CN218771292U - Current limiting device - Google Patents

Abstract

The utility model discloses a current limiting device belongs to current limiting equipment technical field. The current limiting device includes: a switch; a reactor connected in parallel with the switch; the current transformer is connected with the switch in series and is connected with the reactor in series, and the current transformer is used for measuring the current value of the reactor and the switch after being connected in parallel; the repulsion mechanism is connected with the switch; the trigger circuit is connected with the repulsion mechanism in series and is connected with at least two power supplies; and the control loop is respectively connected with the trigger loop and the current transformer, and is used for controlling the trigger loop to discharge to the repulsion mechanism according to the current value measured by the current transformer, and the repulsion mechanism pushes the switch to be switched on or switched off. The current limiting device places the trigger circuit at the ground potential, and the trigger circuit is provided with at least two power supplies, so that the equipment price is reduced, and the equipment availability is improved.

Description

Current limiting device

Technical Field

The utility model belongs to the technical field of the current-limiting equipment, concretely relates to current limiting device.

Background

With the development of economy, the power load is heavier and heavier, and the problem that short-circuit current exceeds the standard exists in part of transformer substations built in early days. The short-circuit current exceeds the rated breaking current of the breaker, and the breaker fails to open the brake in the case of short-circuit fault, thereby seriously affecting the safety of a power grid. The addition of a high-voltage zero-loss deep current limiting device in a power grid is one of effective measures for ensuring the reliable opening of a circuit breaker under the condition that short-circuit current exceeds standard. The principle of the measure is that after a short-circuit fault occurs, an inductor is quickly connected in series in a fault line, the short-circuit current is reduced to be lower than the value of the break-able current of the breaker, and the breaker is guaranteed to be reliably switched off when the short-circuit fault occurs.

The current limiting device has a main current structure that a repulsion mechanism and a trigger circuit are arranged at a high potential, and the potential is equal to one end of a switch. The trigger circuit needs electric energy when working, and the mainstream technology at present transports the electric energy from the ground potential to the high potential through energy supply equipment, is limited by the expensive price of high potential energy supply equipment, and generally a set of current limiting device only disposes an energy supply equipment, and the energy supply has no redundancy, and single energy supply equipment trouble will lead to current limiting device to shut down, seriously influences current limiting device's availability.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: the utility model provides a current limiting device can solve the problem that current limiting device availability is low.

The technical scheme is as follows: the utility model discloses a current limiting device, include:

a switch;

a reactor connected in parallel with the switch;

the current transformer is connected with the switch in series, and the current transformer is connected with the reactor in series;

the repulsion mechanism is connected with the switch;

the trigger circuit is connected with the repulsion mechanism in series and is connected with at least two power supplies;

and the control loop is respectively connected with the trigger loop and the current transformer and is used for controlling the trigger loop to discharge the repulsion mechanism according to the current value measured by the current transformer so as to switch on or switch off the repulsion mechanism and the switch.

In some embodiments, the reactor is coaxially arranged at the switch outer circumferential surface; the reactor and the switch are coaxially arranged, so that the purpose of reducing the floor area can be achieved.

In some embodiments, further comprising:

a first sleeve coaxially sleeved between an outer peripheral surface of the switch and an inner peripheral surface of the reactor;

a pull rod connected between the repulsion mechanism and the switch; the pull rod is used for realizing the contact between the repulsion mechanism and the switch so as to switch on, and the pull rod is also used for realizing the disconnection between the repulsion mechanism and the switch so as to switch off;

the second sleeve is coaxially arranged on the outer peripheral surface of the pull rod;

a metal disc disposed between the first sleeve and the second sleeve, the metal disc being connected to the switch;

the second sleeve is connected with the metal disc and the first sleeve in series.

In some embodiments, the switch includes a stationary contact and a movable contact; the metal disc is connected with the moving contact through a contact finger.

In some embodiments, the current limiting device further comprises:

the first busbar is connected with the static contact;

the second busbar is connected with the metal disc;

the first connecting bar is connected between the reactor and the first busbar;

the second connecting bar is connected between the reactor and the second busbar;

the current transformer is arranged on the first busbar or the second busbar.

In some embodiments, the repulsion mechanism comprises a movable connecting disc, a first coil disc arranged above the movable connecting disc, and a second coil disc arranged below the movable connecting disc, one end of the pull rod is connected with the top of the movable connecting disc, and the other end of the pull rod is connected with the switch through a contact; when the pull rod is in contact with the switch, the switch-on of the switch can be realized; when the pull rod is separated from the switch, the opening of the switch can be realized.

In some embodiments, the switch is a vacuum arc chamber.

In some embodiments, the current transformer is an electronic transformer.

In some embodiments, the tie rod and the second sleeve are both insulating structural members.

In some embodiments, the first sleeve is butted with the second sleeve, and a cavity is formed at intervals among the inner surface of the first sleeve, the inner surface of the second sleeve, the outer surface of the switch and the outer surface of the pull rod, and is filled with insulating gas.

In some embodiments, the insulating gas is sulfur hexafluoride; and sulfur hexafluoride is filled in the cavity to serve as insulating gas, so that the pipe diameter size of the first sleeve and the pipe diameter size of the second sleeve are reduced.

In some embodiments, the current transformer is connected to the control loop by an optical fiber; the current transformer is used for sending the measured current value to the control loop through the optical fiber.

Has the advantages that: compared with the prior art, the current limiting device of the utility model connects the switch and the reactor in parallel; the repulsion mechanism is in contact with or disconnected from the switch and is connected with the trigger circuit in series; connecting a current transformer with a switch in series, connecting the current transformer with a reactor in series, and measuring the current value of the switch and the reactor after being connected in parallel; and the control loop is respectively connected with the current transformer and the trigger loop, and the control loop is used for controlling the trigger loop to discharge the repulsion mechanism according to the current value measured by the current transformer so as to switch on or switch off the repulsion mechanism and the switch. The utility model discloses utilize the trigger circuit to dispose in the ground potential and trigger circuit independently connect two way at least powers, can replace the current expensive equipment that is used for carrying the electric energy to the high potential, reduce the equipment price, improve the current-limiting device availability.

Drawings

The technical solution and other advantages of the present invention will become apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a switch open state of a current limiting device according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a switch closing state of the current limiting device according to an embodiment of the present invention;

fig. 3 is a cross-sectional view illustrating a switch open state of a current limiting device according to an embodiment of the present invention;

reference numeral, 101-switch, 1011-fixed contact, 1012-movable contact, 115-first bus bar, 116-second bus bar, 113-first connecting bar, 114-second connecting bar, 102-reactor, 103-pull rod, 104-repulsion mechanism, 1042-movable connecting bar, 1041-first coil disc, 1043-second coil disc, 105-metal disc, 106-first sleeve, 107-second sleeve, 108-trigger loop, 109-current transformer, 110-control loop, 111-optical fiber, 112-cavity.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the disclosed embodiments are merely exemplary of the invention, and are not intended to limit the invention to the precise embodiments disclosed. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be mechanically connected, may be electrically connected or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. In order to simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention.

In the research and practice process of the prior art, the inventor of the application finds that the structure of most current limiting devices which is responsible for switching off and switching on is arranged separately from a reactor, so that the occupied area is large; transformation of a transformer substation with partial fault current exceeding the standard cannot replace an original circuit breaker due to the fact that the current limiting device occupies a large area, and application of the current limiting device is seriously affected.

Referring to fig. 1, the present invention provides a current limiting device, especially a high-voltage zero-loss deep current limiting device, and belongs to the technical field of current limiting equipment. The current limiting device comprises a switch 101, a reactor 102, a repulsive force mechanism 104, a trigger circuit 108, a current transformer 109 and a control circuit 110.

In an embodiment of the present invention, the current limiting device has a first potential and a second potential, and the first potential is high relative to the second potential. Wherein the second potential is ground potential and the first potential is high potential.

In some embodiments, referring further to fig. 1, the switch 101 is configured at a first potential, i.e., a high potential, and the switch 101 is a structural member for switching on and off; compared with the conventional technology in which a structural member of the current limiting device responsible for switching on and off and the reactor are separately arranged, the reactor 102 is connected in parallel with the switch 101, and the reactor 102 is coaxially configured on the outer peripheral surface of the switch 101, so that the occupied area is large, the current limiting device cannot be installed and an original circuit breaker is replaced, and the design of the coaxial configuration of the reactor 102 and the switch 101 can effectively reduce the occupied area.

The repulsion mechanism 104 is configured at a second potential, namely, a ground potential, and the repulsion mechanism 104 moves due to electromagnetic force to push the switch 101 to be switched on or switched off; the trigger circuit 108 is connected in series with the repulsive force mechanism 104, the trigger circuit 108 is configured at the ground potential, and the trigger circuit 108 is independently connected to at least two power supplies at the ground potential, each power supply being configured to independently supply power to the trigger circuit 108.

In some embodiments, referring further to fig. 1, the flow restriction device further includes a pull rod 103, a metal plate 105, a first sleeve 106, and a second sleeve 107. The first sleeve 106 is coaxially disposed on the outer peripheral surface of the switch 101, and the first sleeve 106 is disposed at a first potential, i.e., a high potential; the switch 101 is connected with the repulsion mechanism 104 through a pull rod 103, the pull rod 103 extends along the longitudinal direction, and the two end parts of the pull rod 103 are respectively connected with the switch 101 and the repulsion mechanism 104; the metal disc 105 is arranged between the first sleeve 106 and the second sleeve 107, and the metal disc 105 is connected with the switch 101; the second sleeve 107 is coaxially sleeved on the outer peripheral surface of the pull rod 103, and the second sleeve 107 is connected in series with the first sleeve 106 and the metal disc 105. In addition, the pull rod 103 and the second sleeve 107 are both insulating structural members.

In some embodiments, referring to fig. 1, the switch 101 includes a fixed contact 1011 and a movable contact 1012, the movable contact 1012 is at a first potential, and the fixed contact 1011 is located at an end of the movable contact 1012 away from the repulsive force mechanism 104.

In some embodiments, referring further to fig. 1, the current limiting device further includes: the contact structure comprises a first busbar 115, a second busbar 116, a first connecting bar 113 and a second connecting bar 114, wherein the first busbar 115 is connected with a fixed contact 1011; the second busbar 116 is connected with the metal disc 105; the first connecting bar 113 is connected between the reactor 102 and the first busbar 115; the second connection bar 114 is connected between the reactor 102 and the second busbar 116; the current transformer 109 is disposed on the first busbar 115 or the second busbar 116.

In some embodiments, referring to fig. 1, the repulsive force mechanism 104 includes a movable connecting plate 1042, a first coil 1041 disposed on the top of the movable connecting plate 1042, and a second coil 1043 disposed on the bottom of the movable connecting plate 1042, wherein one end of the pull rod 103 is connected to the top of the movable connecting plate 1042, and the other end of the pull rod 103 is connected to the movable contact 1012 of the switch 101.

In some embodiments, the current transformer 109 is connected in series with the switch 101, and the current transformer 109 is connected in series with the reactor 102, that is, the current transformer 109 is connected to the first bus bar 115 or the second bus bar 116 connected in series after the high-speed switch 101 is connected in parallel with the reactor 102, and the current transformer 109 is used for monitoring the current in the first bus bar 115 or the second bus bar 116 in real time.

In some embodiments, the current transformer 109 is an electronic transformer.

In some embodiments, the current transformer 109 is connected to the control circuit 110 through an optical fiber 111, and the current transformer 109 is configured to transmit the collected current value signal of the first busbar 115 or the second busbar 116 to the control circuit 110.

In some embodiments, the control circuit 110 is connected to the current transformer 109 and the trigger circuit 108; the current transformer 109 is used for measuring the current value entering or exiting the first busbar 115 or the second busbar 116, and the current transformer 109 is also used for sending the acquired current value of the first busbar 115 or the second busbar 116 to the control circuit 110; the control circuit 110 is configured to generate a switch closing command or a switch opening command according to a current value of the first busbar 115 or the second busbar 116 acquired by the current transformer 109, and send the switch closing command or the switch opening command to the trigger circuit 108, the trigger circuit 108 completes discharge of a capacitance of the closing circuit or the switch opening circuit to the repulsion mechanism 104 according to the received switch opening command or the switch closing command, and the repulsion mechanism 104 moves due to an electromagnetic force to push the switch 101 to close or open. As shown in fig. 1, the control circuit 110 sends a switch closing command, the triggering circuit 108 discharges a closing circuit capacitor to the second coil plate 1043, the second coil plate 1043 and the movable connecting plate 1042 generate an electromagnetic repulsion force, the movable connecting plate 1042 is pushed upward, and the switch 101 is pushed to be closed.

As shown in fig. 1, the control circuit 110 sends a switch opening command, the trigger circuit 108 discharges the capacitor of the opening circuit to the first coil panel 1041, the first coil panel 1041 and the movable connecting panel 1042 generate an electromagnetic repulsion force, the movable connecting panel 1042 is pushed downward, and the switch 101 is further pushed to open.

The control loop 110 is also used to monitor the state of the trigger loop 108, for example, the control loop 110 is used to monitor whether the trigger loop 108 is in a charging state or a discharging state.

In some embodiments, when a bus is short-circuited, when the control circuit 110 monitors that a current value of a first bus bar 115 or a second bus bar 116, which is acquired by a current transformer 109 and is connected in parallel and in series with a reactor 102, of a first bus bar 115 or a second bus bar 116 is greater than a preset threshold, the control circuit 110 controls a trigger circuit 108 to discharge a brake-off loop capacitor to a first coil panel 1041 of a repulsion mechanism 104, the first coil panel 1041 and a dynamic connection panel 1042 generate an electromagnetic repulsion force to push the dynamic connection panel 1042 downwards, the dynamic connection panel 1042 pulls a pull rod 103 downwards, and the pull rod 103 pulls a dynamic contact 1012 of the switch 101 downwards, so that the switch 101 is opened, and at this time, the reactor 101 is connected in series to the bus, so that the current-limiting purpose is achieved when a short-circuit fault occurs in a current-limiting device.

When the current limiting device normally works, the switch 101 is in a closing state, and the closing process of the switch 101 is as follows: the control circuit 110 controls the capacitance of the closing circuit of the trigger circuit 108 to discharge to the second coil plate 1043 of the repulsion mechanism 104, the second coil plate 1043 and the movable connecting plate 1042 generate an electromagnetic repulsion force to push the movable connecting plate 1042 upwards, the movable connecting plate 1042 pushes the pull rod 103 upwards, and the pull rod 103 pushes the movable contact 1012 of the switch 101 upwards, so that the purpose of closing the switch 101 is achieved.

Because the trigger circuit 108 is arranged at the ground potential, and the trigger circuit 108 is independently connected with at least two power supplies, the at least two power supplies are independently connected with the trigger circuit 108 to replace the technical means that only a single energy supply device can be configured when the trigger circuit is arranged at the high potential in the conventional technology, and the problem that the current limiting device is stopped due to the fault of the single energy supply device caused by the non-redundancy energy supply can be solved, so that the trigger circuit 108 of the current limiting device is configured at the ground potential, and the trigger circuit 108 is independently connected with the at least two power supplies, the price of the device is reduced, and the availability of the current limiting device can be improved.

Referring further to fig. 1, the first sleeve 106 has a first potential end and a second distal end, the first potential end of the first sleeve 106 is located at the first potential, and the second distal end is the end of the first sleeve 106 away from the repulsive force mechanism 104; the pull rod 103, the second sleeve 107 each have a first potential end which is at a first potential, i.e. a high potential, and the pull rod 103, the second sleeve 107 each have a second potential end which is at a second potential, i.e. a ground potential.

Further referring to fig. 1, the moving contact 1012 of the switch 101 is connected to the first potential end of the first bushing 106 at a first potential, and the stationary contact 1011 of the switch 101 is connected to the first far end of the first bushing 106; the first potential end of the pull rod 103 is connected with the movable contact 1012 of the switch 101 at a first potential, and the second potential end of the pull rod 103 is connected with the movable connecting plate 1042 of the repulsive force mechanism 104 at a second potential; the first potential end of the second sleeve 107 is connected to the first potential end of the first sleeve 106 at a first potential.

In some embodiments, switch 101 is a vacuum arc chamber.

The first sleeve 106 and the second sleeve 107 extend along the longitudinal direction, the first sleeve 106 is butted with the second sleeve 107, a cavity 112 is formed between the inner surface of the first sleeve 106, the inner surface of the second sleeve 107, the outer surface of the switch 101 and the outer surface of the pull rod 103 at intervals, and the cavity 112 is used for filling insulating gas; preferably, the insulating gas filled in the cavity 112 is sulfur hexafluoride.

Because the switch 101 is connected with the reactor 102 in parallel, the reactor 102 is coaxially configured with the switch 101 and is located at a first potential, namely a high potential, specifically, the reactor 102 is coaxially configured on the peripheral surface of the switch 101, and sulfur hexafluoride is filled in the cavity 112 as an insulating gas, so that the effect of reducing the pipe diameter sizes of the first bushing 106 and the second bushing 107 can be realized, the occupied area of the current limiting device is effectively reduced, and the problems that the occupied area of the current limiting device is large due to the fact that the structure responsible for breaking, namely the switch and the reactor are separately arranged, and the current limiting device cannot be installed to replace an original circuit breaker due to the large occupied area in the prior art can be solved, and therefore the application of the current limiting device is expanded.

The utility model discloses a current limiting device, repulsion mechanism 104 and trigger circuit 108 are established ties, and repulsion mechanism 104 all disposes in the second electric potential with trigger circuit 108, trigger circuit 108 connects at least two sets of powers independently, current transformer 109 and switch 101 are established ties, and current transformer 109 and reactor 102 establish ties, current transformer 109 is used for measuring the current value that gets into or flow reactor 102 and switch 101 after connecting in parallel, control circuit 110 respectively with current transformer 109, trigger circuit 108 is connected, control circuit 110 is used for controlling trigger circuit 108 to discharge repulsion mechanism 104 according to current value that current transformer 109 was measured, control repulsion mechanism 104 and switch 101 separating brake or combined floodgate.

The utility model discloses a dispose trigger circuit 108 at the second potential, and trigger circuit 108 disposes at least two ways of power and is used for independently supplying power for trigger circuit 108, can directly cancel the energy supply equipment of expensive high potential to can reduce the equipment price, improve the current limiting device availability simultaneously, thereby can realize solving the problem that the current limiting device availability is low; furthermore, the reactor 102 and the switch 101 are coaxially arranged at the first potential, and the cavity 112 is filled with sulfur hexafluoride, so that the pipe diameters of the first sleeve 106 and the second sleeve 107 can be reduced, and the floor area can be effectively reduced.

The above detailed description is made on the current limiting device provided by the embodiment of the present invention, and the present invention applies a specific embodiment to explain the principle and the implementation of the present invention, and the description of the above embodiment is only used to help understand the technical scheme and the core idea of the present invention; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present invention in its various embodiments.

Claims (12)

1. A current limiting device, comprising:

a switch (101);

a reactor (102) connected in parallel with the switch (101);

a current transformer (109) connected in series with the switch (101), and the current transformer (109) is connected in series with the reactor (102);

a repulsive force mechanism (104) connected to the switch (101);

a trigger circuit (108) connected in series with the repulsive force mechanism (104), the trigger circuit (108) being connected to at least two power supplies;

and the control circuit (110) is respectively connected with the trigger circuit (108) and the current transformer (109), and the control circuit (110) is used for controlling the trigger circuit (108) to discharge the repulsive force mechanism (104) according to the current value measured by the current transformer (109) so as to switch on or switch off the repulsive force mechanism (104) and the switch (101).

2. The current limiting device according to claim 1, wherein the reactor (102) is coaxially arranged on an outer peripheral surface of the switch (101).

3. The current-limiting device of claim 1, further comprising:

a first bushing (106) coaxially fitted between an outer peripheral surface of the switch (101) and an inner peripheral surface of the reactor (102);

a pull rod (103) connected between the repulsion mechanism (104) and the switch (101);

the second sleeve (107) is coaxially sleeved on the outer peripheral surface of the pull rod (103);

a metal disc (105) arranged between the first sleeve (106) and the second sleeve (107), the metal disc (105) being connected to the switch (101);

the second sleeve (107) is connected in series with the metal disc (105) and the first sleeve (106).

4. A current limiting device according to claim 3, wherein the switch (101) comprises a stationary contact (1011) and a movable contact (1012); the metal disc (105) is connected with the movable contact (1012) through a contact finger.

5. The current-limiting device of claim 4, further comprising:

the first busbar (115) is connected with the static contact (1011);

a second busbar (116) connected to the metal disc (105);

a first connection bar (113) connected between the reactor (102) and the first busbar (115);

a second connecting bar (114) connected between the reactor (102) and the second busbar (116);

the current transformer (109) is arranged on the first busbar (115) or the second busbar (116).

6. The current limiting device according to claim 3, wherein the repulsive force mechanism (104) comprises a movable connecting disc (1042), a first coil disc (1041) disposed above the movable connecting disc (1042), and a second coil disc (1043) disposed below the movable connecting disc (1042), one end of the pull rod (103) is connected to the top of the movable connecting disc (1042), and the other end of the pull rod (103) is connected to the switch (101).

7. A current limiting device according to claim 3, characterized in that the switch (101) is a vacuum arc chamber.

8. The current limiting device according to claim 1, wherein the current transformer (109) is an electronic transformer.

9. The current limiting device according to claim 3, wherein the pull rod (103) and the second sleeve (107) are both insulating structural members.

10. The current limiting device according to claim 7, wherein the first sleeve (106) is abutted with the second sleeve (107), and a cavity (112) is formed by the inner surface of the first sleeve (106), the inner surface of the second sleeve (107) and the interval between the switch (101) and the outer surface of the pull rod (103), and the cavity (112) is filled with insulating gas.

11. The current-limiting device of claim 10, wherein the insulating gas is sulfur hexafluoride.

12. Current limiting device according to claim 1, wherein the current transformer (109) is connected to the control loop (110) by means of an optical fiber (111).

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