Contactor and control method thereof

Abstract

The contactor comprises an electromagnetic assembly, a static contact and a movable assembly, the movable assembly comprises a movable contact, a first elastic part and a driving part which are connected, and the first elastic part is configured to generate elastic force supporting the movable assembly; the driving component is configured to generate electromagnetic driving force through a magnetic field generated by the electromagnetic assembly, and the controller is configured to control a movable contact and a static contact of the movable assembly to be closed and respond to the fact that the sensor detects that the driving component generates displacement based on electric repulsive force generated by current flowing through the movable contact and the static contact. And controlling the electromagnetic assembly to adjust the generated magnetic field so as to reduce electromagnetic driving force which is generated by the driving part according to the generated magnetic field and is opposite to the electric repulsive force, so that the movable contact is not closed with the static contact again. According to the contactor disclosed by the invention, fusion welding of the movable contact and the static contact in the short circuit process can be prevented, so that the contactor fault is avoided, and the equipment reliability is improved.

Description

Technical Field

[0001] The invention relates to an electrical device, in particular to a contactor. Background Art

[0002] As a low-voltage control electrical appliance, contactor can frequently connect and disconnect the main circuit and large-capacity control circuit over a long distance. It is low-cost and easy to produce. Therefore, it is widely used in industrial production, transportation, modern agriculture, people's daily life and other occasions.

[0003] Since the contactor needs to be frequently operated during service, it is required to have a long service life. Mechanical life and electrical life are the two main performance indicators of the contactor. Mechanical life refers to the number of no-load operation cycles that the AC contactor can withstand without repair or replacement of any parts. Mechanical life mainly depends on the mechanical strength of the contactor components and the firmness of the mechanical structure. Electrical life, also known as electrical durability, refers to the number of load connections and disconnections of the contactor before the contact fails under the specified connection and disconnection conditions. Usually, the mechanical life of the contactor is much higher than its electrical life. When normal current flows through the contacts, the electric repulsion between the contacts is not very large, so the moving contact and the static contact can still remain closed. When a short-circuit current flows between the contacts, the electric repulsion between the contacts is large, causing the contacts to separate under the action of the electric repulsion, so arcs may appear between the contacts, and the arcs may cause the contacts to melt. When the contacts are closed again, the molten contacts may weld, that is, the moving contact and the static contact are welded together. Summary of the invention

[0004] The present disclosure provides a contactor, comprising: an electromagnetic component, the electromagnetic component is configured to generate a magnetic field, a static contact, a movable component, the movable component comprises a connected movable contact, a first elastic component and a driving component, wherein the movable contact is configured to be operably closed with the static contact, the first elastic component is configured to generate an elastic force supporting the movable component, the driving component is configured to generate an electromagnetic driving force through the magnetic field generated by the electromagnetic component, a sensor, the sensor is configured to detect the displacement of the driving component based on the electric repulsion force generated by the current flowing through the movable contact and the static contact when the movable contact is closed, and a controller, the controller is configured to: control the closure of the movable contact and the static contact of the movable component, and in response to the sensor detecting the displacement of the driving component based on the electric repulsion force generated by the current flowing through the movable contact and the static contact, control the electromagnetic component to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component based on the generated magnetic field and in the opposite direction to the electric repulsion force.

[0005] According to the contactor of the present disclosure, the elastic force is in the opposite direction to the electromagnetic driving force.

[0006] According to the contactor of the present disclosure, wherein the electrodynamic repulsive force acts on the movable component, and the direction of the electrodynamic repulsive force is opposite to the direction from the movable contact to the stationary contact, the electrodynamic repulsive force includes the Lorentz force and the Holm force.

[0007] According to the contactor of the present disclosure, the magnitude of the electrodynamic repulsive force depends on the shape of the current path of the current, and the shapes of the moving contact and the stationary contact.

[0008] According to the contactor disclosed in the present invention, when the controller controls the electromagnetic component not to generate a magnetic field, the elastic force generated by the first elastic component disconnects the moving contact from the static contact, and the situation in which the moving contact and the static contact of the movable component are closed includes: controlling the electromagnetic component to generate a magnetic field, wherein the driving component generates an electromagnetic driving force through the magnetic field generated by the electromagnetic component, the driving component moves at least a first stroke driven by the electromagnetic driving force, and after the driving component moves the first stroke, the moving contact and the static contact of the movable component are closed.

[0009] According to the contactor disclosed in the present invention, the electromagnetic component and the driving component are configured so that when a normal current flows through the closed static contact and the moving contact, the driving component does not displace at least based on the generated electromotive repulsion force and the electromagnetic driving force, and when a short-circuit current flows through the closed static contact and the moving contact, the driving component displaces at least based on the generated electromotive repulsion force and the electromagnetic driving force.

[0010] According to the contactor disclosed in the present invention, the electromagnetic component includes an iron core and a winding surrounding the iron core, wherein controlling the electromagnetic component to generate a magnetic field includes controlling a control current flowing through the winding to control the electromagnetic component to generate a magnetic field, and the driving component includes an armature, and wherein the electromagnetic component is configured by changing the material and shape of the iron core and the number of turns and shape of the winding, and the driving component is configured by changing the material and shape of the armature, so that when a normal current flows through the closed static contact and the moving contact, the driving component does not displace at least based on the generated electromotive repulsion and the electromagnetic driving force, and when a short-circuit current flows through the closed static contact and the moving contact, the driving component is displaced at least based on the generated electromotive repulsion and the electromagnetic driving force.

[0011] According to the contactor of the present disclosure, the contactor comprises a permanent magnet contactor.

[0012] According to the contactor disclosed in the present invention, the electromagnetic component includes an iron core and a winding surrounding the iron core, wherein controlling the electromagnetic component to generate a magnetic field includes controlling a control current flowing through the winding to control the electromagnetic component to generate a magnetic field, the driving component includes an armature, and wherein the controller is configured to control the control current flowing through the winding so that when a normal current flows through the closed static contact and the moving contact, the driving component does not displace at least based on the generated electromotive repulsion force and the electromagnetic driving force, and when a short-circuit current flows through the closed static contact and the moving contact, the driving component displaces at least based on the generated electromotive repulsion force and the electromagnetic driving force.

[0013] According to the contactor disclosed in the present invention, the movable component includes a second elastic component, wherein the second elastic component is configured to provide pressure to the movable contact in a direction toward the static contact when the movable contact and the static contact are closed, and wherein the driving component is displaced based on the electrostatic repulsive force generated by the current flowing through the movable contact and the static contact, including that the movable contact displaces the driving component after the second elastic component is actuated based on the electrostatic repulsive force.

[0014] According to the contactor disclosed in the present invention, in response to the sensor detecting that the electric repulsive force generated by the driving component based on the current flowing through the moving contact and the static contact has been displaced, controlling the electromagnetic component to adjust the generated magnetic field includes: in response to the sensor detecting that the displacement of the electric repulsive force generated by the driving component based on the current flowing through the moving contact and the static contact is greater than the second stroke, controlling the electromagnetic component to adjust the generated magnetic field.

[0015] According to the contactor of the present disclosure, wherein the second stroke is at least 85% of the first stroke.

[0016] According to the contactor disclosed in the present invention, controlling the electromagnetic component to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component in the opposite direction to the electromotive repulsive force according to the generated magnetic field includes: controlling the electromagnetic component not to generate the magnetic field to reduce the electromagnetic driving force of the driving component to zero, so that the moving contact and the static contact are not closed again.

[0017] According to the contactor disclosed in the present invention, the contactor is a main circuit AC contactor, wherein the static contacts include at least three static contacts corresponding to the three-phase current, and the moving contacts include at least three moving contacts respectively configured in pairs with the three static contacts, and the three moving contacts are configured to be operably closed with the three static contacts respectively.

[0018] According to the contactor disclosed herein, the electromotive repulsion generated on the closed static contacts and the moving contacts corresponding to two phases of the three-phase current is greater than the electromotive repulsion generated on the closed static contacts and the moving contacts corresponding to the other phase of the three-phase current.

[0019] According to the contactor disclosed herein, the contactor is a main circuit DC contactor.

[0020] According to the contactor of the present disclosure, the short circuit current magnitude is at least 10,000 amperes.

[0021] According to the contactor disclosed in the present invention, the sensor is a current sensor, which is configured to detect the displacement of the driving component caused by the electrostatic repulsion generated by the current flowing through the moving contact and the static contact by determining the change of control current caused by the change of the positional relationship between the driving component and the electromagnetic component when the driving component is displaced, wherein the controller is configured to control the electromagnetic component to adjust the generated magnetic field in response to the change of control current detected by the current sensor.

[0022] According to the contactor of the present disclosure, the contactor comprises a normally closed contactor.

[0023] The present disclosure provides a method for controlling a contactor, comprising: controlling, by a controller, the closing of a moving contact and a stationary contact of a movable component, wherein the movable component comprises a connected moving contact, a first elastic component and a driving component, wherein the moving contact is configured to be operably closed with the stationary contact, the first elastic component is configured to generate an elastic force supporting the moving component, the driving component is configured to generate an electromagnetic driving force through a magnetic field generated by an electromagnetic component, in response to a sensor detecting that an electric repulsive force generated by the driving component based on a current flowing through the moving contact and the stationary contact is displaced, the controller controls the electromagnetic component to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component based on the generated magnetic field and in a direction opposite to the electric repulsive force, so that the moving contact does not close with the stationary contact again.

[0024] According to the contactor disclosed in the present invention, when the normal current of the main circuit flows through the contactor, the moving contact and the static contact are closed. When the short-circuit current of the main circuit flows through the contactor, the moving contact and the static contact are disconnected due to the electric repulsion and melted due to the electric arc. When it is detected that the moving contact and the static contact are disconnected due to the electric repulsion caused by the short-circuit current, the electromagnetic force in the opposite direction of the electric repulsion is reduced, so that the moving contact and the static contact cannot be closed again, and the moving contact and the static contact are prevented from being welded, thereby avoiding contactor failure and improving equipment reliability. The mechanism for preventing contact welding during short circuit according to the present invention can be applied to contactors of various shapes and various types or structures of main circuit current paths, and therefore has good flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0026] Figure 1 It is a contactor.

[0027] Figure 2a is a schematic diagram of the Lorentz force in the contactor.

[0028] Figure 2b is a schematic diagram of the Holm force in the contactor.

[0029] Figure 3a A contactor in which a moving contact and a stationary contact are in a closed state according to an embodiment of the present disclosure,

[0030] Figure 3b is a schematic diagram of a short-circuit current path of a main loop current of a contactor according to an embodiment of the present disclosure,

[0031] Figure 3c The contactor is a contactor in which the moving contact and the stationary contact are in a disconnected state according to an embodiment of the present disclosure,

[0032] Figure 4 is a flow chart of a control method of a contactor according to the present disclosure. DETAILED DESCRIPTION

[0033] Before proceeding to the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this disclosure. The terms "include" and "comprises" and their derivatives mean including but not limited to. The term "controller" or "control unit" refers to any device, system, or part thereof that controls at least one operation. Such a controller may be implemented with hardware, or a combination of hardware and software and / or firmware. For example, a controller may include, for example, an application specific integrated circuit (ASIC), a general or dedicated central processing unit (CPU), a digital signal processor (DSP), and a programmable logic device, such as a field programmable gate array (FPGA). The controller may be manufactured as a single printed circuit board (PCB) or distributed on several interconnected PCBs. The controller may contain other processing circuits, for example, a controller may include two processing circuits such as an FPGA and a CPU interconnected on a PCB. The functions associated with any particular controller may be centralized or distributed, whether local or remote. Controller. The phrase "at least one", when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be required. For example, “at least one of A, B, and C” includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A, B, and C.

[0034] Definitions for other specific words and phrases are provided throughout this disclosure. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior and future uses of such defined words and phrases.

[0035] The various embodiments of the principles of the present disclosure described below in conjunction with the accompanying drawings are only for illustration, and should not be interpreted as limiting the scope of the present disclosure in any way. It will be appreciated by those skilled in the art that the principles of the present disclosure can be implemented in any appropriately arranged system or device. In some cases, the actions described in the present disclosure can be performed in different orders, and the desired results can still be achieved. In addition, the process depicted in the accompanying drawings does not necessarily require the specific order shown or the sequential order to achieve the desired results. In a specific embodiment, multitasking and parallel processing may be advantageous.

[0036] The text and drawings are provided as examples only to help understand the present disclosure. They should not be interpreted as limiting the scope of the claims attached to the present disclosure in any way. Although certain embodiments and examples have been provided, it is clear to those skilled in the art based on the content of the present disclosure that the embodiments and examples shown can be changed without departing from the scope of the present disclosure.

[0037] Figure 1 It is a contactor. Figure 1 The contactor shown is an electromagnetic contactor.

[0038] like Figure 1 As shown, Figure 1 The contactor may include a moving contact 101 , a stationary contact 102 , a moving contact elastic component 103 , a driving component 104 , a main elastic component 105 , a winding 106 , an iron core 107 , and a connecting component 108 .

[0039] The moving contact 101 can be configured to be operably closed with the stationary contact 102 to conduct the current flowing through the main circuit. The materials forming the moving contact 101 and the stationary contact 102 can include but are not limited to silver, silver alloy, tungsten, tungsten alloy, copper alloy such as copper-cobalt alloy, etc. The shapes of the moving contact 101 and the stationary contact 102 can include point shape, sheet shape, spherical shape, pile shape, etc.

[0040] The movable contact elastic component 103 can provide the movable contact 101 with pressure toward the static contact 103 when the movable contact 101 and the static contact 103 are closed, so as to make the movable contact 101 and the static contact 103 close more reliably. The movable contact elastic component 103 can include an elastic component such as a spring.

[0041] A control current may flow through the winding 106. When the control current flows through the winding, the winding 106 may generate a magnetic field in the iron core 107. The winding 106 and the iron core 107 may be collectively referred to as an electromagnetic component.

[0042] The driving component 104 can generate an electromagnetic driving force according to the magnetic field generated by the winding 106 and the iron core 107, and drive the movable assembly including the movable contact 101, the connecting component 108 and the driving component 104 to move through the electromagnetic driving force. For example, the movable assembly can be driven to move toward the winding 106 and the iron core 107, so that the movable contact 101 is closed with the static contact 102. The driving component 104 can be, for example, an armature.

[0043] The main elastic component 105 can provide the movable component with a force in the opposite direction to the electromagnetic driving force generated by the electromagnetic component on the driving component 104. For example, when the electromagnetic component does not generate a magnetic field, the main elastic component 105 can provide an upward supporting force for the movable component so that the moving contact and the static contact are not closed. The main elastic component 105 may include an elastic component such as a spring.

[0044] When the normal current of the main circuit flows through the closed static contact 102 and the moving contact 101, the static contact 102 and the moving contact 101 can remain closed. When a short-circuit current much greater than the normal current flows through the closed static contact 102 and the moving contact 101, the closed static contact 102 and the moving contact 101 may be disconnected due to the electromotive repulsion generated by the short-circuit current. The electromotive repulsion may include the Lorentz force and the Holm force. After the disconnection, an arc may appear between the static contact 102 and the moving contact 101, causing the static contact 102 and the moving contact 101 to melt. When the moving contact 101 falls back, the molten static contact 102 and the moving contact 101 may weld, causing the contactor to fail or be damaged. The national standard GB 14048.4 stipulates:

[0045] "Contactor and starter manufacturers should recommend an appropriate short-circuit protection device (SCPD) and provide the relevant characteristics of this SCPD. The rated value of the recommended SCPD should be applicable to all given rated operating currents, rated operating voltages and corresponding usage categories.

[0046] …

[0047] There are two types of coordination (protection types):

[0048] Type 1 coordination requires that the contactor or starter should not cause harm to people and equipment under short-circuit conditions, and it is allowed not to continue to be used before repairing and replacing parts;

[0049] "2" type coordination requires that the contactor or starter should not cause harm to people and equipment under short-circuit conditions, and should be able to continue to be used. Contact welding is allowed, but the manufacturer should specify the method used for equipment maintenance.

[0050] That is to say, in the national standard, when a short-circuit current flows through the contactor, it is allowed not to use the contactor before repairing and replacing parts, or it is allowed to continue to use the contactor but the manufacturer should specify the repair method in the case of contact welding.

[0051] Figure 2a is a schematic diagram of the Lorentz force in the contactor.

[0052] like Figure 2a As shown in the figure, the current of the main circuit flows through the moving conductive rod, the closed moving contact and the static contact, and the U-shaped static conductive rod. The direction of the current flowing through the moving conductive rod is opposite to that of the current flowing through the static conductive rod. Based on the basic principle of electromagnetic field, it can be known that the mutually repelling electromotive force is generated between the opposite currents, and this electromotive repulsion is called the Lorentz force. The Lorentz force is mainly affected by the shape of the current path.

[0053] Figure 2b is a schematic diagram of the Holm force in the contactor.

[0054] Since the closing surfaces of the moving contact and the stationary contact are not completely flat, when the moving contact and the stationary contact are closed, the actual closing area is a few conductive spots of the moving contact and the stationary contact. When the current of the main circuit flows through the conductive spots, the current line shrinks. According to the basic principle of electromagnetic field, the shrinking current line will generate electromotive repulsion on the moving contact and the stationary contact, which is called Holm force. Holm force is mainly affected by the shape of the contact.

[0055] When a large short-circuit current flows through the closed moving and stationary contacts, the electrodynamic repulsive forces including the Lorentz force and the Holm force may be large.

[0056] Figure 3a The invention relates to a contactor in which a moving contact and a stationary contact are in a closed state according to an embodiment of the present invention. Figure 3b Schematic diagram of the short-circuit current path of the main loop current of the contactor according to an embodiment of the present disclosure. Figure 3c The invention relates to a contactor in which a moving contact and a stationary contact are in a disconnected state according to an embodiment of the present disclosure. Figure 3a-3c The contactor shown is an electromagnetic contactor.

[0057] like Figure 3a The contactor shown may include a stationary contact 302, a movable assembly, an electromagnetic assembly, and a controller (not shown) and a sensor (not shown). Figure 3a The moving contact 301 and the stationary contact 302 of the contactor are in a closed state.

[0058] The electromagnetic component may include a winding 305 and an iron core 306. The electromagnetic component may be configured to generate a magnetic field. Specifically, a control current may flow through the winding 305. When the control current flows through the winding, the winding 305 may generate a magnetic field in the iron core 306.

[0059] The movable assembly may include a connected movable contact 301, a driving component 304, and a first elastic component 307. The description of the movable contact 301, the stationary contact 302, and the driving component 304 may be similar to Figure 1 301 and the static contact 102 and the driving component 104 are described. The moving contact 301 can be configured to be operably closed with the static contact. The first elastic component 307 can be configured to generate an elastic force that supports the movement of the movable component. The first elastic component 307 may include an elastic component such as a spring. The driving component 304 can be configured to generate an electromagnetic driving force through a magnetic field generated by an electromagnetic component. For example, the direction of the electromagnetic driving force is opposite to the direction of the elastic force. In one embodiment, the movable component may also include a connecting component 308, which connects the moving contact 301, the first elastic component 307, and the driving component 304 to form a movable component. Alternatively, the moving contact 301, the first elastic component 307, and the driving component 304 of the movable component can be connected together to form a movable component without the connecting component 308.

[0060] The sensor can be configured to detect the displacement of the driving component 304 caused by the electromotive force generated by the main circuit current flowing through the moving contact and the stationary contact when the moving contact and the stationary contact are closed. Figure 3b As shown, this is only for illustration. Figure 2a and Figure 2b As can be seen from the description, the main loop short-circuit current flowing through the moving contact and the stationary contact can generate an electrostatic repulsion force, which may be large enough to cause the driving component 304 of the movable component to be displaced due to the electrostatic repulsion force.

[0061] The controller can be configured to control the moving contact 301 and the static contact 302 of the moving component to close, and in response to the sensor detecting that the moving component is displaced by the electromotive repulsive force generated by the current flowing through the closed moving contact 301 and the static contact 302, control the electromagnetic component to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component according to the generated magnetic field in the opposite direction to the electromotive repulsive force. By reducing the electromagnetic driving force, the moving contact 301 can no longer fall back based on the elastic force of the first elastic component 307.

[0062] According to the contactor of the embodiment of the present disclosure, when a short circuit occurs in the main circuit of the contactor, the moving contact and the static contact are disconnected due to the electric repulsion and melted due to the arc, the controller can control the moving contact not to fall back to the static contact, so that the moving contact and the static contact do not weld, thereby avoiding damage to the moving contact and the static contact, and ensuring that the contactor can still maintain its function after the short circuit. Since the contactor of the embodiment of the present disclosure does not weld the moving and static contacts, the performance of the contactor is higher than the relevant provisions in the national standard GB 14048.4, and can simultaneously meet the "1" type coordination and "2" type coordination in GB 14048.4.

[0063] In one embodiment, when the controller controls the electromagnetic assembly to not generate a magnetic field, the elastic force generated by the first elastic component 307 can disconnect the moving contact 302 from the static contact 301. Figure 3c shown.

[0064] according to Figure 3a-3c When the user wants to connect the main circuit through the contactor, the controller can control the electromagnetic component to generate a magnetic field. The driving component 304 generates an electromagnetic driving force through the magnetic field generated by the electromagnetic component. The driving component 304 moves at least a first stroke under the drive of the electromagnetic driving force. After the driving component 304 moves the first stroke, the moving contact and the static contact of the movable component are reliably closed, such as Figure 3a shown.

[0065] When a normal current flows through the closed static contact 301 and the moving contact 304, the driving component 304 does not displace at least based on the generated electric repulsion and electromagnetic driving force. When a short-circuit current flows through the closed static contact and the moving contact, the driving component 304 is displaced at least based on the generated electric repulsion and electromagnetic driving force. For example, the short-circuit current can be at least 10,000 amperes. It should be understood by those skilled in the art that, according to the design results of the electric repulsion and electromagnetic force, considering the corresponding minimum non-melting welding short-circuit current threshold under different current frames, short-circuit currents of other sizes are also possible. For example, when a short-circuit current flows through the closed static contact and the moving contact, a large electric repulsion force acting on the movable component may be generated, which is sufficient to disconnect the moving contact from the static contact, thereby displacing the driving component 304 according to the embodiment of the present disclosure. When the moving contact 301 and the static contact 302 are disconnected due to the electric repulsion, an arc that can melt the moving and static contacts is generated between the moving contact 301 and the static contact 302. When the sensor detects that the driving component 304 is displaced due to the electric repulsion force generated by the short-circuit current, the controller can control the electromagnetic component to adjust the generated magnetic field. For example, the electromagnetic component can be controlled to reduce the generated magnetic field, thereby reducing the electromagnetic driving force on the driving component. For example, the electromagnetic component can be controlled not to generate a magnetic field to reduce the electromagnetic driving force of the driving component to zero. As a result, the force acting on the driving component in the same direction as the electric repulsion force (for example, the electric repulsion force itself, the elastic force of the first elastic component 307, etc.) is greater than the force in the opposite direction of the electric repulsion force (for example, the electromagnetic driving force, gravity, etc.). In order not to obscure the present invention, the specific force analysis is not described in detail here. Figure 3c As shown, in this way, for example, the driving component 304 can move upward and return to the first stroke, so that the molten movable contact 301 no longer falls back due to the elastic force of the first elastic component 307, or the driving component 304 can move upward and return to a stroke smaller than the first stroke, but still can make the molten movable contact 301 no longer fall back due to the electromagnetic driving force and the elastic force of the first elastic component 307. Therefore, the molten movable contact 301 and the static contact 302 are not welded.

[0066] In one embodiment, when the controller determines through the sensor that the driving component 304 has any displacement due to the electric repulsion generated by the main circuit current, the controller can control the electromagnetic assembly to adjust the generated magnetic field. In another embodiment, in response to the sensor detecting that the displacement of the driving component 304 based on the electric repulsion generated by the current flowing through the moving contact and the static contact is greater than the second stroke, the electromagnetic assembly can be controlled to adjust the generated magnetic field. For example, the second stroke can be at least 85% of the first stroke. In this way, the misoperation of the contactor electromagnetic assembly with respect to adjusting the magnetic field can be reduced, thereby improving the reliability of the contactor.

[0067] Different electromagnetic driving forces can be configured to cooperate with contactors of different structures (for example, contactors with various main circuit current paths and various contact shapes). For example, different driving components, electromagnetic components, and control currents flowing through the electromagnetic components can be configured to cooperate with contactors of different structures to prevent welding from occurring during a short circuit.

[0068] In one embodiment, the electromagnetic assembly or the driving component can be configured so that the electromagnetic assembly and the driving component are matched with contacts of various shapes and the contactor of the main circuit current path, so that when the normal current flows through the closed static contact 301 and the moving contact 304, the driving component 304 does not displace at least based on the generated electromotive repulsion and the electromagnetic driving force. When the short-circuit current flows through the closed static contact and the moving contact, the driving component 304 is displaced at least based on the generated electromotive repulsion and the electromagnetic driving force. For example, the electromagnetic assembly can be configured by changing the material and shape of the iron core 306 and the number of turns and shape of the winding 305. For example, the driving component can be configured by changing the material and shape of the armature 304.

[0069] In one embodiment, the control current flowing through the electromagnetic assembly can be configured to match various shapes of contacts and contactors of the main circuit current path, so that when the normal current flows through the closed static contact 301 and the moving contact 304, the driving component 304 does not displace at least based on the generated electromotive repulsion and electromagnetic driving force. When the short-circuit current flows through the closed static contact and the moving contact, the driving component 304 displaces at least based on the generated electromotive repulsion and electromagnetic driving force.

[0070] In one embodiment, Figure 3a-3c The contactor shown may also include a second elastic component 303. The second elastic component 303 is configured to provide pressure in the direction toward the static contact for the moving contact 301 when the moving contact 301 and the static contact 302 are closed, so that the moving contact 301 and the static contact 302 are closed more reliably. When a short-circuit current flows through the closed moving contact 301 and the static contact 302, the moving contact 301 causes the second elastic component 301 to actuate based on the electromotive repulsion, and after the second elastic component 303 is actuated, the driving component 304 is displaced. The second elastic component 303 may be an elastic component such as a spring. In addition, when the second elastic component 303 provides pressure for the moving contact 301 to make the moving contact 301 and the static contact 302 closed more reliably, the second elastic component 303 may be in a compressed state. However, those skilled in the art should understand that by configuring the second elastic component 303 at different positions, the second elastic component 303 may provide pressure for the moving contact 301 to make the closure reliable when it is in a stretched state.

[0071] like Figure 3a-3cThe contactor shown can be an AC contactor. The AC contactor can include at least three static contacts 302 corresponding to the three-phase current. And the AC contactor can include at least three moving contacts 301 configured in pairs with the three static contacts 302 respectively. The three moving contacts 301 are configured to be operably closed with the three static contacts 302 respectively. In this way, the three-phase AC current of the main circuit can flow through the contactor through three pairs of contacts respectively. The three pairs of contacts can correspond to a drive component and an electromagnetic assembly. When a short-circuit current flows through the contact pair, the electromotive force generated on the closed static contact 302 and the moving contact 301 corresponding to two phases of the three-phase current may be greater than the electromotive force generated on the closed static contact 302 and the moving contact 301 corresponding to the other phase of the three-phase current. By analyzing the electric repulsion on the three pairs of contacts through which the three-phase current flows, or mainly analyzing the larger electric repulsion on two pairs of contacts, different drive components, electromagnetic components, and control currents flowing through the electromagnetic components can be configured to cooperate with contactors of different structures (for example, contactors with different main circuit current path shapes and different contact shapes), thereby avoiding welding of molten contacts during short circuits. Those skilled in the art should understand that, depending on the use scenario of the contactor, more pairs of contacts can be configured for the contactor, and by analyzing the electric repulsion of the contacts, different electromagnetic drive forces can be configured for cooperation, for example, by configuring different drive components, electromagnetic components, and control currents flowing through the electromagnetic components for cooperation. Figure 3a-3c The contactor shown may also be a DC contactor. The DC contactor may include a pair of contacts corresponding to unipolarity, or two pairs of contacts corresponding to bipolarity, etc. By analyzing the electromotive repulsion of the contacts of the DC contactor, different drive components, electromagnetic components, and control currents flowing through the electromagnetic components may be configured for coordination.

[0072] In one embodiment, the sensor may be any sensor capable of directly or indirectly detecting the movement of the drive component 304, such as a current sensor, a position sensor, an inertial sensor, a proximity sensor, etc., but the present disclosure is not limited thereto. For example, the current sensor may be configured to detect the displacement of the drive component based on the electrostatic repulsion generated by the current flowing through the moving contact and the static contact by determining the change in the control current caused by the change in the positional relationship between the drive component and the electromagnetic component when the drive component 304 is displaced due to the electrostatic repulsion. And the controller may be configured to control the electromagnetic component to adjust the generated magnetic field in response to the change in the control current detected by the current sensor, for example, in the winding 305.

[0073] Although the above-mentioned contactor according to the embodiment of the present disclosure is shown, it can be understood by those skilled in the art that the technicians who benefit from the present disclosure can apply the contact welding prevention mechanism of the present disclosure to various combinations of various contactors including electromagnetic contactors / permanent magnet contactors, AC contactors / DC contactors, normally open contactors / normally closed contactors, etc., as well as various other types of contactors.

[0074] Figure 4 is a flow chart of a control method of a contactor according to the present disclosure.

[0075] In S402, the controller controls the closure of the moving contact and the static contact of the active component, wherein the active component includes a connected moving contact, a first elastic component and a driving component, wherein the moving contact is configured to be operably closed with the static contact, the first elastic component is configured to generate an elastic force to support the active component, and the driving component is configured to generate an electromagnetic driving force through a magnetic field generated by an electromagnetic component.

[0076] For example, a relationship can be established between the electromagnetic driving force generated by the magnetic field generated by the electromagnetic component and the electromotive repulsion force generated by the moving contact, to ensure that after a short-circuit current exceeding a certain threshold occurs and flows through the moving contact, the driving component can be displaced under the electromotive repulsion force and the electromagnetic driving force.

[0077] At S404, in response to the sensor detecting that the driving component has displaced the electrostatic repulsive force generated by the current flowing through the moving contact and the static contact, the controller controls the electromagnetic component to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component in the opposite direction to the electrostatic repulsive force based on the generated magnetic field, so that the moving contact does not close with the static contact again.

[0078] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

[0079] Any description in the present invention should not be construed as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of the patented subject matter is limited solely by the claims.

Claims

1. A contactor, comprising: an electromagnetic assembly configured to generate a magnetic field, static contact, A movable component, the movable component comprising a connected movable contact, a first elastic component and a driving component, wherein the movable contact is configured to be operably closed with the static contact, the first elastic component is configured to generate an elastic force supporting the movable component, and the driving component is configured to generate an electromagnetic driving force through a magnetic field generated by the electromagnetic component, a sensor configured to detect displacement of the driving member due to electrodynamic repulsion generated by current flowing through the moving contact and the stationary contact when the moving contact and the stationary contact are closed, and A controller, the controller being configured to: Controlling the closing of the moving contact and the stationary contact of the movable component, in response to the sensor detecting that the driving component is displaced by the electromotive repulsive force generated by the current flowing through the moving contact and the stationary contact, The electromagnetic assembly is controlled to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component according to the generated magnetic field and in the opposite direction to the electromotive repulsive force, so that the moving contact does not close with the static contact again.

2. The contactor according to claim 1, wherein: The elastic force is in the opposite direction to the electromagnetic driving force.

3. The contactor according to claim 1, wherein: The electrodynamic repulsive force acts on the movable component, and the direction of the electrodynamic repulsive force is opposite to the direction from the movable contact to the stationary contact. The electrodynamic repulsive force includes Lorentz force and Holm force.

4. The contactor according to claim 3, wherein: The magnitude of the electrodynamic repulsive force depends on the shape of the current path of the current, and the shapes of the moving contact and the stationary contact.

5. The contactor according to claim 1, wherein: When the controller controls the electromagnetic assembly not to generate a magnetic field, the elastic force generated by the first elastic component disconnects the moving contact from the static contact, and, Among them, controlling the closing of the moving contact and the static contact of the movable component includes: controlling the electromagnetic component to generate a magnetic field, wherein the driving component generates an electromagnetic driving force through the magnetic field generated by the electromagnetic component, The driving component moves at least a first stroke under the driving force of the electromagnetic driving force. After the driving component moves the first stroke, the moving contact and the static contact of the movable component are closed.

6. The contactor according to claim 5, wherein: The electromagnetic assembly and the driving component are configured such that when a normal current flows through the closed static contacts and the moving contacts, the driving component does not displace at least based on the generated electromotive repulsion force and the electromagnetic driving force, and when a short-circuit current flows through the closed static contacts and the moving contacts, the driving component displaces at least based on the generated electromotive repulsion force and the electromagnetic driving force.

7. The contactor according to claim 6, wherein: The electromagnetic component comprises an iron core and a winding surrounding the iron core, wherein controlling the electromagnetic component to generate a magnetic field comprises controlling a control current flowing through the winding to control the electromagnetic component to generate a magnetic field, the driving component comprises an armature, and, The electromagnetic component is configured by changing the material and shape of the iron core and the number of turns and shape of the winding, and the driving component is configured by changing the material and shape of the armature, so that when a normal current flows through the closed static contact and the moving contact, the driving component does not displace at least based on the generated electric repulsion force and the electromagnetic driving force, and when a short-circuit current flows through the closed static contact and the moving contact, the driving component displaces at least based on the generated electric repulsion force and the electromagnetic driving force.

8. The contactor according to claim 1, wherein: The contactor comprises a permanent magnet contactor.

9. The contactor according to claim 5, wherein: The electromagnetic component includes an iron core and a winding surrounding the iron core, wherein controlling the electromagnetic component to generate a magnetic field includes controlling a control current flowing through the winding to control the electromagnetic component to generate a magnetic field, the driving component includes an armature, and wherein the controller is configured to control the control current flowing through the winding so that when a normal current flows through the closed static contact and the moving contact, the driving component does not displace at least based on the generated electric repulsion force and the electromagnetic driving force, and when a short-circuit current flows through the closed static contact and the moving contact, the driving component displaces at least based on the generated electric repulsion force and the electromagnetic driving force.

10. The contactor according to claim 1, wherein: The movable assembly includes a second elastic component, wherein the second elastic component is configured to provide pressure to the movable contact in a direction toward the static contact when the movable contact and the static contact are closed, and, The displacement of the driving component based on the electrodynamic repulsive force generated by the current flowing through the moving contact and the stationary contact includes displacing the driving component after the moving contact causes the second elastic component to actuate based on the electrodynamic repulsive force.

11. The contactor according to claim 5, wherein: In response to the sensor detecting that the driving component is displaced by the electromotive repulsive force generated by the current flowing through the moving contact and the stationary contact, controlling the electromagnetic assembly to adjust the generated magnetic field includes: In response to the sensor detecting that the displacement of the driving component generated by the electromotive repulsive force based on the current flowing through the movable contact and the stationary contact is greater than the second stroke, the electromagnetic assembly is controlled to adjust the generated magnetic field.

12. The contactor according to claim 11, wherein: The second stroke is at least 85% of the first stroke.

13. The contactor according to claim 1, wherein: Controlling the electromagnetic assembly to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component according to the generated magnetic field and in the opposite direction to the electromotive repulsive force includes: The electromagnetic assembly is controlled not to generate a magnetic field, so as to reduce the electromagnetic driving force of the driving component to zero, so that the moving contact does not close with the stationary contact again.

14. The contactor according to claim 5, wherein: The contactor is a main circuit AC contactor, wherein the static contacts include at least three static contacts corresponding to three-phase currents, and the moving contacts include at least three moving contacts respectively configured in pairs with the three static contacts, and the three moving contacts are configured to be operably closed with the three static contacts respectively.

15. The contactor according to claim 14, wherein: The electromotive repulsive force generated on the closed static contacts and the movable contacts corresponding to two phases of the three-phase current is greater than the electromotive repulsive force generated on the closed static contacts and the movable contacts corresponding to the other phase of the three-phase current.

16. The contactor according to claim 5, wherein: The contactor is a main circuit DC contactor.

17. The contactor according to claim 6, wherein: The short-circuit current is at least 10,000 amperes.

18. The contactor according to claim 7-9, wherein: The sensor includes a current sensor configured to detect the displacement of the driving component caused by the electromotive repulsive force generated by the current flowing through the moving contact and the stationary contact by determining the change of the control current caused by the change of the positional relationship between the driving component and the electromagnetic assembly when the driving component is displaced, The controller is configured to control the electromagnetic component to adjust the generated magnetic field in response to the change of the control current detected by the current sensor.

19. The contactor according to claim 1, wherein: The contactor includes a normally closed contactor.

20. A method for controlling a contactor, comprising: The controller controls the closing of the moving contact and the static contact of the active component. The movable component includes a connected movable contact, a first elastic component and a driving component, wherein the movable contact is configured to be operably closed with the static contact, the first elastic component is configured to generate an elastic force to support the movable component, and the driving component is configured to generate an electromagnetic driving force through a magnetic field generated by an electromagnetic component. In response to the sensor detecting that the driving component has displaced the electric repulsive force generated by the current flowing through the moving contact and the stationary contact, the controller controls the electromagnetic component to adjust the generated magnetic field to reduce the electromagnetic driving force generated by the driving component in the opposite direction to the electric repulsive force based on the generated magnetic field, so that the moving contact does not close with the stationary contact again.

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