Electric leakage detection system

Abstract

The utility model provides an electric leakage detection system. The electric leakage detection system comprises an electric leakage detection module configured to detect electric leakage current in the power distribution cabinet; the insulation detection module is configured to detect the insulation resistance of the power distribution cabinet; the humidity detection module is configured to detect the humidity in the power distribution cabinet; the output end of the electric leakage detection module, the output end of the insulation detection module and the output end of the humidity detection module are all connected with the controller; and the controller is connected with the display terminal through a communication module. According to the invention, early warning of the electric leakage fault can be realized.

Description

Technical Field

[0001] The present disclosure relates to the field of distribution automation technology, and in particular, to a leakage detection system. Background Art

[0002] As an important part of the power system, the distribution cabinet can distribute electric energy to each branch according to the needs of different electrical equipment, ensuring that each device can obtain the required voltage and current. Over time, the electrical equipment in the distribution cabinet will gradually age, the insulation performance will decline, and leakage faults are likely to occur. The leakage current may flow to the ground through the outer shell of the distribution cabinet, making the outer shell of the distribution cabinet charged, which poses a serious threat to the safety of operators. At the same time, the leakage current will also cause abnormal operation of the electrical equipment. By setting a leakage detection module in the distribution cabinet, the power supply of the distribution cabinet can be disconnected in time when a leakage fault occurs, thus protecting the safety of personnel and equipment, but it cannot play a role in early warning. Summary of the Utility Model

[0003] Embodiments of the present disclosure provide a leakage detection system to achieve early warning of leakage faults.

[0004] Embodiments of the present disclosure provide a leakage detection system, including:

[0005] A leakage detection module configured to detect the leakage current in the distribution cabinet;

[0006] An insulation detection module configured to detect the insulation resistance of the distribution cabinet;

[0007] A humidity detection module configured to detect the humidity in the distribution cabinet;

[0008] A controller, the output ends of the leakage detection module, the insulation detection module, and the humidity detection module are all connected to the controller;

[0009] A display terminal, the controller is connected to the display terminal through a communication module.

[0010] In an exemplary embodiment of the present disclosure, the insulation detection module includes a sampling resistor RC, a differential amplifier circuit, and a first amplifier circuit.

[0011] The sampling resistor RC is used to sample the insulation resistance of the distribution cabinet. The first input end of the differential amplifier circuit is connected to the first end of the sampling resistor RC, the second input end of the differential amplifier circuit is connected to the second end of the sampling resistor RC, the output end of the differential amplifier circuit is connected to the input end of the first amplifier circuit, and the output end of the first amplifier circuit is the output end of the insulation detection module.

[0012] In an exemplary embodiment of the present disclosure, the power supply terminal of the insulation detection module is connected to the incoming power supply of the power distribution cabinet through a first switch and a second switch in sequence.

[0013] The power supply terminal of the power distribution cabinet is connected to the incoming power supply of the power distribution cabinet through a third switch. The first switch and the third switch are interlocked and controlled, and the control terminal of the second switch is connected to the controller.

[0014] In an exemplary embodiment of the present disclosure, the humidity detection module includes a humidity sensor, a temperature detection circuit, and a subtraction circuit.

[0015] The humidity sensor is used to sense the humidity inside the power distribution cabinet, and the output terminal of the humidity sensor is connected to the first input terminal of the subtraction circuit.

[0016] The temperature detection circuit is used to sense the temperature inside the power distribution cabinet, and the output terminal of the temperature detection circuit is connected to the second input terminal of the subtraction circuit.

[0017] The output terminal of the subtraction circuit is the output terminal of the humidity detection module.

[0018] In an exemplary embodiment of the present disclosure, a second amplifier circuit is provided between the output terminal of the humidity sensor and the first input terminal of the subtraction circuit.

[0019] In an exemplary embodiment of the present disclosure, the temperature detection circuit includes a resistor R11 and a thermistor R12. The first end of the resistor R11 is connected to the output terminal of the second amplifier circuit, the second end of the resistor R11 is grounded through the thermistor R12, and the second end of the resistor R11 is the output terminal of the temperature detection circuit.

[0020] The working principle and beneficial effects of the leakage detection system provided by the embodiments of the present disclosure are as follows:

[0021] In the embodiments of the present disclosure, considering that too low insulation resistance inside the power distribution cabinet will increase the risk of leakage, and at the same time, too high humidity inside the power distribution cabinet will cause a decrease in insulation performance, thereby increasing the risk of leakage. Therefore, on the basis of setting a leakage detection module, the embodiments of the present disclosure also set an insulation detection module and a humidity detection module, and send the output data of the leakage detection module, the output data of the insulation detection module, and the output data of the humidity detection module to the display terminal together. Through the display terminal, the staff can not only understand the leakage situation inside the power distribution cabinet, but also understand the potential leakage risks and take measures in time. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is the circuit schematic diagram of the insulation detection module provided by the embodiment of the present disclosure;

[0024] Figure 2 is the circuit schematic diagram of the humidity detection module provided by the embodiment of the present disclosure. Specific embodiments

[0025] In order to enable those skilled in the art of this technology to better understand this solution, the following will clearly describe the technical solutions in the embodiments of this solution in conjunction with the drawings in the embodiments of this solution. Obviously, the described embodiments are part of the embodiments of this solution, rather than all of the embodiments. Based on the embodiments in this solution, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of protection of this solution.

[0026] The term "including" in the specification, claims, and the above-mentioned drawings of this solution, as well as any other variations, means "including but not limited to", intending to cover non-exclusive inclusion and not limited to the examples listed in the text. In addition, terms such as "first" and "second" are used to distinguish different objects, rather than to describe a specific order.

[0027] The following will describe the implementation of the present disclosure in detail in conjunction with specific drawings:

[0028] The leakage detection system includes:

[0029] A leakage detection module configured to detect the leakage current in the power distribution cabinet;

[0030] An insulation detection module configured to detect the insulation resistance of the power distribution cabinet;

[0031] A humidity detection module configured to detect the humidity in the power distribution cabinet;

[0032] A controller, the output terminals of the leakage detection module, the insulation detection module, and the humidity detection module are all connected to the controller;

[0033] A display terminal, the controller is connected to the display terminal through a communication module.

[0034] In this embodiment, considering that too low insulation resistance in the power distribution cabinet will increase the risk of electric leakage, and at the same time, too high humidity in the power distribution cabinet will lead to a decrease in insulation performance, thus increasing the risk of electric leakage. Therefore, on the basis of setting a leakage detection module, this embodiment of the present disclosure also sets an insulation detection module and a humidity detection module, and sends the output data of the leakage detection module, the output data of the insulation detection module, and the output data of the humidity detection module to the display terminal together. Through the display terminal, the staff can not only understand the electric leakage situation in the power distribution cabinet, but also understand the potential electric leakage risk, and take timely measures (such as replacing aging electrical components in time, or turning on the fan to reduce humidity, etc.) to avoid the occurrence of electric leakage faults.

[0035] Referring to Figure 1 , in an exemplary embodiment of the present disclosure, the insulation detection module includes a sampling resistor RC, a differential amplifier circuit, and a first amplifier circuit.

[0036] The sampling resistor RC is used to sample the insulation resistance of the power distribution cabinet. The first input terminal of the differential amplifier circuit is connected to the first end of the sampling resistor RC, the second input terminal of the differential amplifier circuit is connected to the second end of the sampling resistor RC, the output terminal of the differential amplifier circuit is connected to the input terminal of the first amplifier circuit, and the output terminal of the first amplifier circuit is the output terminal of the insulation detection module.

[0037] In this embodiment, a DC high-voltage generator is usually also provided inside the insulation detection module. The DC high voltage output by it is applied between the incoming power supply of the power distribution cabinet and the ground, and then the voltage across the sampling resistor RC or the current passing through the sampling resistor RC is measured, and the insulation resistance of the power distribution cabinet to the ground is calculated according to Ohm's law. For example, the sampling resistor RC and a known resistor can be used to form two arms of a bridge. One arm is composed of the sampling resistor and the insulation resistance of the power distribution cabinet, and the other arm is composed of the known resistor and the ground connection. The DC high-voltage generator is used to provide an excitation voltage for the bridge, and by measuring the voltage across the sampling resistor RC, the insulation resistance of the power distribution cabinet can be obtained.

[0038] The resistor R1, the resistor R2, the resistor R3, and the operational amplifier U1A constitute a differential amplifier circuit. The two ends of the sampling resistor RC are respectively connected to the first input terminal and the second input terminal of the differential amplifier circuit, and the output voltage of the differential amplifier circuit is proportional to the voltage of the sampling resistor RC.

[0039] The first amplifier circuit is used to convert the output voltage of the differential amplifier circuit to a set voltage level for accurate identification by the controller.

[0040] In this embodiment, the setting of the differential amplifier circuit and the first amplifier circuit realizes the automatic detection of the insulation resistance.

[0041] In an exemplary embodiment of the present disclosure, the power supply terminal of the insulation detection module is sequentially connected to the incoming power supply of the power distribution cabinet through a first switch and a second switch.

[0042] The power supply terminal of the power distribution cabinet is connected to the incoming power supply of the power distribution cabinet through a third switch. The first switch and the third switch are interlocked and controlled, and the control terminal of the second switch is connected to the controller.

[0043] In this embodiment, the first switch and the third switch are interlocked and controlled, that is, the first switch and the second switch cannot be closed simultaneously, so as to ensure the detection of the insulation resistance when the power distribution cabinet is powered off. Specifically, the normally open contact and the normally closed contact of the same relay can be used as the first switch and the third switch respectively to realize the interlock control of the first switch and the third switch.

[0044] When the power distribution cabinet is powered off (that is, the first switch is disconnected), the third switch is closed. At this time, the controller can control the second switch to close to connect the power supply of the insulation detection module and perform the detection of the insulation resistance.

[0045] In this embodiment, the settings of the first switch, the second switch and the third switch can ensure the safe detection of the insulation resistance.

[0046] Refer to Figure 2 In an exemplary embodiment of the present disclosure, the humidity detection module includes a humidity sensor, a temperature detection circuit and a subtraction circuit.

[0047] The humidity sensor is used to sense the humidity inside the power distribution cabinet, and the output terminal of the humidity sensor is connected to the first input terminal of the subtraction circuit.

[0048] The temperature detection circuit is used to sense the temperature inside the power distribution cabinet, and the output terminal of the temperature detection circuit is connected to the second input terminal of the subtraction circuit.

[0049] The output terminal of the subtraction circuit is the output terminal of the humidity detection module.

[0050] In this embodiment, considering that the detection accuracy of the humidity sensor will be affected by temperature. For example, for some polymer wet-sensitive materials, their moisture absorption and desorption capabilities are different at different temperatures. An increase in temperature may cause the moisture absorption of the material to increase or decrease, thereby affecting the response of the sensor to humidity. Therefore, in this embodiment, a temperature detection circuit is added to compensate the output result of the humidity sensor to improve the detection accuracy of the humidity detection module.

[0051] Specifically, resistor R13, resistor R14, resistor R7 and operational amplifier U2B form a subtraction circuit. The output voltage of the humidity sensor is connected to the first input terminal of the subtraction circuit, and the output voltage of the temperature detection circuit is connected to the second input terminal of the subtraction circuit. When the temperature rises, the output voltages of both the humidity sensor and the temperature detection circuit increase simultaneously, such that the output voltage of the subtraction circuit does not increase with the rising temperature. Conversely, when the temperature drops, the output voltages of both the humidity sensor and the temperature detection circuit decrease simultaneously, such that the output voltage of the subtraction circuit does not decrease with the dropping temperature.

[0052] In this embodiment, the setting of the temperature detection circuit and the subtraction circuit realizes the temperature compensation of the output voltage of the humidity sensor, which is beneficial to improving the accuracy of the humidity detection circuit.

[0053] Refer to Figure 2 , in an exemplary embodiment of the present disclosure, a second amplification circuit is provided between the output terminal of the humidity sensor and the first input terminal of the subtraction circuit.

[0054] In this embodiment, resistor R8, resistor R9, resistor R10 and operational amplifier U2A form a second amplification circuit (specifically a non-inverting proportional amplification circuit), which is used to convert the output voltage of the humidity sensor to a set voltage level for the convenience of subsequent circuit processing.

[0055] Refer to Figure 2 , in an exemplary embodiment of the present disclosure, the temperature detection circuit includes resistor R11 and thermistor R12. The first end of resistor R11 is connected to the output terminal of the second amplification circuit, the second end of resistor R11 is grounded through thermistor R12, and the second end of resistor R11 is the output terminal of the temperature detection circuit.

[0056] In this embodiment, the resistance value of thermistor R12 increases with the rising temperature. Resistor R11 and thermistor R12 form a series voltage division circuit, which is arranged between the second amplification circuit and the ground. The terminal voltage of thermistor R12 is the output terminal of the temperature detection circuit. When the temperature rises, the resistance value of thermistor R12 increases, the voltage division of thermistor R12 increases, and the output voltage of the temperature detection circuit increases; when the temperature drops, the resistance value of thermistor R12 decreases, the voltage division of thermistor R12 decreases, and the output voltage of the temperature detection circuit decreases.

[0057] In this embodiment, resistor R11 and thermistor R12 form a temperature detection circuit. By adjusting the resistance values of resistor R11 and thermistor R12, the output voltage of the temperature detection circuit can be adjusted. The circuit structure is simple and the operation is convenient.

[0058] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A leakage detection system, characterized in that: include: A leakage detection module is configured to detect leakage current in the power distribution cabinet; An insulation detection module is configured to detect the insulation resistance of the power distribution cabinet; A humidity detection module is configured to detect the humidity in the power distribution cabinet; A controller, to which the output end of the leakage detection module, the output end of the insulation detection module and the output end of the humidity detection module are all connected; The controller is connected to the display terminal via a communication module.

2. The leakage detection system according to claim 1, characterized in that: The insulation detection module includes a sampling resistor RC, a differential amplifier circuit and a first amplifier circuit. The sampling resistor RC is used to sample the insulation resistance of the distribution cabinet, the first input end of the differential amplifier circuit is connected to the first end of the sampling resistor RC, the second input end of the differential amplifier circuit is connected to the second end of the sampling resistor RC, the output end of the differential amplifier circuit is connected to the input end of the first amplifier circuit, and the output end of the first amplifier circuit is the output end of the insulation detection module.

3. The leakage detection system according to claim 2, characterized in that: The power supply end of the insulation detection module is connected to the incoming power supply of the power distribution cabinet through the first switch and the second switch in sequence. The power supply end of the distribution cabinet is connected to the incoming power supply of the distribution cabinet through a third switch, the first switch and the third switch are interlocked, and the control end of the second switch is connected to the controller.

4. The leakage detection system according to claim 1, characterized in that: The humidity detection module includes a humidity sensor, a temperature detection circuit and a subtraction circuit. The humidity sensor is used to sense the humidity in the power distribution cabinet, and the output end of the humidity sensor is connected to the first input end of the subtraction circuit. The temperature detection circuit is used to sense the temperature in the power distribution cabinet, and the output end of the temperature detection circuit is connected to the second input end of the subtraction circuit. The output end of the subtraction circuit is the output end of the humidity detection module.

5. The leakage detection system according to claim 4, characterized in that: A second amplifying circuit is arranged between the output end of the humidity sensor and the first input end of the subtraction circuit.

6. The leakage detection system according to claim 5, characterized in that: The temperature detection circuit includes a resistor R11 and a thermistor R12, wherein a first end of the resistor R11 is connected to an output end of the second amplifier circuit, a second end of the resistor R11 is grounded via the thermistor R12, and the second end of the resistor R11 is an output end of the temperature detection circuit.

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