Soft start control circuit of high-voltage equipment

Abstract

The utility model discloses a soft start control circuit of high-voltage equipment. The soft start control circuit comprises an SIS allowed start contact, an SIS trip signal contact, a first intermediate relay, a soft start relay, a bypass contactor and a soft starter arranged in a high-voltage soft start cabinet. The SIS permission starting contact and a coil of the first intermediate relay are connected in series with a power supply; one normally open contact of the first intermediate relay is connected in parallel with the two ends of the starting allowing contact; and the SIS tripping signal contact, the closing signal contact of the high-voltage switch cabinet, the other normally open contact of the first intermediate relay and the power supply are sequentially connected in series to form a second loop. The device has the advantages that when the starting condition is met, signal self-locking is achieved through the first intermediate relay, and frequent take-off caused by signal fluctuation is avoided; the power supply end of the soft starter is not controlled by the high-voltage switch cabinet, and when the high-voltage switch cabinet trips, the soft starter still does not lose power, so that a worker can conveniently search fault information.

Description

Technical field:

[0001] The utility model relates to the field of high-voltage equipment control, in particular to a soft start control circuit of high-voltage equipment. Background technology:

[0002] Soft start control circuits are widely used in the start and stop of high-voltage equipment. Soft start can improve the stability of equipment start and stop, and avoid damage to equipment due to sudden changes in voltage or current during the start and stop phases. In actual use, in order to improve the automation level and control accuracy of high-voltage equipment, an automatic interlocking control system will be connected to the soft start control circuit of high-voltage equipment. In the current production process, the most commonly used automatic interlocking control system is the DCS system, which monitors the relevant operating status of high-voltage equipment through the DCS system and controls the soft start cabinet in combination with the operating status.

[0003] With the increasing requirements for the safety of high-voltage equipment operation, it is necessary to connect the SIS system (safety instrument control system) to the soft start control circuit of the high-voltage equipment to take emergency measures for possible dangers in the device or equipment to ensure the safety of production equipment, environment and personnel. However, the current soft start control using the SIS system has the following problems: (1) The sensitivity and control accuracy of the SIS system are higher than those of the traditional DCS control system. When the contacts of the SIS system are connected to the soft start control circuit, the system will start and stop frequently due to the fluctuation of the start signal, which is easy to cause equipment damage; (2) The soft starter power supply of the high-voltage soft start cabinet is controlled by the closing signal of the high-voltage switch cabinet. When the high-voltage switch cabinet trips and loses power, the soft starter of the soft start cabinet also loses power, so it is impossible to find the fault signal through the soft starter. Utility model content:

[0004] The utility model aims to provide a soft start control circuit which can reduce the influence of the fluctuation of the start signal on the SIS system.

[0005] The utility model is implemented by the following technical scheme: a soft start control circuit of high-voltage equipment, including a high-voltage soft start cabinet, a high-voltage switch cabinet, and a high-voltage equipment; the high-voltage soft start cabinet is connected in series between the outgoing line side of the high-voltage switch cabinet and the incoming line side of the high-voltage equipment and also includes a soft start cabinet control circuit; the soft start cabinet control circuit includes a SIS start permission contact, a SIS trip signal contact, a first intermediate relay, a soft start relay, a bypass contactor, and a soft starter arranged inside the high-voltage soft start cabinet;

[0006] The SIS start-permitting contact, the coil of the first intermediate relay and the power supply are connected in series to form a first circuit; a normally open contact of the first intermediate relay is connected in parallel to both ends of the start-permitting contact;

[0007] The SIS trip signal contact, the closing signal contact of the high-voltage switch cabinet, another normally open contact of the first intermediate relay, and the power supply are connected in series in sequence to form a second circuit;

[0008] The signal input end of the soft starter is connected to the output end of another normally open contact of the first intermediate relay, and the signal output end of the soft starter is respectively connected to one end of the coil of the soft start relay and one end of the coil of the bypass contactor; the other end of the coil of the soft start relay and the other end of the coil of the bypass contactor are both connected to the negative pole of the power supply.

[0009] Preferably, it further comprises a transformer, wherein the primary side of the transformer is connected in parallel with the first loop; and the secondary side of the transformer is connected to the power supply end of the soft starter.

[0010] Preferably, it also includes a reset button, which is connected in series in the first circuit.

[0011] Preferably, it also includes an indicator light, which is connected in series in the second circuit, one end of the indicator light is connected to another normally open contact of the first intermediate relay, and the other end of the indicator light is connected to the negative pole of the power supply.

[0012] Preferably, it also includes a fault relay; the coil input end of the fault relay is connected to the output end of the soft starter, the coil output end of the fault relay is connected to the negative pole of the power supply, and a normally closed contact of the fault relay is connected in series between the coil output end of the soft start relay and the negative pole of the power supply.

[0013] Preferably, another normally open contact of the fault relay is connected to the signal input terminal of the high-voltage switch cabinet.

[0014] The utility model has the following advantages: simple structure and high reliability. The SIS system is used to monitor the operating status of the high-voltage equipment. When the starting conditions are met, the signal is self-locked through the first intermediate relay, avoiding frequent starting caused by signal fluctuations. The power supply end of the soft starter is not controlled by the high-voltage switch cabinet. When the high-voltage switch cabinet trips, the soft starter will not lose power, which makes it convenient for workers to find fault information. Description of the drawings:

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art 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 paying creative work.

[0016] Figure 1 This is a connection diagram of the soft start cabinet of Example 1 of the utility model.

[0017] Figure 2 This is a schematic diagram of the control circuit connection of the high-voltage soft start cabinet.

[0018] Figure 3 This is a schematic diagram of the connection between SIS fault signal and high-voltage switchgear.

[0019] High-voltage soft start cabinet 1, high-voltage switch cabinet 2, high-voltage equipment 3, SIS trip signal contact SIS-0, SIS start permission contact SIS-1, first intermediate relay KA1, soft start relay KA2, fault relay KA3, bypass contactor KM, transformer BY, soft starter RQ, reset button SB1, indicator light WID. Specific implementation method:

[0020] 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 of 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.

[0021] Embodiment 1:

[0022] like Figure 1-3 A soft start control circuit of a high-voltage device shown in the figure comprises a high-voltage soft start cabinet 1, a high-voltage switch cabinet 2, a high-voltage device 3, and a soft start cabinet control circuit; wherein the high-voltage soft start cabinet 1 is connected in series between the outgoing line side of the high-voltage switch cabinet 2 and the incoming line side of the high-voltage device 3, such as Figure 1 shown.

[0023] like Figure 2 As shown, the soft start cabinet control circuit includes SIS start permission contact SIS-1, SIS trip signal contact SIS-0, reset button SB1, first intermediate relay KA1, soft start relay KA2, fault relay KA3, bypass contactor KM, transformer BY and soft starter RQ arranged inside the high-voltage soft start cabinet 1.

[0024] The reset button SB1, the SIS start permission contact SIS-1, the coil of the first intermediate relay KA1 and the power supply are connected in series to form a first circuit; a normally open contact KA1-1 of the first intermediate relay KA1 is connected in parallel to both ends of the SIS start permission contact SIS-1.

[0025] The SIS tripping signal contact SIS-0, the closing signal contact DL of the high-voltage switch cabinet 2, another normally open contact KA1-2 of the first intermediate relay KA1, the indicator light WID, and the power supply are connected in series in sequence to form a second circuit.

[0026] The signal input end of the soft starter RQ is connected to the output end of another normally open contact KA1-2 of the first intermediate relay KA1, and the signal output end of the soft starter RQ is respectively connected to one end of the coil of the soft start relay KA2, one end of the coil of the bypass contactor KM, and one end of the coil of the fault relay KA3; the other end of the coil of the bypass contactor KM and the other end of the coil of the fault relay KA3 are both connected to the negative pole of the power supply; a normally closed contact KA3-1 of the fault relay KA3 is connected in series between the other end of the coil of the soft start relay KA2 and the negative pole of the power supply.

[0027] The primary side of the transformer BY is connected in parallel with the first circuit; the secondary side of the transformer BY is connected to the power supply end of the soft starter RQ.

[0028] In addition, a normally open contact KA3-2 of the fault relay KA3 is connected to the signal input terminal of the high-voltage switch cabinet 2, such as Figure 3 shown.

[0029] Instructions for use: Take the start and stop of a high-voltage motor as an example. When using the control circuit of the utility model, first close the high-voltage switch cabinet 2. After the high-voltage switch cabinet 2 is closed, the closing signal contact DL of the high-voltage switch cabinet 2 in the second circuit is energized and closed. During this process, the SIS safety instrument system determines the starting conditions of the high-voltage motor. When SIS determines that the starting conditions are met, SIS allows the starting contact SIS-1 to be energized and closed, and the coil of the first intermediate relay KA1 in the first circuit is energized. At the same time:

[0030] (1) A normally open contact KA1-1 of the first intermediate relay KA1 is closed, and the coil of the first intermediate relay KA1 is not affected by the SIS signal fluctuation, which effectively avoids system damage caused by frequent system start and stop;

[0031] (2) The other normally open contact KA1-2 of the first intermediate relay KA1 in the second circuit is closed, and the indicator light WID is on, indicating that soft start is allowed, and then the motor enters soft start.

[0032] After the signal input end of the soft starter RQ receives the start signal, the signal output end of the soft starter RQ outputs a control signal to the soft start relay KA2, the coil of the soft start relay KA2 is energized, the normally open contact KA2-1 of the soft start relay KA2 is energized, and the soft start cabinet 1 controls the motor to perform soft start. When the soft start is completed, the signal output end of the soft starter RQ outputs a control signal to the bypass contactor KM, the coil of the bypass contactor KM is energized, and the normally open contact KM-1 of the bypass contactor KM is closed. At the same time, the coil of the soft start relay KA2 loses power, the normally open contact KA2-1 of the soft start relay KA2 is disconnected, and the motor enters the bypass full-voltage operation state. When the soft starter RQ detects that a system fault has occurred, the signal output end of the soft starter RQ outputs a control signal to the fault relay KA3, the coil of the fault relay KA3 is energized, and at the same time:

[0033] (1) A normally closed contact KA3-1 of the fault relay KA3 is disconnected, and the motor stops starting;

[0034] (2) A normally open contact KA3-2 of the fault relay KA3 closes, sending a fault signal to the high-voltage switchgear 2.

[0035] When SIS determines that the motor does not meet the starting conditions or needs to be disconnected, the SIS trip signal contact SIS-0 loses power and disconnects, and the motor stops soft starting or trips. When the motor needs to be stopped manually, press the reset button SB1, the coil of the first intermediate relay KA1 loses power, the normally open contact of the first intermediate relay KA1 disconnects, and the control circuit stops running.

[0036] The soft starter RQ is powered directly by the transformer BY. When the closing signal contact of the high-voltage switch cabinet 2 loses power and is disconnected or the SIS trip signal contact is disconnected, the soft starter RQ can be powered normally without being affected. The fault problem can be quickly found through the soft starter RQ.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A soft start control circuit for high voltage equipment, comprising a high voltage soft start cabinet, a high voltage switch cabinet, and a high voltage equipment; the high voltage soft start cabinet is connected in series between the outgoing line side of the high voltage switch cabinet and the incoming line side of the high voltage equipment, characterized in that: It also includes a soft start cabinet control circuit; the soft start cabinet control circuit includes a SIS start permission contact, a SIS trip signal contact, a first intermediate relay, a soft start relay, a bypass contactor, and a soft starter arranged inside the high-voltage soft start cabinet; The SIS start-permitting contact, the coil of the first intermediate relay and the power supply are connected in series to form a first circuit; a normally open contact of the first intermediate relay is connected in parallel to both ends of the start-permitting contact; The SIS trip signal contact, the closing signal contact of the high-voltage switch cabinet, another normally open contact of the first intermediate relay, and the power supply are connected in series in sequence to form a second circuit; The signal input end of the soft starter is connected to the output end of another normally open contact of the first intermediate relay, and the signal output end of the soft starter is respectively connected to one end of the coil of the soft start relay and one end of the coil of the bypass contactor; the other end of the coil of the soft start relay and the other end of the coil of the bypass contactor are both connected to the negative pole of the power supply.

2. The soft start control circuit of a high voltage device according to claim 1, characterized in that: It also includes a transformer, wherein the primary side of the transformer is connected in parallel with the first loop; and the secondary side of the transformer is connected to the power supply end of the soft starter.

3. A soft start control circuit for high voltage equipment according to claim 1 or 2, characterized in that: A reset button is also included, and the reset button is connected in series in the first circuit.

4. A soft start control circuit for high voltage equipment according to claim 3, characterized in that: It also includes an indicator light, which is connected in series in the second circuit, one end of the indicator light is connected to another normally open contact of the first intermediate relay, and the other end of the indicator light is connected to the negative pole of the power supply.

5. The soft start control circuit of a high voltage device according to claim 3, characterized in that: It also includes a fault relay; the coil input end of the fault relay is connected to the output end of the soft starter, the coil output end of the fault relay is connected to the negative pole of the power supply, and a normally closed contact of the fault relay is connected in series between the coil output end of the soft start relay and the negative pole of the power supply.

6. A soft start control circuit for high voltage equipment according to claim 5, characterized in that: Another normally open contact of the fault relay is connected to the signal input terminal of the high-voltage switch cabinet.

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