CN105043229A - Device and method for measuring arc contact contacting travel of high-voltage SF6 circuit breaker - Google Patents

Abstract

The invention provides a device and a method for measuring the arc contact contacting travel of a high-voltage SF6 circuit breaker. The device comprises an angular displacement measurement module, an angular displacement and linear displacement conversion module, and a data acquisition and processing module. The angular displacement measurement module is used for measuring the angular displacement of the main shaft of a circuit breaker. The angular displacement and linear displacement conversion module is used for acquiring the corresponding relationship between the angular displacement of the main shaft of the circuit breaker and the linear displacement of an arc contact of the circuit breaker. The data acquisition and processing module is used for calculating the linear travel of the arc contact. The method is realized based on the above device and solves the problem in the prior art that conventional linear sensors cannot be applied to high-voltage switchgears can be solved. The linear displacement of the arc contact is ingeniously and indirectly acquired based on the corresponding relationship between the angular displacement and the linear displacement by means of a small and lightweight angular displacement sensor. In this way, high-precision measurement tasks can be realized by means of the simple device. The measurement on the contacting travel alone of the arc contact of the high-voltage SF6 circuit breaker is realized.

Description

Device and method for measuring contact stroke of arcing contact of high voltage SF6 circuit breaker

technical field

The design of the product involves on-line monitoring of switchgear in the field of electrical products and electrical appliances, and in particular relates to a measuring device and method for measuring the contact stroke of the arcing contact of a high-voltage SF6 circuit breaker.

Background technique

The existing method for calculating the electrical life of a circuit breaker is mainly the cumulative breaking current method, which calculates the electrical life based on the mass loss of the contacts, and is based on the cumulative method of the electrical life curve of the high-voltage circuit breaker. However, the degree of electrical wear of contacts under different short-circuit currents is different, and the wear amount is not linearly related to the magnitude of the short-circuit current. It is not enough to judge the amount of contact burnout only by the cumulative breaking current; therefore, the judgment of the amount of burnout of the contacts should take into account the different amounts of wear caused by breaking different short-circuit currents each time, so as to give a high-voltage SF6 circuit breaker/GIS The electrical life detection of the current has brought great difficulties. Therefore, it is necessary to innovate the existing electrical life detection situation. It cannot only rely on the magnitude of the breaking current, but monitor and evaluate the electrical life of the circuit breaker by reflecting the overlapping time of the high-voltage SF6 circuit breaker/GIS switching action, which is expected Obtain more accurate electrical life monitoring results, make up for the shortcomings of no effective electrical life monitoring technology and methods for high-voltage SF6 circuit breakers/GIS at home and abroad, and provide theoretical and practical information for the upgrading of high-voltage SF6 circuit breakers/GIS intelligent products. Technical support.

For the high-voltage SF6 circuit breaker/GIS, the contact time of the dynamic and static arc contacts during the switching action is an important index to measure the electrical life of the high-voltage circuit breaker. However, in practical applications, the contact time of the moving and static arcing contacts is not easy to measure, and there is a corresponding relationship between the contact time of the moving and static arcing contacts and the individual contact travel of the arcing contacts, so the contact time can be calculated by measuring the individual contact travel of the arcing contacts .

In the actual measurement, in order to ensure the accuracy of the individual contact stroke measurement of the arcing contact, the circuit breaker switching action stroke curve must be measured with high precision, and the accuracy should be at the level of 0.5mm (or higher). However: High-precision measurements often mean complex measuring devices.

Contents of the invention

Based on this, the present invention discloses a measuring device for the contact stroke of an isolated contact of a high-voltage SF6 circuit breaker;

The device includes an angular displacement measurement module, an angular displacement and linear displacement conversion module, and a data acquisition and processing module;

The angular displacement measurement module includes an angular displacement sensor, and the angular displacement sensor is used to obtain the angular displacement of the main shaft of the circuit breaker, and send the angular displacement to the data acquisition and processing module;

The angular displacement and linear displacement conversion module is used to fit the stored angular displacement of the main shaft of the circuit breaker and the linear stroke of the arc contact into a corresponding relationship curve and send it to the data acquisition and processing module;

The data acquisition and processing module is used to calculate the arcing contact stroke according to the angular displacement of the main shaft of the circuit breaker and the corresponding relationship.

Description of drawings

Fig. 1 is an internal structural diagram of a circuit breaker in an embodiment;

Fig. 2 is the design structural diagram of this work in an embodiment;

Fig. 3 is the statistical result of the angular displacement and the linear displacement stroke of the opening process in one embodiment;

Fig. 4 is the statistical result of angular displacement and linear displacement stroke in the closing process in one embodiment;

Fig. 5 is a comparison diagram between the arc contact stroke fitting result and the actual result in the opening process in one embodiment;

Fig. 6 is an arc contact stroke curve fitting error curve in one embodiment;

Fig. 7 is a comparison diagram between the arc contact stroke fitting result and the actual result in the closing process in one embodiment;

Fig. 8 is a curve fitting error curve of arcing contact travel curve in the closing process in one embodiment.

Detailed ways

Below in conjunction with accompanying drawing 1-8 and embodiment the present invention will be further described:

In one embodiment, the invention discloses a measuring device for the contact stroke of an isolated contact of a high-voltage SF6 circuit breaker;

The device includes an angular displacement measurement module, an angular displacement and linear displacement conversion module, and a data acquisition and processing module;

The angular displacement measurement module includes an angular displacement sensor, and the angular displacement sensor is used to obtain the angular displacement of the main shaft of the circuit breaker, and send the angular displacement to the data acquisition and processing module;

The angular displacement and linear displacement conversion module is used to fit the stored angular displacement of the main shaft of the circuit breaker and the linear stroke of the arc contact into a corresponding relationship curve and send it to the data acquisition and processing module;

The data acquisition and processing module is used to calculate the arcing contact stroke according to the angular displacement of the main shaft of the circuit breaker and the corresponding relationship.

Further, the data collection and processing module includes a data collection and processing circuit based on an ARM chip.

The angular displacement and linear displacement conversion module disclosed in this embodiment obtains the corresponding relationship between the angular displacement of the main shaft of the circuit breaker and the linear stroke of the arc contact through experimental measurement and fitting analysis, so that the angular displacement curve of the circuit breaker can be Draw the travel curve of the arc contact, and realize the calculation of the linear travel of the arc contact based on the measured angular displacement. The ARM data acquisition and processing module adopts the data acquisition and processing circuit based on the ARM chip, and performs data processing according to the angular displacement input by the angular displacement sensor and the data processing program based on the corresponding relationship between the angular displacement of the main shaft of the circuit breaker and the linear stroke of the arc contact. , so as to obtain the linear stroke of the arc contact. This embodiment solves the problem that the linear sensor is difficult to apply to the high-voltage switchgear, and proposes to use a small and light angular displacement sensor. According to the corresponding relationship between the angular displacement and the linear displacement, the linear stroke of the arc contact is ingeniously obtained indirectly, and the simple device is used. The task of realizing high-precision measurement has realized the measurement of the individual contact stroke of the arc contact of the high-voltage SF6 circuit breaker.

In one embodiment, the angular displacement sensor is a WDD35D4 resistive angular displacement sensor.

In this embodiment, considering the convenience of installation of the angular displacement sensor, the necessity of electromagnetic shielding and the requirement of measurement accuracy, a WDD35D4 resistive angular displacement sensor is selected. The WDD35D4 resistive angular displacement sensor used in this embodiment has the thread on it exactly the same as the general connection shaft diameter of the main shaft of the circuit breaker, which avoids mechanical processing. The line is connected to the ARM module to ensure the good anti-interference performance of the system, and its accuracy can also meet the measurement requirements.

In one embodiment, the stored angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact are specifically determined by using the angular displacement sensor installed on the main shaft and the linear displacement sensor at the bottom of the insulating rod when the circuit breaker is opened and closed. Measure the angular displacement of the main shaft and the linear displacement stroke of the arc contact respectively.

This embodiment focuses on how to measure the angular displacement of the main shaft and the linear displacement of the arc contact. However, the angular displacement and linear conversion module in this device is actually a concept or a processing method rather than a specific object. No linear displacement sensor is used in this paper.

In one embodiment, the measured angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact include measuring the angular displacement of the main shaft and the linear displacement of the arcing contact during 25-45 opening and closing times respectively.

In this embodiment, the statistical results of 30 opening and closing operations of the circuit breaker are shown in Figure 3 (opening) and Figure 4 (closing). The maximum deviation of the linear displacement voltage value during the opening process is 3.3% (0.06V), and the maximum deviation of the angular displacement voltage value is 3.2% (0.08V). The maximum deviation of linear displacement voltage value during closing process is 1.1% (0.02V), and the maximum deviation of angular displacement voltage value is 0.3% (0.008V). It can be seen from this that the dispersion of the linear displacement and angular displacement curves of the circuit breaker is small during multiple measurements.

In one embodiment, using the cftool tool in the Matlab software, the angular displacement of the main shaft and the linear displacement stroke of the arc contact during 25-45 times of opening and closing are respectively fitted to the angular displacement of the main shaft of the circuit breaker during the opening process and the closing process Corresponding relationship curve with the linear stroke of the arc contact.

In order to verify the accuracy of fitting the corresponding relationship curve in this embodiment, the AMAMS simulation model is used to simulate the angular displacement of the main shaft of the circuit breaker and the stroke of the arc contact under normal extraction conditions;

Figure 5 shows the comparison between the angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact during the opening process and the actual simulation results. The fitting error is shown in Figure 6. It can be seen from the figure that the fitted results are in good agreement with the actual results.

The comparison diagram of the actual simulation results between the angular displacement of the main shaft and the arc contact travel curve during the circuit breaker closing process is shown in Figure 7; the fitting error curve of the arc contact linear displacement travel curve during the circuit breaker closing process is shown in the attached Figure 8 shows. Similarly, it can be seen from the figure that the fitted results are in good agreement with the actual results.

In one embodiment, the formula of the relationship curve between the angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact during the opening process is as follows:

y＝A ₄ x ⁴ +A ₃ x ³ +A ₂ x ² +A ₁ x ¹ +A ₀

Among them, x represents the angular displacement of the spindle, y represents the linear stroke of the arc contact, and A0~A4 are the corresponding polynomial coefficients.

The formula of the corresponding relationship curve between the angular displacement of the main shaft of the circuit breaker and the linear travel of the arcing contact during the closing process is as follows:

y＝B ₅ x ⁵ +B ₄ x ⁴ +B ₃ x ³ +B ₂ x ² +B ₁ x ¹ +B ₀

Among them, x represents the angular displacement of the spindle, y represents the linear stroke of the arc contact, and B0~B5 are the corresponding polynomial coefficients.

The measuring device for the individual contact stroke of the high-voltage SF6 circuit breaker arc contact according to the present invention has the following advantages:

(1) Practicability: This device can adapt to the requirements of different substations, different electrical main wiring methods, and different secondary circuit designs, and is not affected by the external environment.

(2) Simplicity: This device solves the problem that linear sensors are difficult to apply to high-voltage switchgear, and realizes complex measurement tasks through easy-to-install angular displacement sensors.

(3) Real-time performance: This device can measure the angular displacement of the main shaft in real time and quickly calculate the corresponding linear stroke of the arc contact through the data processing module.

(4) Flexibility: The ARM data processing module of this device can be connected with different control centers, thus making the application of this device more flexible.

(5) Economy: This device has good technical and economic indicators and has strong market potential.

In one embodiment, a method for measuring the contact stroke of an isolated contact of a high-voltage SF6 circuit breaker is disclosed, and the method includes the following steps:

S100, using the angular displacement measurement module to measure the angular displacement of the main shaft of the circuit breaker;

S200. Fitting the stored angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact into a corresponding relationship curve;

S300. Calculate the individual contact stroke of the arcing contact based on the angular displacement of the main shaft of the circuit breaker and the corresponding relationship curve between the angular displacement of the main shaft of the circuit breaker and the linear travel of the arcing contact.

The method described in this embodiment solves the problem that the linear sensor is difficult to apply to the high-voltage switchgear. The small and light angular displacement sensor is used, and according to the corresponding relationship between the angular displacement and the linear displacement, the linear travel of the arc contact is ingeniously and indirectly obtained to realize The task of realizing high-precision measurement with a simple device is realized, and the measurement of the contact stroke of the arc contact of the high-voltage SF6 circuit breaker is realized.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments. It cannot be determined that the specific embodiments of the present invention are limited thereto. Under the present invention, several simple deduction or substitutions can also be made, all of which should be considered as belonging to the protection scope of the present invention determined by the submitted claims.

Claims (8)

1. A measuring device for a high-voltage SF6 circuit breaker lonely contact stroke, characterized in that: The device includes an angular displacement measurement module, an angular displacement and linear displacement conversion module, and a data acquisition and processing module; The angular displacement measurement module includes an angular displacement sensor, and the angular displacement sensor is used to obtain the angular displacement of the main shaft of the circuit breaker, and send the angular displacement to the data acquisition and processing module; The angular displacement and linear displacement conversion module is used to fit the stored angular displacement of the main shaft of the circuit breaker and the linear stroke of the arc contact into a corresponding relationship curve and send it to the data acquisition and processing module; The data acquisition and processing module is used to calculate the arcing contact stroke according to the angular displacement of the main shaft of the circuit breaker and the corresponding relationship. 2. The device according to claim 1, characterized in that, preferably, the angular displacement sensor is a resistive angular displacement sensor. 3. The device according to claim 1, characterized in that: the stored angular displacement of the main shaft of the circuit breaker is measured by an angular displacement sensor installed on the main shaft; the stored linear stroke of the arc contact is Measured by a linear displacement sensor installed at the bottom of the insulating rod. 4. The device according to claim 3, characterized in that: the measured angular displacement of the main shaft of the circuit breaker and the linear travel of the arc contact include measuring the angular displacement of the main shaft and the arc contact when opening and closing for 25-45 times respectively. Contact linear displacement stroke. 5. The device according to claim 4, characterized in that: the angular displacement of the main shaft and the linear displacement stroke of the arc contact are respectively fitted to the process of opening and closing of the gate using the cftool tool in the Matlab software. The corresponding relationship curve between the angular displacement of the main shaft of the gate process circuit breaker and the linear stroke of the arcing contact. 6. The device according to claim 5, characterized in that: the formula of the corresponding relationship curve between the angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact during the opening process is as follows: y＝A ₄ X ⁴ +A ₃ x ³ +A ₂ x ² +A ₁ x ¹ +A ₀ Among them, x represents the angular displacement of the spindle, y represents the linear stroke of the arc contact, and A0~A4 are the corresponding polynomial coefficients. 7. The device according to claim 6, characterized in that the formula of the corresponding relationship curve between the angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact during the closing process is as follows: y＝B ₅ x ⁵ +b ₄ x ⁴ +B ₃ x ³ +B ₂ x ² +B ₁ x ¹ +B ₀ Among them, x represents the angular displacement of the spindle, y represents the linear stroke of the arc contact, and B0~B5 are the corresponding polynomial coefficients. 8. A method for measuring the contact stroke of the high-voltage SF6 circuit breaker orphan contact that utilizes the arbitrary device of claims 1 to 7, it is characterized in that the method comprises the following steps: S100, using the angular displacement measurement module to measure the angular displacement of the main shaft of the circuit breaker; S200. Fitting the stored angular displacement of the main shaft of the circuit breaker and the linear stroke of the arcing contact into a corresponding relationship curve; S300. Calculate the contact stroke of the arcing contact based on the angular displacement of the main shaft of the circuit breaker and the corresponding relationship curve between the angular displacement of the main shaft of the circuit breaker and the linear travel of the arcing contact.