Switching device, energy storage system and control method of charging and discharging circuit

Abstract

The invention discloses a switching device, an energy storage system and a control method of a charging and discharging circuit, the switching device is used for the charging and discharging circuit, the charging and discharging circuit comprises a main loop and a pre-charging circuit, and the main loop comprises at least two branches; comprising first switches respectively arranged corresponding to each branch, and each first switch is respectively used for being connected to the corresponding branch; and the second switch is used for being connected with the pre-charging circuit in parallel, and the second switch is also used for being connected with one of the first switches in series on the branch where the first switch is located. The switching device provided by the invention has the advantages of fewer devices, simpler structure and control logic, lower cost and reduced occupied space while meeting the control function of the charging and discharging circuit.

Description

Technical Field

[0001] The present invention relates to the field of switch technology, and in particular to a switch device and a control method for a battery energy storage system and a charging and discharging circuit. Background Art

[0002] In the current energy storage system, each battery cluster has a high-voltage box to control the charging and discharging of the battery. The working voltage of the high-voltage box in the industry ranges from 1000VDC to 2000VDC, and the working current ranges from 200A to 400A. The high-voltage box usually includes an isolating switch, two main contactors and a pre-charge circuit contactor with a series resistor. The positive and negative poles are short-circuit protected by fuses and current monitored by Hall sensors.

[0003] The traditional high-voltage box electrical circuit control switch adopts the solution of 2 high-voltage DC contactors (main positive and main negative) + 1 pre-charge contactor + isolation switch. It requires more components, larger installation space, cumbersome assembly and more complex control logic.

[0004] To this end, a new type of high-voltage box has emerged in the prior art, which integrates the functions of the switch group in the traditional high-voltage box and only includes two main contactors and two pre-charge contactors, reducing a certain amount of volume and cost. However, the pre-charge contactor is connected in parallel to the main contactor, which means that the pre-charge contactor and the main contactor must both have the isolation capability of a working voltage of 1000VDC to 2000VDC. However, due to space limitations, the electrical clearance of the pre-charge contactor is difficult to meet safety requirements. Summary of the invention

[0005] In view of the technical problems existing in the prior art, the present invention provides a switch device, an energy storage system and a control method for a charge and discharge circuit, which, through structural improvement, satisfies the control function of the charge and discharge circuit while achieving the purpose of simplifying the structure, reducing costs and meeting safety requirements.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a switch device for a charging and discharging circuit, wherein the charging and discharging circuit includes a main circuit and a pre-charging circuit, and the main circuit includes at least two branches; including:

[0007] A first switch is provided for each branch, each first switch is used to be connected to the corresponding branch;

[0008] The second switch is used to be connected in parallel with the pre-charging circuit, and the second switch is also used to be connected in series with one of the first switches on the branch where the one of the first switches is located.

[0009] In a preferred embodiment, the first switches are arranged in linkage to be closed or opened synchronously; and further include a first driving mechanism for driving the first switches to be closed or opened, and a second driving mechanism for driving the second switches to be closed or opened.

[0010] In a preferred embodiment, a third switch is further included, which is used to be connected in series with the pre-charging circuit; the opening and closing state of the third switch is opposite to the opening and closing state of the second switch, and the third switch is driven by the second driving mechanism to be closed or opened.

[0011] In a preferred embodiment, the second driving mechanism includes an electromagnetic assembly, and the armature of the electromagnetic assembly links the second switch and the third switch to be turned on or off when switching between the attracted and released states.

[0012] In a preferred embodiment, the first driving mechanism includes a rotating shaft and a motor for providing a rotational driving force for the rotating shaft, the first switch includes a first moving contact, a first stationary contact and an actuator, and the rotating shaft is rotated to link the actuator to rotate, so that the actuator drives the first moving contact to contact or separate from the first stationary contact.

[0013] In a preferred embodiment, the rotating shaft can be driven to rotate by human power, and the first driving mechanism also includes a control component for controlling whether the circuit where the motor is located is turned on or off; the control component includes a control switch connected in series with the motor, and the control switch is driven to close or open by a control member, and the control member can be operated.

[0014] In a preferred embodiment, the first driving mechanism further includes an energy storage component, the rotating shaft stores energy by rotating the energy storage component, and the energy storage component drives the actuator to rotate by releasing the stored energy, so that the first switch is closed or opened.

[0015] In a preferred embodiment, the rotating shaft is provided with a driving wheel, the actuator includes a driven wheel, the energy storage assembly includes an energy storage driving wheel and at least one movable component, the movable component includes a movable rod, a push rod and an energy storage spring, the energy storage driving wheel is located between the driving wheel and the driven wheel, the push rod is provided on the energy storage driving wheel, and one end of the push rod is adapted to be slidably connected to a first arc hole provided on the driving wheel, and the other end of the push rod is adapted to be slidably connected to a second arc hole provided on the driven wheel; the movable rod is rotatably and slidably provided on a fixed seat located outside the energy storage driving wheel, and one end of the movable rod is movably connected to the push rod, the energy storage spring is sleeved on the movable rod, and is engaged between the push rod and the fixed seat.

[0016] In a preferred embodiment, the actuator includes a contact support, the first stationary contacts are provided with two, the first moving contact is provided on the contact support, and rotates together with the contact support, so that the two ends of the first moving contact are respectively in contact with or separated from the two first stationary contacts;

[0017] The second switch includes a second moving contact and a second stationary contact that cooperate with each other, and the second stationary contact is integrally formed with or electrically connected to one of the first stationary contacts.

[0018] In a preferred embodiment, it also includes a third switch, which is used to be connected in series with the pre-charging circuit, and the opening and closing state of the third switch is opposite to the opening and closing state of the second switch; the third switch includes a third moving contact, which is in contact with or separated from the second static contact, or the third switch includes a third static contact and a third moving contact, the third moving contact is arranged in one of the third static contact and the second static contact, and is closed or disconnected with the other of the third static contact and the second static contact.

[0019] In a preferred embodiment, the second driving mechanism includes an electromagnetic assembly and a push card, and the armature of the electromagnetic assembly is connected to the second moving contact and the third moving contact through the push card.

[0020] In a preferred embodiment, the first switch is provided with an arc extinguishing structure, the arc extinguishing structure comprises an arc extinguishing chamber, the arc extinguishing chamber is provided with a permanent magnet and / or an arc extinguishing grid;

[0021] It also includes a shell, and the first switch, the second switch, the first drive mechanism, and the second drive mechanism are respectively arranged in the shell.

[0022] In a preferred embodiment, it also includes a first auxiliary switch for indicating the open or closed state of the first switch, and the first auxiliary switch is driven by the first movable contact or actuator to close or open; it also includes a second auxiliary switch for indicating the open or closed state of the second switch, and the first auxiliary switch is driven by the second driving mechanism to close or open; it also includes a third auxiliary switch for controlling the timing of stopping the operation of the motor, and the third auxiliary switch is driven by the actuator to close or open.

[0023] In a preferred embodiment, it also includes a main control board, which controls the coordinated actions of the first drive mechanism and the second drive mechanism, so that when the main circuit needs to be connected, the first switch and the second switch are closed successively, and when the main circuit needs to be disconnected, the first switch and the second switch are disconnected synchronously, or the first switch and the second switch are disconnected successively.

[0024] In a preferred embodiment, the branch is set to two, the two branches are respectively a main positive branch and a main negative branch; a pre-charging resistor is connected to the pre-charging circuit; the first switch is set to two, one of the first switches is connected to the main positive branch, and the other first switch is connected to the main negative branch.

[0025] The present invention further provides an energy storage system, comprising a charging and discharging circuit, the battery charging and discharging circuit comprising a main circuit and a pre-charging circuit, the main circuit comprising at least two branches; and further comprising a switching device as described in the present invention above, wherein the second switch is connected in parallel with the pre-charging circuit and is connected in series with one of the first switches on a branch corresponding to one of the first switches; and the remaining first switches are respectively connected to the corresponding branches.

[0026] The present invention further provides a control method for a charging and discharging circuit, which includes a switch device as described in the present invention above. When the main circuit needs to be connected, the first switch is closed, and after detecting that the voltage difference of the battery pack has reached a balance, the second switch is closed; when the main circuit needs to be disconnected, the first switch is disconnected first, and then the second switch is disconnected, or the first switch and the second switch are disconnected at the same time.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The switch device of the present invention includes the first switch and the second switch. While satisfying the control function of the charge and discharge circuit, the switch device has fewer components, simpler structure and control logic, lower cost, and reduced space occupation. In particular, the second switch of the present invention is connected in series with one of the first switches, so that the electrical distance of the second switch can be smaller than the electrical distance of the first switch. Therefore, the second switch can be driven by a relatively simple driving mechanism, which is conducive to reducing technical difficulty, improving working reliability, and further reducing overall volume and cost.

[0029] 2. As a preferred embodiment, each first switch is linked to each other to detect faults, avoid safety problems caused by faulty operation, and enable each first switch to be driven by the same drive mechanism (i.e., the first drive mechanism). In particular, the first drive mechanism includes the shaft and the motor, and the large stroke characteristics of the motor can be used to achieve the large action stroke requirements of the first switch and switch AA, so that the electrical distance of the first switch in the disconnected state can reach the specified safety isolation distance.

[0030] 3. The present invention further includes a third switch, which is used to be connected in series with the pre-charging circuit, and the opening and closing state of the third switch is opposite to the opening and closing state of the second switch, so that the present invention can disconnect the pre-charging circuit when the main circuit is closed, thereby avoiding the pre-charging circuit shunting energy consumption. As a preferred embodiment, the third switch and the second switch are driven by the second driving mechanism, so that the overall structure is relatively simple and the control logic is further simplified.

[0031] 4. The rotating shaft of the first driving mechanism can be driven to rotate manually, making the present invention convenient for staff to perform on-site inspection and maintenance. In particular, the first driving mechanism also includes a control component for controlling whether the circuit where the motor is located is turned on or not, so that when the staff performs manual operation on site, the control component can be used to lock the motor to prevent the motor from being accidentally powered on, thereby making it safer and more reliable for the staff to perform manual operation on site.

[0032] 6. The arrangement of the energy storage assembly enables the present invention to realize instantaneous connection and disconnection of the main switch, thereby avoiding the adverse effect of long contact arc burning time caused by the slow running speed of the motor.

[0033] 7. The present invention integrates the first switch, the second switch, the first drive mechanism, the second drive mechanism, etc. into one housing, so that the overall structure is more concise and easy to transport, apply and connect.

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments; however, the control method of a switch device, an energy storage system, and a charge-discharge circuit of the present invention is not limited to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a connection schematic diagram of the switch device of the present invention;

[0036] Figure 2 The three-dimensional structure diagram of the switch device of the present invention is shown in FIG. Figure 1 (Partial)

[0037] Figure 3 The three-dimensional structure diagram of the switch device of the present invention is shown in FIG. Figure 2 (Reflection of the local);

[0038] Figure 4 It is a schematic diagram of the three-dimensional structure of the first switch, the energy storage component, the rotating shaft, etc. in the combined state of the present invention;

[0039] Figure 5 This is a schematic diagram of the state of the energy storage component of the present invention. Figure 1 ;

[0040] Figure 6 This is a schematic diagram of the state of the energy storage component of the present invention. Figure 2 ;

[0041] Figure 7 This is a schematic diagram of the state of the energy storage component of the present invention. Figure 3 ;

[0042] Figure 8 is an exploded schematic diagram of the second switch, the third switch and the second driving mechanism of the present invention;

[0043] Fig. 9 is a schematic diagram of a combination of the second switch, the third switch and the second driving mechanism of the present invention;

[0044] Fig.10 is a top view of the switch device of the present invention (partial);

[0045] Fig.11 The three-dimensional structure diagram of the switch device of the present invention is shown in FIG. Figure 3 ;

[0046] Fig.12 The three-dimensional structure diagram of the switch device of the present invention is shown in FIG. Figure 4 ;

[0047] In the figure, 1, main switch; 11 / 12, first switch; 13, contact support; 14, first moving contact; 15, contact spring; 16, first static contact; 17, driven wheel; 171, second arc hole; 2, second switch; 21, second static contact; 22, second moving contact; 23, reaction spring; 24, contact lead pin; 25, flexible conductive member; 3, battery pack; 4, power inverter system; 5, main control board; 6, first drive mechanism; 61, rotating shaft; 611, operating hole 611; 62, motor; 63, worm; 64, turbine; 65, first gear; 66, driving wheel; 661, first arc hole; 67 , control switch; 68, control member; 681, operating rod; 69, energy storage assembly; 691, energy storage drive wheel; 692, movable rod; 693, energy storage spring; 694, push rod; 695, fixed seat; 7, second drive mechanism; 71, coil frame; 72, coil; 73, iron core; 74, armature; 75, yoke; 76, restoring spring; 77, push card; 8, third switch; 81, third static contact; 82, third moving contact; 9, arc extinguishing chamber; 10, first auxiliary switch; 20, second auxiliary switch; 30, driving rod; 40, shell; 401, first give way hole; 402, long strip hole; 50, elastic member. DETAILED DESCRIPTION

[0048] In the present invention, the terms "first", "second", "third", etc. are only used to distinguish similar objects, not to describe a specific order or precedence, and cannot be understood as indicating or implying relative importance. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after the association are in an "or" relationship.

[0049] See also Figure 1-Figure 12 As shown, a switch device of the present invention is used in a charging and discharging circuit of an energy storage system, the charging and discharging circuit includes a main circuit and a pre-charging circuit, the main circuit includes at least two branches, the current of the main circuit is a large current, the current of the pre-charging circuit is a small current, the large current is the rated working current, which is usually greater than or equal to 100A, but not limited to this, and the small current is less than the rated working current, which is usually less than 100A, but not limited to this. The switch device of the present invention includes:

[0050] A first switch is provided for each main branch, the first switch is used to connect to the corresponding branch; and

[0051] The second switch 2 is used to be connected in parallel with the pre-charging circuit, and the second switch 2 is also used to be connected in series with one of the first switches on the branch where the one of the first switches is located.

[0052] In this embodiment, if Figure 1 As shown, the main circuit has two branches, namely the main positive branch and the main negative branch. The main positive branch is a circuit connected between the positive electrode of the battery pack 3 of the energy storage system and the positive electrode of the power inverter system 4, and the main negative branch is a circuit connected between the negative electrode of the battery pack 3 and the negative electrode of the power inverter system 4; the pre-charging circuit is connected with a pre-charging resistor R1; the first switch is set to two, and the two first switches 11 and 12 together constitute the main switch 1. In other embodiments, the main circuit is an AC return, in which case, its branches are set to two or more.

[0053] Each first switch 11 is set in linkage to be closed or opened synchronously, and the following is mainly described by taking one of the first switches 11 as an example. The present invention also includes a first drive mechanism 6 for driving the main switch 1 to be closed or opened, and a second drive mechanism 7 for driving the second switch 2 to be closed or opened. The present invention also includes a main control board 5, which controls the first drive mechanism 6 and the second drive mechanism 7 to coordinate actions, so that when the main circuit needs to be connected, each first switch and the second switch 2 are closed successively, and when the main circuit needs to be disconnected, each first switch and the second switch 2 are disconnected synchronously, or the first switch and the second switch 2 are disconnected successively.

[0054] Furthermore, the present invention also includes a third switch 8, which is used to be connected in series with the pre-charging circuit to control whether the pre-charging circuit is disconnected or not. The opening and closing state of the third switch 8 is opposite to the opening and closing state of the second switch 2, and the third switch 8 is driven by the second drive mechanism 7 to be turned on or off. Specifically, the third switch 8 is partially shared with the second switch 2, and the second switch 2 and the third switch 8 share the same set of second drive mechanism 7. As a preferred embodiment, the second drive mechanism 7 includes an electromagnetic component, and the armature of the electromagnetic component is linked to the second switch 2 and the third switch 8 to be turned on or off when the armature is switched between the attraction and release states.

[0055] The first driving mechanism 6 includes a rotating shaft 61 and a motor 62 for providing a rotational driving force for the rotating shaft 61. The rotating shaft 61 is connected or disconnected by rotating the first switch 11. Specifically, the first switch 11 / 12 includes a first moving contact 14, a first stationary contact 16 and an actuator. The rotating shaft 61 is rotated by rotating the actuator, so that the actuator drives the first moving contact 14 to contact or separate with the first stationary contact 16. The motor 62 is specifically connected to the rotating shaft 61 by a gear transmission assembly. Figure 2 , Figure 3 As shown, the gear transmission assembly includes a worm 63, a worm wheel 64, a first gear 65 and a second gear. The worm 63 is coaxially connected to the output shaft of the motor 62. The worm wheel 64 is arranged to rotate, and the axis of the worm wheel 64 is parallel to the axis of the rotating shaft 61. The worm wheel 64 is meshed with the worm 63. The first gear 65 is coaxially connected to the worm wheel 64. The second gear is coaxially connected to the rotating shaft 61, and the first gear 65 is meshed with the second gear. The motor 62 and the coil 72 of the electromagnetic assembly are electrically connected to the main control board 5 respectively. The main control board 5 controls whether the motor 62 and the coil 72 are powered on or not. The main control board 5 can be connected to the battery management system to control whether the motor 62 and the coil 72 are powered on or not according to the signal of the battery management system. Further, the rotating shaft 61 can be driven to rotate manually, so that the main switch 1 of the present invention can be manually operated. The first drive mechanism 6 also includes a control component for controlling whether the circuit where the motor 62 is located is turned on or not, so that when the staff performs on-site manual operation, the control component can be used to lock the motor 62 to prevent the motor 62 from being accidentally powered on, thereby making it safer and more reliable for the staff to perform on-site manual operation. The control component specifically includes a control switch 67 connected in series with the motor 62, and the control switch 67 is driven to close or open by a control member 68, and the control member 68 can be operated. In this way, when the staff needs on-site maintenance, the staff can disconnect the circuit of the motor 62 through the control switch 67, so that the motor 62 will not be accidentally powered on and mistakenly drive the main switch 1. In this embodiment, the control switch 67 is specifically a micro switch, and the control member 68 is set to slide, and the control switch 67 is triggered or released by sliding.

[0056] As a preferred embodiment, the first driving mechanism 6 further includes an energy storage component 69. The rotating shaft 61 stores energy by rotating the linked energy storage component 69, and the energy storage component 69 drives the main switch 1 to close or open by releasing the stored energy. The provision of the energy storage component 69 enables the present invention to achieve instantaneous connection and disconnection of the main switch 1, thereby avoiding the adverse effect of a long contact arc burning time caused by the slow running speed of the motor 62.

[0057] like Figure 4 As shown, a driving wheel 66 is provided on the rotating shaft 61, and the driving wheel 66 is the same as the second gear, but it is not limited thereto. In other embodiments, the driving wheel 66 and the second gear are separate from each other. The actuator includes a driven wheel 17, and the energy storage assembly 69 includes an energy storage driving wheel 691 and at least one movable component. The movable component includes a movable rod 692, a push rod 694 and an energy storage spring 693. The energy storage driving wheel 691 is located between the driving wheel 66 and the driven wheel 17. The driving wheel 66 has a first arc hole 661 arranged concentrically with the corresponding movable component, and the driven wheel 17 has a second arc hole 141 arranged concentrically with the corresponding movable component. The push rod 694 is arranged at the energy storage driving wheel 691. 691, and one end of the push rod 694 is adapted to slide in the first arc hole 661 provided on the driving wheel 66, and the other end of the push rod 694 is adapted to slide in the second arc hole 171 provided on the driven wheel 17; the movable rod 692 is rotatably and slidably provided on a fixed seat 695 located outside the energy storage driving wheel 691, and one end of the movable rod 692 is movably connected to the push rod 694, and the energy storage spring 693 is sleeved on the movable rod 692 and matched between the push rod 694 and the fixed seat. In this embodiment, there are two movable parts, and the two movable parts are separated and located on opposite sides of the energy storage driving wheel 691, and correspondingly, there are two first arc holes 661 and two second arc holes 171 respectively.

[0058] Therefore, when the rotating shaft 61 rotates, the rotating shaft 61 can drive the energy storage driving wheel 691 to rotate, so that the energy storage spring 693 stores energy, and when the energy storage spring 693 releases the stored energy, it drives the driven wheel 17 to rotate, so that the main switch 1 is closed or opened, that is, the first moving contact 14 is in contact with or separated from the first static contact 16. Specifically, the detailed working process of the energy storage component 69 is as follows:

[0059] The driving wheel 66 rotates along the rotation shaft 61 in the closing direction of the main switch 1 (clockwise direction as an example). When one end of the first arc hole 661 on the driving wheel 66 hits the push rod 694 (as shown in FIG. Figure 5 As shown in FIG. 6 , as the driving wheel 66 continues to rotate, the driving wheel 66 drives the energy storage driving wheel 691 to rotate together, so that the movable rod 692 is pushed to rotate and move toward the outside of the energy storage driving wheel 691, and compresses the energy storage spring 693 to achieve energy storage, as shown in FIG. Figure 5Then, the driving wheel 66 continues to drive the energy storage drive wheel 691 to rotate a small angle until the movable rod 692 is rotated to a position where the energy storage spring 693 releases the energy storage, such as Figure 6 As shown; in this process, the top rod 694 slides along the second arc hole 171 of the driven wheel 17, and the driven wheel 17 remains stationary. When the movable rod 692 is rotated to the position where the energy storage spring 693 releases the stored energy, the energy storage spring 693 on the movable rod 692 releases the stored energy, pushing the energy storage drive wheel 691 to rotate rapidly in the direction of closing the main switch 1, as shown in FIG. Figure 7 As shown, the energy storage driving wheel 691 drives the driven wheel 17 to rotate together, thereby closing the main switch 1. During the process of releasing the energy storage spring 693, the driving wheel 66 will continue to rotate until the main switch 1 is fully closed, but the rotation speed of the driving wheel 66 is lower than the speed of the energy storage driving wheel 691, and there is an idle stroke between the two, so the rotation of the driving wheel 66 will not affect the rotation of the energy storage driving wheel 691.

[0060] The driving wheel 66 rotates along with the rotating shaft 61 in the direction in which the main switch 1 is disconnected. When the other end of the first arc-shaped hole 661 on the driving wheel 66 hits the push rod 694, as the driving wheel 66 continues to rotate, the driving wheel 66 drives the energy storage driving wheel 691 to rotate together, so that the movable rod 692 is pushed to rotate and move to the outside of the energy storage driving wheel 691, and compresses the energy storage spring 693 to achieve energy storage; then, the driving wheel 66 continues to drive the energy storage driving wheel 691 to rotate a small angle until the movable rod 692 rotates to a position where the energy storage spring 693 releases the stored energy; during this process, the push rod 694 slides along the second arc-shaped hole 141 of the driven wheel 14, and the driven wheel 14 remains stationary. When the movable rod 692 is rotated to the energy storage spring 693 releasing energy position, the energy storage spring 693 on the movable rod 692 releases the stored energy, pushing the energy storage driving wheel 691 to rotate rapidly in the direction of disconnecting the main switch 1, and the energy storage driving wheel 691 drives the driven wheel 17 to rotate together, thereby disconnecting the main switch 1.

[0061] like Figure 2 , Figure 3 As shown, the actuator also includes a contact support 13, two first static contacts 16 are provided, and the two first static contacts 16 are located on opposite sides of the contact support 12. The first moving contact 14 is provided on the contact support 13 and rotates with the contact support 13, so that the two ends of the first moving contact 14 are respectively closed or disconnected with the two first static contacts 16. The contact supports 13 of each first switch are coaxially connected, so that the contact supports 13 of each first switch can rotate synchronously, and the above-mentioned driven wheel 17 is coaxially connected with the contact support 13 of the first switch 11, so that the driven wheel 17 drives the two contact supports 13 to rotate synchronously.

[0062] Furthermore, there are two first moving contacts 14, which are arranged in parallel along the direction of the rotation axis of the contact support 13, and there is a spacing between the two first moving contacts 14. The natural spacing between the two first moving contacts 14 is slightly smaller than the width of the portion of the first static contact 16 that is used to contact the first moving contact 14. A contact spring 15 is arranged between at least one first moving contact 14 and the contact support 13, which causes the two first static contacts 14 to elastically open and clamp the first static contact 16 when the main switch 1 is closed.

[0063] like Figure 8 , Fig. 9 As shown, the second switch 2 includes a second moving contact 22 and a second static contact 21 that cooperate with each other. The second static contact 21 is integrally formed with one of the first static contacts 16, so as to realize the connection of the second switch 2 with the first switch 11 in series, and achieve the purpose of reducing parts and reducing costs. In other embodiments, the second static contact 21 is electrically connected to one of the first static contacts 16 (specifically, one of the first static contacts 16 of the first switch 11 is used as an example). As a preferred embodiment, the second moving contact 22 adopts an anti-short circuit structure: one end of the second moving contact 22 is rotatably connected to one end of a contact lead-out pin 24, and a flexible conductive member 25 is electrically connected between the two, and the other end of the second moving contact 22 is used to cooperate with the second static contact 21, and a reaction spring 23 is provided on the side of the second moving contact 22 facing the contact lead-out pin 24.

[0064] like Figure 8 , Fig. 9 As shown, the third switch 8 includes a third static contact 81 and a third moving contact 82, and the third moving contact 82 is arranged on one of the third static contact 81 and the second static contact 21, and is closed or disconnected with the other of the third static contact 81 and the second static contact 21. Specifically, in this embodiment, the third moving contact 82 is arranged on the second static contact 21, and cooperates with the third static contact 81, and the third moving contact 82 is a moving spring, one end of which is fixed to the second static contact 21 by welding or riveting, and the other end is provided with a moving contact point, which is used to close or disconnect with the third static contact 81. In other embodiments, the third switch includes a third moving contact, which contacts or separates with the second static contact of the second switch. Therefore, the switch assembly composed of the second switch and the third switch has two moving contacts in total, which is convenient for separately designing the two moving contacts according to the different current carrying capacity of the two circuits switched. In other embodiments, the switch assembly composed of the second switch and the third switch is replaced by a conventional conversion switch in the prior art.

[0065] like Figure 8 , Fig. 9As shown, the second driving mechanism 7 includes not only the electromagnetic assembly but also a push card 77. The armature 74 of the electromagnetic assembly is connected to the second moving contact 22, the third moving contact 82 and the reaction spring 23 through the push card 77 to drive the second switch 2 and the third switch 8 to act respectively. In addition to the armature 74, the electromagnetic assembly also includes a coil frame 71 wound with a coil 72, an armature 74, a yoke 75, an iron core 73 and a restoring spring 76. The iron core 73 is inserted into the axial hole of the coil frame 71. The yoke 75 is L-shaped, one side of which is fixedly connected to one end of the iron core 73, and the other side is located outside the coil frame 71. The armature 74 is rotatably set at the blade of the other side of the yoke 75 by using the restoring spring 76, and the armature 74 is L-shaped, one side of which is used for magnetic attraction with the other end of the iron core 73, and the other side is connected to the push card 77 to drive the push card 77 to act.

[0066] Each first switch is provided with an arc extinguishing structure, which specifically includes an arc extinguishing chamber 9 provided at a location corresponding to each first stationary contact 16 and the first moving contact 14, and the arc extinguishing chamber 9 is provided with a permanent magnet and / or an arc extinguishing grid.

[0067] The present invention further includes a first auxiliary switch 10 for indicating the on / off state of the main switch 1, the first auxiliary switch 10 is linked with the first switch 11, and specifically, the first auxiliary switch 10 is driven by the first moving contact 14 or the actuator to achieve closing or opening. The present invention further includes a second auxiliary switch 20 for indicating the on / off state of the second switch 2, the second auxiliary switch 20 is driven by the second driving mechanism 7. Specifically, as Fig.10 As shown, the first auxiliary switch 10 and the second auxiliary switch 20 are micro switches respectively, and the first auxiliary switch 10 cooperates with the first moving contact 14 through a driving rod 30: the first auxiliary switch 10 is triggered by the rotating driving rod 30 to achieve closing or disconnection, the driving rod 30 is driven to rotate when the first moving contact 14 rotates in the disconnecting direction, and the driving rod 30 is driven to reset by the reset member set thereon to release the first auxiliary switch 10. Specifically, the first auxiliary switch 10 is triggered by the driving rod 30 to achieve closing, the driving rod 9 is driven to rotate when the first moving contact 14 rotates in the disconnecting direction, the reset member includes an elastic member 50, and the driving rod 30 is released when the first moving contact 14 rotates in the closing direction, and the driving rod 30 is reset under the elastic force of the elastic member 10, thereby releasing the first auxiliary switch 10 and disconnecting the first auxiliary switch 10. The second auxiliary switch 20 is driven by the above-mentioned push card 77 to achieve closing or disconnection. The present invention also includes a third auxiliary switch (not shown in the figure) for controlling the operation stop timing of the motor 62, and the third auxiliary switch is driven by the actuator to close or disconnect. Specifically, the third auxiliary switch is electrically connected to the main control board 5 and is driven by a driven wheel 17 of the actuator, and the driven wheel 17 is a cam structure.

[0068] like Fig.11, Fig.12 As shown, the present invention also includes a housing 40, and the above-mentioned first switch 11, switch AA12, second switch 2, first drive mechanism 6, second drive mechanism 7, main control board 5, etc. are respectively arranged in the housing 40, and the other first static contact 16 of the above-mentioned first switch 11, the two first static contacts 16 of the other first switch 12, the contact lead pin 24 of the second switch 2, and the third static contact 81 of the third switch 8 are respectively partially led out of the housing 40 for application connection. In order to achieve stable installation, a support frame 60 (such as Figure 2 As shown in FIG. 1 , the support frame 60 is used as a mounting carrier for each switch and / or driving mechanism, etc. In other embodiments, the main switch 1 and the first driving mechanism 6 are arranged in one housing to form an electric isolating switch, and the second switch 2, the third switch 8 and the second driving mechanism 7 are arranged in another housing to form a conversion switch, and the conversion switch can be replaced by a conventional conversion relay in the prior art.

[0069] In this embodiment, a first operating portion is provided at one end of the rotating shaft 61, and a first clearance hole 401 is provided in the housing 40 corresponding to the first operating portion of the rotating shaft 61; a second operating portion is provided at the control member 68, and a second clearance hole 402 is provided in the housing 40 corresponding to the second operating portion. Fig.11 , Fig.12 As shown, the first operating portion of the rotating shaft 61 is an operating hole 611, but is not limited thereto. The operating hole 611 is located in the housing 40 and corresponds to the first clearance hole 401. The first clearance hole 51 is a round hole. In this way, when the staff performs manual operation, the rotating tool (such as a screwdriver, etc.) can be inserted into the operating hole 611 of the rotating shaft 61 through the first clearance hole 51, thereby driving the rotating shaft 61 to rotate. In other embodiments, the first operating portion is a knob or a handle, etc., which extends out of the housing 401. The second operating portion of the control member 68 is an operating rod 681, which is penetrated by the second clearance hole 402. The second clearance hole 402 is a linear long hole to accommodate the sliding of the operating rod 681.

[0070] A switch device of the present invention, when used, connects the other first static contact 16 of one of the first switches 11 and the contact lead pin 24 of the second switch 2 to the main positive branch, connects the two first static contacts 16 of the other first switch 12 to the main negative branch, connects the third static contact 81 of the third switch 8 to one end of the pre-charging resistor R1, and connects the contact lead pin 24 of the second switch 2 to the other end of the pre-charging resistor R1.

[0071] When the main circuit needs to be connected, the motor 62 starts and drives the main switch 1 to close. At this time, the second switch 2 is in the open state and the third switch 8 is in the closed state. Therefore, the circuit where the pre-charging resistor R1 is located is turned on, and the capacitive or quasi-capacitive load such as the capacitor is charged through the pre-charging resistor R1. When the current drops to a certain level, the battery management system detects that the voltage difference of the battery pack has reached a balance, and the coil 72 of the electromagnetic component is powered on, closing the second switch 2 and disconnecting the third switch 8 at the same time, so that the main circuit works normally. At the same time, the circuit where the pre-charging resistor R1 is located is disconnected to avoid shunt energy consumption.

[0072] When the main circuit needs to be disconnected, the main switch 1 is disconnected first, and then the second switch 2 is disconnected, and the third switch 8 is closed, or the main switch 1 and the second switch 2 are disconnected at the same time, and the third switch 8 is closed.

[0073] Therefore, compared with the prior art, a switch device of the present invention has fewer components, simpler structure and control logic, lower cost, and less space occupied while meeting the battery charging and discharging circuit control function. In particular, the second switch 2 of the present invention is connected in series with the first switch 11, so that the electrical distance of the second switch 2 can be smaller than the electrical distance of the first switch 11, and thus the second switch 2 can be driven by a relatively simple driving mechanism (such as an electromagnetic component), which is conducive to reducing technical difficulty, improving working reliability, and further reducing overall volume and cost.

[0074] See also Figure 1-Figure 12 As shown, an energy storage system of the present invention includes a charging and discharging circuit, the charging and discharging circuit includes a main circuit and a pre-charging circuit, the main circuit includes at least two branches; and also includes a switch device as described above, the second switch 2 is connected in parallel with the pre-charging circuit, and is connected in series with one of the first switches 11 on the branch corresponding to one of the first switches 11; the remaining first switches are connected to the corresponding branches respectively. In this embodiment, as Figure 1 As shown, the energy storage system of the present invention is specifically a battery energy storage system, the charging and discharging circuit is a battery charging and discharging circuit, the main circuit has two branches, the two branches are respectively a main positive branch and a main negative branch, the pre-charging circuit is connected with a pre-charging resistor R1; the first switch is set to two. In other embodiments, the main circuit is an AC return, in which case its branches are set to two or more.

[0075] For the structure and working principle of the switch device, please refer to the previous description thereof, which will not be repeated here.

[0076] A control method for a charging and discharging circuit of the present invention includes a switch device of the present invention as described above, and the control method is as follows: when the main circuit needs to be connected, each first switch is closed, and after detecting that the voltage difference of the battery group has reached a balance, the second switch 2 is closed; when the main circuit needs to be disconnected, each first switch is disconnected first, and then the second switch 2 is disconnected, or each first switch and the second switch 2 are disconnected at the same time.

[0077] Since the switching device of the present invention also includes a third switch 8, in the control method, before the second switch 2 is closed, the third switch 8 is in a closed state, so that the circuit where the pre-charging resistor R1 is located is connected, thereby realizing pre-charging current limiting; when the second switch 2 is closed, the third switch 8 is disconnected, so that the main circuit works normally. At the same time, the circuit where the pre-charging resistor R1 is located is disconnected, thereby avoiding shunting energy consumption in the circuit where the pre-charging resistor R1 is located.

[0078] The switch device, energy storage system and control method of the charge and discharge circuit of the present invention, the unrelated parts are the same as the prior art or can be implemented by using the prior art.

[0079] The above embodiments are only used to further illustrate a switch device, an energy storage system, and a control method for a charge and discharge circuit of the present invention, but the present invention is not limited to the embodiments. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the technical solution of the present invention.

Claims

1. A switch device for a charge-discharge circuit, wherein the charge-discharge circuit comprises a main circuit and a pre-charge circuit, wherein the main circuit comprises at least two branches; characterized in that: include: A first switch is provided for each branch, each first switch is used to be connected to the corresponding branch; The second switch is used to be connected in parallel with the pre-charging circuit, and the second switch is also used to be connected in series with one of the first switches on the branch where the one of the first switches is located.

2. The switch device according to claim 1, characterized in that: The first switches are arranged in linkage to be closed or opened synchronously; and the first drive mechanism for driving the first switches to be closed or opened and the second drive mechanism for driving the second switches to be closed or opened are also included.

3. The switch device according to claim 2, characterized in that: It also includes a third switch, which is used to be connected in series with the pre-charging circuit; the opening and closing state of the third switch is opposite to the opening and closing state of the second switch, and the third switch is driven by the second driving mechanism to be closed or opened.

4. The switch device according to claim 2 or 3, characterized in that: The second driving mechanism includes an electromagnetic assembly.

5. The switch device according to claim 2, characterized in that: The first driving mechanism includes a rotating shaft and a motor for providing rotational driving force for the rotating shaft. The first switch includes a first moving contact, a first stationary contact and an actuator. The rotating shaft rotates through a rotation linkage, so that the actuator drives the first moving contact to contact or separate from the first stationary contact.

6. The switch device according to claim 5, characterized in that: The rotating shaft can be driven to rotate by human power, and the first driving mechanism also includes a control component for controlling whether the circuit where the motor is located is turned on or off; the control component includes a control switch connected in series with the motor, and the control switch is driven to close or open by a control member, and the control member can be operated.

7. The switch device of the battery charging and discharging circuit according to claim 5, characterized in that: The first driving mechanism further includes an energy storage component. The rotating shaft stores energy by rotating the energy storage component. The energy storage component drives the actuator to rotate by releasing the stored energy, so that the first switch is closed or opened.

8. The switch device of the battery charging and discharging circuit according to claim 7, characterized in that: The rotating shaft is provided with a driving wheel, the actuator includes a driven wheel, the energy storage assembly includes an energy storage driving wheel and at least one movable component, the movable component includes a movable rod, a push rod and an energy storage spring, the energy storage driving wheel is located between the driving wheel and the driven wheel, the push rod is arranged on the energy storage driving wheel, and one end of the push rod is adapted to be slidably connected to a first arc hole provided on the driving wheel, and the other end of the push rod is adapted to be slidably connected to a second arc hole provided on the driven wheel; the movable rod is rotatably and slidably arranged on a fixed seat located outside the energy storage driving wheel, and one end of the movable rod is movably connected to the push rod, the energy storage spring is sleeved on the movable rod, and is fitted between the push rod and the fixed seat.

9. The switch device according to claim 5, characterized in that: The actuator includes a contact support, the first stationary contacts are provided with two, the first moving contact is provided on the contact support and rotates together with the contact support, so that the two ends of the first moving contact are respectively in contact with or separated from the two first stationary contacts; The second switch includes a second moving contact and a second stationary contact that cooperate with each other, and the second stationary contact is integrally formed with or electrically connected to one of the first stationary contacts.

10. The switch device according to claim 9, characterized in that: It also includes a third switch, which is used to be connected in series with the pre-charging circuit, and the opening and closing state of the third switch is opposite to the opening and closing state of the second switch; the third switch includes a third moving contact, which is in contact with or separated from the second static contact, or the third switch includes a third static contact and a third moving contact, the third moving contact is arranged in one of the third static contact and the second static contact, and is closed or disconnected with the other of the third static contact and the second static contact.

11. The switch device according to claim 10, characterized in that: The second driving mechanism includes an electromagnetic assembly and a push card, and the armature of the electromagnetic assembly is connected to the second moving contact and the third moving contact through the push card.

12. The switch device according to claim 2, characterized in that: The first switch is provided with an arc extinguishing structure, the arc extinguishing structure comprises an arc extinguishing chamber, the arc extinguishing chamber is provided with a permanent magnet and / or an arc extinguishing grid; It also includes a shell, and the first switch, the second switch, the first drive mechanism, and the second drive mechanism are respectively arranged in the shell.

13. The switch device according to claim 5, characterized in that: It also includes a first auxiliary switch for indicating the open or closed state of the first switch, which is driven by the first movable contact or actuator to close or open; it also includes a second auxiliary switch for indicating the open or closed state of the second switch, which is driven by the second drive mechanism to close or open; it also includes a third auxiliary switch for controlling the timing of stopping the operation of the motor, which is driven by the actuator to close or open.

14. The switch device according to claim 2, characterized in that: It also includes a main control board, which controls the coordinated actions of the first drive mechanism and the second drive mechanism, so that when the main circuit needs to be connected, the first switch and the second switch are closed successively, and when the main circuit needs to be disconnected, the first switch and the second switch are disconnected synchronously, or the first switch and the second switch are disconnected successively.

15. The switch device according to claim 1, characterized in that: The number of branches is two, the two branches are respectively a main positive branch and a main negative branch; a pre-charging resistor is connected to the pre-charging circuit; the number of the first switches is two, one of the first switches is connected to the main positive branch, and the other first switch is connected to the main negative branch.

16. An energy storage system, comprising a charge and discharge circuit, the battery charge and discharge circuit comprising a main circuit and a pre-charge circuit, the main circuit comprising at least two branches; characterized in that: It also includes a switching device as described in any one of claims 1-15, wherein the second switch is connected in parallel with the pre-charging circuit and is connected in series with one of the first switches on a branch corresponding to one of the first switches; and the remaining first switches are respectively connected to corresponding branches.

17. A method for controlling a charge-discharge circuit, the charge-discharge circuit comprising a switch device according to any one of claims 1 to 15, characterized in that: When the main circuit needs to be connected, the first switch is closed, and after detecting that the voltage difference of the battery pack has reached a balance, the second switch is closed; when the main circuit needs to be disconnected, the first switch is disconnected first, and then the second switch is disconnected, or the first switch and the second switch are disconnected at the same time.

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