A soft start switch thyristor control circuit

Abstract

The utility model discloses a soft start switch thyristor control circuit, including thyristor input power, isolation commutating switch, first vacuum contactor, second vacuum contactor, thyristor, soft start control device and motor. The utility model adds vacuum contactor at the controllable silicon power end, can cut off the controllable silicon completely when it does not attract and hold, both prolongs the service life of controllable silicon, and avoids the self -operation of equipment after the breakdown of controllable silicon, when the breakdown of controllable silicon in operation, the control part can control the contactor to open, and the power of controllable silicon is cut off, prevents the forcible operation of equipment, and ground monitoring room can stop the failure soft starter quickly, realizes the equipment stop running, and simultaneously also avoids the possible equipment short circuit, personnel injury and gas explosion risk when stopping artificially.

Description

Technical Field

[0001] This utility model relates to the field of circuit technology, and in particular to a soft-start switch thyristor control circuit. Background Technology

[0002] In underground coal mine production, the belt conveyor control system plays a crucial role in coal transportation and is a vital link in ensuring efficient coal mine production. As the core device for motor starting in the belt conveyor control system, the stable operation of the soft start switch is essential. The soft start switch primarily utilizes thyristor voltage regulation technology to achieve smooth motor starting. During the starting process, by controlling the firing angle of the thyristor, the output voltage is gradually changed, causing the motor's starting current to rise according to a predetermined curve, avoiding the large current surge of traditional direct starting. The soft start switch not only reduces the impact on the power grid and extends the service life of the motor and equipment, but also enables soft stopping of the motor, reducing mechanical shock. In underground coal mine belt conveyor control systems, it ensures the smooth starting of the belt conveyor, preventing problems such as belt slippage and material spillage caused by excessive starting impact.

[0003] However, traditional soft-start switches have many drawbacks: after the isolation handle is energized, the power supply terminal of the thyristor remains energized even without starting. If the thyristor breaks down, the switch will bypass the control section and force the start-up. During operation after startup, if the thyristor breaks down, the control section will lose its control capability, causing the equipment to run forcibly. Moreover, when the thyristor breaks down, the ground control room cannot stop the equipment operation and can only send personnel to the site to stop it. In addition, manually stopping a switch with a broken thyristor may cause a short circuit in the equipment, posing a risk of injury to operators or a gas explosion.

[0004] Therefore, it is necessary to propose a soft-start switch thyristor control circuit to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a soft-start switch thyristor control circuit to solve the problem of non-stop failure after the thyristor of the existing soft-start switch breaks down.

[0006] This utility model provides a soft-start switch thyristor control circuit, including a thyristor input power supply, an isolating reversing switch, a first vacuum contactor, a second vacuum contactor, a thyristor, a soft-start control device, and a motor. The thyristor input power supply is connected to the isolating reversing switch, the isolating reversing switch is connected to the first vacuum contactor, the first vacuum contactor is connected to the second vacuum contactor, and the second vacuum contactor is connected to the motor. The thyristor is connected between the two ends of the soft-start control device, one end of which is connected between the first and second vacuum contactors, and the other end is connected between the second vacuum contactor and the motor.

[0007] Furthermore, the input terminal of the isolating reversing switch is directly connected to the input power supply, and the output terminal of the isolating reversing switch is fixedly connected to the input terminal of the first vacuum contactor through a copper busbar.

[0008] Furthermore, both the first vacuum contactor and the second vacuum contactor are vacuum arc-extinguishing contactors.

[0009] Furthermore, the thyristor is a bidirectional thyristor, with its anode connected to the first end of the soft-start control device and its cathode connected to the second end of the soft-start control device.

[0010] Furthermore, the wiring terminals of the soft-start control device are connected to the wiring terminals of the first vacuum contactor and the second vacuum contactor via crimp connectors.

[0011] The beneficial effects of this utility model are as follows: This utility model adds a vacuum contactor to the power supply end of the thyristor. When the contactor is not engaged, it can completely disconnect the power to the thyristor, which not only extends the service life of the thyristor but also prevents the equipment from running on its own after the thyristor breaks down. When the thyristor breaks down during operation, the control part can control the contactor to open and disconnect the power to the thyristor, preventing the equipment from running forcibly. The ground monitoring room can quickly stop the faulty soft starter to stop the equipment. At the same time, it also avoids the risks of equipment short circuits, personnel injuries, and gas explosions that may occur when manually stopping the equipment. Attached Figure Description

[0012] To more clearly illustrate the technical solution of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the soft-start switch thyristor control circuit provided by this utility model.

[0014] Diagram description: 1-Isolation reversing switch; 2-First vacuum contactor; 3-Second vacuum contactor; 4-SCR; 5-Soft start control device. Detailed Implementation

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be pointed out that the following detailed description is illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0016] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0017] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions has been enlarged, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0018] Please see Figure 1 This utility model embodiment provides a soft-start switch thyristor control circuit, including: a thyristor input power supply, an isolation reversing switch 1, a first vacuum contactor 2, a second vacuum contactor 3, a thyristor 4, a soft-start control device 5, and a motor. Figure 1 In the diagram, X1, X2, and X3 indicate that the soft start switch is connected to the input power supply terminal, while D1, D2, and D3 indicate that the soft start switch is connected to the output terminal and connected to the motor.

[0019] The thyristor input power supply is connected to the isolation reversing switch 1, the isolation reversing switch 1 is connected to the first vacuum contactor 2, the first vacuum contactor 2 is connected to the second vacuum contactor 3, and the second vacuum contactor 3 is connected to the motor; the thyristor 4 is connected between the two ends of the soft start control device 5; one end of the soft start control device 5 is connected between the first vacuum contactor 2 and the second vacuum contactor 3, and the other end of the soft start control device 5 is connected between the second vacuum contactor 3 and the motor.

[0020] To address the issue of uninterrupted operation after a thyristor breakdown in a soft-start switch, a first vacuum contactor is added to the input power supply section of the thyristor. The core design principle is to effectively control the thyristor's input power supply, rapidly cutting off the power supply in the event of a thyristor breakdown, thus stopping the machine. Vacuum contactors offer advantages such as high breaking capacity, rapid action, and high reliability, making them ideal for use in environments like underground coal mines where equipment reliability requirements are extremely high.

[0021] In this embodiment, the input terminal of the isolating reversing switch 1 is directly connected to the input power supply, and the output terminal of the isolating reversing switch 1 is fixedly connected to the input terminal of the first vacuum contactor 2 via a copper busbar. Both the first vacuum contactor 2 and the second vacuum contactor 3 are vacuum arc-extinguishing contactors. The silicon controlled rectifier (SCR) 4 is a bidirectional thyristor; the anode of the SCR 4 is connected to the first terminal of the soft-start control device 5, and the cathode of the SCR 4 is connected to the second terminal of the soft-start control device 5. The terminals of the soft-start control device 5 are connected to the terminals of the first vacuum contactor 2 and the second vacuum contactor 3 via crimp connectors.

[0022] The startup process of the soft-start switch thyristor control circuit of this utility model is as follows:

[0023] When the soft start switch is activated, the internal control relay inside the switch actuates first. This is the first step in the entire startup process; the action of the internal control relay is equivalent to issuing a start command, preparing for subsequent operations.

[0024] The first vacuum contactor at the input power terminal of the thyristor is activated. After the internal control relay operates, it immediately triggers the activation of the first vacuum contactor, causing it to quickly engage. Only when the first vacuum contactor successfully engages can power be smoothly connected to the power input terminal of the thyristor, providing the necessary power conditions for the normal operation of the thyristor.

[0025] Once the first vacuum contactor engages, power is successfully connected to the thyristor's power input terminal. At this point, the soft-start control device controls the thyristor to conduct, initiating the soft-start operation according to the preset soft-start time. During this stage, the soft-start switch gradually increases the output voltage by controlling the thyristor's firing angle according to the preset start curve, enabling the motor to start smoothly and avoiding large current surges.

[0026] Once the soft start time ends, the second vacuum contactor engages, and the equipment enters direct start operation. After the motor completes the soft start process and reaches a certain speed, the second vacuum contactor engages, directly connecting the motor to the power grid and allowing it to enter a normal, stable operating state.

[0027] In the event of a thyristor breakdown, the central control operator immediately issues a stop signal. The control relay then de-energizes and trips. Upon receiving the stop signal, the control relay immediately de-energizes and trips. The tripping action of the control relay is the key link in the entire fault response mechanism, directly controlling the tripping of the first vacuum contactor. The tripping of the first vacuum contactor completely de-energizes the thyristor. After the control relay de-energizes and trips, the first vacuum contactor also trips, cutting off the input power to the thyristor. Thus, even if the thyristor has broken down, the motor will immediately stop running due to the loss of power supply, fundamentally solving the problem of the motor not stopping after a thyristor breakdown.

[0028] In summary, this utility model addresses the issue of uninterrupted operation after thyristor breakdown in underground conveyor belt control systems in coal mines. It proposes an improved solution by adding a first vacuum contactor to the thyristor input power supply section, and details the improved startup process and fault response mechanism. This solution effectively solves the problem of uninterrupted operation after thyristor breakdown, significantly improving the reliability, stability, and safety of the conveyor belt control system, bringing substantial economic and social benefits to coal mining enterprises.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in sequences other than those illustrated or described herein.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A soft-start switch thyristor control circuit, characterized in that, include: The system includes a thyristor input power supply, an isolation reversing switch (1), a first vacuum contactor (2), a second vacuum contactor (3), a thyristor (4), a soft-start control device (5), and a motor. The thyristor input power supply is connected to the isolation reversing switch (1), the isolation reversing switch (1) is connected to the first vacuum contactor (2), the first vacuum contactor (2) is connected to the second vacuum contactor (3), and the second vacuum contactor (3) is connected to the motor. The thyristor (4) is connected between the two ends of the soft start control device (5); one end of the soft start control device (5) is connected between the first vacuum contactor (2) and the second vacuum contactor (3), and the other end of the soft start control device (5) is connected between the second vacuum contactor (3) and the motor.

2. The soft-start switch thyristor control circuit as described in claim 1, characterized in that, The input terminal of the isolation reversing switch (1) is directly connected to the input power supply, and the output terminal of the isolation reversing switch (1) is fixedly connected to the input terminal of the first vacuum contactor (2) through a copper busbar.

3. The soft-start switch thyristor control circuit as described in claim 1, characterized in that, Both the first vacuum contactor (2) and the second vacuum contactor (3) are vacuum arc-extinguishing contactors.

4. The soft-start switch thyristor control circuit as described in claim 1, characterized in that, The thyristor (4) is a bidirectional thyristor. The anode of the thyristor (4) is connected to the first end of the soft-start control device (5), and the cathode of the thyristor (4) is connected to the second end of the soft-start control device (5).

5. The soft-start switch thyristor control circuit as described in claim 1, characterized in that, The terminals of the soft-start control device (5) are connected to the terminals of the first vacuum contactor (2) and the second vacuum contactor (3) via a crimp connector.

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