High-voltage switching device, power converter and energy storage system

Abstract

The utility model provides a high-voltage switching device, a power converter and an energy storage system, and the high-voltage switching device comprises at least two electrical interfaces, a switching mechanism, a housing, a first grid group, a second grid group and a third grid group. The switching mechanism is used for disconnecting the electrical connection of the at least two electrical interfaces, the shell is used for fixing the at least two electrical interfaces and forming at least one arc extinguish chamber, each arc extinguish chamber is used for accommodating a first grid plate group, a second grid plate group and a third grid plate group, the first grid plate group comprises a plurality of first grid plates arranged at intervals along a first direction, and the second grid plate group comprises a plurality of second grid plates arranged at intervals along a second direction. The second grid sheet group comprises a plurality of second grid sheets which are arranged at intervals in the first direction, the third grid sheet group comprises a plurality of third grid sheets which are arranged at intervals in the first direction, the first grid sheet group, the second grid sheet group and the third grid sheet group are arranged at intervals in the first direction, and the first grid sheet group and the second grid sheet group are arranged at intervals in the second direction; the first direction is perpendicular to the second direction. According to the arrangement, the number of the grid plates in the arc extinguish chamber can be increased, and the arc extinguish capability of the high-voltage switching device is further improved.

Description

Technical Field

[0001] The present application relates to the field of power distribution technology, and in particular to a high-voltage switching device, a power converter and an energy storage system. Background Art

[0002] A switching device is an electronic component used to connect or disconnect the current in one or more circuits, and it usually plays a control and protection role in the power system. If the voltage of the circuit where the switching device is located is not less than 10-20V, and the current is not less than 80-100mA, an arc will be generated between the contacts of the switching device when the switching device is disconnected. On the one hand, the generation of the arc prolongs the circuit breaking time. On the other hand, due to the high temperature of the arc, it is easy to endanger the safe operation of the power system, causing casualties and significant property losses. When the switching device is used in a high-voltage circuit, the switching device is required to have the ability to cool and extinguish the arc to reduce the harm caused by the arc. However, the existing high-voltage switching devices have poor cooling effect on the arc, which limits their wide application. Utility Model Content

[0003] In a first aspect, the present application provides a high-voltage switch device, comprising at least two electrical interfaces, a switch mechanism, a housing, a first grid group, a second grid group and a third grid group. The switch mechanism is used to disconnect the electrical connection of the at least two electrical interfaces, the housing is used to fix the at least two electrical interfaces and to form at least one arc extinguishing chamber, each arc extinguishing chamber is used to accommodate the first grid group, the second grid group and the third grid group, the first grid group includes a plurality of first grids arranged at intervals along a first direction, the second grid group includes a plurality of second grids arranged at intervals along the first direction, the third grid group includes a plurality of third grids arranged at intervals along the first direction, the first grid group is arranged at intervals with the second grid group and the third grid group respectively along the first direction, the second grid group and the third grid group are arranged at intervals along the second direction, and the first direction is perpendicular to the second direction. That is, the first grid group and the second grid group are surrounded by a containing space, and the containing space is used to accommodate the third grid group. In this way, the number of grids can be increased in a limited space, thereby improving the arc extinguishing ability of the high-voltage switch device.

[0004] In a possible implementation, along the first direction, the distance between the first grid sheet group and the second grid sheet group is smaller than the distance between the first grid sheet group and the third grid sheet group. With this arrangement, when the electrical connection of at least two electrical interfaces is disconnected and an arc is generated, the arc will pass through the first grid sheet group, the second grid sheet group, and the third grid sheet group in sequence, thereby extending the cooling path of the arc and improving the arc extinguishing capability of the high-voltage switch device.

[0005] In a possible implementation, the size of the second grid sheet group along the first direction is larger than the size of the third grid sheet group, and the size of the first grid sheet group along the second direction is larger than the sum of the size of the second grid sheet group and the size of the third grid sheet group. In other words, the first grid sheet group and the second grid sheet group are arranged to form a receiving space, and the receiving space is used to accommodate the third grid sheet group. In this way, the number of grid sheets can be increased within a limited space, thereby improving the arc extinguishing capability of the high-voltage switch device.

[0006] In a possible embodiment, the high-voltage switch device includes a first arc-starting plate, wherein one end of the first arc-starting plate is arranged between the housing and the second grid plate group along the first direction, and the distance between one end of the first arc-starting plate and the second grid plate group along the first direction is less than the distance between the second grid plate group and the third grid plate group along the second direction. In this way, the arc will be conducted to one end of the first arc-starting plate after passing through the second grid plate group, and will not be conducted to a third grid plate in the third grid plate group, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. The other end of the first arc-starting plate is arranged between the first grid plate group and the third grid plate group along the first direction, and the distance between the other end of the first arc-starting plate and the third grid plate group along the first direction is less than the distance between the second grid plate group and the third grid plate group along the second direction. In this way, after the arc is conducted to one end of the first arc-starting plate, the arc will further enter the third grid plate group through the other end of the first arc-starting plate, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device.

[0007] In a possible implementation, along the first direction, the distance between the other end of the first arc-starting plate and the third grid plate group is smaller than the distance between the other end of the first arc-starting plate and the first grid plate group. That is, along the first direction, the third grid plate group is closer to the other end of the first arc-starting plate than the first grid plate group. With such an arrangement, the arc can be smoothly guided from the second grid plate group to the third grid plate group, thereby extending the arc cooling path and improving the arc extinguishing capability of the high-voltage switch device.

[0008] In a possible implementation, one end of the first arc-starting piece is connected to the other end of the first arc-starting piece through a connecting piece, an insulating plate is included between the connecting piece and the third grid piece group along the second direction, the connecting piece, the third grid piece group and the insulating plate are arranged to form at least one air channel, one end of the first arc-starting piece and the housing are arranged to form another air channel along the first direction, and one air channel is connected to the outside of the arc extinguishing chamber through another air channel. When the arc passes through the third grid piece group, high-temperature gas is generated in the arc extinguishing chamber, and the high-temperature gas can be better discharged to the outside of the arc extinguishing chamber through the setting of the air channel, thereby improving the safety of the high-voltage switch device.

[0009] In a possible embodiment, the high-voltage switch device includes a second arc-starting plate, wherein one end of the second arc-starting plate is arranged between the third grid plate group and the housing along the second direction, and the other end of the second arc-starting plate is arranged between the third grid plate group and the housing along the first direction. Along the first direction, the distance between one end of the second arc-starting plate and the first grid plate group is greater than the distance between the other end of the first arc-starting plate and the first grid plate group. That is, along the first direction, the other end of the first arc-starting plate is located between the first grid plate group and one end of the second arc-starting plate. Specifically, when the electrical connection of at least two electrical interfaces is disconnected and an arc is generated, the arc entering the arc extinguishing chamber will be elongated due to the action of the electric force. Among them, one end of the arc is attracted to the first grid plate group, the other end of the arc is attracted by one end of the second arc-starting plate and further guided to the third grid plate group by the other end of the second arc-starting plate, and there is a voltage difference between the two ends of the arc. Based on this, when the arc is elongated, by setting the other end of the first arc-starting plate between the first grid group and one end of the second arc-starting plate, the arc can be further attracted to the other end of the first arc-starting plate, so that there is a voltage difference between the other end of the first arc-starting plate and one end of the first grid group and the second arc-starting plate, respectively, so that the arc can pass through the first grid group, the second grid group and the third grid group more smoothly, thereby improving the arc extinguishing ability of the high-voltage switching device.

[0010] In a possible implementation, the distance between one end of the second arc-starting piece and the third grid piece group along the second direction is greater than the distance between the other end of the second arc-starting piece and the third grid piece group along the first direction. With this arrangement, when the arc is attracted by one end of the second arc-starting piece, the arc can better enter the third grid piece group through the other end of the second arc-starting piece, thereby extending the arc cooling path and improving the arc extinguishing capability of the high-voltage switch device.

[0011] In a possible embodiment, the high-voltage switch device includes a through-current bar, which is used to connect at least two electrical interfaces, and the through-current bar includes a weak section, and the switch mechanism is used to disconnect the weak section. Along the first direction, the distance between the weak section and the first grid sheet group is less than the distance between the weak section and the second grid sheet group, and along the second direction, the distance between the weak section and the third grid sheet group is less than the distance between the weak section and the second grid sheet group. That is to say, when the weak section is disconnected, one end of the arc is preferentially attracted to the first grid sheet group, and the other end of the arc is preferentially attracted to the third grid sheet group. When the voltage difference between one end of the arc and the voltage difference between the other end of the arc is large, the arc is divided into multiple sections along the path of the first grid sheet group-the second grid sheet group-the third grid sheet group and finally extinguished. Therefore, such a setting can make the arc smoothly enter the first grid sheet group, the second grid sheet group and the third grid sheet group, thereby improving the arc extinguishing ability of the high-voltage switch device.

[0012] In the second aspect, the present application provides an energy storage system, comprising a high-voltage switch device as described in any one of the first aspects and one or more battery packs, the battery pack and the high-voltage switch device are connected through a DC bus, and when the current flowing through the high-voltage switch device is greater than the current threshold, the switch mechanism of the high-voltage switch device disconnects the electrical connection of at least two electrical interfaces. In this way, when one or more battery packs in the energy storage system have a short circuit or overcurrent fault, the high-voltage switch device can promptly cut off the short-circuit current loop, thereby preventing the short-circuit fault from spreading to the power converter or load side connected to the battery pack, thereby ensuring the safety and stability of the power supply system.

[0013] In the third aspect, the present application provides a power converter, comprising a high-voltage switch device, an inverter circuit, a DC input terminal and an AC output terminal as described in any one of the first aspects, the DC input terminal is used to connect a photovoltaic module or an energy storage system, the AC output terminal is used to connect a load, the high-voltage switch device is connected between the inverter circuit and the DC input terminal, or the high-voltage switch device is connected between the inverter circuit and the AC output terminal, and when the current flowing through the high-voltage switch device is greater than the current threshold, the switch mechanism of the high-voltage switch device disconnects the electrical connection of at least two electrical interfaces. In this way, when a short circuit or overcurrent fault occurs inside the power converter, the short-circuit current loop can be cut off in time, thereby preventing the short-circuit fault from spreading to the battery pack or load side connected thereto, thereby ensuring the safety and stability of the power supply system.

[0014] In general, the present application significantly increases the number of grids that can be accommodated in the arc extinguishing chamber by performing special size design and spatial arrangement on the first grid group, the second grid group and the third grid group, thereby effectively improving the arc extinguishing ability of the high-voltage switch device. In addition, the present application effectively realizes the series connection of the second grid group and the third grid group through the design of the first arc-starting plate, thereby allowing the arc to pass smoothly through the first grid group, the second grid group and the third grid group, extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. In addition, the present application also sets an air duct based on the above structure, thereby better discharging the high-temperature gas in the arc extinguishing chamber, improving the working stability and safety of the high-voltage switch device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a network diagram for the solar-storage scenario;

[0016] Figure 2 This is a network diagram of the energy storage system;

[0017] Figure 3 Provide a schematic diagram of the appearance of a high-voltage switch device for this application;

[0018] Figure 4 An exploded schematic diagram of a high voltage switch device is provided for this application;

[0019] Figure 5 An explosion diagram of an arc extinguishing grid group in a short-circuit device provided in the present application;

[0020] Figure 6 The following are provided for this application: Figure 3 The AA' plane shown is a cross-sectional view of the high-voltage switch device obtained by the cross section;

[0021] Figure 7 A schematic diagram of the structure of the insulation board provided for this application;

[0022] Figure 8 The arc provided for this application is Figure 6 A schematic diagram of the flow path in the cross-sectional view shown;

[0023] Fig. 9 A schematic diagram of the structure of the lower shell provided for this application;

[0024] Fig.10 A schematic diagram of the positional relationship between the breaking piston and the flow row provided in the present application;

[0025] Fig.11 This is a schematic diagram of the structure of the flow row provided in this application. DETAILED DESCRIPTION

[0026] See also Figure 1 , Figure 1 This is a network diagram for the photovoltaic storage scenario. On the one hand, when there is sufficient sunlight, the photovoltaic module converts solar energy into direct current through the photovoltaic effect and transmits the direct current to the power converter. Subsequently, the power converter converts the direct current from the photovoltaic module into alternating current and transmits the alternating current to the grid or load. On the other hand, when there is insufficient sunlight, the energy storage battery can also output direct current to the power converter. Subsequently, the power converter converts the direct current from the energy storage battery into alternating current and transmits the alternating current to the grid or load. In practical applications, the power converter can be either a photovoltaic inverter or an energy storage converter. Unlike a photovoltaic inverter, the energy storage converter can convert the direct current from the photovoltaic module or the energy storage battery into alternating current for use by the load, and can also convert the alternating current from the grid into direct current to charge the energy storage system.

[0027] Specifically, the power converter includes a DC input terminal ( Figure 1 ), Maximum Power Point Tracking (MPPT) circuit, inverter circuit (Direct Current / Alternating Current, DC / AC circuit) and AC output terminal ( Figure 1The DC input terminal is used to connect to the photovoltaic module or the energy storage battery, the AC output terminal is used to connect to the load or the power grid, the MPPT circuit is used to change the output power of the photovoltaic module, and the inverter circuit is used to convert the DC power into the AC power.

[0028] In recent years, with the increase in the rated power of power converters, power converters can be connected to more photovoltaic modules or energy storage systems. However, when a photovoltaic module or energy storage battery has a short-circuit fault, a large short-circuit current will spread to the power converter and cause damage to the power converter. In response to this, the industry usually connects a high-voltage switch device in series between the DC input end of the power converter and the inverter circuit. When the current flowing through the high-voltage switch device exceeds the current threshold, the high-voltage switch device quickly cuts off the short-circuit loop, thereby avoiding damage to the power converter. Similarly, with the increase in the rated power of the power converter, when there is a problem with the power converter itself, a large short-circuit current will also spread to the load connected to it and cause damage to the load. In response to this, a high-voltage switch device can be connected in series between the AC output end of the power converter and the inverter circuit. When the current passing through the high-voltage switch device exceeds the current threshold, the high-voltage switch device quickly cuts off the short-circuit loop, thereby avoiding damage to the load.

[0029] In addition, see Figure 2 , high-voltage switching devices can also be applied to energy storage systems. Specifically, the energy storage system includes a battery pack and a high-voltage switching device, which are connected by a DC bus. When the energy storage system is discharged, the DC power output by one or more battery packs first passes through the high-voltage switching device and then flows to the power converter, which further converts the DC power into AC power and supplies power to the load. When a short circuit occurs in the battery pack in the energy storage system, the current flowing through the high-voltage switching device also increases synchronously until the current flowing through the high-voltage switching device exceeds the current threshold. The high-voltage switching device quickly cuts off the short-circuit loop, thereby preventing the short-circuit current from spreading to the power converter and causing damage to it.

[0030] It can be seen from the above description that with the increase in the rated power of power converters, it is crucial to equip power converters or energy storage systems with high-voltage switching devices. When a short circuit or overcurrent fault occurs, since the current flowing through the high-voltage switching device is large, the voltage across the high-voltage switching device is high. When the high-voltage switching device cuts off the short-circuit loop, an arc usually occurs. An arc is a discharge phenomenon with concentrated energy, high temperature, and strong brightness. If the arc is not extinguished for a long time, it will cause the burning or even explosion of related electrical appliances, endangering the safety of the power system. In this regard, the present application provides a high-voltage switching device that can quickly cut off the short-circuit loop and cool the arc. The following will be specifically combined with the attached Figure 3-11 Provide explanation.

[0031] First, the present application provides a high voltage switch device. Figure 3 , Figure 3A schematic diagram of the appearance of the high voltage switch device provided in this application, such as Figure 3 As shown, the high-voltage switch device includes a housing, a flow bar 20 and two electrical interfaces 21. Among them, the housing includes an upper housing 10 and a lower housing 30 arranged relatively along a first direction (i.e., the direction of the x-axis). The flow bar 20 is fixed between the upper housing 10 and the lower housing 30. The two electrical interfaces 21 are connected through the flow bar 20 and are used to be connected to devices or circuits outside the high-voltage switch device. In addition, the lower housing 30 is also provided with an opening 31, and the opening 31 is used to discharge the high-temperature gas in the high-voltage switch device. In actual application scenarios, in order to ensure the flow capacity, the material of the flow bar 20 and the electrical interface 21 can be copper, aluminum or copper-aluminum alloy, etc., and this application does not limit this. In addition, in actual applications, the upper housing 10 and the lower housing 30 can also be integrally formed, or the setting of the upper housing 10 can be cancelled, and this application does not limit this. In addition, in actual applications, the number of electrical interfaces 21 can also be set as needed, not limited to two, and can also be greater than two, and this application does not limit this.

[0032] See also Figure 4 , Figure 4 The exploded diagram of the high voltage switch device provided in this application is shown in FIG. Figure 4 As shown, the high-voltage switch device also includes a switch mechanism, which includes a power generator 52 and a disconnecting piston 51. When the power generator 52 is not activated, the switch mechanism is accommodated in the upper shell 10. When the power generator 52 is activated, the power generator 52 pushes the disconnecting piston 51 to move along the first direction to the lower shell 30. During the movement of the disconnecting piston 51, the disconnecting piston 51 cuts off the weak section 22 of the flow bar 20, thereby disconnecting the electrical connection between the two electrical interfaces 21. Since the voltage difference between the two electrical interfaces 21 is large, an arc will be generated when the weak section 22 is disconnected. In order to cool the arc in time, the high-voltage switch device also includes an arc extinguishing grid group 40. The arc extinguishing grid group 40 is accommodated in the arc extinguishing chamber formed by the lower shell 30. It is worth mentioning that in Figure 4 In the embodiment, the lower shell 30 forms two arc extinguishing chambers, each of which is used to accommodate an arc extinguishing grid group 40. In practical applications, one or more arc extinguishing chambers can also be set as needed, and this application does not limit this. Specifically, along the first direction, the arc extinguishing grid group 40 is located between the lower shell 30 and the current bar 20. When the weak section 22 is disconnected, the fracture corresponding to the weak section 22 will bend toward the arc extinguishing grid group 40 and allow the arc to enter the arc extinguishing grid group 40. The multiple grids included in the arc extinguishing grid group 40 can better cool the arc, thereby avoiding damage to related equipment caused by the arc. In addition, since the arc will generate more high-temperature gas during the cooling process, by setting an opening 31 on the side of the lower shell 30, the high-temperature gas inside the high-voltage switch device can be smoothly removed.

[0033] See also Figure 5 , Figure 5 The exploded schematic diagram of the arc extinguishing grid group 40 provided in the present application. Specifically, the arc extinguishing grid group 40 includes a first grid group 41, a second grid group 42 and a third grid group 43. Among them, the first grid group 41 includes a plurality of first grids arranged at intervals along the first direction, the second grid group 42 includes a plurality of second grids arranged at intervals along the first direction, and the third grid group 43 includes a plurality of third grids arranged at intervals along the first direction. Along the first direction, the first grid group 41 is arranged at intervals with the second grid group 42 and the third grid group 43, respectively, and along the second direction (i.e., the direction of the y-axis), the second grid group 42 is arranged at intervals with the third grid group 43, wherein the first direction is perpendicular to the second direction. Further, along the first direction, the size of the second grid group 42 is greater than the size of the third grid group 43, and along the second direction, the size of the first grid group 41 is greater than the sum of the sizes of the second grid group 42 and the third grid group 43. That is, the first grid plate group 41 and the second grid plate group 42 can enclose an accommodation space, and the accommodation space is used to accommodate the third grid plate group 43. Such an arrangement can increase the number of grid plates in the arc extinguishing chamber, thereby improving the arc extinguishing capability of the high-voltage switch device.

[0034] In order to better understand the special setting of the arc extinguishing grid group 40 in the present solution and the beneficial effects it brings, the implementation principle of the arc extinguishing of the grid will be specifically introduced below. As mentioned above, when the breaking piston 51 cuts off the flow bar 20 and generates an arc, the arc will enter the arc extinguishing grid group 40 under the action of the electric force. Since the arc extinguishing grid group 40 includes a plurality of grids arranged at intervals, the arc will be cut into several sections and finally extinguished. Specifically, when the arc enters the arc extinguishing grid group 40, each grid will become an electrode, and there is a voltage drop between two adjacent grids, that is, the two adjacent grids can be equivalent to a battery. Therefore, the arc extinguishing grid group 40 can be equivalent to a battery cluster formed by connecting a plurality of batteries in series. When the total voltage drop that a plurality of grids arranged at intervals can withstand is greater than the arc voltage of the arc, that is, when all the batteries in the above-mentioned battery cluster are working and the voltage corresponding to the battery cluster is greater than the arc voltage of the arc, the arc will be extinguished. It is worth mentioning that when the thickness of the grid pieces in the arc extinguishing grid group 40 and the interval between two adjacent grid pieces are determined, the more grid pieces in the arc extinguishing grid group 40, the more batteries in the battery cluster, and the stronger the arc extinguishing ability of the arc extinguishing grid group 40. In addition, although the size of the first grid piece group 41 along the second direction is greater than the sum of the sizes of the second grid piece group 42 and the third grid piece group 43, in terms of arc extinguishing ability, if the distance between two adjacent first grid pieces in the first grid piece group 41 along the first direction is equal to the distance between two adjacent second grid pieces in the second grid piece group 42 along the first direction, then the voltage drop between the two adjacent first grid pieces in the first grid piece group 41 is substantially equal to the voltage drop between the two adjacent second grid pieces in the second grid piece group 42. Based on this, it can be understood that the present application significantly increases the number of grid pieces that can be accommodated in the arc extinguishing chamber by performing special size design and spatial arrangement on the first grid piece group 41, the second grid piece group 42 and the third grid piece group 43, thereby effectively improving the arc extinguishing ability of the arc extinguishing grid group 40.

[0035] Continue to see Figure 5 , along the second direction, one end of the first grid group 41 is aligned with one end of the second grid group 42 away from the third grid group 43, along the second direction, the other end of the first grid group 41 is aligned with one end of the third grid group 43 away from the second grid group 42, along the third direction (i.e., the direction where the z-axis is located), one end of the first grid group 41 is aligned with one end of the second grid group 42 and one end of the third grid group 43, and along the third direction, the other end of the first grid group 41 is aligned with the other end of the second grid group 42 and the other end of the third grid group 43. The third direction is perpendicular to the first direction and the second direction. In this way, the volume of the arc extinguishing chamber can be reduced, thereby significantly improving the volume density of the high-voltage switch device.

[0036] Continue to see Figure 5The arc extinguishing grid group 40 further includes a fixing plate 44, which is made of insulating material and is used to fix the first grid group 41, the second grid group 42 and the third grid group 43. Specifically, the fixing plate 44 includes a plurality of hollow areas arranged at intervals, and the grids included in the first grid group 41, the second grid group 42 and the third grid group 43 are all provided with protrusions extending along the third direction, and the hollow areas are engaged with the protrusions to achieve fixation. Further, the arc extinguishing grid group 40 further includes a filter grid 45, which is arranged opposite to the opening 31 located in the lower shell 30. By providing the filter grid 45, when particulate matter is mixed in the high-temperature gas generated in the inner cavity of the high-voltage switch device, the filter grid 45 can effectively filter out these particulate matter, thereby improving the safety of the high-voltage switch device.

[0037] See also Figure 6 , Figure 6 For Figure 3 The A-A' plane shown is a cross-sectional view of the high-voltage switch device obtained by cross-section. Figure 6 As shown, the high-voltage switch device also includes a first arc-starting piece 46. Among them, one end 461 of the first arc-starting piece is arranged between the lower shell 30 and the second grid sheet group 42 along the first direction, and the distance between one end 461 of the first arc-starting piece and the second grid sheet group 42 along the first direction is less than the distance between the second grid sheet group 42 and the third grid sheet group 43 along the second direction. In this way, after the arc passes through the second grid sheet group 42, the arc will be conducted to one end 461 of the first arc-starting piece, and will not be conducted to a third grid sheet in the third grid sheet group 43, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. Further, the other end 462 of the first arc-starting piece is arranged between the first grid sheet group 41 and the third grid sheet group 43 along the first direction, and the distance between the other end 462 of the first arc-starting piece and the third grid sheet group 43 along the first direction is less than the distance between the second grid sheet group 42 and the third grid sheet group 43 along the second direction. With such arrangement, after the arc is conducted to one end 461 of the first arc-starting plate, the arc will enter the third grid plate group 43 through the other end 462 of the first arc-starting plate, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. Further, along the first direction, the distance between the other end 462 of the first arc-starting plate and the third grid plate group 43 is less than the distance between the other end 462 of the first arc-starting plate and the first grid plate group 41. That is, along the first direction, the other end 462 of the first arc-starting plate is closer to the third grid plate group 43 than the first grid plate group 41. With such arrangement, the arc can be smoothly guided from the second grid plate group 42 to the third grid plate group 43, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. By providing the first arc-starting plate 46, the arc of the second grid plate group 42 can be smoothly introduced into the third grid plate group 43.

[0038] Continue to see Figure 6, the high-voltage switch device also includes a second arc-starting piece 47. Among them, one end 471 of the second arc-starting piece is arranged between the third grid piece group 43 and the partition wall 32 along the second direction, and the other end 472 of the second arc-starting piece is arranged between the lower shell 30 and the third grid piece group 43 along the first direction. It is worth mentioning that the partition wall 32 is a part of the lower shell 30, and the partition wall 32 is used to separate the lower shell 30 into two arc-extinguishing chambers, each arc-extinguishing chamber is used to accommodate an arc-extinguishing grid group 40, and the two arc-extinguishing grid groups 40 are symmetrical about the partition wall 32. In addition, one end of the partition wall 32 along the first direction is also fixedly connected to the through-current bar 20 by screws, thereby better fixing the through-current bar 20. When the high-voltage switch device has only one arc-extinguishing chamber, the partition wall 32 can be cancelled. At this time, one end 471 of the second arc-starting piece is arranged between the third grid piece group 43 and the side wall of the lower shell 30 along the second direction. In addition, the distance between one end 471 of the second arc-starting plate and the third grid plate group 43 along the second direction is greater than the distance between the other end 472 of the second arc-starting plate and the third grid plate group 43 along the first direction. In this way, when the arc is attracted by one end 471 of the second arc-starting plate, the arc can better enter the third grid plate group 43 through the other end 472 of the second arc-starting plate, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. In addition, along the first direction, the distance between one end 471 of the second arc-starting plate and the first grid plate group 41 is greater than the distance between the other end 462 of the first arc-starting plate and the first grid plate group 41. That is, along the first direction, the other end 462 of the first arc-starting plate is located between the first grid plate group 41 and one end 471 of the second arc-starting plate. In this way, the arc can smoothly pass through the first grid plate group 41, the second grid plate group 42 and the third grid plate group 43. The specific principle will be described in detail below.

[0039] Continue to see Figure 6, the high-voltage switch device also includes a third arc-starting piece 48. Among them, along the first direction, the third arc-starting piece 48 is located between the through-current bar 20 and the first grid sheet group 41, one end 481 of the third arc-starting piece extends toward the through-current bar 20 along the first direction and contacts the through-current bar 20, and the other end 482 of the third arc-starting piece extends along the second direction and is arranged at intervals with the first grid sheet group 41. In addition, along the second direction, the distance between one end 481 of the third arc-starting piece and the weak section 22 is smaller than the distance between the first grid sheet group 41 and the weak section 22. That is to say, whether in the first direction or the second direction, the third arc-starting piece 48 is closer to the weak section 22 than the first grid sheet group 41. In this way, when the weak section 22 of the through-current bar 20 is disconnected, the arc can be smoothly guided into the first grid sheet group 41 by the third arc-starting piece 48, thereby ensuring that the arc can completely pass through all the first grid sheets included in the first grid sheet group 41, thereby improving the arc extinguishing ability of the high-voltage switch device. It is worth mentioning that, in actual application, one end 481 of the third arc-starting piece can be arranged close to the through-current bar 20, that is, there can also be a gap between the first bent portion 4212 and the through-current bar 20, and the present application does not limit this. In addition, the third arc-starting piece 48 and part of the first grid sheet close to the through-current bar 20 are also connected to the through-current bar 20 by fixing members such as screws, so as to better fix the arc-extinguishing grid group 40 in the arc-extinguishing chamber.

[0040] Continue to see Figure 6 , one end 461 of the first arc-starting plate is connected to the other end 462 of the first arc-starting plate by a connecting plate 463, and an insulating plate 48 is further arranged between the connecting plate 463 and the third grid plate group 43 along the second direction. To better illustrate the structure of the insulating plate 48, please continue to refer to Figure 7 .like Figure 7As shown, the insulating plate 48 includes a first flat plate 482 and a second flat plate 483, wherein the first flat plate 482 is bonded to a side of the connecting plate 463 facing the third grid plate group 43, and the second flat plate 483 is bonded to a side of the other end 462 of the first arc-starting plate facing the third grid plate group 43. It is worth noting that, in order to ensure the effective bonding of the second flat plate 483 and the other end 462 of the first arc-starting plate, the first arc-starting plate 46 also includes a third end 464, the third end 464 of the first arc-starting plate extends toward the second grid plate group 41 along the second direction, and the third end 464 of the first arc-starting plate is located between the other end 462 of the first arc-starting plate and the third grid plate group 43 along the first direction. Further, the third end 464 of the first arc-starting plate is connected to the other end 462 of the first arc-starting plate and is spaced apart, and the two are surrounded to form a narrow gap, and the second flat plate 483 is inserted into the narrow gap. It should be noted that, in practical applications, the second plate 483 can also be directly and effectively attached to the other end 462 of the first arc-starting plate through a fastener, a clamp or even a viscous medium, thereby omitting the third end 464 of the first arc-starting plate, and the present application does not impose any restrictions on this. Further, a protrusion 481 is also provided on one side of the first plate 482 facing the third grid plate group 43, and the protrusion 481 is engaged with the third grid plate group 43, thereby achieving better fixation. On this basis, the insulating plate 48, the third grid plate group 43, and the connecting plate 463 are arranged to form at least one air channel. Further, one end 461 of the first arc-starting plate is arranged at intervals with the lower shell 30 along the first direction and is arranged to form another air channel, and the other air channel is connected to the outside of the arc-extinguishing chamber through the opening 31 of the lower shell 30. Further, the above-mentioned one air channel is connected to the outside of the arc-extinguishing chamber through another air channel, thereby discharging the high-temperature gas generated during the arc extinguishing process of the third grid plate group 43 out of the arc-extinguishing chamber.

[0041] Continue to see Figure 6 , one end 461 of the first arc-starting piece, the other end 462 of the first arc-starting piece, the other end 472 of the second arc-starting piece, the other end 482 of the third arc-starting piece, the third grid piece and the second grid piece all extend along the second direction and are parallel to the first grid piece. In this way, the volume of the arc-extinguishing chamber can be reduced, thereby significantly improving the volume density of the high-voltage switch device.

[0042] In order to better explain the arc extinguishing principle of the high voltage switch device provided by this application, please refer to Figure 8 , Figure 8 For the arc Figure 6 As described above, when the current flowing through the flow bar 20 exceeds the current threshold, the power generator 52 pushes the breaking piston 51 to move toward the bottom of the inner cavity. The movement of the breaking piston 51 will break the weak section 22 of the flow bar 20, and an arc will be generated between the broken ends of the weak section 22. Figure 8The arc extinguishing grid group 40 on the right side in the middle is used as an example. When the electrical connection of at least two electrical interfaces 21 is disconnected and an arc is generated, the arc entering the arc extinguishing chamber will be elongated due to the effect of the electromotive force. One end of the arc is attracted by one end 481 of the third arc-starting plate and further guided to the first grid group 41 by the other end 482 of the third arc-starting plate, and the other end of the arc is attracted by one end 471 of the second arc-starting plate and further guided to the third grid group 43 by the other end 472 of the second arc-starting plate. There is a voltage difference between the two ends of the arc. Furthermore, when the arc is elongated, by setting the other end 462 of the first arc-starting plate between the first grid group 41 and one end 471 of the second arc-starting plate, the arc can be further attracted to the other end 462 of the first arc-starting plate, so that there is a voltage difference between the other end 462 of the first arc-starting plate and the first grid group 41 and the other end 472 of the second arc-starting plate, respectively, so that the arc can pass through the first grid group 41, the second grid group 41 and the third grid group 43 more smoothly, thereby improving the arc extinguishing ability of the high-voltage switching device. In practical applications, when the voltage difference between one end of the arc and the other end of the arc is large, if the other end 462 of the first arc-starting piece is not disposed between the first grid piece group 41 and the one end 471 of the second arc-starting piece, the arc may flow chaotically in the arc-extinguishing grid group 40, that is, the arc cannot be divided into multiple sections and finally extinguished along the path of the third arc-starting piece 48-first grid piece group 41-second grid piece group 42-first arc-starting piece 46-third grid piece group 43-second arc-starting piece 47. Therefore, such an arrangement allows the arc to smoothly enter the first grid piece group 41, the second grid piece group 42 and the third grid piece group 43, thereby improving the arc extinguishing ability of the high-voltage switch device.

[0043] It is worth mentioning that the arc extinguishing grid group 40 provided in the present application can be applied to any scenario requiring high-voltage arc extinguishing. However, in order to better demonstrate the working principle of the high-voltage switch device provided in the present application, the above drawings reflect the flow bar 20 used to connect the two electrical interfaces 21, and the arc extinguishing principle of the high-voltage switch device is described in detail in combination with the flow path of the arc when the weak section 22 of the flow bar 20 is disconnected. In practical applications, the above-mentioned arc extinguishing grid group 40 can also be directly set between two switch contacts or between a moving contact and a stationary contact, and then extinguish the arc when the switch is opened and closed, thereby improving the safety and reliability of the high-voltage switch device.

[0044] See also Fig. 9 , Fig. 9 Schematic diagram of the structure of the lower housing 30 provided in this application. Fig. 9As shown in the figure, the bottom of the lower housing 30 is stepped. The thickness of the stepped surface 33 near the opening 31 of the lower housing 30 is smaller than that of the stepped surface 33 far from the opening 31 of the lower housing 30. Specifically, along the first direction, the stepped surface 33 near the opening 31 of the lower housing 30 is opposite to and spaced from one end 461 of the first arcing piece, thus enclosing an air duct. The air duct communicates with the outside through the opening 31 of the lower housing 30. Further, a transition surface is connected between the stepped surface 33 near the opening 31 of the lower housing 30 and the stepped surface 34 far from the opening 31 of the lower housing 30. The transition surface is inclined with respect to the first direction. In addition, the third grid piece group 43 is arranged on the stepped surface 34 far from the opening 31 of the lower housing 30, so that the position of the third grid piece group 43 in the lower housing 30 remains basically unchanged, improving the structural stability of the high-voltage switch device.

[0045] To better illustrate the process of the opening piston 51 cutting off the current-carrying busbar 20, refer to Fig.10 , Fig.10 which is a schematic diagram of the positional relationship between the opening piston 51 and the current-carrying busbar 20 provided in this application. As Fig.10 shown, the opening piston 51 is cylindrical, and the current-carrying busbar 20 is flat strip-shaped. Along the first direction, the opening piston 51 is arranged opposite to the weak section 22 of the current-carrying busbar 20. The opening piston 51 includes four insulating arms 521 extending along the first direction. Among them, two adjacent insulating arms 521 are arranged opposite to each other along the second direction or the third direction. It is worth mentioning that an insulating wall 522 is also connected between the two insulating arms 521 arranged opposite to each other along the third direction, and the insulating wall 522 also extends along the first direction. Further, along the first direction, the weak section 22 is arranged opposite to the insulating wall 522. When the opening piston 51 moves towards the bottom of the lower housing 30, the insulating wall 522 cuts off the weak section 22, thus interrupting the current-carrying busbar 20.

[0046] To better illustrate the process of the insulating wall 522 interrupting the current-carrying busbar 20, refer to Fig.11 , Fig.11 which is a schematic diagram of the structure of the current-carrying busbar 20 provided in this application. Specifically, the thicknesses of both the first end 201 and the second end 202 of the current-carrying busbar are d1, and the thickness of the weak section 22 is d2, where d2 < d1. When the opening piston 51 interrupts the weak section 22, the current-carrying busbar 20 on one side of the weak section 22 bends towards the arc extinguishing grid group 40 along the first direction. As described above, the weak section 22 and the insulating wall 522 of the opening piston 51 are arranged opposite to each other along the first direction. Therefore, when the opening piston 51 moves towards the bottom of the inner cavity, the weak section 22 can be cut off more smoothly, thereby increasing the breaking speed of the current-carrying busbar 20.

[0047] In general, the present application significantly increases the number of grids that can be accommodated in the arc extinguishing chamber by performing special size design and spatial arrangement on the first grid group 41, the second grid group 42 and the third grid group 43, thereby effectively improving the arc extinguishing ability of the high-voltage switch device. In addition, the present application effectively realizes the series connection of the second grid group 42 and the third grid group 43 through the design of the first arc-starting plate 46, thereby allowing the arc to smoothly pass through the first grid group 41, the second grid group 42 and the third grid group 43, thereby extending the cooling path of the arc and improving the arc extinguishing ability of the high-voltage switch device. In addition, the present application also sets an air duct based on the above structure, thereby better discharging the high-temperature gas in the arc extinguishing chamber, and improving the working stability and safety of the high-voltage switch device.

[0048] Furthermore, the present application also provides an energy storage system, which includes the above-mentioned high-voltage switch device and one or more battery packs, the battery pack and the high-voltage switch device are connected through a DC bus, and when the current flowing through the high-voltage switch device is greater than the current threshold, the switch mechanism of the high-voltage switch device disconnects the electrical connection of at least two electrical interfaces. In this way, when one or more battery packs in the energy storage system have a short circuit or overcurrent fault, the high-voltage switch device can promptly cut off the short-circuit current loop, thereby preventing the short-circuit fault from spreading to the power converter or load side connected to the battery pack, thereby ensuring the safety and stability of the power supply system.

[0049] Furthermore, the present application provides a power converter, which includes the above-mentioned high-voltage switch device, an inverter circuit, a DC input terminal and an AC output terminal, wherein the DC input terminal is used to connect a photovoltaic module or an energy storage system, and the AC output terminal is used to connect a load, and the high-voltage switch device is connected between the inverter circuit and the DC input terminal, or the high-voltage switch device is connected between the inverter circuit and the AC output terminal, and when the current flowing through the high-voltage switch device is greater than the current threshold, the switch mechanism of the high-voltage switch device disconnects the electrical connection of at least two electrical interfaces. With such an arrangement, when a short circuit or overcurrent fault occurs inside the power converter, the short-circuit current loop can be cut off in time, thereby preventing the short-circuit fault from spreading to the battery pack or load side connected thereto, thereby ensuring the safety and stability of the power supply system.

[0050] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A high voltage switch device, characterized in that: include: At least two electrical interfaces; A switch mechanism, the switch mechanism being used to disconnect the electrical connection of the at least two electrical interfaces; A shell, wherein the shell is used to fix the at least two electrical interfaces, and the shell is used to form at least one arc extinguishing chamber, each of the arc extinguishing chambers is used to accommodate a first grid plate group, a second grid plate group and a third grid plate group, the first grid plate group includes a plurality of first grid plates arranged at intervals along a first direction, the second grid plate group includes a plurality of second grid plates arranged at intervals along the first direction, the third grid plate group includes a plurality of third grid plates arranged at intervals along the first direction, the first grid plate group is arranged at intervals with the second grid plate group and the third grid plate group respectively along the first direction, the second grid plate group and the third grid plate group are arranged at intervals along the second direction, and the first direction is perpendicular to the second direction.

2. The high voltage switch device according to claim 1, characterized in that: Along the first direction, a distance between the first grid plate group and the second grid plate group is smaller than a distance between the first grid plate group and the third grid plate group.

3. The high voltage switch device according to claim 1 or 2, characterized in that: The size of the second grid plate group along the first direction is larger than the size of the third grid plate group, and the size of the first grid plate group along the second direction is larger than the sum of the size of the second grid plate group and the size of the third grid plate group.

4. The high voltage switch device according to claim 1, characterized in that: The high voltage switch device comprises a first arc-starting piece, wherein: One end of the first arc-starting plate is arranged between the housing and the second grid plate group along the first direction, and the distance between one end of the first arc-starting plate and the second grid plate group along the first direction is smaller than the distance between the second grid plate group and the third grid plate group along the second direction; The other end of the first arc-starting plate is arranged between the first grid plate group and the third grid plate group along the first direction, and the distance between the other end of the first arc-starting plate and the third grid plate group along the first direction is smaller than the distance between the second grid plate group and the third grid plate group along the second direction.

5. The high voltage switch device according to claim 4, characterized in that: Along the first direction, the distance between the other end of the first arc-starting plate and the third grid plate group is smaller than the distance between the other end of the first arc-starting plate and the first grid plate group.

6. The high voltage switch device according to claim 5, characterized in that: One end of the first arc-striking plate is connected to the other end of the first arc-striking plate through a connecting plate, and an insulating plate is included between the connecting plate and the third grid plate group along the second direction, the connecting plate, the third grid plate group and the insulating plate are arranged to form at least one air channel, and one end of the first arc-striking plate and the shell are arranged to form another air channel along the first direction, and the one air channel is connected to the outside of the arc extinguishing chamber through the other air channel.

7. The high voltage switch device according to any one of claims 4 to 6, characterized in that: The high voltage switch device comprises a second arc starting piece, wherein: One end of the second arc-starting plate is arranged between the third grid plate group and the shell along the second direction; The other end of the second arc-starting plate is arranged between the third grid plate group and the shell along the first direction; Along the first direction, a distance between one end of the second arc-starting plate and the first grid plate group is greater than a distance between the other end of the first arc-starting plate and the first grid plate group.

8. The high voltage switch device according to claim 7, characterized in that: A distance between one end of the second arc-starting plate and the third grid plate group along the second direction is greater than a distance between the other end of the second arc-starting plate and the third grid plate group along the first direction.

9. The high voltage switch device according to claim 1, characterized in that: The high-voltage switch device comprises a through-current bar, the through-current bar is used to connect the at least two electrical interfaces, the through-current bar comprises a weak section, and the switch mechanism is used to disconnect the weak section; Along the first direction, the distance between the weak section and the first grid plate group is smaller than the distance between the weak section and the second grid plate group; Along the second direction, a distance between the weak section and the third grid plate group is smaller than a distance between the weak section and the second grid plate group.

10. An energy storage system, characterized in that: It comprises a high-voltage switch device as described in any one of claims 1 to 9 and one or more battery packs, wherein the battery pack is connected to the high-voltage switch device via a DC bus, and when the current flowing through the high-voltage switch device is greater than a current threshold, the switch mechanism of the high-voltage switch device disconnects the electrical connection of the at least two electrical interfaces.

11. A power converter, characterized in that: It comprises a high-voltage switch device, an inverter circuit, a DC input terminal and an AC output terminal as described in any one of claims 1 to 9, the DC input terminal is used to connect a photovoltaic component or an energy storage system, the AC output terminal is used to connect a load, the high-voltage switch device is connected between the inverter circuit and the DC input terminal, or the high-voltage switch device is connected between the inverter circuit and the AC output terminal, and when the current flowing through the high-voltage switch device is greater than a current threshold, the switch mechanism of the high-voltage switch device disconnects the electrical connection of the at least two electrical interfaces.

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