Middle and low voltage distribution safety operation management system in mining area

Abstract

The utility model provides a mining area medium and low voltage distribution safe operation management system. The mining area medium and low voltage distribution safety operation management system comprises a soft start circuit, the soft start circuit comprises a bidirectional thyristor and a trigger circuit, the trigger circuit comprises a rectifier bridge, a first voltage acquisition circuit, a first subtraction circuit, a diode D7, a second subtraction circuit and a trigger board, and the input end of the rectifier bridge is connected with an AC power supply. The first voltage acquisition circuit is configured to acquire the output voltage of the rectifier bridge, the output end of the first voltage acquisition circuit is connected to the first input end of the first subtraction circuit, the second input end of the first subtraction circuit is connected with a reference voltage, and the output end of the first subtraction circuit is connected to the anode of the diode D7; the cathode of the diode D7 is connected to the first input end of the second subtraction circuit, and the second input end of the second subtraction circuit is connected with the first signal output end of the controller. The protection effect of the soft starter in the power distribution system can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of power distribution automation technology, and in particular to a low-voltage power distribution safety operation management system in a mining area. Background Art

[0002] Mining operations require the use of high-power electrical equipment such as hoists, ventilators, and crushers. These electrical equipment have large starting currents, which can cause a significant impact on the equipment. Therefore, soft starters are usually used to start these electrical equipment. Soft starters can gradually increase the supply voltage when the equipment starts, allowing the equipment to start smoothly.

[0003] A soft starter usually includes a bidirectional thyristor and a trigger circuit, in which the bidirectional thyristor is connected to the power supply circuit of the electrical equipment. By inputting a gradually increasing command signal into the trigger circuit, the trigger circuit can be controlled to output a corresponding trigger pulse to the control end of the bidirectional thyristor, thereby controlling the conduction angle of the bidirectional thyristor to gradually increase, and the power supply voltage of the electrical equipment to gradually increase, so that the electrical equipment can be started smoothly.

[0004] When the grid voltage is normal, the soft starter can effectively protect the electrical equipment from the impact of large current. However, when the grid voltage fluctuates greatly, for example, when the grid voltage is too high, a large current impact will still occur during the soft start process. Utility Model Content

[0005] The embodiments of the present disclosure provide a low-voltage power distribution safety operation management system in a mining area to improve the protection effect of a soft starter in a power distribution system.

[0006] The embodiment of the present disclosure provides a safe operation management system for low-voltage power distribution in a mining area, including a soft start circuit, the soft start circuit including a bidirectional thyristor and a trigger circuit, the trigger circuit including a rectifier bridge, a first voltage acquisition circuit, a first subtraction circuit, a diode D7, a second subtraction circuit and a trigger board.

[0007] The first end of the bidirectional thyristor is used to connect to the AC power supply, and the second end of the bidirectional thyristor is used to connect to the power supply end of the electrical equipment;

[0008] The input end of the rectifier bridge is connected to the AC power supply. The first voltage acquisition circuit is configured to collect the output voltage of the rectifier bridge. The output end of the first voltage acquisition circuit is connected to the first input end of the first subtraction circuit. The second input end of the first subtraction circuit is connected to the reference voltage. The output end of the first subtraction circuit is connected to the anode of the diode D7. The cathode of the diode D7 is connected to the first input end of the second subtraction circuit. The second input end of the second subtraction circuit is connected to the first signal output end of the controller. The output end of the second subtraction circuit is connected to the signal input end of the trigger board. The trigger board is used to control the trigger angle of the bidirectional thyristor.

[0009] In an exemplary embodiment of the present disclosure, the first voltage acquisition circuit includes a resistor R1 and a resistor R2, the first end of the resistor R1 is connected to the first output end of the rectifier bridge, the second end of the resistor R1 is connected to the second output end of the rectifier bridge through the resistor R2, and the second end of the resistor R1 is the output end of the first voltage acquisition circuit.

[0010] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes a first switch, a second switch, and a second voltage acquisition circuit.

[0011] The second voltage acquisition circuit is configured to acquire an AC power supply voltage. The first switch is configured to be connected in parallel with both ends of the bidirectional thyristor. The second switch is connected in series in the trigger circuit. The first switch and the second switch are interlocked.

[0012] The controller is configured as:

[0013] When the electrical equipment is started, the first switch is controlled to be opened and the second switch is controlled to be closed;

[0014] After the electric equipment is started, the first switch is controlled to be closed and the second switch is controlled to be opened;

[0015] When the AC power supply voltage is greater than a first set value, the second switch is controlled to be closed and the first switch is controlled to be opened.

[0016] In an exemplary embodiment of the present disclosure, the first switch is a normally open contact of the first relay, the second switch is a normally closed contact of the first relay, and the control end of the first relay is connected to the second signal output end of the controller.

[0017] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes a backup power supply and a transfer switch.

[0018] The first input end of the switch is connected to the AC power supply, the second end of the switch is connected to the backup power supply, the output end of the switch is connected to the power supply end of the electrical equipment, and the control end of the switch is connected to the third signal output end of the controller.

[0019] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes a reactive power compensation module, which is connected in parallel with the AC power supply.

[0020] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes:

[0021] The leakage protection module is used to cut off the line power supply when a leakage fault occurs.

[0022] The working principle and beneficial effects of the low-voltage power distribution safety operation management system for mining areas provided by the embodiments of the present disclosure are as follows:

[0023] In the disclosed embodiment, a rectifier bridge converts the voltage of an AC power source into a DC voltage, which can represent the voltage of the AC power source. A first voltage acquisition circuit is used to acquire the output voltage of the rectifier bridge. The output voltage of the first voltage acquisition circuit is connected to a first input terminal of a first subtraction circuit. The second input terminal of the first subtraction circuit is connected to a reference voltage, and the first subtraction circuit outputs the difference between the voltages at the two input terminals.

[0024] When the AC power supply voltage is normal, the output voltage of the rectifier bridge is less than the reference voltage, the output voltage of the first subtraction circuit is less than zero, the diode D7 is cut off, the first input end of the second subtraction circuit is zero, and the output voltage of the second subtraction circuit is equal to the input voltage of its second input end (that is, the voltage of the first signal output end of the controller). By controlling the signal voltage of the first signal output end to gradually increase, the trigger circuit can be controlled to output a corresponding trigger pulse to the control end of the bidirectional thyristor, thereby controlling the conduction angle of the bidirectional thyristor to gradually increase, the power supply voltage of the electrical equipment to gradually increase, and the electrical equipment to start smoothly.

[0025] When the AC power supply voltage is too high, the output voltage of the rectifier bridge is greater than the reference voltage, the output voltage of the first subtraction circuit is greater than zero, the diode D7 is turned on, and the output voltage of the first subtraction circuit is connected to the first input terminal of the second subtraction circuit and subtracted from the voltage of the first signal output terminal of the controller. The voltage of the first signal output terminal of the controller decreases, the trigger board outputs a corresponding trigger pulse, and reduces the trigger angle of the bidirectional thyristor, thereby reducing the power supply voltage of the electrical equipment and preventing damage to the electrical equipment caused by excessively high voltage.

[0026] The embodiments of the present disclosure can not only realize the soft start function of the electrical equipment, but also prevent the electrical equipment from being damaged by excessively high AC power supply voltage, thereby further improving the protection effect of the soft starter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 1 is a schematic diagram of a soft start circuit provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] To help those skilled in the art better understand this solution, the following will clearly describe the technical solutions in the embodiments of this solution in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of this solution, not all of it. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of this solution.

[0030] Throughout the specification, claims, and accompanying figures of this solution, the term "including" and any variations thereof mean "including, but not limited to," and are intended to cover non-exclusive inclusions and are not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish between different objects, not to describe a specific order.

[0031] The following describes the implementation of the present disclosure in detail with reference to the accompanying drawings:

[0032] Reference Figure 1 The low-voltage power distribution safety operation management system in the mining area includes a soft start circuit, which includes a bidirectional thyristor and a trigger circuit. The trigger circuit includes a rectifier bridge, a first voltage acquisition circuit, a first subtraction circuit, a diode D7, a second subtraction circuit and a trigger board.

[0033] The first end of the bidirectional thyristor is used to connect to the AC power supply, and the second end of the bidirectional thyristor is used to connect to the power supply end of the electrical equipment;

[0034] The input end of the rectifier bridge is connected to the AC power supply. The first voltage acquisition circuit is configured to collect the output voltage of the rectifier bridge. The output end of the first voltage acquisition circuit is connected to the first input end of the first subtraction circuit. The second input end of the first subtraction circuit is connected to the reference voltage. The output end of the first subtraction circuit is connected to the anode of the diode D7. The cathode of the diode D7 is connected to the first input end of the second subtraction circuit. The second input end of the second subtraction circuit is connected to the first signal output end of the controller. The output end of the second subtraction circuit is connected to the signal input end of the trigger board. The trigger board is used to control the trigger angle of the bidirectional thyristor.

[0035] In this embodiment, the AC power supply is a three-phase power supply, and the bidirectional thyristors include SCR1 to SCR3. The three bidirectional thyristors are connected in series in the three-phase circuit. In the trigger circuit, diodes D1 to D6 form a three-phase rectifier bridge, op amp U1A, resistors R4 and R3 form a first subtraction circuit, and op amp U1B, resistors R6 and R7 form a second subtraction circuit. The rectifier bridge converts the AC power supply voltage into a DC voltage, which can represent the voltage level of the AC power supply. The first voltage acquisition circuit is used to acquire the output voltage of the rectifier bridge. The output voltage of the first voltage acquisition circuit is connected to the first input terminal of the first subtraction circuit. The second input terminal of the first subtraction circuit is connected to a reference voltage, and the first subtraction circuit outputs the difference between the two input voltages.

[0036] When the AC power supply voltage is normal, the output voltage of the rectifier bridge is less than the reference voltage REF, the output voltage of the first subtraction circuit is less than zero, the diode D7 is cut off, the first input end of the second subtraction circuit is zero, and the output voltage of the second subtraction circuit is equal to the input voltage of its second input end (that is, the voltage of the instruction signal INS output by the first signal output end of the controller). By controlling the voltage of the first signal output end to gradually increase, the trigger circuit can be controlled to output a corresponding trigger pulse to the control end of the bidirectional thyristor, thereby controlling the conduction angle of the bidirectional thyristor to gradually increase, the power supply voltage of the electrical equipment to gradually increase, and the electrical equipment to start smoothly.

[0037] When the AC power supply voltage is too high, the output voltage of the rectifier bridge is greater than the reference voltage REF, the output voltage of the first subtraction circuit is greater than zero, the diode D7 is turned on, and the output voltage of the first subtraction circuit is connected to the first input terminal of the second subtraction circuit, and is subtracted from the voltage of the first signal output terminal of the controller (that is, the command signal INS). The command signal INS is reduced, and the reduced command signal INS is connected to the input terminal of the trigger board. The trigger board outputs a corresponding trigger pulse and reduces the trigger angle of the bidirectional thyristor, thereby reducing the power supply voltage of the electrical equipment and preventing damage to the electrical equipment caused by excessively high voltage.

[0038] This embodiment can not only realize the soft start function of the electrical equipment, but also prevent the electrical equipment from being damaged by excessively high AC power supply voltage, thereby further improving the protection effect of the soft starter.

[0039] In an exemplary embodiment of the present disclosure, the first voltage acquisition circuit includes a resistor R1 and a resistor R2, the first end of the resistor R1 is connected to the first output end of the rectifier bridge, the second end of the resistor R1 is connected to the second output end of the rectifier bridge through the resistor R2, and the second end of the resistor R1 is the output end of the first voltage acquisition circuit.

[0040] In this embodiment, resistors R1 and R2 form a series voltage divider circuit, and the terminal voltage of resistor R2 is proportional to the output voltage of the rectifier bridge. Therefore, the output voltage of the rectifier bridge can be obtained by detecting the terminal voltage of resistor R2. The circuit structure is simple and easy to implement.

[0041] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes a first switch, a second switch, and a second voltage acquisition circuit.

[0042] The second voltage acquisition circuit is configured to acquire an AC power supply voltage. The first switch is configured to be connected in parallel with both ends of the bidirectional thyristor. The second switch is connected in series in the trigger circuit. The first switch and the second switch are interlocked.

[0043] The controller is configured as:

[0044] When the electrical equipment is started, the first switch is controlled to be opened and the second switch is controlled to be closed;

[0045] After the electric equipment is started, the first switch is controlled to be closed and the second switch is controlled to be opened;

[0046] When the AC power supply voltage is greater than a first set value, the second switch is controlled to be closed and the first switch is controlled to be opened.

[0047] In this embodiment, when the electrical equipment is just started, the first switch is opened, the second switch is closed, and the bidirectional thyristors SCR1~SCR3 are connected to the power supply circuit of the electrical equipment. By inputting a gradually increasing command signal INS into the trigger circuit, the trigger circuit can be controlled to output a corresponding trigger pulse to the control end of the bidirectional thyristor, thereby controlling the conduction angle of the bidirectional thyristor to gradually increase, and the power supply voltage of the electrical equipment to gradually increase, so that the electrical equipment is started smoothly.

[0048] After the electrical equipment is started, the first switch is controlled to be closed and the second switch is controlled to be opened, and the electrical equipment enters a normal operating state.

[0049] During the operation of the electrical equipment, the second voltage acquisition circuit acquires the real-time AC power supply voltage. When the AC power supply voltage is greater than the first set value, the controller determines that the AC power supply voltage is too high. At this time, the second switch can be controlled to close and the first switch can be controlled to open, and the bidirectional thyristors SCR1~SCR3 are connected to the power supply circuit of the electrical equipment again, making full use of the voltage limiting effect of the soft start circuit to reduce the voltage at the power supply end of the electrical equipment, thereby avoiding damage to the electrical equipment caused by excessive voltage.

[0050] In an exemplary embodiment of the present disclosure, the first switch is a normally open contact of the first relay, the second switch is a normally closed contact of the first relay, and the control end of the first relay is connected to the second signal output end of the controller.

[0051] In this embodiment, the first switch and the second switch can be the normally open and normally closed contacts of the same relay. When the electrical device starts, the first relay does not operate, the normally open contact opens (i.e., the first switch opens), and the normally closed contact closes (i.e., the second switch closes), connecting the bidirectional thyristors SCR1-SCR3 to the electrical device's power supply circuit, thereby implementing a soft start function. After the electrical device completes startup, the first relay operates, the normally open contact closes (i.e., the first switch closes), and the normally closed contact opens (i.e., the second switch opens), connecting the first switch to the power supply circuit.

[0052] In this embodiment, the normally open contact and the normally closed contact of the first relay are used as the first switch and the second switch respectively, thereby achieving interlocking control of the first switch and the second switch.

[0053] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes a backup power supply and a transfer switch.

[0054] The first input end of the switch is connected to the AC power supply, the second end of the switch is connected to the backup power supply, the output end of the switch is connected to the power supply end of the electrical equipment, and the control end of the switch is connected to the third signal output end of the controller.

[0055] In this embodiment, the continuity of power supply in the mining area is of vital importance. By setting up a backup power supply and a switching switch, when the AC power supply fails, the line is damaged, etc., the switching switch will switch the power supply to the backup power supply in a very short time, ensuring the continuous operation of the electrical equipment and avoiding production interruptions, equipment damage and safety accidents caused by power outages.

[0056] In this embodiment, the setting of the backup power supply and the transfer switch provides a double guarantee for the power supply of the mining area, which is conducive to the smooth progress of the mining operation.

[0057] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes a reactive power compensation module, which is connected in parallel with the AC power supply.

[0058] In this embodiment, the electrical equipment in the mining area is mostly inductive loads, such as motors and transformers. These devices consume a large amount of reactive power during operation, increasing current and losses in the power distribution system. By implementing a reactive power compensation module, reactive current in the power grid can be reduced, minimizing losses in the lines and transformers. Furthermore, changes in reactive power can cause fluctuations in the AC power supply voltage. Therefore, reducing reactive power can stabilize the grid voltage, reduce voltage fluctuations, and ensure the normal operation of the electrical equipment.

[0059] In an exemplary embodiment of the present disclosure, the low-voltage power distribution safety operation management system in a mining area further includes:

[0060] The leakage protection module is used to cut off the line power supply when a leakage fault occurs.

[0061] In this example, the mining area is a complex environment with numerous electrical devices. Leakage faults are prone to occur due to factors such as aging equipment, insulation damage, and moisture. The leakage protection module can promptly detect leakage current and quickly cut off the line power supply when a leakage fault occurs, effectively preventing electric shock accidents and further improving the safety of the power distribution system.

[0062] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A low voltage power distribution safety operation management system in a mining area, characterized in that: It includes a soft start circuit, which includes a bidirectional thyristor and a trigger circuit. The trigger circuit includes a rectifier bridge, a first voltage acquisition circuit, a first subtraction circuit, a diode D7, a second subtraction circuit and a trigger board. The first end of the bidirectional thyristor is used to connect to an AC power supply, and the second end of the bidirectional thyristor is used to connect to a power supply end of an electrical device; The input end of the rectifier bridge is connected to an AC power supply. The first voltage acquisition circuit is configured to acquire the output voltage of the rectifier bridge. The output end of the first voltage acquisition circuit is connected to the first input end of the first subtraction circuit. The second input end of the first subtraction circuit is connected to the reference voltage. The output end of the first subtraction circuit is connected to the anode of the diode D7. The cathode of the diode D7 is connected to the first input end of the second subtraction circuit. The second input end of the second subtraction circuit is connected to the first signal output end of the controller. The output end of the second subtraction circuit is connected to the signal input end of the trigger board. The trigger board is used to control the trigger angle of the bidirectional thyristor.

2. The low-voltage power distribution safety operation management system for mining areas according to claim 1, characterized in that: The first voltage acquisition circuit includes a resistor R1 and a resistor R2. The first end of the resistor R1 is connected to the first output end of the rectifier bridge, and the second end of the resistor R1 is connected to the second output end of the rectifier bridge through the resistor R2. The second end of the resistor R1 is the output end of the first voltage acquisition circuit.

3. The low-voltage power distribution safety operation management system for mining areas according to claim 1, characterized in that: It also includes a first switch, a second switch and a second voltage acquisition circuit, The second voltage acquisition circuit is configured to acquire an AC power supply voltage, the first switch is configured to be connected in parallel with both ends of the bidirectional thyristor, the second switch is connected in series in the trigger circuit, and the first switch and the second switch are interlocked. The controller is configured to: When the electrical equipment is started, the first switch is controlled to be opened and the second switch is controlled to be closed; After the electric equipment is started, the first switch is controlled to be closed and the second switch is controlled to be opened; When the AC power supply voltage is greater than a first set value, the second switch is controlled to be closed and the first switch is controlled to be opened.

4. The low-voltage power distribution safety operation management system for mining areas according to claim 3, characterized in that: The first switch is a normally open contact of the first relay, the second switch is a normally closed contact of the first relay, and the control end of the first relay is connected to the second signal output end of the controller.

5. The low-voltage power distribution safety operation management system for mining areas according to claim 1, characterized in that: Also includes backup power supply and transfer switch, The first input end of the switching switch is connected to the AC power supply, the second end of the switching switch is connected to the backup power supply, the output end of the switching switch is connected to the power supply end of the electrical equipment, and the control end of the switching switch is connected to the third signal output end of the controller.

6. The mining area medium and low voltage power distribution safety operation management system according to claim 1, characterized in that: It also includes a reactive power compensation module, which is connected in parallel with the AC power supply.

7. The mining area medium and low voltage power distribution safety operation management system according to claim 1, further comprising: The leakage protection module is used to cut off the line power supply when a leakage fault occurs.

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