Underground coal mine live-line equipment maintenance protection device

Abstract

The utility model relates to the technical field of power supply equipment, in particular to a coal mine underground live-line equipment maintenance protection device. A cover opening detection module is arranged on a subordinate equipment switch, when a technician turns on the subordinate equipment switch, the cover opening detection module detects an emergency stop signal and sends the emergency stop signal to a safe power supply host, and the safe power supply host judges the subordinate equipment switch which is opened according to a resistance value in a conduction circuit so as to send a reminding signal; when the safety power supply host is powered on, an intermediate relay of the safety power supply host is released, a normally-closed point is closed, a feeder switch quick-break loop is connected, a feeder switch circuit breaker trips, power supply to each lower-level equipment switch is stopped, and electric shock accidents caused by live-line cover opening of technicians are effectively avoided. The protection device provided by the utility model does not depend on standard operation of technicians, can improve the working efficiency of maintainers, and can prevent the technicians from being injured due to electrification of lower-level equipment during maintenance caused by illegal operation of the technicians.

Description

Technical Field

[0001] This application relates to the field of power supply equipment technology, and in particular to a maintenance and protection device for live equipment in coal mines. Background Technology

[0002] The underground power supply and distribution system in a coal mine consists of feeder switches, electromagnetic starters, junction boxes, power cables, and mining equipment. When electrical professionals inspect electrical equipment, they must strictly adhere to safety procedures and measures such as "power outage, voltage testing, discharge, and grounding" to avoid electric shock. However, in actual production, we have found that a significant number of technicians, for various reasons, engage in unsafe operations such as repairing electrical equipment while it is energized. Ultimately, ensuring the above-mentioned power outage and restoration procedures relies entirely on the standardized operation of personnel; it cannot eliminate the risk of electric shock from the equipment or from the source. If technicians are electrocuted due to unsafe operations, it will cause burns, and in severe cases, endanger their lives. Utility Model Content

[0003] This utility model aims to solve the electric shock accidents caused by improper operation of live-line maintenance in coal mines.

[0004] The technical solution adopted by this utility model to solve the aforementioned problem is:

[0005] A protective device for live-line equipment maintenance in coal mines is applied to the power supply and distribution system in coal mines. It primarily addresses electric shock accidents caused by technicians improperly opening covers to inspect live electrical equipment. The power supply and distribution system includes a feeder switch and multiple downstream equipment switches and junction boxes. The feeder switch supplies power to each downstream equipment switch, and the junction boxes protect the cable connections downstream of the feeder switch. The feeder switch is also connected to a safety power supply host. Each downstream equipment switch and the junction box cover and body are equipped with an open-cover detection module. These open-cover detection modules are connected in parallel and to the input terminal of the safety power supply host. The parallel branches of each open-cover detection module are connected... There is a position resistor, and the line between the safety power supply host and the feeder switch is connected to the normally closed contact of an intermediate relay. When the cover of one of the downstream equipment switches or junction boxes is opened, the cover opening detection module detects the emergency stop signal and sends it to the safety power supply host. The safety power supply host determines the position of the downstream equipment switch or junction box that has opened based on the emergency stop signal and the position resistor, and issues a warning signal. At the same time, the safety power supply host controls the normally closed contact of the intermediate relay to close, and the line where the normally closed contact of the intermediate relay is located is connected. After receiving the instantaneous trip signal, the feeder switch trips, the circuit breaker in the feeder switch trips, and the feeder switch stops supplying power to each downstream equipment switch.

[0006] Compared with the prior art, the advantages of this utility model, which adopts the above technical solution, are as follows:

[0007] This invention utilizes a protective device that incorporates a cover-opening detection module on downstream equipment switches and junction boxes. When the cover of a downstream equipment switch or junction box is opened, the detection module detects an emergency stop signal and sends it to the safety power supply host. The host, after processing the signal on its internal circuit board, controls the intermediate relay to release, causing the normally closed contact of the relay to close. This triggers a trip of the feeder switch due to a quick-break fault, de-energizing the downstream equipment switches and junction boxes connected to the feeder switch. This ensures the safety of personnel maintaining the switches and junction boxes. Simultaneously, the safety power supply host can determine which downstream equipment switch or junction box has been opened using a position resistor. The host also broadcasts a warning, "Personnel working, do not close," and locks the feeder switch until the cover-opening detection module resets. Only then can the feeder switch be closed, achieving inherently safe power supply.

[0008] As a preferred embodiment, a further technical solution of this utility model is:

[0009] The downstream equipment switches include electromagnetic starters, and the power supply switch supplies power to the electromagnetic starters. The electromagnetic starters are used to connect to the mining equipment.

[0010] The cover opening detection module is at least one of a magnetic switch, a magnetic sensor, and a distance sensor. These components, capable of detecting position changes, facilitate the detection of whether the covers of downstream devices are open.

[0011] The magnetic switch is a normally closed type. When the downstream equipment switch is not open, the magnetic switch is disconnected from the safety power supply host. When the downstream equipment switch is open, the magnetic switch is connected to the safety power supply host, the intermediate relay in the safety power supply host releases its normally closed point and closes, the power supply switch reports a quick trip fault and the downstream equipment switch is de-energized. Attached Figure Description

[0012] Figure 1 This is a block diagram illustrating the protection principle of the protection device according to an embodiment of this application;

[0013] Figure 2 This is a schematic diagram of the signal transmission of the protection device according to an embodiment of this application;

[0014] Figure 3 This is an electrical schematic diagram of the power supply switch according to an embodiment of this application; Detailed Implementation

[0015] The present invention will be further described below with reference to embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0016] Reference Figure 1-3This application discloses a protective device for the maintenance of live electrical equipment in coal mines, which is applied to the power supply and distribution system in coal mines. It mainly solves the problem of electric shock accidents caused by technicians opening covers to maintain electrical equipment in violation of regulations. The power supply and distribution system includes a feeder switch and multiple downstream equipment switches and junction boxes. The feeder switch supplies power to each downstream equipment switch, which in turn controls various mining equipment in the coal mine. The junction boxes protect the cable connections at the feeder switch's downstream end. The feeder switch is also connected to a safety power supply host. Each downstream equipment switch and the junction box's cover and body are equipped with an open-cover detection module. These open-cover detection modules are connected in parallel to the input of the safety power supply host. The first output of the safety power supply host is connected in series with the coil of an intermediate relay. A quick-break branch is connected between the safety power supply host and the feeder switch. The normally closed contact of the intermediate relay is connected to this quick-break branch. One end of the quick-break branch is connected to the output of the safety power supply host, and the other end is connected to the +24V and 46# terminals of the feeder switch. By controlling the on / off state of the first output of the safety power supply host, the coil of the intermediate relay is energized or de-energized, thereby controlling the quick-break branch to conduct or disconnect. This allows the power supply switch to receive an instantaneous trip signal. Specifically, the output terminals 1# and 8# of the power supply switch output AC127V to power the safety power supply host. The output terminal 6# of the power supply switch is connected in series with the coil SJ through the normally open contact J1-1, and the output terminal 7# of the power supply switch is connected in series with the coil of the trip relay HZ2 through the normally closed contact J1-2. When the normally closed contact ZJ1 of the intermediate relay closes, the switch DS closes synchronously. Terminal 46# and +24V are shorted to the power supply switch. The stationary contact of the trip relay HZ2 is connected to one end of the shunt coil F and the undervoltage coil S. The shunt coil F and the undervoltage coil S are connected in parallel. The normally closed contact of the trip relay HZ2 is connected to terminal 18# of the power supply switch and to the other end of the undervoltage coil S. The normally open contact of the trip relay HZ2 is connected to terminal 19# of the power supply switch and to the other end of the shunt coil F. The shunt coil F and the undervoltage coil S are used to control the circuit breaker of the power supply switch.

[0017] In this embodiment, a position resistor is connected between the parallel branches of each cover opening detection module, and a normally closed contact of an intermediate relay is connected on the line between the safety power supply host and the feeder switch. When the cover of one of the downstream equipment switches or junction boxes is opened, the cover opening detection module detects an emergency stop signal and sends it to the safety power supply host. The safety power supply host determines the position of the downstream equipment switch or junction box that has opened based on the emergency stop signal and the position resistor, and issues a reminder signal. The safety power supply host also controls the normally closed contact of the intermediate relay to close, and the line where the normally closed contact of the intermediate relay is located is connected. After receiving the instantaneous trip signal, the feeder switch trips, the circuit breaker in the feeder switch trips, and the feeder switch stops supplying power to each downstream equipment switch.

[0018] The protection principle of this embodiment is as follows:

[0019] Taking a power supply circuit as an example, during normal power supply, check that the cover and body of the downstream equipment switch are closed, close the isolating handle of the power supply switch, the control transformer is energized, and the AC127V output from terminals 1# and 8# of the power supply switch provides working power to the safety power supply host. The power supply switch supplies power to the downstream equipment switch. At this time, the first output terminal of the safety power supply host outputs voltage, energizing the coil of the intermediate relay. The normally closed contact ZJ1 of the intermediate relay opens, the quick-break branch is broken, and terminals 46# and +24V... When there is no short-circuit signal, the normally open contact J1-1 of the power supply switch closes and the normally closed contact J1-2 opens. At this time, the coil of the trip relay HZ2 is de-energized, the stationary contact and the normally closed contact of the trip relay HZ2 close, and the normally closed contact of the trip relay HZ2 is connected to the branch of terminal 18#. The undervoltage coil S is energized, the shunt coil F is de-energized, the circuit breaker of the power supply switch operates normally, and the power supply switch supplies power to each downstream equipment switch normally. When a downstream equipment switch of this circuit is opened, the cover opening detection module detects an emergency. When the emergency stop signal is received, the connection between the cover-opening detection module and the safety power supply host is established. Upon receiving the emergency stop signal, the first output of the safety power supply host stops supplying power to the intermediate relay coil. The intermediate relay coil is de-energized, causing the normally closed contact ZJ1 to close, opening the instantaneous trip branch. A short-circuit signal is input to terminal 46# and the +24V terminal of the feeder switch. The feeder switch controls the normally open contact J1-1 to open and the normally closed contact J1-2 to close, energizing the coil of the trip relay HZ2. When the circuit is open, the stationary contact of the trip relay HZ2 disconnects from its normally closed contact and connects to its normally open contact. The normally open contact of the trip relay HZ2 is connected to the branch of terminal 19#. At this time, the undervoltage coil S is de-energized and the shunt coil F is energized. The circuit breaker in the feeder switch trips, and the feeder switch stops supplying power to the downstream equipment switches. At this time, all downstream equipment switches in the entire feeder circuit are de-energized. Even if a technician accidentally closes the switch of another downstream equipment switch in this circuit, this circuit will not be energized.

[0020] In this embodiment, position resistors are connected between the parallel branches of each cover-opening detection module. The resistance values ​​of each position resistor are different. The position resistors are used by the safety power supply host to determine which lower-level device switch has been opened. Specifically, when the cover of a lower-level device switch is opened, the connection line between the safety power supply host and the lower-level device switch is connected. The total resistance value in the circuit at this time can be used to determine the number of series resistors and the corresponding resistors in the connected circuit, thereby determining which lower-level device switch has been opened. Based on the determination of the lower-level device switch that has been opened, the safety power supply host generates a corresponding sound reminder signal, such as "Personnel are working on lower-level device switch No. XX, do not close the circuit", and displays the reminder content on the display screen of the safety power supply host, thereby preventing other technicians from accidentally closing the circuit.

[0021] In this embodiment, preferably, the power supply switch is a BKD16-400Z / 1140 (660) mine explosion-proof power supply switch; the downstream equipment switch includes multiple electromagnetic starters, the power supply switch supplies power to the electromagnetic starters, and the electromagnetic starters are used to connect the underground mining equipment.

[0022] In this embodiment, both the wiring cavity and the main cavity of the electromagnetic starter are equipped with cover opening detection modules, and the two cover opening detection modules are connected in parallel. The cover opening detection module includes at least one of a magnetic proximity switch, a magnetic sensor, and a distance sensor. Preferably, the magnetic proximity switch is a normally closed magnetic switch MS. When the lower-level device switch is not open, the magnetic proximity switch is disconnected from the safety power supply host. When a lower-level device switch is opened, the magnetic proximity switch is connected to the safety power supply host, and the safety power supply host receives a signal, thereby controlling the power supply switch to stop supplying power to the lower-level device switch.

[0023] This invention utilizes a protective device that incorporates a cover-opening detection module on the downstream equipment switch. When a technician opens the downstream equipment switch, the detection module detects the signal and sends it to the safety power supply host. The safety power supply host determines the opened downstream equipment switch based on the resistance value in the conductive circuit, thus issuing a warning signal to alert the personnel. Furthermore, the safety power supply host, through internal calculations, controls the normally closed contact of the intermediate relay to close, causing the feeder switch to receive an instantaneous trip signal. This trips the feeder switch circuit breaker, stopping power supply to all downstream equipment switches. This protective device ensures that the power supply to and from downstream equipment switches depends on the equipment itself, not on the technician's proper operation. This improves the efficiency of maintenance personnel and prevents technicians from being injured by improper operation that could result in downstream equipment becoming energized during maintenance.

[0024] The above description is only a preferred embodiment of the present utility model and does not limit the scope of the present utility model. All equivalent changes made based on the content of the present utility model specification and its drawings are included within the scope of the present utility model.

Claims

1. A maintenance and protection device for live electrical equipment in coal mines, applied in the power supply and distribution system of coal mines, the power supply and distribution system including a feeder switch and multiple downstream equipment switches and junction boxes, the feeder switch supplying power to each downstream equipment switch, the junction boxes protecting the cable connection positions at the rear end of the feeder switch, characterized in that: The feeder switch is also connected to a safety power supply host. Each downstream equipment switch and junction box cover and body is equipped with a cover opening detection module. The cover opening detection modules are connected in parallel and connected to the input terminal of the safety power supply host. A position resistor is connected between the parallel branches of each cover opening detection module. The normally closed contact of an intermediate relay is connected on the line between the safety power supply host and the feeder switch. When the cover of one of the downstream equipment switches or junction boxes is opened, the cover opening detection module detects an emergency stop signal and sends it to the safety power supply host. The safety power supply host determines the position of the downstream equipment switch or junction box with the open cover based on the emergency stop signal and the position resistor, and issues a warning signal. The safety power supply host controls the normally closed contact of the intermediate relay to close, and the line where the normally closed contact of the intermediate relay is located is connected. After receiving the instantaneous trip signal, the feeder switch trips. The circuit breaker in the feeder switch trips, and the feeder switch stops supplying power to each downstream equipment switch.

2. The coal mine underground electrical equipment maintenance and protection device according to claim 1, characterized in that: The downstream equipment switches include electromagnetic starters, and the power supply switch supplies power to the electromagnetic starters. The electromagnetic starters are used to connect to the mining equipment.

3. The maintenance and protection device for live electrical equipment in coal mines according to claim 1, characterized in that: The cover opening detection module is one of a magnetic switch, a magnetic sensor, or a distance sensor.

4. The coal mine underground electrical equipment maintenance and protection device according to claim 3, characterized in that: The magnetic switch is a normally closed type. When the downstream equipment switch is not open, the magnetic switch is disconnected from the safety power supply host. When the downstream equipment switch is open, the magnetic switch is connected to the safety power supply host, the intermediate relay in the safety power supply host is released, which drives the feeder switch to trip and the downstream equipment switch is de-energized.

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