Distribution network equipment resistance test circuit, device and test method

Abstract

The invention relates to a distribution network equipment resistance test circuit, device and test method. The distribution network equipment resistance test circuit comprises a control circuit, a selection circuit and a power supply circuit. The control circuit is used for controlling the working mode of the power supply circuit and the selection mode of the selection circuit, and the selection circuit is used for enabling the power supply circuit to be connected with a direct-current resistor in distribution network equipment in the direct-current mode or enabling the power supply circuit to be connected with a direct-current resistor in the distribution network equipment in the insulation mode. The power supply circuit is used for being connected with an insulation resistor of the distribution network equipment; and the power supply circuit is used for providing a constant current source for the distribution network equipment in the constant current source mode so as to enable the distribution network equipment to output an analog voltage signal, or providing a constant voltage source for the distribution network equipment in the constant voltage source mode so as to enable the distribution network equipment to output an analog current signal. By adopting the structure, the test efficiency of the distribution network equipment can be improved.

Description

Technical Field

[0001] The present application relates to the field of resistance testing technology, and in particular to a resistance testing circuit, device and testing method for distribution network equipment. Background Art

[0002] Resistance testers are indispensable tools for electrical safety testing and grounding project acceptance, which usually include DC resistance testers and insulation resistance testers. In actual work, DC resistance testers and insulation resistance testers are often used to test distribution network equipment.

[0003] Current DC resistance testers and insulation resistance testers have a series of cumbersome operating steps when performing tests. Each test requires repeated wiring and disconnection operations according to the test requirements. For example, according to the test requirements, the object under test needs to be correctly connected to the corresponding interface of the test instrument to ensure that the circuit connection is correct in order to perform accurate testing. After each test, the connection line between the object under test and the test instrument needs to be removed for the next test. This process may take a long time, especially if the connection line is complicated or the wiring is inconvenient, the test efficiency is low. Summary of the invention

[0004] Based on this, it is necessary to provide a distribution network equipment resistance testing circuit, device and testing method that can improve testing efficiency in response to the above technical problems.

[0005] In a first aspect, the present application provides a distribution network equipment resistance test circuit. The distribution network equipment resistance test circuit includes a control circuit, a selection circuit and a power supply circuit;

[0006] The control circuit is connected to the power supply circuit and the selection circuit respectively, and is used to control the working mode of the power supply circuit and the selection mode of the selection circuit, wherein the working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode;

[0007] The selection circuit is connected to the power supply circuit and is used to enable the power supply circuit to be connected to a DC resistor in a distribution network device in the DC mode, or to enable the power supply circuit to be connected to an insulation resistor of the distribution network device in the insulation mode;

[0008] The power supply circuit is used to provide a constant current source to the network distribution device in the constant current source mode so that the network distribution device outputs an analog voltage signal, or to provide a constant voltage source to the network distribution device in the constant voltage source mode so that the network distribution device outputs an analog current signal.

[0009] In one embodiment, the power supply circuit includes a constant current source unit and a constant voltage source unit; the power supply circuit includes a plurality of voltage output terminals;

[0010] Each of the voltage output terminals is used to connect to the constant current source unit and the constant voltage source unit respectively.

[0011] In one embodiment, the power supply circuit further includes a plurality of switch units, and the plurality of switch units of the power supply circuit are all connected to the control circuit;

[0012] Each of the voltage output terminals is used to connect to the constant current source unit and the constant voltage source unit respectively through the plurality of switch units of the power supply circuit.

[0013] In one embodiment, the power supply circuit includes a first voltage output terminal, a second voltage output terminal, and a third voltage output terminal, and the plurality of switch units of the power supply circuit include a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a fifth switch unit, and a sixth switch unit;

[0014] The first voltage output terminal is used to connect to the constant current source unit through the first switch unit and connect to the constant voltage source unit through the second switch unit;

[0015] The second voltage output terminal is used to connect to the constant current source unit through the third switch unit and connect to the constant voltage source unit through the fourth switch unit;

[0016] The third voltage output terminal is used to connect to the constant current source unit through the fifth switch unit and connect to the constant voltage source unit through the sixth switch unit.

[0017] In one embodiment, each of the voltage output terminals is further used to connect to the DC resistance of at least one of the distribution network devices and the insulation resistance of at least one of the distribution network devices respectively.

[0018] In one embodiment, the selection circuit further includes a plurality of switch units, and the switch units of the selection circuit are all connected to the control circuit;

[0019] Each of the voltage output terminals is further used to connect to the DC resistance of at least one of the distribution network devices and the insulation resistance of at least one of the distribution network devices respectively through the plurality of switch units of the selection circuit.

[0020] In one embodiment, the distribution network device resistance test circuit further includes a signal acquisition circuit connected to the distribution network device, an analog-to-digital conversion circuit connected to the signal acquisition circuit, and a signal isolation circuit respectively connected to the analog-to-digital conversion circuit and the control circuit;

[0021] The signal acquisition circuit is used to acquire the analog voltage signal or analog current signal output by the distribution network device;

[0022] The analog-to-digital conversion circuit is used to obtain the analog voltage signal and convert the analog voltage signal into a digital voltage signal, or obtain the analog current signal and convert the analog current signal into a digital current signal;

[0023] The signal isolation circuit is used to achieve electrical isolation between the analog-to-digital conversion circuit and the control circuit.

[0024] In one embodiment, the distribution network device resistance test circuit further includes a key circuit connected to the control circuit and a display circuit connected to the control circuit;

[0025] The key circuit is used to receive different test instructions, generate control logic according to the test instructions, and send the control logic to the control circuit, so that the control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit according to the control logic;

[0026] The display circuit is used to display the resistance value of the corresponding resistance of the distribution network device calculated by the control circuit.

[0027] In a second aspect, the present application also provides a method for testing the resistance of a distribution network device, which is applied to the distribution network device resistance test circuit provided in the first aspect of the present application. The method includes:

[0028] The control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit. The working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode;

[0029] The selection circuit, in the DC mode, enables the power supply circuit to connect to the DC resistance in the distribution network device, or, in the insulation mode, enables the power supply circuit to connect to the insulation resistance of the distribution network device;

[0030] The power supply circuit provides a constant current source to the distribution network device in the constant current source mode, so that the distribution network device outputs an analog voltage signal, or provides a constant voltage source to the distribution network device in the constant voltage source mode, so that the distribution network device outputs an analog current signal.

[0031] In a third aspect, the present application also provides a device for testing the resistance of a distribution network device. The distribution network device resistance test device includes the distribution network device resistance test circuit provided in the first aspect of the present application.

[0032] The above-mentioned resistance test circuit, device and test method for distribution network equipment. The resistance test circuit for distribution network equipment includes a control circuit, a selection circuit and a power supply circuit. The control circuit is respectively connected to the power supply circuit and the selection circuit, and is used to control the working mode of the power supply circuit and the selection mode of the selection circuit. The working modes include a constant current source mode and a constant voltage source mode, and the selection modes include a DC mode and an insulation mode. The selection circuit is connected to the power supply circuit, and is used to, in the DC mode, enable the power supply circuit to connect to the DC resistance in the distribution network equipment, or, in the insulation mode, enable the power supply circuit to connect to the insulation resistance of the distribution network equipment. The power supply circuit is used to provide a constant current source to the distribution network equipment in the constant current source mode, so that the distribution network equipment outputs an analog voltage signal, or, in the constant voltage source mode, provide a constant voltage source to the distribution network equipment, so that the distribution network equipment outputs an analog current signal. In this application, the control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit, so that the power supply circuit can automatically switch the control to provide a constant current source to the DC resistance of the distribution network equipment and provide a constant voltage source to the insulation resistance of the distribution network equipment. Only one wiring is required, and the combination of DC resistance test and insulation resistance test can be intelligently realized. The functions of two test instruments are integrated into one, so that it has multiple test functions. By using a customized special test line, the operator can realize the one-time wiring test function without the need to replace the DC resistance test line and the insulation test line, that is, all test lines are connected at one time, and the on / off of the current inside the circuit is controlled through the control circuit, so as to realize the measurement of DC resistance or insulation resistance, and improve the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a structural block diagram of a resistance test circuit for distribution network equipment in an embodiment;

[0035] Figure 2 It is a structural block diagram of a power supply circuit in an embodiment;

[0036] Figure 3 It is a structural block diagram of a power supply circuit, a selection circuit and distribution network equipment in an embodiment;

[0037] Figure 4 It is a structural block diagram of a resistance test circuit for distribution network equipment in another embodiment;

[0038] Figure 5 It is a structural block diagram of an analog-to-digital conversion circuit in an embodiment;

[0039] Figure 6 It is a schematic flowchart of a method for testing the resistance of a distribution network device in an embodiment. Detailed implementation manners

[0040] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] It can be understood that the terms "first", "second", etc. used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first resistor can be called the second resistor, and similarly, the second resistor can be called the first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0043] It can be understood that "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is an electrical signal or data transmission between the connected circuits, modules, units, etc.

[0044] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0045] In an embodiment, as Figure 1 shown, a resistance test circuit for a distribution network device is provided. The resistance test circuit for the distribution network device includes a control circuit 100, a selection circuit 300, and a power supply circuit 200; wherein:

[0046] The control circuit 100 is respectively connected to the power supply circuit 200 and the selection circuit 300, and is used to control the working mode of the power supply circuit 200 and the selection mode of the selection circuit 300. The working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode.

[0047] The selection circuit 300 is connected to the power supply circuit 200, and is used to connect the DC resistance in the power distribution network device 10 by the power supply circuit 200 in the DC mode, or to connect the insulation resistance of the power distribution network device 10 by the power supply circuit 200 in the insulation mode.

[0048] The power supply circuit 200 is used to provide a constant current source to the power distribution network device 10 in the constant current source mode, so that the power distribution network device 10 outputs an analog voltage signal, or to provide a constant voltage source to the power distribution network device 10 in the constant voltage source mode, so that the power distribution network device 10 outputs an analog current signal.

[0049] In the above power distribution network device resistance test circuit, it includes a control circuit, a selection circuit and a power supply circuit; the control circuit is respectively connected to the power supply circuit and the selection circuit, and is used to control the working mode of the power supply circuit and the selection mode of the selection circuit. The working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode; the selection circuit is connected to the power supply circuit, and is used to connect the DC resistance in the power distribution network device by the power supply circuit in the DC mode, or to connect the insulation resistance of the power distribution network device by the power supply circuit in the insulation mode; the power supply circuit is used to provide a constant current source to the power distribution network device in the constant current source mode, so that the power distribution network device outputs an analog voltage signal, or to provide a constant voltage source to the power distribution network device in the constant voltage source mode, so that the power distribution network device outputs an analog current signal. In this application, the control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit, so that the power supply circuit can automatically switch the control of providing a constant current source to the DC resistance of the power distribution network device and providing a constant voltage source to the insulation resistance of the power distribution network device. Only one wiring is required, and the combination of DC resistance test and insulation resistance test can be intelligently realized. The functions of two test instruments are integrated into one, so that it has multiple test functions; by using a customized special test line, the operator can realize the one-time wiring test function without the need to replace the DC resistance test line and the insulation test line, that is, all test lines are connected at one time, and the on / off of the current inside the circuit is controlled by the control circuit, so as to realize the measurement of DC resistance or insulation resistance, and improve the test efficiency.

[0050] In one embodiment, as Figure 2As shown, the power supply circuit includes a constant current source unit and a constant voltage source unit, and the power supply circuit includes a plurality of voltage output terminals; each of the voltage output terminals is used to connect the constant current source unit and the constant voltage source unit respectively.

[0051] Among them, the constant current source unit of the power supply circuit is used to provide a constant current source, and the resistance value of the DC resistance is measured through the constant current source. The constant voltage source unit of the power supply circuit is used to provide a constant voltage source, and the leakage current of the insulation resistance is measured through the constant voltage source. Specifically, for the DC resistance test part corresponding to the constant current source in the embodiments of the present application, the test range is 0~2KΩ, the measurement accuracy is ±0.2%, the resolution is 0.1μΩ, and the test current range is 5mA - 10A. For the insulation resistance test part corresponding to the constant voltage source in the embodiments of the present application, the measured resistance range is 0~1000GΩ, and multiple voltage levels of 500V / 1000V / 2500V / 5000V can be provided.

[0052] In one implementation, both the constant current source unit and the constant voltage source unit are connected to the control circuit, and the constant current of the constant current source unit and each voltage level of the constant voltage source unit are adjusted through the control circuit.

[0053] The constant current source unit and the constant voltage source unit in the embodiments of the present application may both include a standard resistor or a protection resistor, which are used to form a test circuit with the constant current source or the constant voltage source and the resistor under test. The embodiments of the present application do not specifically limit its structure. For example, when testing the DC resistance, the resistance value of the resistor under test can be obtained through the voltage on the standard resistor, the resistance value of the standard resistor, and the voltage of the resistor under test; when testing the insulation resistance, the resistance value of the resistor under test can be obtained through the current on the standard resistor, the resistance value of the standard resistor, and the leakage current of the resistor under test.

[0054] The power supply circuit in the embodiments of the present application further includes a plurality of voltage output terminals. Among them, each voltage output terminal is used to provide voltage for its corresponding object under test. Specifically, each voltage output terminal includes a positive voltage output and a negative voltage output.

[0055] In a possible implementation, the power supply circuit further includes a plurality of switch units, and the plurality of switch units of the power supply circuit are all connected to the control circuit; each of the voltage output terminals is used to connect the constant current source unit and the constant voltage source unit respectively through the plurality of switch units of the power supply circuit.

[0056] Exemplarily, please continue to refer to Figure 2, the power supply circuit includes a first voltage output terminal, a second voltage output terminal, and a third voltage output terminal. The multiple switch units of the power supply circuit include a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a fifth switch unit, and a sixth switch unit; the first voltage output terminal is used to be connected to the constant current source unit through the first switch unit and to the constant voltage source unit through the second switch unit; the second voltage output terminal is used to be connected to the constant current source unit through the third switch unit and to the constant voltage source unit through the fourth switch unit; the third voltage output terminal is used to be connected to the constant current source unit through the fifth switch unit and to the constant voltage source unit through the sixth switch unit.

[0057] The switch units in the embodiments of the present application are used to protect and control the operation of the entire test circuit. The switch units are used to achieve disconnection or conduction according to the control signals of the control circuit. The switch units may include relays, and the relays include coils and switches.

[0058] In this embodiment, multiple voltage output terminals can be used to simultaneously test multiple DC resistances or multiple insulation resistances in the distribution network equipment, further improving the test efficiency.

[0059] In one embodiment, as Figure 3 shown, each of the voltage output terminals is also used to be respectively connected to at least one DC resistance of the distribution network equipment and at least one insulation resistance of the distribution network equipment.

[0060] Specifically, the selection circuit further includes multiple switch units, and the switch units of the selection circuit are all connected to the control circuit; each of the voltage output terminals is also used to be respectively connected to at least one DC resistance of the distribution network equipment and at least one insulation resistance of the distribution network equipment through the multiple switch units of the selection circuit.

[0061] Exemplarily, the first voltage output terminal is connected to the first DC resistance of the distribution network equipment through the seventh switch unit, and the first voltage output terminal is connected to the first insulation resistance of the distribution network equipment through the eighth switch unit; the second voltage output terminal is connected to the second DC resistance of the distribution network equipment through the ninth switch unit, and the second voltage output terminal is connected to the second insulation resistance of the distribution network equipment through the tenth switch unit; the third voltage output terminal is connected to the third DC resistance of the distribution network equipment through the 11th switch unit, and the third voltage output terminal is connected to the third insulation resistance of the distribution network equipment through the 12th switch unit.

[0062] It can be understood that the first voltage output terminal of the embodiment of the present application can be connected to the DC resistance and / or insulation resistance of multiple distribution network devices through different switching units, and the same applies to the second voltage output terminal and the third voltage output terminal. The DC resistance and / or insulation resistance connected to different voltage output terminals can be the same. The control circuit of the embodiment of the present application can also control the current or voltage range output by different voltage output terminals, so as to be able to select a more suitable and accurate voltage output terminal for the measured resistance.

[0063] For example, please continue to refer to Figure 3 , when the control unit controls the constant current source unit to work, the first switching unit, the seventh switching unit, the third switching unit, the ninth switching unit, the fifth switching unit, and the 11th switching unit are closed, and other switching units are open. The first voltage output terminal is used to provide a constant current source for the first DC resistance, the second voltage output terminal is used to provide a constant current source for the second DC resistance, and the third voltage output terminal is used to provide a constant current source for the third DC resistance.

[0064] Furthermore, the seventh switching unit can also be connected to the second DC resistance and the third DC resistance, and the same applies to the ninth switching unit and the 11th switching unit. The current flowing through the first voltage output terminal, the second voltage output terminal, and the third voltage output terminal can be the same or different. The control circuit can select a more suitable voltage output terminal for different DC resistances to perform resistance testing.

[0065] In one embodiment, as Figure 4 shown, the distribution network device resistance testing circuit further includes a signal acquisition circuit 400 connected to the distribution network device, an analog-to-digital conversion circuit 500 connected to the signal acquisition circuit 400, and a signal isolation circuit 600 respectively connected to the analog-to-digital conversion circuit 500 and the control circuit 100.

[0066] The signal acquisition circuit 400 is used to acquire the analog voltage signal or analog current signal output by the distribution network device.

[0067] Among them, the signal acquisition circuit 400 includes a voltage detection unit or a current detection unit connected to each measured resistance in a one-to-one correspondence. Specifically, a differential amplifier circuit can also be included on the path connecting each DC resistance to the voltage detection unit and each insulation resistance to the current detection unit. The signal acquisition circuit 400 can also include a voltage detection unit or a current detection unit for acquiring the voltage of the standard resistance or protection resistance in the power supply circuit.

[0068] The analog-to-digital conversion circuit 500 is used to obtain the analog voltage signal and convert the analog voltage signal into a digital voltage signal, or obtain the analog current signal and convert the analog current signal into a digital current signal.

[0069] The signal isolation circuit 600 is used to electrically isolate the control circuit 100 and the analog-to-digital conversion circuit 500 to protect the components in the circuit and avoid noise interference.

[0070] In one embodiment, as Figure 5 shown, the analog-to-digital conversion circuit includes an A / D conversion chip. Specifically, in actual application, the analog-to-digital conversion circuit includes an A / D conversion chip and some peripheral circuits. In some embodiments, the A / D conversion chip has two or more input terminals. One input terminal of the A / D conversion chip is connected to the voltage input, and the other input terminal is connected to the current input, performing analog-to-digital conversion on the analog voltage signal and the analog current signal respectively, and alternately outputting the digital electrical signal representing the voltage and the digital electrical signal representing the current to the control circuit. Further, the A / D conversion chip can be an AD7705 chip or an AD7706 chip. AD7705 / AD7706 is a 16-bit Σ-Δ type A / D converter launched by AD Company, which is used to measure low-frequency analog signals. AD7705 has two fully differential input channels, and AD7706 has three quasi-differential input channels.

[0071] In one embodiment, the distribution network equipment resistance test circuit further includes a key circuit connected to the control circuit and a display circuit connected to the control circuit.

[0072] The key circuit is used to receive different test instructions, generate control logic according to the test instructions, and send the control logic to the control circuit, so that the control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit according to the control logic.

[0073] The display circuit is used to display the resistance value of the corresponding resistance of the distribution network equipment calculated by the control circuit.

[0074] In one embodiment, the distribution network equipment resistance test can also include a discharge circuit connected to the power supply circuit and the distribution network equipment. After each test channel is completed, it automatically starts two steps of "small resistance discharge" and "direct grounding discharge", avoiding the generation of electric sparks. At the same time, long-distance testing is adopted, and the wiring head uses a slender pointed clamp head, which can be directly fixed on the equipment, and people can measure without approaching the equipment.

[0075] Based on the same inventive concept, the embodiment of the present application also provides a distribution network equipment resistance test method for implementing the above-mentioned distribution network equipment resistance test circuit. The implementation solution provided by this method to solve the problem is similar to the implementation solution recorded in the above circuit. Therefore, the specific limitations in one or more embodiments of the following distribution network equipment resistance test method can refer to the limitations on the distribution network equipment resistance test circuit in the above text, and will not be repeated here.

[0076] In one embodiment, as Figure 6 shown, a method for testing the resistance of a distribution network device is provided, and the method includes:

[0077] Step 602, the control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit, the working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode.

[0078] Step 604, the selection circuit, in the DC mode, causes the power supply circuit to be connected to the DC resistance in the distribution network device, or, in the insulation mode, causes the power supply circuit to be connected to the insulation resistance of the distribution network device.

[0079] Step 606, the power supply circuit provides a constant current source to the distribution network device in the constant current source mode, so that the distribution network device outputs an analog voltage signal, or provides a constant voltage source to the distribution network device in the constant voltage source mode, so that the distribution network device outputs an analog current signal.

[0080] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the indication of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps or stages in other steps.

[0081] Based on the same inventive concept, an embodiment of the present application further provides a device for testing the resistance of a distribution network device, and the device for testing the resistance of the distribution network device includes the aforementioned provided resistance testing circuit for the distribution network device.

[0082] In the description of this specification, the descriptions referring to terms such as "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or features described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0083] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0084] The above-described embodiments only express several implementation manners of the present application, and their descriptions are relatively specific and detailed. However, it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A resistance test circuit for distribution network equipment, characterized in that, The resistance test circuit of the distribution network device includes a control circuit, a selection circuit, and a power supply circuit; The control circuit is respectively connected to the power supply circuit and the selection circuit, and is used to control the working mode of the power supply circuit and the selection mode of the selection circuit. The working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode; The selection circuit is connected to the power supply circuit, and is used to, in the DC mode, enable the power supply circuit to connect to the DC resistance in the distribution network device, or, in the insulation mode, enable the power supply circuit to connect to the insulation resistance of the distribution network device; The power supply circuit is used to provide a constant current source to the distribution network device in the constant current source mode, so that the distribution network device outputs an analog voltage signal, or provide a constant voltage source to the distribution network device in the constant voltage source mode, so that the distribution network device outputs an analog current signal.

2. The resistance test circuit of the distribution network equipment according to claim 1, characterized in that The power supply circuit includes a constant current source unit and a constant voltage source unit; the power supply circuit includes multiple voltage output terminals; Each of the voltage output terminals is used to connect to the constant current source unit and the constant voltage source unit respectively.

3. The resistance test circuit of the distribution network equipment according to claim 2, characterized in that The power supply circuit further includes multiple switch units, and the multiple switch units of the power supply circuit are all connected to the control circuit; Each of the voltage output terminals is used to connect to the constant current source unit and the constant voltage source unit respectively through the multiple switch units of the power supply circuit.

4. The resistance test circuit for distribution network equipment according to claim 3, characterized in that The power supply circuit includes a first voltage output terminal, a second voltage output terminal, and a third voltage output terminal, and the multiple switch units of the power supply circuit include a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a fifth switch unit, and a sixth switch unit; The first voltage output terminal is used to connect to the constant current source unit through the first switch unit and connect to the constant voltage source unit through the second switch unit; The second voltage output terminal is used to connect to the constant current source unit through the third switch unit and connect to the constant voltage source unit through the fourth switch unit; The third voltage output terminal is used to connect to the constant current source unit through the fifth switch unit and connect to the constant voltage source unit through the sixth switch unit.

5. The resistance test circuit of the distribution network equipment according to claim 2, characterized in that Each of the voltage output terminals is further used to connect to the DC resistance of at least one of the distribution network devices and the insulation resistance of at least one of the distribution network devices respectively.

6. The resistance test circuit for distribution network equipment according to claim 5, characterized in that, The selection circuit further includes multiple switch units, and the switch units of the selection circuit are all connected to the control circuit; Each of the voltage output terminals is further used to connect to the DC resistance of at least one of the distribution network devices and the insulation resistance of at least one of the distribution network devices respectively through the multiple switch units of the selection circuit.

7. The resistance test circuit of the distribution network equipment according to claim 1, characterized in that The resistance test circuit of the distribution network device further includes a signal acquisition circuit connected to the distribution network device, an analog-to-digital conversion circuit connected to the signal acquisition circuit, and a signal isolation circuit respectively connected to the analog-to-digital conversion circuit and the control circuit; The signal acquisition circuit is used to acquire the analog voltage signal or analog current signal output by the distribution network device; The analog-to-digital conversion circuit is used to obtain the analog voltage signal and convert the analog voltage signal into a digital voltage signal, or obtain the analog current signal and convert the analog current signal into a digital current signal; The signal isolation circuit is used to achieve electrical isolation between the analog-to-digital conversion circuit and the control circuit.

8. The resistance test circuit of the distribution network equipment according to claim 1, wherein The distribution network equipment resistance test circuit further includes a key circuit connected to the control circuit and a display circuit connected to the control circuit; The key circuit is used to receive different test instructions, generate control logic according to the test instructions, and send the control logic to the control circuit, so that the control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit according to the control logic; The display circuit is used to display the resistance value of the corresponding resistance of the distribution network equipment calculated by the control circuit.

9. A method for testing the resistance of distribution network equipment, characterized in that, Applied to the distribution network equipment resistance test circuit according to any one of claims 1-8, the method includes: The control circuit controls the working mode of the power supply circuit and the selection mode of the selection circuit. The working mode includes a constant current source mode and a constant voltage source mode, and the selection mode includes a DC mode and an insulation mode; In the DC mode, the selection circuit enables the power supply circuit to be connected to the DC resistance in the distribution network equipment, or in the insulation mode, enables the power supply circuit to be connected to the insulation resistance of the distribution network equipment; In the constant current source mode, the power supply circuit provides a constant current source to the distribution network equipment, so that the distribution network equipment outputs an analog voltage signal, or in the constant voltage source mode, provides a constant voltage source to the distribution network equipment, so that the distribution network equipment outputs an analog current signal.

10. A resistance testing device for distribution network equipment, characterized in that, Including the distribution network equipment resistance test circuit according to any one of claims 1-8.

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