An insulation resistance detection system and method

Abstract

The present invention discloses a detection system for insulation resistance, including: an acquisition device and a control device; the acquisition device includes an acquisition circuit, which is used to connect to a measurement object and output a measurement voltage corresponding to the measurement object measured by a bridge method to the control device; the control device connected to the acquisition device is used to control the resistance value of a variable resistor in the acquisition circuit and the reference voltage value of a variable power supply, and calculate the insulation resistance value of the measurement object according to the measurement voltage; the present invention controls the resistance value of a variable resistor in the acquisition circuit and the reference voltage value of a variable power supply through a control device, and can realize variable range, multi-voltage input and multi-bridge measurement, so that after multiple measurements, the measurement range can be adjusted to fully match the insulation resistance value of the measurement object, thereby improving the measurement accuracy and applicability and enhancing the user experience. In addition, the present invention also discloses a detection method for insulation resistance, which also has the above-mentioned beneficial effects.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical safety detection, and in particular to a detection system and method for insulation resistance. Background Art

[0002] With the continuous updating and expansion of modern technology, higher requirements are also put forward for the reliability of power systems and high-voltage equipment. Accidents or damages of electrical equipment are usually closely related to insulation defects. The large capacity, high voltage, diversified structure and sealing of electrical equipment should put forward newer and higher requirements for electrical equipment. The use of large-capacity equipment is increasing, and its insulation performance cannot be tested with ordinary megohmmeters.

[0003] In the prior art, the power test regulations require a series of insulation performance tests for numerous power equipment such as cables, motors, generators, transformers, mutual inductors, high-voltage switches, and lightning arresters, which require the use of insulation testers. The detection method of traditional insulation testers requires setting a fixed voltage and measurement range. However, the measurement range of the insulation resistance of the above-mentioned power equipment often ranges from a few K to several G. The single voltage and measurement range of the existing insulation tester is difficult to accurately measure different power equipment with large differences in insulation resistance (insulation resistance value), resulting in low measurement accuracy.

[0004] Therefore, how to automatically adjust the measurement range so that it can match the insulation resistance of the measured object (power equipment), improve measurement accuracy and applicability, and enhance user experience is an urgent problem that needs to be solved today. Summary of the invention

[0005] The purpose of the present invention is to provide a detection system and method for insulation resistance, so as to automatically adjust the measurement range so that it can match the insulation resistance value of the measurement object, thereby improving the measurement accuracy and applicability.

[0006] In order to solve the above technical problems, the present invention provides an insulation resistance detection system, comprising: a collection device and a control device;

[0007] The acquisition device includes an acquisition circuit, which is used to connect to the measurement object and output a measurement voltage corresponding to the measurement object measured by the bridge method to the control device;

[0008] The control device connected to the acquisition device is used to control the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply, and calculate the insulation resistance value of the measured object according to the measured voltage.

[0009] Optionally, the acquisition circuit includes: a first variable resistor, a second variable resistor, a third variable resistor, a fourth variable resistor and a variable power supply circuit;

[0010] Wherein, the first end of the first variable resistor is used to be connected to the first end of the measured object, the second end of the first variable resistor is connected to the first end of the second variable resistor, and their common end is connected to the output end of the variable power supply circuit, the first end of the third variable resistor is used to be connected to the second end of the measured object, the second end of the third variable resistor is connected to the first end of the fourth variable resistor, and their common end is used to be connected to the input end of the control device to output the measurement voltage to the control device, and the second end of the second variable resistor is connected to the second end of the fourth variable resistor, and their common end is grounded;

[0011] Correspondingly, the control device is specifically used to control the resistance values ​​of the first variable resistor, the second variable resistor, the third variable resistor and the fourth variable resistor and the reference voltage value of the variable power supply circuit.

[0012] Optionally, the first variable resistor, the second variable resistor, the third variable resistor and the fourth variable resistor are all specifically variable digital resistors, and the variable power supply circuit is specifically a variable digital power supply circuit.

[0013] Optionally, the acquisition device further includes:

[0014] The amplifier circuit is used to amplify the measurement voltage and output the amplified measurement voltage to the control device; wherein the measurement voltage output terminal of the acquisition circuit is connected to the input terminal of the control device through the amplifier circuit.

[0015] Optionally, the system further includes:

[0016] The human-computer interaction device connected to the control device is used to display the insulation resistance value using a display component, generate corresponding control parameters according to user operations using an operating device, and send them to the control component.

[0017] Optionally, the system further includes:

[0018] The communication device connected to the control device is used to send the insulation resistance value to the corresponding terminal.

[0019] In addition, the present invention also provides an insulation resistance detection method, which is applied to the insulation resistance detection system as described in any one of the above items, comprising:

[0020] After the acquisition circuit is connected to the measurement object, the current measurement voltage sent by the acquisition circuit is obtained;

[0021] Determining whether the current measured voltage is within a measurement range corresponding to a current reference voltage value and / or a current resistance value;

[0022] If not, then according to the current measurement voltage, calculate and adjust the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply, and perform the step of obtaining the current measurement voltage sent by the acquisition circuit;

[0023] If so, the insulation resistance value of the measured object is calculated according to the current measured voltage, the current reference voltage value and the current resistance value.

[0024] Optionally, the calculating and adjusting the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measured voltage includes:

[0025] According to the current measurement voltage and the measurement range, a next measurement range is selected, and the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply are adjusted to the resistance value and voltage value corresponding to the next measurement range.

[0026] Optionally, the calculating and adjusting the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measured voltage includes:

[0027] If the current measured voltage is greater than the maximum value of the measurement range, a next resistance value is calculated, and the resistance value of the variable resistor in the acquisition circuit is adjusted to the next resistance value; wherein the next resistance value is less than the current resistance value;

[0028] If the current measured voltage is less than the minimum value of the measurement range, a next resistance value is calculated, and the resistance value of the variable resistor in the acquisition circuit is adjusted to the next resistance value; wherein the next resistance value is greater than the current resistance value.

[0029] Optionally, after calculating the insulation resistance value of the measured object according to the current measured voltage, the current reference voltage value and the current resistance value, the method further includes:

[0030] Determining whether the insulation resistance value is less than a preset warning value;

[0031] If so, the dangerous circuit corresponding to the measured object is disconnected, and an alarm is issued using human-computer interaction equipment and communication equipment.

[0032] The present invention provides an insulation resistance detection system, comprising: a collection device and a control device; the collection device comprises a collection circuit, which is used to connect with a measurement object and output a measurement voltage corresponding to the measurement object measured by a bridge method to the control device; the control device connected to the collection device is used to control the resistance value of a variable resistor in the collection circuit and the reference voltage value of a variable power supply, and calculate the insulation resistance value of the measurement object according to the measurement voltage;

[0033] It can be seen that the present invention can realize variable range, multi-voltage input and multi-bridge measurement by controlling the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply through the control device, so that the measurement range can be adjusted to fully match the insulation resistance value of the measured object after multiple measurements, thereby improving the measurement accuracy and applicability and enhancing the user experience. In addition, the present invention also provides a method for detecting insulation resistance, which also has the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0035] Figure 1 A structural block diagram of an insulation resistance detection system provided by an embodiment of the present invention;

[0036] Figure 2 A circuit diagram of a collection circuit of an insulation resistance detection system provided by an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of a detection process of an insulation resistance detection system provided by an embodiment of the present invention;

[0038] Figure 4 The present invention provides a flowchart of a method for detecting insulation resistance. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Please refer to Figure 1 , Figure 1 This is a structural block diagram of an insulation resistance detection system provided by an embodiment of the present invention. The system may include: a collection device 10 and a control device 20;

[0041] The acquisition device 10 includes an acquisition circuit, which is used to connect to the measurement object and output a measurement voltage corresponding to the measurement object measured by the bridge method to the control device 20;

[0042] The control device 20 connected to the acquisition device 10 is used to control the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply, and calculate the insulation resistance value of the measurement object according to the measured voltage.

[0043] Among them, the acquisition circuit in the acquisition device 10 in this embodiment can be a circuit composed of a variable resistor and a variable power supply. When the circuit is connected to the measurement object (such as an electric power device), the bridge method can be used to measure the measurement voltage corresponding to the measurement object and output it to the control device 20. Specifically, the specific circuit structure of the acquisition circuit composed of a variable resistor and a variable power supply in the acquisition device 10 can be set by the designer according to practical scenarios and user needs, such as Figure 2 As shown, the acquisition device 10 may include four variable resistors, namely a first variable resistor (R1), a second variable resistor (R2), a third variable resistor (R3) and a fourth variable resistor (R4), and a variable power supply circuit that outputs a reference voltage (Uref) at an output end; wherein the first end of the first variable resistor is used to connect to the first end of the measurement object (Rx), the second end of the first variable resistor is connected to the first end of the second variable resistor, and their common end is connected to the output end of the variable power supply circuit, the first end of the third variable resistor is used to connect to the second end of the measurement object, the second end of the third variable resistor is connected to the first end of the fourth variable resistor, and their common end is used to connect to the input end of the control device 20, outputting the measurement voltage (Ux) to the control device 20, and the second end of the second variable resistor is connected to the second end of the fourth variable resistor, and their common end is grounded. As long as the control device 20 can calculate the insulation resistance value of the measurement object according to the measurement voltage sent by the acquisition device 10, this embodiment does not impose any restrictions on this.

[0044] It can be understood that the purpose of this embodiment is to control the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply through the control device 20 connected to the acquisition device 10, such as controlling Figure 2 The resistance values ​​of R1, R2, R3 and R4 and the reference voltage value (Uref) output by the variable power supply circuit make the measurement range of the insulation resistance of the measurement object of the system provided by this embodiment variable (variable range), the reference voltage value variable (multi-voltage input) and the resistance value of the variable resistor variable (multi-bridge measurement), so that the control device 20 can adjust the measurement range to fully match the insulation resistance of the measurement object after multiple measurements, thereby improving the measurement accuracy. Specifically, the specific structural types of the variable resistor and the variable power supply in the acquisition circuit of this embodiment can be set by the designer, such as Figure 2The four variable resistors R1, R2, R3 and R4 are all set as variable digital resistors, and the variable power supply is set as a variable digital power supply circuit that outputs a reference voltage. As long as the control device 20 can control the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply, this embodiment does not impose any restrictions on this.

[0045] Specifically, the control device 20 such as a processor in this embodiment can calculate the insulation resistance value of the measured object according to the measured voltage. The specific calculation method can be set by the designer. Since the control device 20 can control the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply, the control device 20 can determine the resistance value of the variable resistor and the reference voltage value of the variable power supply corresponding to the received measured voltage. The acquisition device 10 includes Figure 2 When the acquisition circuit is shown, the control device can calculate the insulation resistance value (Rx) of the measured object by the following formula. This embodiment does not impose any limitation on this.

[0046]

[0047] Correspondingly, in order to facilitate the control device 20 to receive the measurement voltage output by the acquisition circuit in the acquisition device 10, the acquisition device 10 in this embodiment may further include an amplifier circuit for amplifying the measurement voltage, so that the control device 20 can receive the amplified measurement voltage, that is, the measurement voltage output terminal of the acquisition circuit is connected to the input terminal of the control device 20 through the amplifier circuit, such as Figure 2 The common end connected to the third variable resistor (R3) and the fourth variable resistor (R4) can be used as the measurement voltage output end of the acquisition circuit, and connected to the input end of the control device 20 through the amplifier circuit. Correspondingly, the control device 20 can determine the measurement voltage before amplification according to the amplification factor of the amplifier circuit.

[0048] Furthermore, in order to facilitate users to understand the usage of the system provided by this embodiment, as shown in FIG. Figure 1 The system provided in the embodiment may further include a human-machine interaction device 30 connected to the control device 20, which is used to display the insulation resistance value using a display component. That is, the human-machine interaction device 30 may be provided with a display device such as a display screen, which displays the insulation resistance value of the measured object calculated by the control device 20. Specifically, the specific content displayed by the display component in the human-machine interaction device 30 may be set by the designer. It may only display the insulation resistance value of the measured object calculated by the control device 20, or it may display the resistance value of the variable resistor in the acquisition circuit set by the control device 20 (such as Figure 2 The resistance value of R1-R4 in the figure), the reference voltage value of the variable power supply (such as Figure 2 The voltage value of Uref in the Figure 2 The voltage value of Ux in FIG. 1 is not limited in this embodiment.

[0049] Correspondingly, such as Figure 1 As described, the system provided in the embodiment may further include a communication device 40 connected to the control device 20, for sending the insulation resistance value to the corresponding terminal. For example, the control device 10 may send the calculated insulation resistance value and other parameters of the measured object (such as the resistance value of the variable resistor, the reference voltage value and the measured voltage value of the variable power supply, etc.) to the display of the human-computer interaction device 30 and the communication device 40, respectively, and the communication device uploads it to the terminal (such as the cloud platform) of the preset communication address, so that the user can obtain the measurement status of the measured object regardless of whether the user is near or far from the display device.

[0050] It should be noted that, in order to ensure the safety of the measured object, the control device 20 provided in this embodiment can also control the controllable switches such as AC contactors and relays in the dangerous circuit corresponding to the measured object when the insulation resistance value of the measured object is less than the preset warning value, cut off the dangerous circuit, and the human-computer interaction device 30 and the communication device 40 give an alarm. That is, the control device 20 can also be connected to the control end of the controllable switch in the dangerous circuit corresponding to the measured object. Among them, the above-mentioned dangerous circuit can be a circuit that is prone to safety hazards when the insulation resistance value of the measured object is less than the preset warning value.

[0051] Correspondingly, the human-computer interaction device 30 in this embodiment may also include an operating device such as a key device, so as to generate corresponding control parameters (such as factory settings and preset warning values) according to user operations and send them to the control component 20. Correspondingly, the human-computer interaction device 30 may also be connected to the communication device 40, so as to send the preset communication address set by the user using the operating device to the communication device 40.

[0052] Specifically, the specific process of calculating the insulation resistance value of the measured object by the system provided in this embodiment can be as follows: Figure 3 As shown, firstly, the factory settings and preset warning values ​​and communication address and other parameters are set, and then the control device 20 automatically sets the resistance value of the variable resistor in the acquisition circuit (bridge resistance, such as Figure 2 After the system is initialized, the control device 20 receives the measured voltage output by the acquisition circuit and determines whether the measured voltage is within the measurement range; if not, the resistance value of the variable resistor and the reference voltage value of the variable power supply are calculated; if yes, the insulation resistance value of the measured object is calculated, and it is determined whether the insulation resistance value is less than the preset warning value (insulation warning); if less than, an alarm is issued and the dangerous circuit corresponding to the measured object is disconnected; if not less than, the process is terminated or the insulation resistance value is displayed. This embodiment does not impose any restrictions on this.

[0053] Correspondingly, when measuring the insulation resistance of the object to be measured in a high-voltage environment, the insulation resistance is relatively high at this time, the system initialization is completed, the control device 20 collects the measurement voltage, the measurement voltage at this time will be too small, increase the bridge resistance, measure again until the measurement voltage is within the optimal range, and then calculate the insulation resistance. When measuring the insulation resistance of the object to be measured in a low-voltage environment, the insulation resistance is relatively low at this time, the system initialization is completed, the control device 20 collects the measurement voltage, the measurement voltage at this time will be too large, reduce the bridge resistance, measure again until the voltage value is within the optimal range, and then calculate the insulation resistance.

[0054] In this embodiment, the embodiment of the present invention controls the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply by the control device, so as to realize variable range, multi-voltage input and multi-bridge measurement, so that after multiple measurements, the measurement range can be adjusted to fully match the insulation resistance of the measured object, thereby improving the measurement accuracy and applicability and enhancing the user experience.

[0055] Based on the above examples, please refer to Figure 4 , Figure 4 This is a flow chart of a method for detecting insulation resistance provided by an embodiment of the present invention. The method can be applied to the insulation resistance detection system provided by the above embodiment, and may include:

[0056] Step 101: After the acquisition circuit is connected to the measurement object, the current measurement voltage sent by the acquisition circuit is obtained.

[0057] The current measured voltage in this step may be the measured voltage value currently received by a control device such as a processor in the insulation resistance detection system. Correspondingly, this step may also include setting the current resistance value of the variable resistor in the acquisition circuit (such as Figure 2 The resistance values ​​of R1-R4 in the figure) and the current reference voltage value of the variable power supply (such as Figure 2 The step of determining the voltage value of Uref in the variable resistor (the voltage value of Uref in the variable resistor) enables the acquisition circuit to send the current measured voltage to the control device when the variable resistor is at the current resistance value and the variable power supply is at the current reference voltage value.

[0058] Step 102: determine whether the current measured voltage is within the measurement range corresponding to the current reference voltage value and / or the current resistance value; if not, proceed to step 103; if yes, proceed to step 104.

[0059] It can be understood that the current reference voltage value and the current resistance value in this step can be the reference voltage value of the variable power supply and the resistance value of the variable resistor corresponding to the current measurement voltage output by the acquisition circuit. The measurement range corresponding to the current reference voltage value and / or the current resistance value in this step can be set by the designer according to the practical scenario and user needs, and can be a fixed measurement range; it can also be a measurement range corresponding to the current reference voltage value or the current resistance value, such as the measurement range changes accordingly with the change of the current reference voltage value or the current resistance value; it can also be a measurement range corresponding to the current reference voltage value and the current resistance value, such as the measurement range changes accordingly with the change of the current reference voltage value and the current resistance value. This embodiment does not impose any restrictions on this.

[0060] Step 103: Calculate and adjust the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measured voltage, and enter step 101.

[0061] It can be understood that the purpose of this step is to adjust the measured voltage value collected at the next moment by calculating and adjusting the resistance value of the variable resistor and / or the reference voltage value of the variable power supply in the acquisition circuit when the measured voltage value collected at the current moment is not in the optimal measurement range, until the measured voltage value collected is in the optimal measurement range.

[0062] Specifically, the specific method for the control device in this step to calculate and adjust the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measurement voltage can be set by the designer according to the practical scenario and user needs. For example, when multiple measurement ranges and the resistance value of the variable resistor and the reference voltage value of the variable power supply corresponding to each measurement range are pre-set, this step can select the next measurement range according to the current measurement voltage and measurement range, and adjust the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply to the resistance value and voltage value corresponding to the next measurement range. When setting a measurement range, this step can first determine whether the current measurement voltage is greater than the maximum value of the measurement range or less than the minimum value of the measurement range. If the current measurement voltage is greater than the maximum value of the measurement range, the next resistance value is calculated, and the resistance value of the variable resistor in the acquisition circuit is adjusted to the next resistance value; wherein the next resistance value is less than the current resistance value; if the current measurement voltage is less than the minimum value of the measurement range, the next resistance value is calculated, and the resistance value of the variable resistor in the acquisition circuit is adjusted to the next resistance value; wherein the next resistance value is greater than the current resistance value. This embodiment does not impose any restrictions on this.

[0063] Step 104: Calculate the insulation resistance value of the measured object according to the current measured voltage, the current reference voltage value and the current resistance value.

[0064] It can be understood that the purpose of this step is to calculate the insulation resistance value of the measured object according to the current measured voltage, the current reference voltage value and the current resistance value when the measured voltage value collected at the current moment is within the optimal measurement range.

[0065] Specifically, the specific method for the control device in this step to calculate the insulation resistance value of the measured object according to the current measured voltage, the current reference voltage value and the current resistance value can be set by the designer. For example, if the current measured voltage is Figure 2 When the measured voltage value (Ux) output by the acquisition circuit is not amplified by the amplification circuit, the insulation resistance value (Rx) of the measured object can be directly calculated by the following formula:

[0066]

[0067] Among them, R1 to R4 are the resistance values ​​of four variable resistors in the acquisition circuit respectively, and Uref is the reference voltage value of the variable power supply.

[0068] When the current measured voltage is the measured voltage value after amplification by the amplifier circuit, the control device can first determine the measured voltage value before amplification according to the amplification factor of the amplifier circuit, and then control the resistance value of the variable resistor in the acquisition circuit controlled by itself (such as Figure 2 The resistance value of R1-R4 in the figure) and the reference voltage value of the variable power supply (such as Figure 2 The insulation resistance value of the measured object is calculated by using the voltage value of Uref in the measurement. This embodiment does not impose any restriction on this.

[0069] Correspondingly, in order to enable the user to understand the calculated insulation resistance value of the measured object, this step may also include the step of using a display device in the human-computer interaction device to display the insulation resistance value and other parameters of the measured object (such as the resistance value of the variable resistor, the reference voltage value and the measured voltage value of the variable power supply, etc.), and the step of using a communication device to send the insulation resistance value and other parameters of the measured object to a corresponding terminal.

[0070] It should be noted that, in order to ensure the safety of the measured object, the method provided in this embodiment can also control the controllable switches such as AC contactors and relays in the dangerous circuit corresponding to the measured object when the insulation resistance value of the measured object is less than the preset warning value, cut off the dangerous circuit, and alarm the display device and communication device in the human-computer interaction device. That is, after this step, it can include the steps of determining whether the insulation resistance value is less than the preset warning value; if so, disconnecting the dangerous circuit corresponding to the measured object, and using the human-computer interaction device and the communication device to alarm.

[0071] In this embodiment, the embodiment of the present invention calculates and adjusts the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measured voltage.

[0072] In this embodiment, when the current measurement voltage is not within the measurement range corresponding to the current reference voltage value and / or the current resistance value, the embodiment of the present invention calculates and adjusts the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measurement voltage, thereby realizing variable range, multi-voltage input and multi-bridge measurement of the insulation resistance of the measurement object, so that after multiple measurements, the measurement range can be adjusted to fully match the insulation resistance of the measurement object, thereby improving measurement accuracy and applicability and enhancing user experience.

[0073] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other. For the method disclosed in the embodiment, since it corresponds to the system disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the system description.

[0074] The above is a detailed introduction to the insulation resistance detection system and method provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An insulation resistance detection system, characterized in that: include: Acquisition equipment and control equipment; The acquisition device includes an acquisition circuit, which is used to connect to the measurement object and output a measurement voltage corresponding to the measurement object measured by the bridge method to the control device; The control device connected to the acquisition device is used to control the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply, and calculate the insulation resistance value of the measurement object according to the measurement voltage; Wherein, the acquisition circuit includes: a first variable resistor, a second variable resistor, a third variable resistor, a fourth variable resistor and a variable power supply circuit; Wherein, the first end of the first variable resistor is used to be connected to the first end of the measured object, the second end of the first variable resistor is connected to the first end of the second variable resistor, and their common end is connected to the output end of the variable power supply circuit, the first end of the third variable resistor is used to be connected to the second end of the measured object, the second end of the third variable resistor is connected to the first end of the fourth variable resistor, and their common end is used to be connected to the input end of the control device to output the measurement voltage to the control device, and the second end of the second variable resistor is connected to the second end of the fourth variable resistor, and their common end is grounded; Correspondingly, the control device is specifically used to control the resistance values ​​of the first variable resistor, the second variable resistor, the third variable resistor and the fourth variable resistor and the reference voltage value of the variable power supply circuit; The first variable resistor, the second variable resistor, the third variable resistor and the fourth variable resistor are all specifically variable digital resistors, and the variable power supply circuit is specifically a variable digital power supply circuit; Also includes: The human-computer interaction device connected to the control device is used to display the insulation resistance value using a display component, generate corresponding control parameters according to user operations using an operating device, and send them to the control device.

2. The insulation resistance detection system according to claim 1, characterized in that: The acquisition device further includes: an amplifier circuit, used for amplifying the measurement voltage and outputting the amplified measurement voltage to the control device; wherein the measurement voltage output terminal of the acquisition circuit is connected to the input terminal of the control device through the amplifier circuit; The communication device connected to the control device is used to send the insulation resistance value to the corresponding terminal.

3. A method for detecting insulation resistance, characterized in that: The insulation resistance detection system as claimed in claim 1 or 2 comprises: After the acquisition circuit is connected to the measurement object, the current measurement voltage sent by the acquisition circuit is obtained; Determining whether the current measured voltage is within a measurement range corresponding to a current reference voltage value and / or a current resistance value; If not, then according to the current measurement voltage, calculate and adjust the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply, and perform the step of obtaining the current measurement voltage sent by the acquisition circuit; If so, the insulation resistance value of the measured object is calculated according to the current measured voltage, the current reference voltage value and the current resistance value.

4. The method for detecting insulation resistance according to claim 3, characterized in that: The step of calculating and adjusting the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measured voltage includes: According to the current measurement voltage and the measurement range, a next measurement range is selected, and the resistance value of the variable resistor in the acquisition circuit and the reference voltage value of the variable power supply are adjusted to the resistance value and voltage value corresponding to the next measurement range.

5. The method for detecting insulation resistance according to claim 3, characterized in that: The step of calculating and adjusting the resistance value of the variable resistor in the acquisition circuit and / or the reference voltage value of the variable power supply according to the current measured voltage includes: If the current measured voltage is greater than the maximum value of the measurement range, a next resistance value is calculated, and the resistance value of the variable resistor in the acquisition circuit is adjusted to the next resistance value; wherein the next resistance value is less than the current resistance value; If the current measured voltage is less than the minimum value of the measurement range, a next resistance value is calculated, and the resistance value of the variable resistor in the acquisition circuit is adjusted to the next resistance value; wherein the next resistance value is greater than the current resistance value.

6. The method for detecting insulation resistance according to any one of claims 3 to 5, characterized in that: After calculating the insulation resistance value of the measured object according to the current measured voltage, the current reference voltage value and the current resistance value, the method further includes: Determining whether the insulation resistance value is less than a preset warning value; If so, the dangerous circuit corresponding to the measured object is disconnected, and an alarm is issued using human-computer interaction equipment and communication equipment.

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