Interlocking control circuit of coal conveying belt brake and high-voltage motor

Abstract

A coal conveying belt brake and high-voltage motor interlocking control circuit comprises a travel switch used for sensing whether a brake is in a band-type brake state or not, the travel switch is closed when the brake is in a band-type brake state, and the travel switch is opened when the brake is opened; the travel switch is connected in series with a normally open contact of the time relay and an interlocking relay for interlocking control of the high-voltage motor, the interlocking relay is an opening mechanism for controlling a power switch of the high-voltage motor, and time setting set delay of the time relay is used as maloperation prevention delay. The time relay is connected in series with a normally open contact of the controlled high-voltage motor power switch, and when the high-voltage motor switch loop is powered on, the controlled high-voltage motor power switch is powered on, and the normally open contact is closed at the moment; when the high-voltage motor switch loop loses power, the controlled high-voltage motor power switch loses power, and the normally open contact is disconnected. According to the utility model, the coal conveying belt motor can be reliably stopped when the band-type brake loses power.

Description

Technical Field

[0001] The utility model belongs to the coal conveying system supporting the thermal power generating unit, and relates to an auxiliary control circuit for a coal conveying belt conveyor. Background Art

[0002] The coal conveying belt conveyor is an important equipment in the coal conveying system. During the normal operation or startup of the belt conveyor, the coal conveying belt brake works reliably to release the brake. To avoid the drive shaft being locked and unable to stop the belt conveyor in time and damage the equipment in case of abnormal power failure or mechanical failure of the electro-hydraulic brake. Therefore, when the above abnormal situation occurs, the high-voltage motor power supply of the belt conveyor can be reliably cut off to stop the belt conveyor. It is necessary to optimize the interlock in the control circuit of the electro-hydraulic brake of the belt conveyor and the main motor of the coal conveying belt operation, so as to realize reliable stopping of the coal conveying belt motor when the brake loses power. Summary of the Invention

[0003] In order to overcome the deficiencies of the existing coal conveying belt conveyor, the utility model provides an interlock control circuit for the coal conveying belt brake and the high-voltage motor, which realizes reliable stopping of the coal conveying belt motor when the brake loses power.

[0004] The technical solution adopted by the utility model to solve its technical problems is as follows:

[0005] It includes a travel switch for sensing whether the brake is in the braking state. When the brake brakes, the travel switch closes; when the brake is released, the travel switch opens. The travel switch is connected in series with the normally open contact of a time relay and an interlock relay for interlock control of the high-voltage motor. The interlock relay is the opening mechanism of the controlled high-voltage motor power switch. The time setting of the time relay is set as the anti-misoperation delay. The time relay is connected in series with the normally open contact of the controlled high-voltage motor power switch. When the high-voltage motor switch circuit is powered on, that is, the controlled high-voltage motor power switch is powered on, the normally open contact closes at this time; when the high-voltage motor switch circuit loses power, that is, the controlled high-voltage motor power switch loses power, the normally open contact opens at this time.

[0006] The beneficial effects of the utility model are mainly manifested in: realizing reliable stopping of the coal conveying belt motor when the brake loses power, and improving safety. Brief Description of the Drawings

[0007] Figure 1 It is the schematic diagram of the interlock control circuit for the coal conveying belt brake and the high-voltage motor.

[0008] Figure 2 It is the schematic diagram of adding a travel switch to the coal conveying belt brake. Among them, is the travel switch. Detailed Embodiment

[0009] The following further describes the utility model with reference to the drawings.

[0010] Reference Figure 1 and Figure 2 A control circuit for interlocking a coal conveyor belt brake with a high-voltage motor includes a limit switch SQ for sensing whether the brake is in a holding state. When the brake is holding, the limit switch SQ is closed; when the brake is released, the limit switch SQ is open. The limit switch SQ is connected in series with the normally open contact kt of a time relay KT and an interlocking relay TQ for interlocking control of the high-voltage motor. The interlocking relay TQ is the tripping mechanism of the controlled high-voltage motor power switch QF. The time setting of the time relay KT is set to a delay as an anti-maloperation delay. The time relay KT is connected in series with the normally open contact qf of the controlled high-voltage motor power switch QF. When the high-voltage motor switch circuit is energized, i.e., the controlled high-voltage motor power switch QF is energized, the normally open contact qf is closed; when the high-voltage motor switch circuit is de-energized, i.e., the controlled high-voltage motor power switch QF is de-energized, the normally open contact qf is open.

[0011] In this embodiment, the original operating mode is as follows: the high-voltage motor, i.e., the coal conveyor belt motor and the brake, uses independent power supply circuits. The coal conveyor belt motor is centrally controlled by DCS, and the brake motor is controlled by a switch cabinet with its circuit breaker always in the closed state. When the coal conveyor belt motor is closed, the normally open contact of the auxiliary relay closes, connecting the brake motor control circuit, the brake is energized and opened, and the coal conveyor belt operates normally.

[0012] When the original coal conveyor belt starts, its brake is interlocked and activated. If the brake fails to work properly, the coal conveyor belt will stop immediately. Based on the changes in the energization of the brake during the operation of the coal conveyor belt, the limit switch is installed on the top of the coal conveyor belt brake. After power failure, the limit switch will reliably operate. After the limit switch changes position, its contacts will correctly trigger the interlock relay, and the controlled switch of the high-voltage motor will trip to stop the coal conveyor belt. To prevent accidental contact by personnel, a detachable protective cover is added to the limit switch.

[0013] In the existing programmable trip circuit of the local control cabinet for the belt conveyor motor, a limit switch for the holding brake is added. When the brake is engaged, the normally open point of the limit switch is changed to the closed point to start the trip circuit. When the brake is released, i.e. when it is energized, the normally open point of the limit switch is on standby to perform the protection trip.

[0014] To ensure the normal restart of the belt conveyor after it has stopped, the control circuit selects whether the brake travel switch protection is activated after the belt conveyor is energized or running. This is achieved by adding a 10kV switch auxiliary contact trigger time relay for the belt conveyor as a necessary starting logic condition for the brake travel switch protection. To prevent false tripping of the travel switch protection, the time relay is set with a corresponding delay (5S) as a delay to prevent false tripping.

[0015] After the modification of the control circuit of the coal conveying brake and the coal conveying high-voltage motor is completed, a simulation of the coal conveying belt conveyor brake losing power is carried out. After the brake is applied, the limit switch changes position, and the coal conveying belt conveyor stops operating.

[0016] The interlocking control circuit for the coal conveyor belt and brake in this embodiment can lock the start of the belt high-voltage motor when the brake motor loses power or the brake locks up. During operation, it can also immediately trip the belt motor switch after the brake device is activated for some reason, thus protecting the equipment from damage.

[0017] The embodiments described in this specification are merely examples of implementations of the inventive concept and are for illustrative purposes only. The scope of protection of this utility model should not be considered limited to the specific forms described in these embodiments; rather, it extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A control circuit for interlocking a coal conveyor belt brake with a high-voltage motor, characterized in that, The system includes a limit switch for sensing whether the brake is in a holding state. The limit switch closes when the brake is engaged and opens when the brake is disengaged. The limit switch is connected in series with the normally open contact of a time relay and an interlocking relay for interlocking control of the high-voltage motor. The interlocking relay is the tripping mechanism of the controlled high-voltage motor power switch. The time setting of the time relay is used as an anti-maloperation delay. The time relay is connected in series with the normally open contact of the controlled high-voltage motor power switch. When the high-voltage motor switch circuit is energized, i.e., the controlled high-voltage motor power switch is energized, the normally open contact closes. When the high-voltage motor switch circuit is de-energized, i.e., the controlled high-voltage motor power switch is de-energized, the normally open contact opens.

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