An isolating switch online monitoring device and method

Abstract

The present application provides an isolating switch online monitoring device and method, which relate to the technical field of online monitoring of power systems. The device provides a high-frequency signal to the isolating switch through a high-frequency power supply circuit, measures the resistance of the isolating switch through a loop resistance measurement circuit, obtains a first resistance change curve, and determines a second resistance change curve of the isolating switch in combination with the contact temperature in a measurement period and a pre-stored temperature-resistance correspondence relationship, corrects the first resistance change curve through the second resistance change curve, and finally obtains a contact resistance change curve. In this way, the influence of external interference on the resistance measurement result during the measurement process can be reduced, so that the measurement result accurately reflects the change of the contact resistance, thereby improving the reliability of isolating switch fault monitoring.

Description

Technical Field

[0001] The present application belongs to the technical field of online monitoring of power systems, and in particular, relates to an online monitoring device and method for disconnectors. Background Art

[0002] The statements in this section merely provide background technical information related to the present application and do not necessarily constitute prior art.

[0003] Isolating switches usually refer to high-voltage isolating switches, which are used in lines with a rated voltage of 1kV or above. After opening, a reliable insulation gap is established to separate the equipment or lines that need to be repaired from the power supply with an obvious disconnection point to ensure the safety of maintenance personnel and equipment. In addition, the lines can be switched according to operational needs. It has a simple structure and plays an important role in high-voltage distribution networks.

[0004] During long-term use, the contact resistance of the isolating switch increases, the contact heats up, and in severe cases, the contact is damaged, affecting the transmission and distribution of electric energy and the safe and reliable operation of the system. Most of the current online monitoring devices for isolating switches use the method of measuring loop resistance to judge the contact quality of the isolating switch. However, the resistance measurement process is affected by external environments such as rain, snow, and electromagnetic interference, so that the measurement results cannot directly reflect the changes in the contact resistance of the contacts, resulting in low reliability of isolating switch fault monitoring. Summary of the invention

[0005] In order to solve the above problems, the present application provides an online monitoring device and method for an isolating switch, the purpose of which is to improve the accuracy of the monitoring results of the isolating switch so that it can accurately reflect the changes in the contact resistance of the contacts.

[0006] In order to achieve the above objectives, this application mainly includes the following aspects:

[0007] In a first aspect, an embodiment of the present application provides an online monitoring device for an isolating switch, comprising: a controller, a high-frequency power supply circuit, a loop resistance measurement circuit, and a temperature measurement circuit;

[0008] The high-frequency power supply circuit is connected to both ends of the isolating switch to provide a high-frequency signal for the isolating switch; the loop resistance measurement circuit is used to measure the resistance of the isolating switch; the temperature measurement circuit is used to measure the temperature of the contacts of the isolating switch; the controller is used to determine a first resistance change curve of the isolating switch according to the resistance obtained during the measurement period; determine a second resistance change curve of the isolating switch according to the contact temperature during the measurement period and the pre-stored temperature-resistance correspondence; correct the first resistance change curve according to the second resistance change curve, determine the corrected curve as the contact resistance change curve, and send it to the remote control end.

[0009] In a possible implementation, the high-frequency power supply circuit includes a high-frequency power supply and a low-frequency filter circuit, and the high-frequency power supply and the low-frequency filter circuit are connected in series and connected to both ends of the isolation switch.

[0010] In a possible implementation, the loop resistance measurement circuit includes a preamplifier circuit, an AD conversion circuit, and an operation processing circuit.

[0011] In a possible implementation manner, the controller is used to determine an average of a first resistance value in the first resistance change curve and a second resistance value in the second resistance change curve at each moment in a measurement period as the resistance value of the contact resistance.

[0012] In a possible implementation manner, the controller is further configured to determine a mean value of a change curve of the contact resistance of the contact points, and filter out resistance data whose difference from the mean value exceeds a preset threshold value.

[0013] In a possible implementation manner, the controller sequentially sends each resistance value in the contact resistance variation curve to the remote control terminal through a wireless communication circuit.

[0014] In a second aspect, an embodiment of the present application provides an online monitoring method for an isolating switch, comprising:

[0015] Obtain the resistance value and contact temperature of the isolating switch;

[0016] Determine a first resistance change curve of the isolating switch according to the resistance value obtained during the measurement period;

[0017] Determine a second resistance variation curve of the isolating switch according to the contact temperature within the measurement cycle and the pre-stored temperature-resistance correspondence;

[0018] The first resistance change curve is corrected according to the second resistance change curve, the corrected curve is determined as the contact resistance change curve of the contact point, and is sent to the remote control terminal.

[0019] In a possible implementation manner, the method further includes: filtering out resistance data whose difference with the mean value exceeds a preset threshold value according to the mean value of the contact resistance variation curve.

[0020] In a third aspect, an embodiment of the present application provides a computer device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the steps of the online monitoring method for the isolating switch as described in any possible implementation manner of the first aspect above are performed.

[0021] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the online monitoring method for an isolating switch as described in any possible implementation manner in the first aspect above are executed.

[0022] Beneficial effects of this application:

[0023] The present application provides an online detection device for an isolating switch, which provides a high-frequency signal for the isolating switch through a high-frequency power supply circuit, measures the resistance of the isolating switch through a loop resistance measurement circuit, obtains a first resistance change curve, and determines a second resistance change curve of the isolating switch in combination with the contact temperature in a measurement period and a pre-stored temperature-resistance correspondence, and corrects the first resistance change curve through the second resistance change curve to finally obtain a contact resistance change curve. In this way, the influence of external interference on the resistance measurement result during the measurement process can be reduced, so that the measurement result accurately reflects the change of the contact resistance, thereby improving the reliability of the isolating switch fault monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0025] Figure 1 It is one of the structural schematic diagrams of the disconnector online monitoring device provided in the embodiment of the present application;

[0026] Figure 2 This is the second structural schematic diagram of the disconnector online monitoring device provided in the embodiment of the present application;

[0027] Figure 3 It is a flow chart of the online monitoring method of the isolating switch provided in the embodiment of the present application;

[0028] Figure 4 It is a schematic diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] At present, the contact quality of the isolating switch is usually determined by measuring the loop resistance. In the actual measurement process, especially for the monitoring of outdoor isolating switches, the measurement results will be affected by the external environment such as rain, snow, and electromagnetic interference, so that the measurement results cannot directly reflect the change of the contact resistance, resulting in low reliability of isolating switch fault monitoring. Based on this, the present application provides an isolating switch online monitoring device and method to improve the accuracy of the isolating switch monitoring results so that it can accurately reflect the change of the contact resistance.

[0033] Embodiment 1

[0034] See also Figure 1 , Figure 1 is one of the structural schematic diagrams of the disconnector online monitoring device provided in the embodiment of the present application, such as Figure 1 As shown in , an online monitoring device for an isolating switch includes: a controller 110, a high-frequency power supply circuit 120, a loop resistance measurement circuit 130 and a temperature measurement circuit 140;

[0035] The high-frequency power supply circuit 120 is connected to both ends of the isolating switch 150 to provide a high-frequency signal for the isolating switch 150; the loop resistance measurement circuit 130 is used to measure the resistance of the isolating switch 150; the temperature measurement circuit 140 is used to measure the temperature of the contacts of the isolating switch 150; the controller 110 is used to determine a first resistance change curve of the isolating switch 150 according to the resistance obtained during the measurement period; determine a second resistance change curve of the isolating switch 150 according to the contact temperature during the measurement period and the pre-stored temperature-resistance correspondence; correct the first resistance change curve according to the second resistance change curve, determine the corrected curve as the contact resistance change curve, and send it to the remote control end.

[0036] In specific implementation, due to the increase in contact resistance of the contact and the increase in contact temperature, the measurement of contact temperature is relatively stable in rain, snow, electromagnetic interference and other environments, but the conversion process between contact temperature and resistance is relatively complex, and the temperature change is not obvious. Therefore, this embodiment obtains the second resistance change curve of the disconnector through the temperature-resistance correspondence relationship, which is used to correct the resistance measurement value to improve the accuracy of the measurement result.

[0037] Specifically, the high-frequency power supply circuit transmits high-frequency waves to the isolating switch, and then the loop resistance measurement circuit obtains the resistance value of the isolating switch by measuring the voltage and current of the high-frequency waves; the temperature of the isolating switch contacts is measured by adding a temperature measurement circuit, and the measured resistance value and temperature data are sent to the controller. The controller determines the first resistance change curve of the isolating switch according to the resistance value obtained during the measurement cycle, and determines the second resistance change curve of the isolating switch through the measured contact temperature and the pre-stored temperature-resistance correspondence, thereby correcting the first resistance change curve through the second resistance change curve, determining the corrected curve as the contact resistance change curve, and sending it to the remote control end.

[0038] As an optional implementation, Figure 2 As shown in , the high-frequency power supply circuit 120 includes a high-frequency power supply 121 and a low-frequency filter circuit 122, which are connected in series and connected to both ends of the isolating switch. In a specific implementation, the high-frequency power supply transmits high-frequency waves to the isolating switch, and the low-frequency filter circuit blocks the low-frequency current through the high-frequency current to prevent the power frequency voltage from entering the measurement circuit.

[0039] As an optional implementation, the loop resistance measurement circuit 130 includes a preamplifier circuit 131, an AD conversion circuit 132, and an operation processing circuit 133. In a specific implementation, the signals at both ends of the isolation switch are passed through the preamplifier circuit, the AD conversion circuit, and the operation processing circuit to obtain a resistance value, and the voltage reduction method can be used to achieve the measurement of the resistance value.

[0040] As an optional implementation, the controller 110 is used to determine the average of the first resistance value of the first resistance change curve and the second resistance value of the second resistance change curve at each moment in the measurement period as the resistance of the contact point. In a specific implementation, the average of the resistance values ​​at each moment in the first resistance change curve and the second resistance change curve can be calculated, and the average can be determined as the resistance of the contact resistance, or corresponding weights can be set respectively, and the resistance of the contact point contact resistance can be calculated according to the corresponding weights.

[0041] As an optional implementation, the controller 110 is further used to determine the mean value of the contact resistance change curve, and filter out the resistance data whose difference with the mean value exceeds a preset threshold value. In a specific implementation, in order to enable the measurement result to directly reflect the change of the contact resistance, after obtaining the contact resistance change curve, the abnormal resistance value can be filtered out according to its mean value.

[0042] As an optional implementation, the controller 110 sends each resistance value in the contact resistance change curve to the remote control terminal in sequence through a wireless communication circuit. In a specific implementation, the wireless communication circuit includes a GPRS, WiFi, zigbee or other wireless communication circuits.

[0043] Embodiment 2

[0044] See also Figure 3 , Figure 3 Schematic diagram of the process of the online monitoring method of the isolating switch provided in the embodiment of the present application. Figure 3 As shown in , this embodiment also provides an isolating switch online monitoring method, including:

[0045] S301: Obtain the resistance value and contact temperature of the isolating switch;

[0046] S302: Determine a first resistance change curve of the isolating switch according to the resistance value obtained in the measurement period;

[0047] S303: determining a second resistance variation curve of the isolating switch according to the contact temperature within the measurement period and the pre-stored temperature-resistance correspondence relationship;

[0048] S304: Correcting the first resistance change curve according to the second resistance change curve, determining the corrected curve as the contact resistance change curve, and sending it to the remote control terminal.

[0049] As an optional implementation, the method further includes: filtering out resistance data whose difference with the mean value exceeds a preset threshold value according to the mean value of the contact resistance variation curve.

[0050] The isolating switch online monitoring method of this embodiment and the isolating switch online monitoring device described above are based on the same inventive concept, so the specific implementation method of the isolating switch online monitoring method can be found in the embodiment section of the isolating switch online monitoring device described above, and will not be repeated here.

[0051] Embodiment 3

[0052] See also Figure 4 , Figure 4 Schematic diagram of a computer device according to an embodiment of the present application. Figure 4 As shown in , the computer device 400 includes a processor 410 , a memory 420 and a bus 430 .

[0053] The memory 420 stores machine-readable instructions executable by the processor 410. When the computer device 400 is running, the processor 410 communicates with the memory 420 via the bus 430. When the machine-readable instructions are executed by the processor 410, the above-mentioned Figure 3 The specific implementation of the steps of the isolating switch online monitoring method in the method embodiment shown can be found in the method embodiment, which will not be repeated here.

[0054] Embodiment 4

[0055] Based on the same application concept, an embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the online monitoring method for the isolating switch described in the above method embodiment are executed.

[0056] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0057] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An online monitoring device for an isolating switch, characterized in that: include: Controller, high frequency power supply circuit, loop resistance measurement circuit and temperature measurement circuit; The high-frequency power supply circuit is connected to both ends of the isolating switch to provide a high-frequency signal for the isolating switch; the loop resistance measurement circuit is used to measure the resistance of the isolating switch; the temperature measurement circuit is used to measure the temperature of the contacts of the isolating switch; the controller is used to determine a first resistance change curve of the isolating switch according to the resistance obtained during the measurement period; determine a second resistance change curve of the isolating switch according to the contact temperature during the measurement period and the pre-stored temperature-resistance correspondence; correct the first resistance change curve according to the second resistance change curve, determine the corrected curve as the contact resistance change curve, and send it to the remote control end; The loop resistance measurement circuit includes a preamplifier circuit, an AD conversion circuit and an operation processing circuit, and the signals at both ends of the isolation switch are passed through the preamplifier circuit, the AD conversion circuit and the operation processing circuit to obtain a resistance value; The controller is used to determine the average of the first resistance value in the first resistance change curve and the second resistance value in the second resistance change curve at each moment in the measurement period as the resistance value of the contact resistance; The controller is also used to filter out resistance data whose difference with the mean value exceeds a preset threshold value according to the mean value of the change curve of the contact resistance of the contact points.

2. The disconnector online monitoring device according to claim 1, characterized in that: The high-frequency power supply circuit includes a high-frequency power supply and a low-frequency filter circuit. The high-frequency power supply and the low-frequency filter circuit are connected in series and connected to both ends of the isolation switch.

3. The disconnector online monitoring device according to claim 1, characterized in that: The controller sends each resistance value in the contact resistance variation curve to the remote control terminal in sequence through the wireless communication circuit.

4. A disconnector online monitoring method, characterized in that: include: Obtaining the resistance value and contact temperature of the isolating switch; wherein the resistance value of the isolating switch is obtained through a loop resistance measuring circuit, and the loop resistance measuring circuit includes a preamplifier circuit, an AD conversion circuit and an operation processing circuit; Determine a first resistance change curve of the isolating switch according to the resistance value obtained during the measurement period; Determine a second resistance variation curve of the isolating switch according to the contact temperature within the measurement cycle and the pre-stored temperature-resistance correspondence; Correcting the first resistance change curve according to the second resistance change curve, determining the corrected curve as the contact resistance change curve of the contact point, and sending it to the remote control terminal; Determine the average of the first resistance value in the first resistance change curve and the second resistance value in the second resistance change curve at each moment in a measurement period as the resistance value of the contact point contact resistance; According to the mean value of the contact resistance variation curve, the resistance data whose difference with the mean value exceeds a preset threshold value are filtered out.

5. A computer device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, the steps of the online monitoring method for the disconnector as claimed in claim 4 are performed.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the disconnector online monitoring method according to claim 4 are executed.

Images