Method for improving power density of network construction type energy storage converter

Abstract

The invention relates to a method for improving the power density of a network construction type energy storage converter, and the method comprises the steps: arranging two reactors of the network construction type energy storage converter side by side, and placing an AC switch between the two reactors, the alternating current sides of the two reactors are connected in parallel through the laminated busbar, the switching soft copper bar and the switching hard copper bar in sequence and converge to the upper port of the alternating current switch. According to the energy storage converter, the number of electrical elements in the energy storage converter is reduced, and the distance between the electric reactor and the alternating current switch is reduced, so that the integration level and the power density of the energy storage converter are improved, and the size of the energy storage converter is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage converter integration, and in particular relates to a method for improving the power density of a grid-type energy storage converter. Background Art

[0002] The switches and reactors of outdoor converter cabinets are mostly connected by copper bars. When the power is large, even single-phase copper bars need to be used. At present, two power circuits are mostly connected in parallel inside a single converter, and two independent switches are used on the AC side. This greatly increases the size of the converter cabinet and is not convenient for improving product integration. In particular, the energy storage converter of the grid-building product has a short-term overload requirement of three times 10S or even higher, which requires a higher compact integrated design. Summary of the invention

[0003] The purpose of the present invention is to provide a method for improving the power density of a grid-type energy storage converter, so as to solve the problem of low integration of the energy storage converter.

[0004] A method of improving the power density of a grid-type energy storage converter of the present invention is achieved as follows: A method for improving the power density of a grid-type energy storage converter comprises arranging two reactors of the grid-type energy storage converter side by side, placing an AC switch between the two reactors, and connecting the AC sides of the two reactors in parallel through a laminated busbar, a transfer soft copper busbar and a transfer hard copper busbar in sequence and converging them to the upper port of the AC switch.

[0005] Furthermore, the laminated busbar of each reactor is connected to the three-phase transfer hard copper bar through the three-phase transfer soft copper bar, and the transfer hard copper bars of the two reactors are connected in parallel in pairs on the corresponding upper ports of the AC switch.

[0006] Furthermore, the laminated busbars are arranged vertically.

[0007] Furthermore, the AC switch is located between the two reactors and arranged in front, wherein the laminated busbar corresponding to one of the reactors is straight, and the laminated busbar corresponding to the other reactor is Z-shaped.

[0008] Furthermore, the transfer hard copper busbar corresponding to the straight laminated busbar is located at the rear side thereof, and the transfer soft copper busbar connected therebetween is arranged horizontally; The transfer hard copper busbar corresponding to the Z-shaped laminated busbar is located above it, and the transfer soft copper busbar connected between the two is arranged vertically.

[0009] Furthermore, the three-phase connecting copper bars of the reactor extend out to the same length, and the laminated busbar is flush with the mounting surface of the connecting copper bar on the corresponding reactor.

[0010] Furthermore, rivet nuts are respectively provided on the connecting copper bars of the reactors, on the connecting soft copper bar connected to one of the reactors, and on the transition hard copper bar connected to the other reactor.

[0011] Furthermore, the thickness of the laminated busbar is 15-18 mm.

[0012] Furthermore, the assembly error spacings on both sides of the laminated busbar are respectively ±(8-12) mm.

[0013] Furthermore, a support hole is provided on the laminated busbar near its lower edge, and support members are installed on both sides of the support hole.

[0014] After adopting the above technical solution, the present invention has the following beneficial effects: (1) The present invention uses a connection method of a laminated busbar and a transfer copper busbar to achieve the connection between the reactor and the AC switch, which can effectively reduce the distance between the reactor and the AC switch, thereby improving the integration and power density of the energy storage converter and reducing the volume of the converter; (2) The present invention connects two reactors in parallel on the same AC switch, and can control the opening and closing of two power circuits through one AC switch, thereby reducing the number of electrical components in the energy storage converter and further reducing the size of the converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 It is a structural diagram of the connection part between the reactor and the AC switch in the grid-type energy storage converter of the preferred embodiment of the present invention; Figure 2 It is a left view of the connection part between the reactor and the AC switch in the grid-type energy storage converter of the preferred embodiment of the present invention; Figure 3 It is a right view of the connection part between the reactor and the AC switch in the grid-type energy storage converter of the preferred embodiment of the present invention; Figure 4 It is a top view of the connection part between the reactor and the AC switch in the grid-type energy storage converter of the preferred embodiment of the present invention; Figure 5 It is a rear view of the connection part between the reactor and the AC switch in the grid-type energy storage converter of the preferred embodiment of the present invention; Figure 6 It is a structural diagram of the right laminated busbar part in the grid-type energy storage converter of the preferred embodiment of the present invention; Figure 7 It is a structural diagram of the left laminated busbar part in the grid-type energy storage converter in the preferred embodiment of the present invention; In the figure: AC switch 1, right inductor 2, right laminated busbar 21, right transfer soft copper busbar 22, right transfer hard copper busbar 23, connecting copper busbar Ⅰ24, rivet nut Ⅰ25, connecting hole Ⅰ26, rivet nut Ⅲ27, supporting hole Ⅰ28, left inductor 3, left laminated busbar 31, left transfer soft copper busbar 32, left transfer hard copper busbar 33, connecting copper busbar Ⅱ34, rivet nut Ⅱ35, connecting hole Ⅱ36, rivet nut Ⅳ37, supporting hole Ⅱ38, supporting part 4, epoxy pad 5. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] like Figure 1-7 As shown, a method for improving the power density of a grid-type energy storage converter is provided, wherein two reactors of the grid-type energy storage converter are arranged side by side, and an AC switch 1 is placed between the two reactors, and the AC sides of the two reactors are respectively connected in parallel through a laminated busbar, a transfer soft copper busbar, and a transfer hard copper busbar and converged to the upper port of the AC switch 1.

[0020] The present invention controls the power circuits where two reactors are located through an AC switch 1. When any power circuit fails, the controller of the energy storage converter will lock the AC switch 1 to shut down the power circuits where the two reactors are located.

[0021] By using a single AC switch 1 to control two power circuits, the number of electrical components of the energy storage converter can be reduced, thereby reducing the overall size of the energy storage converter.

[0022] In order to realize the connection between the AC side of the reactor and the AC switch 1, the laminated busbar of each reactor is connected to the three-phase transfer hard copper bar through the three-phase transfer soft copper bar, and the transfer hard copper bars of the two reactors are connected in parallel in pairs on the corresponding upper ports of the AC switch 1.

[0023] Among them, the left reactor 3 is located on the left side of the AC switch 1, and the corresponding connections between it and the AC switch 1 are the left laminated busbar 31, the left transfer soft copper busbar 32 and the left transfer hard copper busbar 33; the right reactor 2 is located on the right side of the AC switch 1, and the corresponding connections between it and the AC switch 1 are the right laminated busbar 21, the right transfer soft copper busbar 22 and the right transfer hard copper busbar 23.

[0024] In order to increase the current carrying capacity, the laminated busbars are arranged vertically.

[0025] When the laminated busbars are arranged vertically, hot air will not be squeezed, which is conducive to the circulation and discharge of hot air. Therefore, under the condition of the same current carrying capacity, the temperature of the vertically arranged laminated busbars is lower, and the corresponding vertically arranged laminated busbars can increase the current carrying capacity of the laminated busbars.

[0026] In order to allow the two reactors to be staggered front to back when converging at the AC switch 1 to save layout space, the AC switch 1 is located between the two reactors and arranged in the front. The laminated busbar corresponding to one of the reactors is straight, and the laminated busbar corresponding to the other reactor is Z-shaped.

[0027] In this embodiment, the right laminated busbar 21 is straight, and the left laminated busbar 31 is Z-shaped.

[0028] Among them, the front straight part and the rear straight part of the Z-shaped left stacked busbar 31 are not at the same height, and the rear straight part is higher than the front straight part. In this way, the front-to-back and up-down misalignment between the left stacked busbar 31 and the right stacked busbar 21 can be achieved at the same time, thereby achieving the effect of saving layout space.

[0029] In order to stagger the laminated busbars, transfer soft copper busbars and transfer hard copper busbars corresponding to the two reactors, the transfer hard copper busbar corresponding to the straight laminated busbar is located at its rear side; the transfer hard copper busbar corresponding to the Z-shaped laminated busbar is located above it.

[0030] Specifically, the right end of the straight right stacked busbar is connected to the connection copper bar I24 of the right reactor 2, and the left end is connected to the lower end of the right transfer hard copper bar 23 on the rear side thereof through the right transfer soft copper bar 22, and the upper end of the right transfer copper bar is connected to the upper port of the AC switch 1; The left end of the Z-shaped left laminated busbar 31 is connected to the connecting copper bar II 34 of the left inductor 3, and the right end is connected to the lower end of the left turning hard copper bar 33 above it through the left turning soft copper bar 32, and the inner end of the left turning hard copper bar 33 is connected to the upper end of the AC switch 1.

[0031] In order to facilitate the connection between the AC side of the reactor and the laminated busbar, the three-phase connecting copper bars of the reactor are extended to the same length, and the mounting surface of the laminated busbar and the connecting copper bar on the corresponding reactor are flush.

[0032] In this embodiment, the connection copper bars of the AC sides of the two reactors are located at the front side thereof, and the upper opening of the AC switch 1 is located at the rear side thereof. One end of the laminated busbar is connected to the corresponding connection copper bar, and the other end extends to the rear side of the AC switch 1, and then connected to the upper opening of the AC switch 1 through the corresponding transfer soft copper bar and transfer hard copper bar.

[0033] In order to achieve the connection between the reactor and the laminated busbar, and the transition soft copper bar and the transition hard copper bar, rivet nuts are respectively provided on the connecting copper bar of the reactor, the connecting soft copper bar connected to one of the reactors, and the transition hard copper bar connected to the other reactor.

[0034] Specifically, the inner side of the mounting surface of the connecting copper busbar Ⅰ24 of the right inductor 2 is respectively provided with rivet nuts Ⅰ25, and bolts are screwed into the connecting holes Ⅰ26 on the right laminated busbar 21 to be connected with the corresponding rivet nuts Ⅰ25; the inner side of the mounting surface of the connecting copper busbar Ⅱ34 of the left inductor 3 is also provided with rivet nuts Ⅱ35, and bolts are screwed into the connecting holes Ⅱ36 on the left laminated busbar 31 to be connected with the corresponding rivet nuts Ⅱ35.

[0035] In addition, a rivet nut III27 is provided on the right-hand soft copper busbar 22, and the bolt is screwed into the through hole on the right-hand hard copper busbar 23 to connect with the corresponding rivet nut III27; a rivet nut IV37 is provided on the upper end of the left-hand hard copper busbar 33, and the bolt is screwed into the through hole on the left-hand soft copper busbar 32 to connect with the corresponding rivet nut IV37.

[0036] Since the connection between the connecting copper bar I 24 and the right laminated busbar 21, the connection between the connecting copper bar II 34 and the left laminated busbar 31, the connection between the right transfer soft copper bar 22 and the right transfer hard copper bar 23, and the connection between the left transfer hard copper bar 33 and the left transfer soft copper bar 32 are all inconvenient to connect, the connection is made by means of compression rivet nuts, which can facilitate installation and disassembly and assembly during subsequent maintenance.

[0037] In addition, the right laminated busbar 21 and the right transfer soft copper busbar 22, and the left laminated busbar 31 and the left transfer soft copper busbar 32 are directly connected by external bolts, nuts and other connectors. Taking the right laminated busbar 21 and the right transfer soft copper busbar 22 as an example, the bolts are passed through the corresponding through holes of the right laminated busbar 21 and the right transfer soft copper busbar 22, and then the bolts are assembled to connect the two.

[0038] In order to ensure the conduction effect of the laminated busbar, the thickness of the laminated busbar is 15-18mm.

[0039] Preferably, the thickness of the laminated busbar is 16.5 mm, and each laminated busbar includes three-phase copper bars, and the thickness of each phase copper bar is 5 mm. Due to the skin effect, the selection of 5 mm copper bars can not only maximize the copper bar thickness of the laminated busbar, but also reduce the height dimension of each phase copper bar, further compressing the height dimension of the laminated busbar, and making it more convenient to arrange the laminated busbar in the cabinet.

[0040] In order to ensure the effective installation of the laminated busbar, the assembly error spacing on both sides of the laminated busbar is ± (8-12mm).

[0041] Preferably, the assembly error spacings on both sides of the laminated busbar are respectively ±10 mm. The selection of this assembly error spacing can reduce the precision requirement of assembly manufacturing and reduce stress concentration.

[0042] The existing energy storage converter connected with copper bars has a current carrying capacity of 1674A per phase under rated working conditions, and a 1.1 times long-term overload current of 1841A. Under the current carrying conditions of this embodiment: in the horizontal direction, when the copper bars of each phase of A, B, and C are arranged horizontally, the width of the copper bars is 80mm, and the sum of the insulation distance on both sides of the copper bars and the assembly error spacing is 30mm respectively. Theoretically, the required width of each phase of the copper bars is 140mm (i.e. 80+30+30=140mm). In addition, it is difficult to dissipate heat when the copper bars are arranged horizontally, and the current carrying capacity of the same cross-sectional size is less than that of the vertical arrangement. In the height direction, due to the other structures in the converter cabinet, the three-phase copper bars cannot actually be arranged within the existing height size, and the horizontal spacing must be further enlarged until at least two phases can be arranged in the horizontal direction, that is, two of the phases are on the same horizontal plane, and the other phase is alone on the horizontal plane. Therefore, the actual horizontal spacing is at least 140mm+80mm+30mm=250mm, which directly increases the size and volume of the converter cabinet.

[0043] Under the current-carrying conditions of this embodiment, the thickness of the laminated busbar of the present invention is only 18 mm, the assembly error spacing on both sides is 20 mm, and the actual required width is only 18 mm + 20 mm + 20 mm = 58 mm. Compared with the 250 mm width required for the existing copper busbar connection, the width is reduced by 76.8%, that is, the size of the converter is greatly reduced, the internal structure is more compact, the integration is higher, and the power density of the converter is effectively improved.

[0044] In addition, the present invention adopts a laminated busbar, which can reduce the bolt connection of the copper busbar overlap, making it easier to integrate and assemble.

[0045] In order to support the weight of the laminated busbar, a support hole is provided on the laminated busbar near its lower edge, and support members 4 are installed on both sides of the support hole.

[0046] Specifically, the support hole is a through hole that penetrates the laminated busbar, and epoxy pads 5 are provided on both side surfaces of the through hole to ensure the strength at the support hole.

[0047] Among them, the support member 4 is an L-shaped structure, the two support members 4 on both sides of the same support hole are arranged back to back, and the upper end of the vertical plate of the support member 4 is assembled at the corresponding support hole by bolts, and the horizontal plate is fixed to the bottom plate of the cabinet by bolts and other connecting parts to achieve support for the laminated busbar, reduce the stress of the connecting copper busbar connected thereto, and avoid breakage of the connecting copper busbar during transportation.

[0048] In this embodiment, there are two support holes I28 on the right laminated busbar 21, which are respectively located at the lower right corner of the right laminated busbar 21 and below the AC switch 1; there are two support holes II38 on the left laminated busbar 31, which are respectively located at the lower left corner of the left laminated busbar 31 and near the lower right corner of the left laminated busbar 31.

[0049] The present invention can significantly reduce the integrated size of the converter and improve its power density by stacking busbars and connecting the power circuits where the two reactors are located in parallel on the same AC switch 1, that is, the output power of the converter is increased under a certain cabinet volume.

[0050] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for improving the power density of a grid-type energy storage converter, characterized in that: Two reactors of a grid-type energy storage converter are arranged side by side, and an AC switch (1) is placed between the two reactors. The AC sides of the two reactors are connected in parallel through a laminated busbar, a transfer soft copper busbar, and a transfer hard copper busbar, respectively, and converged to the upper port of the AC switch (1).

2. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: The laminated busbar of each reactor is connected to the three-phase transfer hard copper bar through the three-phase transfer soft copper bar, and the transfer hard copper bars of the two reactors are connected in parallel to the corresponding upper ports of the AC switch (1) in pairs per phase.

3. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: The laminated busbars are arranged vertically.

4. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: The AC switch (1) is located between two reactors and arranged in the front, wherein the laminated busbar corresponding to one reactor is straight, and the laminated busbar corresponding to the other reactor is Z-shaped.

5. The method for improving the power density of a grid-type energy storage converter according to claim 4, characterized in that: The transfer hard copper busbar corresponding to the straight laminated busbar is located at the rear side thereof, and the transfer soft copper busbar connected between the two is arranged horizontally; The transfer hard copper busbar corresponding to the Z-shaped laminated busbar is located above it, and the transfer soft copper busbar connected between the two is arranged vertically.

6. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: The three-phase connecting copper bars of the reactor extend out to the same length, and the stacked busbar is flush with the mounting surface of the connecting copper bar on the corresponding reactor.

7. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: Compression rivet nuts are respectively arranged on the connecting copper bars of the reactors, on the connecting soft copper bar connected to one of the reactors, and on the transition hard copper bar connected to the other reactor.

8. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: The thickness of the laminated busbar is 15-18 mm.

9. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: The assembly error spacings on both sides of the laminated busbar are ±(8-12) mm respectively.

10. The method for improving the power density of a grid-type energy storage converter according to claim 1, characterized in that: A support hole is provided on the laminated busbar near its lower edge, and support members (4) are installed on both sides of the support hole.

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