Coal mine intelligent power supply monitoring system feeder switch selective leakage protection circuit

Abstract

The application provides a coal mine intelligent power supply monitoring system feeder switch selective leakage protection circuit, and belongs to the technical field of coal mines. The coal mine intelligent power supply monitoring system feeder switch selective leakage protection circuit comprises an input cable, a transformer circuit is electrically connected to the input cable, three groups of SK switches are electrically connected to the transformer circuit, an A cable, a B cable and a C cable are respectively electrically connected to the three groups of SK switches, a total switch is electrically connected between the transformer circuit and the three groups of SK switches, a branch switch is electrically connected to one side of the total switch, a capacitor is electrically connected to the total switch, and one end of the capacitor is electrically connected to an auxiliary ground. The application avoids overstep tripping, ensures leakage protection safety, reduces repair time, and automatically attracts and resets in time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mines, in particular to a selective leakage protection circuit for a feeder switch of a coal mine intelligent power supply monitoring system. BACKGROUND

[0002] Due to the particularity of underground power supply in coal mines, leakage protection should be sensitive and reliable, and cannot misoperate. With the deepening of the underground mining field and the improvement of production capacity, the underground power supply distance is prolonged and tends to be complex, the low-voltage power supply line and load of the mining area transformer substation to the mining area head face are increased, the capacitive current of the power grid to the ground is increased, and the leakage protection of the total feeder switch is prone to misoperation. At present, the leakage protection of the underground transformer substation low-voltage power supply system cannot completely realize selectivity, and when the lower line fails, it causes "overstep" tripping (the total switch trips before the branch switch), which affects the power supply of other normal lines and cannot guarantee the protection reliability, affects production, and the longer the time for restoring power supply; the influence is particularly prominent for the head face with a long power supply line. In addition, when performing remote leakage test, "overstep" tripping occurs, which needs to be repeatedly operated, greatly prolongs the time for restoring power supply of the lower equipment, and becomes a "short board" of the coal mine intelligent power supply monitoring system. SUMMARY

[0003] In order to make up for the above shortcomings, the present application provides a selective leakage protection circuit for a feeder switch of a coal mine intelligent power supply monitoring system, which aims to improve the fact that the leakage protection of the underground transformer substation low-voltage power supply system cannot completely realize selectivity, and when the lower line fails, it causes "overstep" tripping (the total switch trips before the branch switch), which affects the power supply of other normal lines and cannot guarantee the protection reliability, affects production, and the longer the time for restoring power supply; the influence is particularly prominent for the head face with a long power supply line.

[0004] The present application provides a selective leakage protection circuit for a feeder switch of a coal mine intelligent power supply monitoring system, which includes an input cable, a transformer circuit is electrically connected to the input cable, three groups of SK switches are electrically connected to the transformer circuit, an A cable, a B cable and a C cable are respectively electrically connected to the three groups of SK switches, a total switch is electrically connected between the transformer circuit and the three groups of SK switches, a branch switch is electrically connected to one side of the total switch, a capacitor is electrically connected to the total switch, an auxiliary ground is electrically connected to one end of the capacitor, a current induction coil is inductively connected to the A cable, the B cable and the C cable, two groups of output ends are electrically connected to the current induction coil, an electric resistance is electrically connected to the C cable, an LS isolation module is electrically connected to the electric resistance, and the LS isolation module is electrically connected to the auxiliary ground.

[0005] In the implementation process, a 0.68 mu F non-polar capacitor is connected between the neutral point of the reactor in the leakage protection loop of the total switch of each low-voltage power supply system and the filter, so as to avoid the misoperation of the total switch, ensure the reliability of power supply, improve the accuracy of protection operation to cut off the fault line, avoid the "overstep" tripping to cause the loss of power of the normal line and affect the production, solve the "overstep" tripping during the remote leakage test, and greatly shorten the recovery time of the lower-level equipment to supply power, solve the big "short board" of the intelligent power supply monitoring system of the coal mine, meet the requirements of the selective leakage protection of the low-voltage power supply in the mine, ensure the reliability and selectivity of the power supply quality and protection, greatly improve the normal power supply operation of the equipment, and reduce the number of equipment downtime.

[0006] In a specific embodiment, one end of the transformer circuit is electrically connected to an auxiliary ground, and the voltage of the input coil of the transformer is 3-40V.

[0007] In the implementation process, low-voltage power supply can be realized, and the transformer circuit can be safely protected.

[0008] In a specific embodiment, an intelligent reset system is further included, the intelligent reset system includes a relay, the relay is connected to the total switch, and the relay is used for reverse attraction reset when the total switch trips to stabilize power supply.

[0009] In the implementation process, the relay can effectively realize the attraction reset of the total switch and realize automatic control and adjustment.

[0010] In a specific embodiment, a boost module is electrically connected to the relay, and the boost module is used to increase the power supply voltage, so that the relay can realize the attraction of the total switch.

[0011] In the implementation process, the setting of the boost module can supply power to the relay, so that the relay can realize the attraction reset of the total switch.

[0012] In a specific embodiment, one end of the capacitor is electrically connected to a current detection circuit, the current detection circuit is electrically connected to an amplification module, and the amplification module is electrically connected to a processing module.

[0013] In the implementation process, the current detection circuit is used to detect the current of the capacitor and amplify and process the current signal.

[0014] In a specific embodiment, the current detection circuit is used to detect the current on the capacitor, and when the total switch is off, the current detection circuit cannot detect the current signal at the connection point of the capacitor, or the current slowly and continuously decreases due to the energy storage characteristics of the capacitor, which proves that the total switch is off.

[0015] In the above implementation process, the on-off of the total switch is detected by the current detection circuit, which facilitates automatic control and adjustment.

[0016] In a specific embodiment, the amplification module is used to amplify the current signal detected by the current detection circuit, improve the stability of the current detection signal, and the processing module is used to convert the detected analog signal into a digital signal and filter the digital signal.

[0017] In the above implementation process, the initial current detection signal is small, and after amplification by the amplification module, interference and loss can be prevented, and the processing module can effectively convert and process the current signal.

[0018] In a specific embodiment, the processing module is electrically connected with a control module, the control module is electrically connected with a voltage regulation module, and the voltage regulation module is electrically connected with a power supply.

[0019] In the above implementation process, the control module can control and adjust the system, and the voltage regulation module can provide stable power supply.

[0020] In a specific embodiment, the voltage regulation module includes a step-down circuit, a voltage stabilizing circuit and a filter circuit, the power supply uses a lithium battery pack, and the voltage stabilizing circuit is used to stabilize the output voltage fluctuation of the lithium battery pack.

[0021] In the above implementation process, the step-down circuit can effectively reduce the voltage to prevent damage to the control module due to excessive voltage, and the voltage stabilizing circuit can maintain stable voltage output.

[0022] In a specific embodiment, the control module is electrically connected with an auxiliary module, the auxiliary module includes an alarm module and an indicator light, the alarm module uses an audible and visual alarm, the indicator light is used to display the running state of the total switch, and the auxiliary module further includes a storage module, the storage module includes a ROM storage module for storing running program and algorithm and a RAM storage module for storing running log.

[0023] In the above implementation process, the auxiliary module can increase the operation convenience of the system, can timely display the running state of the total switch and the on-off state of the total switch, and can keep the storage from being chaotic. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0025] Fig. 1 This is a schematic diagram of the circuit structure provided in the embodiments of this application;

[0026] Fig. 2 A schematic diagram of an intelligent reset system provided for an embodiment of this application. Detailed Implementation

[0027] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the equipment or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] Please see Figs. 1-2This application provides a selective leakage current protection circuit for a power supply switch in a coal mine intelligent power supply monitoring system, including an input cable. A transformer circuit is electrically connected to the input cable. Three sets of SK switches are electrically connected to the transformer circuit. A cable, a B cable, and a C cable are electrically connected to the three sets of SK switches, respectively. A main switch is electrically connected between the transformer circuit and the three sets of SK switches. A branch switch is electrically connected to one side of the main switch. A capacitor is electrically connected to the main switch, with one end of the capacitor electrically connected to auxiliary ground. Current sensing coils are inductively connected to the A, B, and C cables. Two sets of output terminals are electrically connected to the current sensing coils. A resistor is electrically connected to the C cable. An LS isolation module is electrically connected to the resistor, and the LS isolation module is electrically connected to auxiliary ground.

[0036] In the above implementation process, a 0.68μF non-polarized capacitor is connected to ground between the neutral point of the reactor and the filter in the leakage protection circuit of the main switch of each low-voltage power supply system. This avoids malfunction of the main switch, ensures the reliability of power supply, improves the accuracy of protection action in cutting off faulty lines, avoids "over-level" tripping that causes power loss to normal lines and affects production, solves the problem of "over-level" tripping during remote leakage tests that requires repeated operations, greatly shortens the power restoration time of downstream equipment, solves a major "shortcoming" of the coal mine intelligent power supply monitoring system, meets the requirements of selective leakage protection for underground low-voltage power supply, ensures power quality and the reliability and selectivity of protection, greatly improves the normal power supply operation of equipment, and reduces the number of times equipment stops without cause.

[0037] In this embodiment, one end of the transformer circuit is electrically connected to auxiliary ground, and the voltage of the input coil of the transformer is 3-40V, which can realize low-voltage power supply and can realize safety protection for the transformer circuit.

[0038] This application also includes an intelligent reset system, which includes a relay connected to the main switch. The relay is used to reverse-energize and reset the main switch when it trips, ensuring stable power supply. A boost module is electrically connected to the relay to increase the supply voltage, enabling the relay to activate the main switch. One end of the capacitor is electrically connected to a current detection circuit, which is electrically connected to an amplification module. A processing module is electrically connected to the amplification module. The current detection circuit detects the current in the capacitor. When the main switch is off, the current detection circuit... If no current signal is detected at the capacitor connection point, or if the current decreases slowly and continuously due to the capacitor's energy storage characteristics, it indicates that the main switch is open. The amplification module amplifies the current signal detected by the current detection circuit to improve its stability. The processing module converts the detected analog signal into a digital signal and filters the digital signal. The processing module is electrically connected to a control module, which in turn is electrically connected to a voltage regulation module. The voltage regulation module is electrically connected to a power supply. The voltage regulation module includes a step-down circuit, a voltage regulator circuit, and a filter circuit. The power supply uses a lithium battery pack. The circuit is used to stabilize the output voltage fluctuations of the lithium battery pack. The control module is electrically connected to an auxiliary module, which includes an alarm module and indicator lights. The alarm module uses an audible and visual alarm, and the indicator lights display the operating status of the main switch. The auxiliary module also includes a storage module, comprising a ROM storage module for storing the running program and algorithm, and a RAM storage module for storing the running log. The relay effectively activates and resets the main switch, enabling automated control and adjustment. The boost module provides power to the relay, allowing it to activate and reset the main switch. The current detection circuit monitors the capacitor's current. The system detects current and processes the current signal, using a current detection circuit to detect the on / off state of the main switch, facilitating automated control and adjustment. The initial current signal is relatively small; after amplification by the amplification module, interference and signal loss are prevented. The processing module effectively converts and processes the current signal. The control module controls and regulates the system, while a voltage regulation module provides stable power. A step-down circuit effectively reduces voltage to prevent damage to the control module from excessive voltage, and a voltage regulator maintains stable output voltage. An auxiliary module enhances the system's ease of operation, promptly displaying the main switch's operating status and on / off condition, and storing the information correctly.

[0039] Specifically, the working principle of the selective leakage current protection circuit of the feeder switch in this coal mine intelligent power supply monitoring system is as follows: During use, the system is induced to supply power through a transformer circuit. A 0.68μF non-polarized capacitor is connected to ground between the neutral point of the reactor and the filter in the leakage current protection circuit of the main switch of each low-voltage power supply system. This prevents malfunctions of the main switch, ensures the reliability of the power supply, improves the accuracy of the protection action in cutting off faulty lines, avoids "over-level" tripping causing power loss to normal lines and affecting production, and solves the problem of "over-level" tripping during remote leakage current testing, which previously required repeated operations. This significantly shortens the power restoration time for downstream equipment, addresses a major "shortcoming" of the coal mine intelligent power supply monitoring system, meets the requirements for selective leakage current protection in underground low-voltage power supply, ensures power quality and the reliability and selectivity of protection, greatly improves the normal power supply operation of equipment, reduces the number of unexplained equipment shutdowns, and typically connects an intelligent reset system to the capacitor. The intelligent reset system can detect and intelligently reset the tripping of the main switch.

[0040] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A selective leakage current protection circuit for the feeder switch of a coal mine intelligent power supply monitoring system, characterized in that, The system includes an input cable, to which a transformer circuit is electrically connected. Three sets of SK switches are electrically connected to the transformer circuit. A cable, a B cable, and a C cable are electrically connected to the three sets of SK switches respectively. A main switch is electrically connected between the transformer circuit and the three sets of SK switches. A branch switch is electrically connected to one side of the main switch. A capacitor is electrically connected to the main switch, with one end of the capacitor electrically connected to auxiliary ground. Current sensing coils are inductively connected to the A, B, and C cables. Two sets of output terminals are electrically connected to the current sensing coils. A resistor is electrically connected to the C cable, and an LS isolation module is electrically connected to the resistor. The LS isolation module is electrically connected to auxiliary ground. It also includes an intelligent reset system, which includes a relay connected to the main switch. The relay is used to reverse the circuit and reset the main switch when it trips, thus ensuring stable power supply. One end of the capacitor is electrically connected to a current detection circuit, the current detection circuit is electrically connected to an amplification module, and the amplification module is electrically connected to a processing module. The current detection circuit is used to detect the current on the capacitor. When the main switch is off, the current detection circuit cannot detect a current signal at the connection point between the capacitor and the capacitor, or the current decreases slowly and continuously due to the energy storage characteristics of the capacitor, which proves that the main switch is off.

2. The selective leakage protection circuit for the feeder switch of the intelligent power supply monitoring system for coal mines according to claim 1, characterized in that, One end of the transformer circuit is electrically connected to auxiliary ground, and the voltage of the input coil of the transformer is 3-40V.

3. The selective leakage current protection circuit for the feeder switch of the intelligent power supply monitoring system for coal mines according to claim 1, characterized in that, The relay is electrically connected to a boost module, which is used to increase the supply voltage so that the relay can activate the main switch.

4. The selective leakage protection circuit for the feeder switch of the intelligent power supply monitoring system for coal mines according to claim 1, characterized in that, The amplification module is used to amplify the current signal detected by the current detection circuit to improve the stability of the current detection signal. The processing module is used to convert the detected analog signal into a digital signal and to filter the digital signal.

5. The selective leakage protection circuit for the feeder switch of the intelligent power supply monitoring system in coal mines according to claim 4, characterized in that, The processing module is electrically connected to a control module, the control module is electrically connected to a voltage regulating module, and the voltage regulating module is electrically connected to a power supply.

6. The selective leakage current protection circuit for the feeder switch of the intelligent power supply monitoring system in coal mines according to claim 5, characterized in that, The voltage regulation module includes a step-down circuit, a voltage regulator circuit, and a filter circuit. The power supply is a lithium battery pack, and the voltage regulator circuit is used to stabilize the output voltage fluctuations of the lithium battery pack.

7. The selective leakage protection circuit for the feeder switch of the intelligent power supply monitoring system in coal mines according to claim 5, characterized in that, The control module is electrically connected to an auxiliary module, which includes an alarm module and an indicator light. The alarm module is an audible and visual alarm, and the indicator light is used to display the operating status of the main switch. The auxiliary module also includes a storage module, which includes a ROM storage module for storing the running program body and algorithm, and a RAM storage module for storing the running log.

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