A coal mine power supply current protection device

Abstract

The utility model discloses a coal mine power supply current protection device, which involves the field of coal mine current protection technology, including a power supply module for power supply; a protection control module for power transmission; a mining equipment module for connecting with mining equipment; a current sampling module for current sampling, signal amplification and conversion; a signal comparison module for setting an overcurrent threshold, performing a first-level voltage reduction and a second-level voltage reduction process on the overcurrent threshold and outputting a first voltage threshold and a second voltage threshold, and performing a voltage comparison between the first voltage threshold and the second voltage threshold and the overcurrent threshold; an overcurrent detection module for overcurrent judgment; a timing control module for setting a timing time; a signal processing module for detecting whether a current mutation occurs, and controlling the protection control module to cut off power when a current mutation occurs and an overcurrent occurs. The utility model coal mine power supply current protection device can avoid the situation where the current protection is not timely due to a current mutation, and if no mutation occurs, normal overcurrent protection is performed.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mine current protection, in particular to a coal mine power supply current protection device. Background Art

[0002] With the continuous development of mining level, the modernization level of coal mining is getting higher and higher. During mine production, more underground equipment is required, such as mine hoists, mine ventilators, mine lighting, etc. The normal operation of these equipment requires a stable power supply. In order to avoid damage to underground equipment caused by overcurrent, a power supply current protection device will be used to perform power-off protection when overcurrent occurs. The power supply current protection device in the prior art generally adopts a comparator, a reference power supply, etc. The overcurrent threshold is set by the reference power supply, so that the comparator can judge whether the sampled current exceeds the overcurrent threshold, and perform power-off protection when the overcurrent threshold is exceeded. However, when the underground equipment fails, the short-circuit current will rise rapidly and is prone to mutation, which may easily cause untimely overcurrent protection and pose certain safety hazards. Therefore, it needs to be improved. Utility Model Content

[0003] The embodiment of the utility model provides a coal mine power supply current protection device to solve the problems raised in the above background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A coal mine power supply current protection device, comprising: a power supply module, a protection control module, a mining equipment module, a current sampling module, a signal comparison module, an overcurrent detection module, a timing control module and a signal processing module;

[0006] A power module, used to access DC power;

[0007] A protection control module, connected to the power module, the signal processing module and the mining equipment module, for transmitting DC power to the mining equipment module and stopping the transmission of power upon receiving a first protection signal output by the signal processing module;

[0008] A mining equipment module, used to receive the DC power transmitted by the protection control module and to supply power to the connected mining equipment;

[0009] A current sampling module is connected to the mining equipment module, and is used to sample the electric energy current flowing through the mining equipment module and output a current signal, amplify and convert the current signal, and output a voltage signal;

[0010] A signal comparison module is connected to the power module and the current sampling module, and is used to set an overcurrent threshold, perform a primary voltage reduction and a secondary voltage reduction process on the overcurrent threshold and output a first voltage threshold and a second voltage threshold respectively, and output a second control signal when the voltage signal is greater than the first voltage threshold, and output a first control signal when the voltage signal is greater than the second voltage threshold;

[0011] An overcurrent detection module, connected to the current sampling module, and configured to output a third control signal when the voltage signal is greater than an overcurrent threshold;

[0012] A timing control module, connected to the signal comparison module, for outputting a high-level signal and setting a timing time, and when the duration of the received first control signal exceeds the timing time, stopping outputting the high-level signal and outputting a low-level signal;

[0013] The signal processing module is connected to the signal comparison module, the timing control module and the overcurrent detection module, and is used to perform signal self-locking and output a first protection signal when a high-level signal and a second control signal are received simultaneously or when a second control signal and a third control signal are received simultaneously.

[0014] As a further solution of the utility model: the power supply module includes a mining power supply interface, a first capacitor, a first voltage regulator and a second capacitor; the protection control module includes a first relay switch; the mining equipment module includes a mining equipment interface;

[0015] Preferably, the first end of the mining power interface is connected to one end of the first capacitor, the first end of the first voltage regulator and the moving end of the first relay switch, the fixed end of the first relay switch is connected to the first end of the mining equipment interface, the third end of the first voltage regulator is connected to the first end of the second capacitor and the signal comparison module, the second end of the mining power interface, the other end of the first capacitor, the second end of the first voltage regulator and the second end of the second capacitor are all grounded, and the second end of the mining equipment interface is connected to the current sampling module.

[0016] As a further solution of the utility model: the current sampling module includes a first resistor, a first operational amplifier, a second resistor and a third resistor;

[0017] Preferably, the in-phase end of the first operational amplifier is connected to the second end of the mining equipment interface and is grounded through a first resistor, the inverting end of the first operational amplifier is connected to one end of the third resistor and is grounded through a second resistor, and the other end of the third resistor is connected to the output end of the first operational amplifier, the signal comparison module and the overcurrent detection module.

[0018] As a further solution of the utility model: the signal comparison module includes a fourth resistor, a fifth resistor, a first diode, a second diode, a first comparator and a second comparator;

[0019] Preferably, the first end of the fourth resistor is connected to the first end of the second capacitor, the second end of the fourth resistor is connected to the anode of the first diode and grounded through the fifth resistor, the cathode of the first diode is connected to the inverting end of the second comparator and the anode of the second diode, the cathode of the second diode is connected to the inverting end of the first comparator, the in-phase end of the first comparator and the in-phase end of the second comparator are both connected to the output end of the first op amp, the output end of the second comparator is connected to the signal processing module, and the output end of the first comparator is connected to the timing control module.

[0020] As a further solution of the utility model: the signal processing module includes a fourth diode, a third diode, a fifth diode, a sixth diode and a first logic device;

[0021] Preferably, the anode of the fourth diode is connected to the output end of the second comparator, the cathode of the fourth diode is connected to the cathode of the sixth diode and the A end of the first logic device, the B end of the first logic device is connected to the cathode of the third diode and the cathode of the fifth diode, the anode of the fifth diode is connected to the F end of the first logic device, the anode of the sixth diode and the protection control module, and the anode of the third diode is connected to the timing control module.

[0022] As a further solution of the utility model: the overcurrent detection module includes a third comparator and a seventh diode;

[0023] Preferably, the inverting terminal and the non-inverting terminal of the third comparator are respectively connected to the output terminal of the first operational amplifier and the second end of the fourth resistor, the output terminal of the third comparator is connected to the anode of the seventh diode, and the cathode of the seventh diode is connected to the B terminal of the first logic device.

[0024] As a further solution of the utility model: the timing control module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first switch tube, a third capacitor and a second switch tube;

[0025] Preferably, the collector of the first switching tube is connected to one end of the eighth resistor and is connected to the third end of the first regulator through a sixth resistor, the other end of the eighth resistor is connected to the anode of the third diode and the collector of the second switching tube, the emitter of the first switching tube is connected to one end of the seventh resistor and one end of the third capacitor and is connected to the base of the second switching tube through a ninth resistor, the base of the first switching tube is connected to the output end of the first comparator, and the other end of the seventh resistor, the other end of the third capacitor and the emitter of the second switching tube are all grounded.

[0026] As a further solution of the utility model: the protection control module also includes a third switch tube, a first relay and a first power supply;

[0027] Preferably, the base of the third switch tube is connected to the F terminal of the first logic device, the emitter of the third switch tube is grounded, the collector of the third switch tube is connected to one end of the first relay, and the other end of the first relay is connected to the first power supply.

[0028] Compared with the prior art, the beneficial effects of the utility model are as follows: the coal mine power supply current protection device of the utility model can use the current sampling module to sample the current of the mining equipment module and amplify and convert the sampled signal, and the signal comparison module can perform two levels of voltage comparison processing on the converted signal, and cooperate with the timing time set by the timing control module to determine whether the current has a sudden change within the specified current range and timing time. When a sudden change occurs, the signal processing module performs signal self-locking and controls the power-off protection of the protection control module, and current protection can be performed in advance to avoid the situation where the current protection is not timely due to the sudden change of current. If no sudden change occurs, the overcurrent detection module performs normal overcurrent detection, and when overcurrent occurs, cooperates with the signal processing module to control the power-off work of the protection control module, thereby improving the safety of coal mine power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 The present invention provides a schematic block diagram of a coal mine power supply current protection device.

[0031] Figure 2 The present invention provides a circuit diagram of a coal mine power supply current protection device.

[0032] Figure 3 This is a connection circuit diagram of the protection control module provided by the example of the utility model. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] In one embodiment, see Figure 1, a coal mine power supply current protection device, comprising: a power supply module 1, a protection control module 2, a mining equipment module 3, a current sampling module 4, a signal comparison module 5, an overcurrent detection module 6, a timing control module 7 and a signal processing module 8;

[0035] Specifically, the power module 1 is used to access DC power;

[0036] The protection control module 2 is connected to the power module 1, the signal processing module 8 and the mining equipment module 3, and is used to transmit DC power to the mining equipment module 3, and stop the transmission of power when receiving the first protection signal output by the signal processing module 8;

[0037] The mining equipment module 3 is used to receive the DC power transmitted by the protection control module 2 and supply power to the connected mining equipment;

[0038] The current sampling module 4 is connected to the mining equipment module 3, and is used to sample the electric energy current flowing through the mining equipment module 3 and output a current signal, amplify and convert the current signal and output a voltage signal;

[0039] A signal comparison module 5 is connected to the power module 1 and the current sampling module 4, and is used to set an overcurrent threshold, perform a primary voltage reduction and a secondary voltage reduction process on the overcurrent threshold and output a first voltage threshold and a second voltage threshold respectively, and output a second control signal when the voltage signal is greater than the first voltage threshold, and output a first control signal when the voltage signal is greater than the second voltage threshold;

[0040] An overcurrent detection module 6, connected to the current sampling module 4, for outputting a third control signal when the voltage signal is greater than an overcurrent threshold;

[0041] A timing control module 7, connected to the signal comparison module 5, for outputting a high-level signal and setting a timing time, and when the duration of the received first control signal exceeds the timing time, stopping outputting the high-level signal and outputting a low-level signal;

[0042] The signal processing module 8 is connected to the signal comparison module 5, the timing control module 7 and the overcurrent detection module 6, and is used to perform signal self-locking and output a first protection signal when a high-level signal and a second control signal are received simultaneously or when a second control signal and a third control signal are received simultaneously.

[0043] In a specific embodiment, the power supply module 1 can adopt a power supply circuit composed of a mining power supply interface, a capacitor and a voltage stabilizer, can access DC power and perform voltage stabilization and filtering on the DC power; the protection control module 2 can adopt a protection control circuit composed of relays, transistors, etc., and can control the transmission state of electric energy according to the level state of the signal output by the signal processing module 8; the mining equipment module 3 can adopt a mining equipment module 3 composed of a mining equipment interface to receive electric energy and transmit the received electric energy to the connected mining equipment; the current sampling module 4 can adopt a current sampling circuit composed of a resistor and an operational amplifier, can sample the electric energy current flowing through the mining equipment module 3, and amplify and convert the sampled signal into voltage; the signal comparison module 5 can adopt a signal comparison circuit composed of a resistor, a diode and a comparator, can set an overcurrent threshold, and perform a primary voltage reduction and a secondary voltage reduction process on the overcurrent threshold to provide a first voltage threshold and a second voltage threshold; the overcurrent detection module 6 can adopt an overcurrent detection circuit composed of a comparator and a diode, and perform overcurrent detection in conjunction with the overcurrent threshold; the timing control module 7 can adopt a timing control circuit composed of a transistor, a capacitor, a resistor, etc., the capacitor conducts electric energy, and then sets the timing time according to the conduction state of the transistor; the signal processing module 8 can adopt a signal processing circuit composed of a diode and a logic chip, and can judge whether a current mutation occurs according to the state of the signal output by the signal comparison module 5, and control the operation of the protection control module 2 according to the signal output by the overcurrent detection module 6.

[0044] In another embodiment, see Figure 1 , Figure 2 and Figure 3 The power module 1 includes a mining power interface, a first capacitor C1, a first voltage regulator IC1 and a second capacitor C2; the protection control module 2 includes a first relay switch K1-1; the mining equipment module 1 includes a mining equipment interface;

[0045] Specifically, the first end of the mining power interface is connected to one end of the first capacitor C1, the first end of the first voltage regulator IC1 and the moving end of the first relay switch K1-1, the fixed end of the first relay switch K1-1 is connected to the first end of the mining equipment interface, the third end of the first voltage regulator IC1 is connected to the first end of the second capacitor C2 and the signal comparison module 5, the second end of the mining power interface, the other end of the first capacitor C1, the second end of the first voltage regulator IC1 and the second end of the second capacitor C2 are all grounded, and the second end of the mining equipment interface is connected to the current sampling module 4.

[0046] In a specific embodiment, the first voltage regulator IC1 may be a 7805 voltage regulator; the first relay switch K1 - 1 may be a normally closed switch.

[0047] Further, the current sampling module 4 includes a first resistor R1, a first operational amplifier OP1, a second resistor R2 and a third resistor R3;

[0048] Specifically, the in-phase end of the first operational amplifier OP1 is connected to the second end of the mining equipment interface and is grounded through the first resistor R1, the inverting end of the first operational amplifier OP1 is connected to one end of the third resistor R3 and is grounded through the second resistor R2, and the other end of the third resistor R3 is connected to the output end of the first operational amplifier OP1, the signal comparison module 5 and the overcurrent detection module 6.

[0049] In a specific embodiment, the first resistor R1 can be used as a current sampling resistor; the first operational amplifier OP1 can be an OP07 operational amplifier, which cooperates with the first resistor R1, the second resistor R2 and the third resistor R3 to amplify and convert the input signal into voltage.

[0050] Further, the signal comparison module 5 includes a fourth resistor R4, a fifth resistor R5, a first diode D1, a second diode D2, a first comparator A1 and a second comparator A2;

[0051] Specifically, the first end of the fourth resistor R4 is connected to the first end of the second capacitor C2, the second end of the fourth resistor R4 is connected to the anode of the first diode D1 and grounded through the fifth resistor R5, the cathode of the first diode D1 is connected to the inverting end of the second comparator A2 and the anode of the second diode D2, the cathode of the second diode D2 is connected to the inverting end of the first comparator A1, the in-phase end of the first comparator A1 and the in-phase end of the second comparator A2 are both connected to the output end of the first operational amplifier OP1, the output end of the second comparator A2 is connected to the signal processing module 8, and the output end of the first comparator A1 is connected to the timing control module 7.

[0052] In a specific embodiment, the fourth resistor R4 and the fifth resistor R5 provide an overcurrent threshold; the first diode D1 performs a first-level voltage reduction process on the overcurrent threshold to provide a first voltage threshold, and the second diode D2 performs a second-level voltage reduction process on the first voltage threshold to provide a second voltage threshold; the first comparator A1 and the second comparator A2 can both use LM358 comparators.

[0053] Further, the signal processing module 8 includes a fourth diode D4, a third diode D3, a fifth diode D5, a sixth diode D6 and a first logic device U1;

[0054] Specifically, the anode of the fourth diode D4 is connected to the output end of the second comparator A2, the cathode of the fourth diode D4 is connected to the cathode of the sixth diode D6 and the A end of the first logic device U1, the B end of the first logic device U1 is connected to the cathode of the third diode D3 and the cathode of the fifth diode D5, the anode of the fifth diode D5 is connected to the F end of the first logic device U1, the anode of the sixth diode D6 and the protection control module 2, and the anode of the third diode D3 is connected to the timing control module 7.

[0055] In a specific embodiment, the first logic device U1 can be an AND gate chip, which can cooperate with the fourth diode D4, the third diode D3, the fifth diode D5 and the sixth diode D6 to perform high-level self-locking on the input signal.

[0056] Further, the overcurrent detection module 6 includes a third comparator A3 and a seventh diode D7;

[0057] Specifically, the inverting terminal and the non-inverting terminal of the third comparator A3 are respectively connected to the output terminal of the first operational amplifier OP1 and the second terminal of the fourth resistor R4, the output terminal of the third comparator A3 is connected to the anode of the seventh diode D7, and the cathode of the seventh diode D7 is connected to the B terminal of the first logic device U1.

[0058] In a specific embodiment, the third comparator A3 can be a LM358 comparator.

[0059] Further, the timing control module 7 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first switch tube V1, a third capacitor C3 and a second switch tube V2;

[0060] Specifically, the collector of the first switch tube V1 is connected to one end of the eighth resistor R8 and is connected to the third end of the first regulator IC1 through the sixth resistor R6, the other end of the eighth resistor R8 is connected to the anode of the third diode D3 and the collector of the second switch tube V2, the emitter of the first switch tube V1 is connected to one end of the seventh resistor R7 and one end of the third capacitor C3 and is connected to the base of the second switch tube V2 through the ninth resistor R9, the base of the first switch tube V1 is connected to the output end of the first comparator A1, and the other end of the seventh resistor R7, the other end of the third capacitor C3 and the emitter of the second switch tube V2 are all grounded.

[0061] In a specific embodiment, the first switch tube V1 and the second switch tube V2 can both be NPN-type triodes. The first switch tube V1 is turned on and provides electrical energy to the third capacitor C3. The third electrical energy is used to store energy. When the electrical energy of the third electrical energy is stored to the turn-on voltage of the second switch tube V2, the second switch tube V2 will be triggered to turn on. The time consumed in this process is the timing time.

[0062] Furthermore, the protection control module 2 also includes a third switch tube V3, a first relay K1 and a first power supply VCC1;

[0063] Specifically, the base of the third switch tube V3 is connected to the F terminal of the first logic device U1, the emitter of the third switch tube V3 is grounded, the collector of the third switch tube V3 is connected to one end of the first relay K1, and the other end of the first relay K1 is connected to the first power supply VCC1.

[0064] In a specific embodiment, the third switch tube V3 may be an NPN transistor; the first relay K1 controls the disconnection of the first relay switch K1 - 1 by magnetic attraction.

[0065] In a coal mine power supply current protection device of the present embodiment, DC power is connected to the mining power interface, and then transmitted to the mining equipment interface through the first relay switch K1-1, so as to power the mining equipment connected to the mining equipment interface. The first voltage stabilizer IC1 performs voltage stabilization processing, and the first resistor R1 samples the electric energy current flowing through the mining equipment. The first operational amplifier OP1 cooperates with the second resistor R2 and the third resistor R3 to amplify the sampled signal and convert it into a voltage signal. At the same time, the fourth resistor R4 and the fifth resistor R5 set the overcurrent threshold. The overcurrent threshold is respectively subjected to the primary step-down and the secondary step-down processing by the first diode D1 and the second diode D2, and the first voltage threshold and the second voltage threshold are output respectively. When the voltage signal is greater than the second voltage threshold, the first comparator A1 outputs a high level, which triggers the first switch tube V1 to turn on, and the third capacitor C3 stores energy. During the period when the electric energy stored in C3 reaches the turn-on voltage of the second switch tube V2 after being stepped down by the ninth resistor R9, if the voltage signal is greater than the first voltage threshold, the second comparator A2 will output a high level. At this time, both the A and B ends of the first logic chip are high levels, and the third diode D3, the fourth diode D4, the fifth diode D5 and the sixth diode D6 are cooperated to perform high-level self-locking and control the third switch tube V3 to be turned on, so that the first relay K1 is energized and controls the first relay switch K1-1 to be disconnected. If the electric energy stored in the third electric energy triggers the second switch tube V2 to be turned on, the second comparator A2 does not output a high level. At this time, the anode of the third diode D3 is a low level until the voltage signal is greater than the overcurrent threshold. The third comparator A3 outputs a high level, which will trigger the first logic chip to self-lock and control the third switch tube V3 to be turned on, and the first relay switch K1-1 is disconnected to stop power supply.

[0066] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0067] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A coal mine power supply current protection device, characterized in that: The coal mine power supply current protection device comprises: a power supply module, a protection control module, a mining equipment module, a current sampling module, a signal comparison module, an overcurrent detection module, a timing control module and a signal processing module; The power module is used to access direct current power; The protection control module is connected to the power supply module, the signal processing module and the mining equipment module, and is used to transmit DC power to the mining equipment module, and stop the transmission of power when receiving the first protection signal output by the signal processing module; The mining equipment module is used to receive the DC power transmitted by the protection control module and supply power to the connected mining equipment; The current sampling module is connected to the mining equipment module, and is used to sample the electric energy current flowing through the mining equipment module and output a current signal, amplify and convert the current signal, and output a voltage signal; The signal comparison module is connected to the power module and the current sampling module, and is used to set the overcurrent threshold, perform primary and secondary voltage reduction processing on the overcurrent threshold and output the first voltage threshold and the second voltage threshold respectively, and output the second control signal when the voltage signal is greater than the first voltage threshold, and output the first control signal when the voltage signal is greater than the second voltage threshold; The overcurrent detection module is connected to the current sampling module and is used to output a third control signal when the voltage signal is greater than the overcurrent threshold; The timing control module is connected to the signal comparison module, and is used to output a high-level signal and set a timing time, and when the duration of the received first control signal exceeds the timing time, stop outputting the high-level signal and output a low-level signal; The signal processing module is connected to the signal comparison module, the timing control module and the overcurrent detection module, and is used to perform signal self-locking and output a first protection signal when a high-level signal and a second control signal are received simultaneously or when a second control signal and a third control signal are received simultaneously.

2. A coal mine power supply current protection device according to claim 1, characterized in that: The power supply module includes a mining power supply interface, a first capacitor, a first voltage regulator and a second capacitor; the protection control module includes a first relay switch; the mining equipment module includes a mining equipment interface; The first end of the mining power interface is connected to one end of the first capacitor, the first end of the first voltage regulator and the moving end of the first relay switch, the fixed end of the first relay switch is connected to the first end of the mining equipment interface, the third end of the first voltage regulator is connected to the first end of the second capacitor and the signal comparison module, the second end of the mining power interface, the other end of the first capacitor, the second end of the first voltage regulator and the second end of the second capacitor are all grounded, and the second end of the mining equipment interface is connected to the current sampling module.

3. A coal mine power supply current protection device according to claim 2, characterized in that: The current sampling module includes a first resistor, a first operational amplifier, a second resistor and a third resistor; The in-phase end of the first operational amplifier is connected to the second end of the mining equipment interface and is grounded through the first resistor, the inverting end of the first operational amplifier is connected to one end of the third resistor and is grounded through the second resistor, and the other end of the third resistor is connected to the output end of the first operational amplifier, the signal comparison module and the overcurrent detection module.

4. A coal mine power supply current protection device according to claim 3, characterized in that: The signal comparison module includes a fourth resistor, a fifth resistor, a first diode, a second diode, a first comparator and a second comparator; The first end of the fourth resistor is connected to the first end of the second capacitor, the second end of the fourth resistor is connected to the anode of the first diode and grounded through the fifth resistor, the cathode of the first diode is connected to the inverting end of the second comparator and the anode of the second diode, the cathode of the second diode is connected to the inverting end of the first comparator, the non-inverting end of the first comparator and the non-inverting end of the second comparator are both connected to the output end of the first operational amplifier, the output end of the second comparator is connected to the signal processing module, and the output end of the first comparator is connected to the timing control module.

5. A coal mine power supply current protection device according to claim 4, characterized in that: The signal processing module includes a fourth diode, a third diode, a fifth diode, a sixth diode and a first logic device; The anode of the fourth diode is connected to the output end of the second comparator, the cathode of the fourth diode is connected to the cathode of the sixth diode and the A end of the first logic device, the B end of the first logic device is connected to the cathode of the third diode and the cathode of the fifth diode, the anode of the fifth diode is connected to the F end of the first logic device, the anode of the sixth diode and the protection control module, and the anode of the third diode is connected to the timing control module.

6. A coal mine power supply current protection device according to claim 5, characterized in that: The overcurrent detection module includes a third comparator and a seventh diode; The inverting terminal and the non-inverting terminal of the third comparator are respectively connected to the output terminal of the first operational amplifier and the second terminal of the fourth resistor, the output terminal of the third comparator is connected to the anode of the seventh diode, and the cathode of the seventh diode is connected to the B terminal of the first logic device.

7. A coal mine power supply current protection device according to claim 5, characterized in that: The timing control module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first switch tube, a third capacitor and a second switch tube; The collector of the first switch tube is connected to one end of the eighth resistor and is connected to the third end of the first regulator through the sixth resistor, the other end of the eighth resistor is connected to the anode of the third diode and the collector of the second switch tube, the emitter of the first switch tube is connected to one end of the seventh resistor and one end of the third capacitor and is connected to the base of the second switch tube through the ninth resistor, the base of the first switch tube is connected to the output end of the first comparator, and the other end of the seventh resistor, the other end of the third capacitor and the emitter of the second switch tube are all grounded.

8. A coal mine power supply current protection device according to claim 5, characterized in that: The protection control module also includes a third switch tube, a first relay and a first power supply; The base of the third switch tube is connected to the F terminal of the first logic device, the emitter of the third switch tube is grounded, the collector of the third switch tube is connected to one end of the first relay, and the other end of the first relay is connected to the first power supply.

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