An insulation detection circuit and device based on unbalanced bridge mode

Abstract

The utility model discloses an insulation detection circuit and device based on unbalanced bridge mode, insulation detection circuit includes power, upper bridge arm, lower bridge arm and the first switch of connecting between upper bridge arm and lower bridge arm, one end of upper bridge arm is connected with the positive pole of power, one end of lower bridge arm is connected with the negative pole of power, and upper bridge arm includes first resistance to be measured, second switch and first voltage dividing resistance, and lower bridge arm includes second resistance to be measured, third switch and third voltage dividing resistance. The efficient, stable, sensitive insulation detection scheme based on unbalanced electric bridge mode of the application can monitor the insulation state of electrical equipment under complex environment in real time, and through effective signal processing, the safety and reliability of equipment are improved.

Description

Technical Field

[0001] This utility model relates to an insulation detection circuit and device based on an unbalanced bridge mode. Background Technology

[0002] As the safety requirements of power and electronic equipment continue to increase, the monitoring of insulation performance is becoming increasingly important. Traditional insulation testing methods typically employ balanced bridge mode or simple resistance measurement methods. These methods have poor sensitivity and interference resistance, making it difficult to accurately identify minute insulation changes in complex electrical environments. Utility Model Content

[0003] The main objective of this invention is to provide an insulation detection circuit and device based on an unbalanced bridge mode, in order to solve the aforementioned technical problems.

[0004] To achieve the above objectives, this utility model proposes an insulation detection circuit based on an unbalanced bridge mode, comprising a power supply, an upper bridge arm, a lower bridge arm, and a first switch connected between the upper bridge arm and the lower bridge arm. One end of the upper bridge arm is connected to the positive terminal of the power supply, and one end of the lower bridge arm is connected to the negative terminal of the power supply. The upper bridge arm includes a first resistor to be measured, a second switch, and a first voltage divider resistor, and the lower bridge arm includes a second resistor to be measured, a third switch, and a second voltage divider resistor.

[0005] In one embodiment, the first terminal of the first switch is connected between the first resistor under test and the second resistor under test, and the second terminal of the first switch is connected to the first terminal of the second switch and the second terminal of the second voltage divider resistor.

[0006] In one embodiment, the second terminal of the second switch is connected to the first terminal of the first voltage divider resistor, and the second terminal of the first voltage divider resistor is connected to the positive terminal of the power supply.

[0007] In one embodiment, the first end of the second voltage divider resistor is connected to the second end of the third switch, and the first end of the third switch is connected to the negative terminal of the power supply.

[0008] In one embodiment, the insulation detection circuit based on the unbalanced bridge mode further includes a first voltage divider circuit and a second voltage divider circuit, which are connected in parallel to the power supply.

[0009] In one embodiment, the first voltage divider circuit includes a third voltage divider resistor, a fourth voltage divider resistor, a fifth voltage divider resistor, and a sixth voltage divider resistor connected in series, and the second terminal of the first switch is connected between the fourth voltage divider resistor and the fifth voltage divider resistor.

[0010] In one embodiment, the second voltage divider circuit includes a seventh voltage divider resistor and an eighth voltage divider resistor connected in series.

[0011] In addition, this utility model also provides an insulation detection device based on an unbalanced bridge mode, which includes the insulation detection circuit based on the unbalanced bridge mode as described above.

[0012] In this invention, the insulation detection circuit based on an unbalanced bridge mode includes a power supply, an upper bridge arm, a lower bridge arm, and a first switch connected between the upper and lower bridge arms. One end of the upper bridge arm is connected to the positive terminal of the power supply, and one end of the lower bridge arm is connected to the negative terminal of the power supply. The upper bridge arm includes a first resistor to be measured, a second switch, and a first voltage divider resistor. The lower bridge arm includes a second resistor to be measured, a third switch, and a second voltage divider resistor. This application provides a highly efficient, stable, and sensitive insulation detection scheme based on an unbalanced bridge mode, which can monitor the insulation status of electrical equipment in complex environments in real time. Through effective signal processing, it improves the safety and reliability of the equipment. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the insulation detection circuit based on the unbalanced bridge mode according to an embodiment of the present invention.

[0015] Explanation of the reference numerals: R1, first voltage divider resistor; R2, second voltage divider resistor; R3, third voltage divider resistor; R4, fourth voltage divider resistor; R5, fifth voltage divider resistor; R6, sixth voltage divider resistor; R7, seventh voltage divider resistor; R8, eighth voltage divider resistor; Rp, first resistor under test; Rn, second resistor under test; K1, first switch; K2, second switch; K3, third switch.

[0016] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0019] Furthermore, in this utility model, the use of terms such as "first," "second," etc., is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0020] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0021] This invention provides an insulation detection circuit based on an unbalanced bridge mode.

[0022] like Figure 1 As shown, the insulation detection circuit based on unbalanced bridge mode provided in this embodiment of the present invention includes a power supply, an upper bridge arm, a lower bridge arm, and a first switch K1 connected between the upper bridge arm and the lower bridge arm. One end of the upper bridge arm is connected to the positive terminal of the power supply, and one end of the lower bridge arm is connected to the negative terminal of the power supply. The upper bridge arm includes a first resistor to be measured Rp, a second switch K2, and a first voltage divider resistor R1. The lower bridge arm includes a second resistor to be measured Rn, a third switch K3, and a second voltage divider resistor R2.

[0023] In this embodiment, the efficient, stable, and sensitive insulation detection scheme based on the unbalanced bridge mode can monitor the insulation status of electrical equipment in complex environments in real time, and improve the safety and reliability of the equipment through effective signal processing.

[0024] This application changes the equivalent resistance of the two electrodes to ground by switching the second switch K2 and the third switch K3, thereby obtaining the unbalanced detection voltage on the positive and negative detection resistors and calculating the insulation resistance of the positive and negative electrodes. The insulation resistance to be measured will change with the insulation state, causing the voltage output of the bridge circuit to change, thus providing a monitoring signal.

[0025] For example, the system uses an ADC to sample signals to ensure real-time performance and accuracy. The acquired digital signals are filtered for noise reduction. Through algorithm analysis, changes in insulation resistance can be obtained in real time. Differential signal transmission is employed to minimize the impact of external electromagnetic interference. Furthermore, the system incorporates multi-stage filtering circuits to further reduce noise, improve measurement accuracy, and enhance system reliability. It is understood that existing circuit structures can be used for signal sampling, noise reduction, and transmission; these will not be elaborated upon in this application.

[0026] Specifically, the first end of the first switch K1 is connected between the first resistor under test Rp and the second resistor under test Rn, and the second end of the first switch K1 is connected to the first end of the second switch K2 and the second end of the second voltage divider resistor R2.

[0027] The second terminal of the second switch K2 is connected to the first terminal of the first voltage divider resistor R1, and the second terminal of the first voltage divider resistor R1 is connected to the positive terminal of the power supply. The first terminal of the second voltage divider resistor R2 is connected to the second terminal of the third switch K3, and the first terminal of the third switch K3 is connected to the negative terminal of the power supply.

[0028] The insulation detection circuit based on the unbalanced bridge mode further includes a first voltage divider circuit and a second voltage divider circuit, which are connected in parallel to the power supply. The first voltage divider circuit includes a third voltage divider resistor R3, a fourth voltage divider resistor R4, a fifth voltage divider resistor R5, and a sixth voltage divider resistor R6 connected in series. The second terminal of the first switch K1 is connected between the fourth voltage divider resistor R4 and the fifth voltage divider resistor R5. The second voltage divider circuit includes a seventh voltage divider resistor R7 and an eighth voltage divider resistor R8 connected in series.

[0029] Based on the above embodiments, the detection process of the insulation detection circuit of this application is as follows:

[0030] All initialization is completed when the vehicle is powered on;

[0031] When the insulation detection circuit is not working, the first switch K1, the second switch K2, and the third switch K3 are disconnected to avoid the influence of circuit parameters on the insulation performance of the whole machine.

[0032] When the test begins, the first switch K1 is closed, the voltage values ​​across the 5-ohm resistors of the upper and lower bridge arms are sampled, the voltage of the upper and lower bridge arms is obtained, and an equation is written according to Kirchhoff's Current Law (KCL).

[0033] If the voltage of the upper bridge arm is greater than that of the lower bridge arm, close the second switch K2, measure the voltage of the upper and lower bridge arms again, and write an equation according to Kirchhoff's Current Law (KCL). Combine the equation from the previous step with the equation to calculate the second resistance to be measured, Rn.

[0034] If the voltage of the upper bridge arm is less than or equal to the voltage of the lower bridge arm, close the third switch K3, remeasure the voltage of the upper and lower bridge arms, and write an equation according to Kirchhoff's Current Law (KCL). Combine this equation with the previous equation to calculate the first resistance to be measured, Rp.

[0035] Finally, the insulation condition is determined based on the insulation resistance value.

[0036] The first switch K1, the second switch K2, and the third switch K3 are all disconnected, and the insulation detection circuit stops working.

[0037] Furthermore, this utility model also provides an insulation detection device based on an unbalanced bridge mode, which includes the insulation detection circuit based on the unbalanced bridge mode as described above. Since this insulation detection device adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0038] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An insulation detection circuit based on an unbalanced bridge mode, characterized in that, The insulation detection circuit based on unbalanced bridge mode includes a power supply, an upper bridge arm, a lower bridge arm, and a first switch connected between the upper bridge arm and the lower bridge arm. One end of the upper bridge arm is connected to the positive terminal of the power supply, and one end of the lower bridge arm is connected to the negative terminal of the power supply. The upper bridge arm includes a first resistor to be tested, a second switch, and a first voltage divider resistor. The lower bridge arm includes a second resistor to be tested, a third switch, and a second voltage divider resistor.

2. The insulation detection circuit based on unbalanced bridge mode according to claim 1, characterized in that, The first terminal of the first switch is connected between the first resistor to be tested and the second resistor to be tested, and the second terminal of the first switch is connected to the first terminal of the second switch and the second terminal of the second voltage divider resistor.

3. The insulation detection circuit based on unbalanced bridge mode according to claim 2, characterized in that, The second terminal of the second switch is connected to the first terminal of the first voltage divider resistor, and the second terminal of the first voltage divider resistor is connected to the positive terminal of the power supply.

4. The insulation detection circuit based on unbalanced bridge mode according to claim 3, characterized in that, The first end of the second voltage divider resistor is connected to the second end of the third switch, and the first end of the third switch is connected to the negative terminal of the power supply.

5. The insulation detection circuit based on unbalanced bridge mode according to claim 1, characterized in that, The insulation detection circuit based on the unbalanced bridge mode further includes a first voltage divider circuit and a second voltage divider circuit, which are connected in parallel to the power supply.

6. The insulation detection circuit based on unbalanced bridge mode according to claim 5, characterized in that, The first voltage divider circuit includes a third voltage divider resistor, a fourth voltage divider resistor, a fifth voltage divider resistor, and a sixth voltage divider resistor connected in series, and the second terminal of the first switch is connected between the fourth voltage divider resistor and the fifth voltage divider resistor.

7. The insulation detection circuit based on unbalanced bridge mode according to claim 5, characterized in that, The second voltage divider circuit includes a seventh voltage divider resistor and an eighth voltage divider resistor connected in series.

8. An insulation detection device based on an unbalanced bridge mode, characterized in that, The insulation detection device based on unbalanced bridge mode includes the insulation detection circuit based on unbalanced bridge mode as described in any one of claims 1-7.

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