Method and device for measuring internal operating voltage of non-intrusive GIS (Gas Insulated Switchgear) equipment

Abstract

The invention relates to a non-intrusive GIS equipment internal operation voltage measuring method and device, and belongs to the technical field of high-voltage electrical equipment monitoring. According to the method, aiming at the problems of complex installation, equipment power failure, ferromagnetic resonance risk and the like in the existing intrusive voltage measurement technology, an annular induction electrode is arranged on the surface of a basin-type insulator of GIS equipment to measure the induction voltage of the basin-type insulator; and based on a transfer function determined by a coupling circuit model composed of the high-voltage arm capacitor, the stray capacitor and the low-voltage arm capacitor, the operation voltage of the conducting rod in the GIS is accurately inversed and calculated. The device correspondingly comprises an annular induction electrode, a sensor and a calculation unit. Complete non-intrusive measurement is achieved, installation is convenient, power failure is not needed, the internal structure of equipment is not changed, introduction of additional fault points is avoided, the measurement process is stable and reliable, the device can adapt to different voltage grades by adjusting the low-voltage arm capacitor, and universality is high.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage electrical equipment monitoring technology, and relates to a method and device for measuring the internal operating voltage of a non-intrusive GIS device. Background Technology

[0002] Gas-insulated switchgear (GIS) is a key component of modern power systems, and reliable monitoring of its internal condition is crucial for ensuring the safe and stable operation of the power grid. Currently, monitoring technologies in this field have developed in a diversified manner, and existing technical solutions can be mainly divided into two categories.

[0003] One type of technology focuses on monitoring the mechanical characteristics of equipment, partial discharge signals, and gas composition analysis. Specifically, this involves monitoring and analyzing the current waveforms of the opening or closing coils, collecting vibration signals during equipment operation, or detecting the content of decomposition products of sulfur hexafluoride gas. While this type of method assesses equipment status through indirect parameters and has some effectiveness, it fails to directly reflect core electrical parameter information.

[0004] Another type of technology directly monitors the core electrical parameter inside the equipment—the operating voltage. Among these, non-invasive voltage measurement technology, a cutting-edge approach, aims to retrieve and continuously monitor internal voltage information by measuring external physical fields, such as spatial electric fields, that have a deterministic correlation with the internal voltage, without damaging the original insulation structure of the equipment. This method represents a significant development trend in the field because it avoids the risks associated with direct electrical connections.

[0005] However, traditionally, directly obtaining the internal voltage information of gas-insulated switchgear requires invasive measurement methods. These methods rely on installing electromagnetic or capacitive voltage transformers inside the equipment. These methods have inherent technical drawbacks. First, the installation process requires establishing a direct or voltage-dividing electrical connection with the high-voltage conductor. This not only complicates the installation process and necessitates power outages for operation, but also introduces a serious safety hazard: equipment failure due to ferroresonance in the voltage transformer. Second, the built-in voltage transformer itself, as an independent high-voltage device, increases potential fault points within the gas-insulated switchgear and may alter the internal electric field distribution, thus posing a long-term potential threat to the overall insulation reliability of the equipment.

[0006] Therefore, there is an urgent need in this field for a non-invasive technical solution that can accurately measure the internal operating voltage of gas-insulated switchgear without changing the original structure of the equipment or introducing additional risks. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a non-invasive method and device for measuring the internal operating voltage of GIS equipment. Currently, mainstream invasive GIS internal voltage measurement and monitoring devices are installed inside the closed GIS pipes, which presents problems such as installation difficulty, high cost, and potential interference with the normal operation of the GIS equipment. This invention proposes a non-invasive method for monitoring and measuring the internal voltage of GIS. Through a coupled circuit model of bus conductor-induction electrode-GIS enclosure-grounding conductor, the induced voltage of the external induction electrode is used as a medium to invert the internal conductor operating voltage, achieving real-time and accurate measurement and monitoring of the internal voltage of the GIS.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A method for measuring the internal operating voltage of a non-invasive GIS device, the method comprising the following steps: A ring-shaped induction electrode is installed on the surface of the basin-type insulator of the GIS equipment; The induced voltage generated on the annular inductive electrode is measured by a sensor. ; The induced voltage Input to the computing unit; and the computing unit based on the induced voltage Operating voltage on the internal conductive rod of GIS The operating voltage is calculated and output based on the preset relationship between them. .

[0009] Furthermore, the preset relationship is determined through a coupling circuit model, which includes: High voltage arm capacitor It is formed between the conductive rod and the annular sensing electrode; Stray capacitance It is formed between the annular induction electrode and the GIS grounding housing; and low-voltage arm capacitors It is installed in the measuring device and connected to the ring-shaped sensing electrode.

[0010] Furthermore, the operating voltage With the induced voltage The relationship between them is determined by the transfer function. The description is as follows:

[0011] in, ω is the angular frequency.

[0012] Furthermore, by adjusting the low-voltage arm capacitor The capacitance value is adjusted to control the induced voltage. The amplitude can be adjusted to adapt to the measurement requirements of different voltage levels.

[0013] A non-invasive device for measuring the internal operating voltage of a GIS device, the device comprising: A ring-shaped induction electrode, disposed on the surface of the basin-type insulator of the GIS equipment, is used to induce the operating voltage on the conductive rod inside the GIS. Related induced voltage ; A sensor, connected to the annular sensing electrode, is used to collect the induced voltage. ; And a computing unit, which is connected to the sensor, for receiving the induced voltage. The operating voltage is calculated and output based on a preset relationship. .

[0014] Furthermore, the device also includes a measurement circuit, which comprises a low-voltage arm capacitor. The low-voltage arm capacitor It is connected between the ring-shaped sensing electrode and ground.

[0015] Furthermore, the measurement circuit utilizes a high-voltage arm capacitor. and stray capacitance Coupled with the internal conductive rod and grounding housing of the GIS, wherein the high-voltage arm capacitor The stray capacitance is formed by the structure between the conductive rod and the annular sensing electrode. It is formed by the structure between the ring-shaped inductive electrode and the GIS grounding housing.

[0016] Furthermore, the computing unit pre-stores the operating voltage. With the induced voltage Transfer function between The transfer function is:

[0017] The computing unit is configured to calculate based on the transfer function and the acquired induced voltage. The operating voltage is obtained by inversion. .

[0018] Furthermore, the annular induction electrode is made of a metallic material and tightly covers the surface of the basin insulator.

[0019] Furthermore, the low-voltage arm capacitor It is an adjustable capacitor, and the induced voltage is changed by adjusting its capacitance value. The measurement range.

[0020] The beneficial effects of this invention are as follows: (1) This invention completely changes the traditional installation mode of voltage measuring devices. The measuring device does not need to be installed inside the closed pipe of GIS equipment, but is cleverly set on the surface of the external basin insulator. This external installation method makes the installation and disassembly operations simple and convenient, greatly reducing the construction difficulty and time cost, while completely avoiding the need for equipment power outages caused by internal installation operations.

[0021] (2) Due to the adoption of a completely non-intrusive design concept, this device will not cause any interference to the original insulation structure and electric field distribution inside the GIS during the monitoring process. This not only eliminates potential fault points introduced by adding internal components, but more importantly, it fundamentally eliminates safety hazards such as ferroresonance that may be caused by traditional voltage transformers, and significantly improves the overall operational reliability of the power system.

[0022] (3) This invention achieves accurate inversion from external induced voltage to internal operating voltage by establishing a precise coupled circuit model. This measurement method is less affected by the strong electromagnetic environment inside GIS pipelines, has high signal acquisition stability, and can achieve long-term reliable and accurate measurement, providing an accurate data foundation for equipment status monitoring.

[0023] (4) By adjusting the low-voltage arm capacitor parameters in the measurement circuit, the amplitude range of the induced voltage can be flexibly adjusted. This design allows the same measuring device to adapt to different voltage levels and application scenarios, achieving a wider voltage measurement range and enhancing the product's versatility and practicality.

[0024] (5) The entire measurement system has a simple structure and clear connections between its components. The cooperation between the ring-shaped induction electrode and the measurement unit achieves efficient energy coupling and information transmission. The simple structural design not only reduces manufacturing costs but also improves the stability and reliability of the system during long-term operation.

[0025] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the GIS equipment pipeline structure; Figure 2 This is a schematic diagram of the voltage measuring device of the present invention; Figure 3 This is a schematic diagram of the voltage measurement circuit model of the present invention; Figure 4 This is a schematic diagram of the equivalent coupled circuit. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] Example 1: Measurement Implementation Method Based on Fixed-Parameter Capacitive Voltage Divider First, please refer to Figure 1 This is a structural diagram of the GIS equipment pipeline. The GIS equipment mainly consists of a GIS grounding metal shell, an internal high-voltage conductive rod, and a basin-type insulator for support and insulation. The key aspect of this invention lies in the surface area of ​​the basin-type insulator.

[0031] Please combine Figure 2The figure illustrates a schematic diagram of the voltage measuring device of the present invention. As shown, a ring-shaped induction electrode made of a highly conductive metallic material such as brass or stainless steel is tightly covered and fixed to the flange surface of a basin-type insulator using a high-voltage resistant insulating adhesive. The ring-shaped induction electrode is separated from the internal high-voltage conductive rod by the insulating material of the basin-type insulator, naturally forming a high-voltage arm capacitor. Simultaneously, a distributed capacitance, i.e., stray capacitance, also exists between the ring-shaped induction electrode and the GIS grounded metal casing. .

[0032] The core components of the measuring device also include a high-input-impedance voltage sensor and a computing unit composed of a microprocessor. The sensor is electrically connected to the ring-shaped sensing electrode via a coaxial shielded signal line, enabling high-precision and interference-resistant acquisition of the induced voltage on the sensing electrode. The computing unit is connected to the output of the sensor.

[0033] The workflow of this embodiment is as follows: When the high-voltage conductive rod inside the GIS carries the power frequency operating voltage... At that time, according to the principle of capacitive voltage division, a relatively low voltage will be induced on the ring-shaped induction electrode. The sensor collects the induced voltage in real time. The instantaneous waveform is obtained and transmitted to the computing unit after analog-to-digital conversion. The computing unit pre-stores data based on... Figure 3 and Figure 4 The voltage inversion algorithm derived from the model shown.

[0034] Figure 3 A schematic diagram of the voltage measurement circuit model of the present invention is shown. Figure 4 This is a schematic diagram of its equivalent coupling circuit.

[0035] According to this model, the high-voltage arm capacitor... Stray capacitance The low-voltage arm capacitance is preset to a fixed value in the measuring device. Together, they form a capacitor voltage divider. Its transfer function is:

[0036] because and Due to the geometry of the GIS, the low-voltage arm capacitance can be considered a constant after installation and fixation. High-stability fixed capacitors are also selected. Therefore, precise calibration is achieved. , and The value of this value determines a fixed proportionality coefficient. K , The computing unit will collect the data. The value is multiplied by the preset scaling factor. K It can calculate and output the actual operating voltage inside the GIS in real time. The effective value and waveform are obtained. This method is simple in structure, low in cost, and suitable for stable monitoring scenarios with small voltage fluctuations.

[0037] Example 2: Wide-range adaptive measurement device based on adjustable low-voltage arm capacitance The basic structure of the device in this embodiment is the same as that in Embodiment 1, including a ring-shaped sensing electrode, a high input impedance sensor, and a computing unit. Its key improvement lies in the low-voltage arm capacitor in the measurement circuit. In this embodiment, the low-voltage arm capacitor... It employs a programmable variable capacitor array or a digitally controlled capacitor module. This adjustable capacitor... The control interface is connected to the computing unit and receives its instructions to adjust the capacitance value.

[0038] This embodiment adds a range adaptive adjustment function to the workflow of Embodiment 1. The system initiates the adaptive process during the initial installation of the device or when a voltage exceeding the current range is detected. The calculation unit first adjusts the current range... Value Measured values, preliminary estimates The size. If Too small a value leads to a degraded signal-to-noise ratio, or If the value is too large and approaches the upper limit of the sensor's range, the calculation unit will calculate according to the formula. The revealed relationship leads to adjustable capacitors Issue control command: Increase The value will cause the induced voltage Reduce, to prevent under ultra-high voltage Exceeding the sensor's range will cause saturation or damage; conversely, reducing the range will reduce its capacity. It will make Increasing the amplitude allows for obtaining a signal with sufficient amplitude even when measuring lower voltages, ensuring measurement accuracy.

[0039] Adjust to the appropriate After the value is updated, the computing unit will use the updated value. The accurate scaling factor should be recalculated. K Then, for subsequent data collection The signal is calculated precisely to obtain This design allows the same measuring device to be flexibly applied to GIS equipment with different voltage levels, ranging from tens of kilovolts to hundreds of kilovolts, without the need to change hardware, thus achieving automatic range matching and greatly enhancing the device's versatility, intelligence, and economy.

[0040] Example 3: High-precision measurement system with online self-calibration function In this system, the measuring device also includes a ring-shaped sensing electrode, a sensor, a computing unit, and an adjustable low-voltage arm capacitor. In addition, the system integrates a high-precision standard voltage source and a solid-state switching device controlled by a computing unit.

[0041] Its detailed workflow includes two modes: periodic online calibration and normal measurement. Online calibration mode: The system performs this calibration periodically or automatically upon each startup. The computing unit controls a switching switch to temporarily disconnect the ring-shaped induction electrode from the coupling circuit of the GIS high-voltage conductor and connect it to an internal standard voltage source. The standard voltage source applies a known amplitude. The calibration signal and frequency. The sensor measures the response voltage at this time. The computing unit will and The comparison is performed to calculate the actual gain or deviation of the current measurement channel. This process can correct for measurement errors caused by factors such as electronic component aging and temperature drift. After calibration, the switch automatically returns to normal operating mode.

[0042] Normal measurement mode: The system operates according to the procedure in Example 2, and has range adaptive function. However, in voltage calculation... At this time, a correction coefficient obtained in calibration mode will be introduced to compensate for the measurement results, thereby ensuring the output operating voltage. It offers long-term high accuracy and stability. This design is particularly suitable for applications requiring extremely high measurement accuracy or long-term stable monitoring.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method of measuring the internal operating voltage of a non-invasive GIS device, characterized in that: The method comprises the following steps: An annular induction electrode is arranged on the surface of the basin-type insulator of the GIS device; measuring the induced voltage generated on the ring-shaped induction electrode by means of a sensor ; The induced voltage is input to a computing unit; and the computing unit calculates and outputs the operating voltage based on a preset relationship between the induced voltage and the operating voltage on the conductive rod inside the GIS.

2. The method of claim 1, wherein: The preset relationship is determined by a coupling circuit model, and the coupling circuit model comprises: High-voltage arm capacitance formed between the conductive rod and the ring-shaped induction electrode; Stray capacitance formed between the ring-shaped induction electrode and a GIS ground shell and a low voltage arm capacitor a measurement device and connected to the ring-shaped induction electrode.

3. The method of claim 2, wherein: The operating voltage The relationship between the induced voltage is described by the transfer function Specifically: wherein is the angular frequency.

4. The method of claim 3, wherein: By adjusting the capacitance value of the low-voltage arm capacitor to adjust the amplitude of the induced voltage to adapt to the measurement requirements of different voltage levels.

5. A device for non-intrusive measurement of the internal operating voltage of GIS equipment, characterized by: The device comprises: A ring-shaped induction electrode is arranged on the surface of a pot-type insulator of a GIS device, and is used to induce a running voltage on a conductive rod inside the GIS a related induced voltage ; a sensor connected to the ring-shaped induction electrode for collecting the induction voltage ; and a computing unit connected to the sensor for receiving the induced voltage and calculating and outputting the operating voltage based on a predetermined relationship .

6. The apparatus of claim 5, wherein: The device also includes a measurement circuit, which comprises a low-voltage arm capacitor. The low-voltage arm capacitor It is connected between the ring-shaped sensing electrode and ground.

7. The apparatus of claim 6, wherein: The measurement circuit is coupled to the GIS through a high voltage arm capacitor and a stray capacitance with the high voltage arm capacitor formed by the structure between the conducting rod and the ring shaped inductive electrode, and the stray capacitance formed by the structure between the ring shaped inductive electrode and the GIS grounded housing.

8. The apparatus of claim 7, wherein: The computing unit has pre-stored the operating voltage The transfer function between the induced voltage The transfer function is:​ The computing unit is configured to determine the operating voltage from the transfer function and the induced voltage The inversion yields the operating voltage .

9. The apparatus of claim 5, wherein: The annular induction electrode is made of metal material and closely covers the surface of the basin-type insulator.

10. The apparatus of claim 6, wherein: The low voltage arm capacitance is an adjustable capacitance, by adjusting its capacitance value to change the measurement range of the induced voltage .

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