in claim 1, characterized in that, The data output terminal of the isolated digital converter is connected to the transient recorder via optical fiber for signal transmission.

10. The high-voltage switch pre-breakdown time measuring device as described in claim 1, characterized in that, The high-voltage switch pre-breakdown time measurement device also includes a host computer, and the transient recorder is connected to the host computer.

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