Device for delay breaking control switch

Abstract

The utility model discloses a device of a delay breaking control switch, and relates to the field of electrical technology. The control circuit comprises a power supply, a change-over switch, a first silicon controlled rectifier, a second silicon controlled rectifier, a third silicon controlled rectifier, a fourth silicon controlled rectifier and a first rectifier stack, an L phase line of the power supply is divided into four branches after passing through a control loop fuse, and the first branch is respectively connected with a cathode of the first silicon controlled rectifier and an anode of the second silicon controlled rectifier. The second branch is connected with a first pin of the change-over switch, a second pin of the change-over switch is connected with an anode of the first silicon controlled rectifier and a cathode of the second silicon controlled rectifier, the third branch is connected with a third pin of the change-over switch, and a fourth pin of the change-over switch is respectively connected with a cathode of the third silicon controlled rectifier and an anode of the fourth silicon controlled rectifier. The fourth branch is connected with the anode of the third silicon controlled rectifier and the cathode of the fourth silicon controlled rectifier. A time delay structure is connected in parallel on the local and remote control of the change-over switch, so that the problem of equipment shutdown caused by instantaneous power failure of a control branch during switching is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrical technology field, especially relate to a device of time-delay breaking control switch. BACKGROUND

[0002] In the enterprise electric power drag and control system, the drag equipment motor involved is basically divided into "on-site" control and "remote" PLC control, when the PLC appears a fault or needs PLC shutdown for maintenance, in order to continue to start the important drag equipment on site, the operator will use the change-over switch to switch the electrical control branch to the on-site state, this switching process will cause the equipment to stop due to the instantaneous power failure of the change-over switch, in addition, when the equipment running in the "on-site" state needs to restore remote control, the change-over switch also needs to be switched to the "remote" position, and the equipment needs to be stopped and started again, which brings many inconveniences to the continuity of production, and the frequent start and stop of the equipment also indirectly affects the service life of the equipment. UTILITY MODEL CONTENTS

[0003] In view of the above technical problems, the utility model provides a device of time-delay breaking control switch, which is used to solve the problem that the motor of the drag equipment will cause the equipment to stop when performing on-site control and remote PLC control.

[0004] In order to achieve the above purpose, the technical scheme of the utility model is as follows:

[0005] A device of time-delay breaking control switch, comprising a power supply, a change-over switch, a first thyristor, a second thyristor, a third thyristor, a fourth thyristor and a first rectifier stack, the L-phase line of the power supply is divided into four branches after passing through a control circuit fuse, the first branch is connected to the cathode of the first thyristor and the anode of the second thyristor, the second branch is connected to the first pin of the change-over switch, the second pin of the change-over switch is connected to the anode of the first thyristor and the cathode of the second thyristor, the third branch is connected to the third pin of the change-over switch, the fourth pin of the change-over switch is connected to the cathode of the third thyristor and the anode of the fourth thyristor, and the fourth branch is connected to the anode of the third thyristor and the cathode of the fourth thyristor;

[0006] The gate of the first thyristor and the second thyristor is connected to the AC input end of the first rectifier stack, one end of the DC output end of the first rectifier stack is connected in series with a first current-limiting resistor, the other end of the first current-limiting resistor is connected with a first non-polarity capacitor and a first discharge resistor respectively, and the first non-polarity capacitor and the first discharge resistor are connected in parallel and connected to the other end of the DC output end of the first rectifier stack;

[0007] The gate of the third thyristor and the fourth thyristor is connected to the AC input end of the second rectifier stack, one end of the DC output end of the second rectifier stack is connected with the second current-limiting resistor in series, the other end of the second current-limiting resistor is connected with the second non-polarity capacitor and the second discharging resistor respectively, and the second non-polarity capacitor and the second discharging resistor are connected with the other end of the DC output end of the second rectifier stack in parallel;

[0008] The cathode of the second thyristor is connected with the N-phase line of the power supply after being connected with the local stop button, the local start button, the normally closed contact of the thermal relay and the contactor coil in sequence;

[0009] The local start button is connected with the normally open contact of the PLC output intermediate relay and the normally open contact of the contactor in parallel;

[0010] The cathode of the fourth thyristor is connected with the normally open contact of the PLC output intermediate relay and connected with the normally closed contact of the PLC output intermediate relay.

[0011] Compared with the prior art, the application can effectively solve the problem that the contactor coil loses power and the drag equipment stops running due to the operation of the change-over switch when the running equipment is switched between the local state and the centralized state, when the pins of the change-over switch are disconnected, a break voltage can be formed between the pins, the thyristor can be automatically triggered to conduct, the power-on state of the contactor coil is maintained, the delay disconnection in the operation process of the change-over switch is realized, the running equipment is prevented from stopping, the continuity and stability of the equipment operation are ensured, the reliability and safety of the entire system operation are improved, unnecessary downtime caused by state switching is reduced, the production efficiency is improved, and the damage of the equipment caused by frequent start-stop is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is the circuit principle diagram of the utility model.

[0013] In the drawing:

[0014] SA, change-over switch; V1, first thyristor; V2, second thyristor; V3, third thyristor; V4, fourth thyristor; UR1, first rectifier stack; FU, control circuit fuse; 1, first branch; 2, second branch; 3, third branch; 4, fourth branch; R1, first current-limiting resistor; C1, first non-polarity capacitor; R2, first discharging resistor; UR2, second rectifier stack; R3, second current-limiting resistor; C2, second non-polarity capacitor; R4, second discharging resistor; SB1, local stop button; SB2, local start button; KH, normally closed contact of thermal relay; KM1, contactor coil; KA2, normally open contact of PLC output intermediate relay; KM2, normally open contact of contactor; KA1, normally closed contact of PLC output intermediate relay. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model is further explained in detail below in combination with specific implementation manners and with reference to the drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0016] The utility model relates to a kind of time-delay control switch devices, including power supply, conversion switch SA, first thyristor V1, second thyristor V2, third thyristor V3, fourth thyristor V4 and first rectifier stack UR 1, the L phase wire of power supply is divided into four branches after passing through control loop fuse FU, first branch 1 is connected with the cathode of first thyristor V1 and the anode of second thyristor V2 respectively, second branch 2 is connected with the first pin of conversion switch SA, the second pin of conversion switch SA is connected with the anode of first thyristor V1 and the cathode of second thyristor V2, third branch 3 is connected with the third pin of conversion switch SA, the fourth pin of conversion switch SA is connected with the cathode of third thyristor V3 and the anode of fourth thyristor V4 respectively, fourth branch 4 is connected with the anode of third thyristor V3 and the cathode of fourth thyristor V4 respectively;

[0017] The gate of first thyristor V1 and second thyristor V2 is connected at the AC input end of first rectifier stack UR 1, one end of the DC output end of first rectifier stack UR 1 is connected with first current-limiting resistor R 1, the other end of first current-limiting resistor R 1 is connected with first non-polarity capacitor C 1 and first discharge resistor R 2 respectively, first non-polarity capacitor C 1 and first discharge resistor R 2 are connected with the other end of the DC output end of first rectifier stack UR 1 after being connected in parallel;

[0018] The gate of third thyristor V3 and fourth thyristor V4 is connected at the AC input end of second rectifier stack UR 2, one end of the DC output end of second rectifier stack UR 2 is connected with second current-limiting resistor R 3, the other end of second current-limiting resistor R 3 is connected with second non-polarity capacitor C 2 and second discharge resistor R 4 respectively, second non-polarity capacitor C 2 and second discharge resistor R 4 are connected with the other end of the DC output end of second rectifier stack UR 2 after being connected in parallel;

[0019] The cathode of second thyristor V2 is connected with N phase wire of power supply after being connected with local stop button SB 1, local start button SB 2, thermal relay normally closed contact KH and contactor coil KM in turn;

[0020] Local start button SB 2 is connected with PLC output intermediate relay normally open contact KA2 and contactor normally open contact KM2 in parallel;

[0021] The cathode of the fourth thyristor V4 is connected to the normally closed contact KA1 of the PLC output relay and connected to the normally open contact KA2 of the PLC output relay.

[0022] In the case of the running equipment in the on-site state, the contactor coil KM is kept in the power-on running state through the control circuit fuse FU, the first pin and the second pin of the change-over switch SA, the on-site stop button SB1, the contactor normally open contact KM2 and the thermal relay normally closed contact KH. When the running equipment needs to be switched to the centralized state control, the change-over switch SA can be directly operated. In the operation, the change-over switch SA will pass through the zero position and then reach the centralized state control position. In this process, the first pin and the second pin of the change-over switch SA will be in the open state, and the contactor coil KM will lose power, resulting in the shutdown of the dragging equipment. In the case of using the design, the first pin and the second pin of the change-over switch SA are disconnected, and a break voltage is formed between the first pin and the second pin. Due to the action of the break voltage, the L-phase line of the power supply is connected to the AC input end of the first rectifier stack UR1 through the cathode to the gate of the first thyristor V1, and the N-phase line of the power supply is connected to the other AC input end of the first rectifier stack UR1 through the cathode to the gate of the second thyristor V2. In this way, the first non-polarity capacitor C1 is charged through the DC output end of the first rectifier stack UR1 and the first current-limiting resistor R1. This charging current is also the trigger current of the first thyristor V1 and the second thyristor V2, which necessarily makes the thyristors conducting under the positive voltage. In this way, the first pin and the second pin are connected, preventing the loss of power of the contactor coil KM. When the electric quantity of the first non-polarity capacitor C1 reaches a certain degree, the current flowing through the gate branch of the first thyristor V1 and the second thyristor V2 will be reduced to below the trigger threshold current of the first thyristor V1 and the second thyristor V2, so that the first thyristor V1 and the second thyristor V2 are in the cut-off state. In this way, the delay disconnection in the operation process of the first pin and the second pin of the change-over switch SA is completed, preventing the running equipment from stopping. When the change-over switch SA switches to the on-site control state, the effect is the same as when the change-over switch SA switches to the centralized control state, and no further description is made.

[0023] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An apparatus for time delay break control of a switch, characterized by: The power supply, the change-over switch (SA), the first thyristor (V1), the second thyristor (V2), the third thyristor (V3), the fourth thyristor (V4) and the first rectifier stack (UR1) are included. The L-phase line of the power supply is divided into four branches after passing through the control circuit fuse (FU). The first branch (1) is connected to the cathode of the first thyristor (V1) and the anode of the second thyristor (V2) respectively. The second branch (2) is connected to the first pin of the change-over switch (SA). The second pin of the change-over switch (SA) is connected to the anode of the first thyristor (V1) and the cathode of the second thyristor (V2). The third branch (3) is connected to the third pin of the change-over switch (SA). The fourth pin of the change-over switch (SA) is connected to the cathode of the third thyristor (V3) and the anode of the fourth thyristor (V4) respectively. The fourth branch (4) is connected to the anode of the third thyristor (V3) and the cathode of the fourth thyristor (V4) respectively. The gates of the first thyristor (V1) and the second thyristor (V2) are connected to the AC input end of the first rectifier stack (UR1). The DC output end of the first rectifier stack (UR1) is connected to the first current-limiting resistor (R1) in series. The other end of the first current-limiting resistor (R1) is connected to the first non-polarity capacitor (C1) and the first discharge resistor (R2) respectively. The first non-polarity capacitor (C1) and the first discharge resistor (R2) are connected to the other end of the DC output end of the first rectifier stack (UR1) in parallel. The gates of the third thyristor (V3) and the fourth thyristor (V4) are connected to the AC input end of the second rectifier stack (UR2). The DC output end of the second rectifier stack (UR2) is connected to the second current-limiting resistor (R3) in series. The other end of the second current-limiting resistor (R3) is connected to the second non-polarity capacitor (C2) and the second discharge resistor (R4) respectively. The second non-polarity capacitor (C2) and the second discharge resistor (R4) are connected to the other end of the DC output end of the second rectifier stack (UR2) in parallel. The cathode of the second thyristor (V2) is connected to the local stop button (SB1), the local start button (SB2), the thermal relay normally closed contact (KH) and the contactor coil (KM1) in sequence, and then connected to the N-phase line of the power supply. The local start button (SB2) is connected in parallel to the PLC output intermediate relay normally open contact (KA2) and the contactor normally open contact (KM2). The cathode of the fourth thyristor (V4) is connected to the PLC output intermediate relay normally closed contact (KA1), and then connected to the PLC output intermediate relay normally open contact (KA2).

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