Direct current busbar power supply equipment of lithium ion battery

Abstract

The utility model provides direct current busbar power supply equipment of lithium ion batteries, which relates to the technical field of batteries and comprises an alternating current device group, one side of the alternating current device group is connected with commercial power, the other side of the alternating current device group is connected with a plurality of bidirectional inverters through direct current busbars, and each bidirectional inverter is correspondingly connected with one lithium ion battery; when each lithium ion battery is charged, the direct current passes through a direct current busbar and is subjected to voltage transformation through a bidirectional inverter, and then the lithium ion battery is charged. And during discharging, the current of the lithium ion battery flows back to the direct-current busbar and then flows to other charged lithium ion batteries after being subjected to voltage transformation by the corresponding bidirectional inverter. The beneficial effects of the utility model are that the problem that a direct current busbar only needs one inversion process from alternating current to direct current after two voltage inversion processes in traditional battery charging and discharging is solved, and the current only flows at a direct current end and does not need to return to a mains supply line when the battery discharges is solved, so that a large amount of inversion energy consumption is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a direct current busbar power supply device of a lithium ion battery. Background Art

[0002] Lithium battery is a new type of battery with advantages such as high energy density, high power density, long life and environmental friendliness. It is widely used in electric vehicles, energy storage systems, mobile communications, portable electronic products and other fields. The performance and quality of lithium batteries are closely related to their production process. The capacity separation process is an important part of the lithium battery production process. Its main purpose is to sort the capacity, performance and grade the battery.

[0003] The lithium battery capacity division process usually includes two stages: formation and capacity division. The formation stage is to charge and discharge the battery to make it reach a stable state, and the capacity division stage is to test the battery charge and discharge to measure its parameters such as capacity and internal resistance. The capacity division stage consumes a lot of electricity. On the one hand, during the charging process, AC power is obtained from the power grid and converted into DC power. On the other hand, during the discharge process, DC power is converted into AC power and fed back to the power grid. Both processes require two inversions, resulting in energy loss and heat generation, reducing the efficiency and quality of capacity division, and increasing production costs and environmental burdens.

[0004] Therefore, how to improve the energy consumption control level of lithium battery capacity division process, reduce energy loss and heat generation in the capacity division process, improve capacity division efficiency and quality, and reduce production costs and environmental burden is an important issue currently faced by lithium battery manufacturers. To this end, it is urgent to innovate the charging and discharging mode of lithium battery capacity division and seek a more energy-saving, efficient and reliable capacity division solution. Utility Model Content

[0005] In view of the problems existing in the prior art, the utility model provides a DC busbar power supply device for a lithium-ion battery, comprising:

[0006] An AC group, one side of the AC group is connected to the mains, and the other side of the AC group is connected to a plurality of bidirectional inverters via a DC busbar, and each of the bidirectional inverters is respectively connected to a corresponding lithium-ion battery.

[0007] Preferably, the AC group includes an AC master and at least one AC slave, and each of the AC slaves is connected in parallel with the AC master.

[0008] Preferably, the AC master and the mains as well as each of the AC slaves and the mains are connected via a three-phase five-wire power supply line.

[0009] Preferably, an isolating switch is provided on one side of each bidirectional inverter connected to the DC busbar.

[0010] Preferably, the master switch and the slave switch are both PCS switches.

[0011] Preferably, each of the bidirectional inverters is a DC / DC bidirectional inverter.

[0012] The above technical solution has the following advantages or beneficial effects: it solves the problem that traditional battery charging and discharging undergoes two voltage inversion processes, and the DC busbar only needs one AC to DC inversion process. When the battery is discharged, the current only flows at the DC end and does not need to return to the AC power line, saving a lot of inverter energy consumption. The use of PCS AC converter reduces the impact of AC-DC conversion on grid fluctuations, making the grid quality more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a schematic structural diagram of a DC busbar power supply device for a lithium-ion battery in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to the implementation mode, and other implementation modes may also fall within the scope of the present invention as long as they meet the purpose of the present invention.

[0015] In a preferred embodiment of the present utility model, based on the above problems existing in the prior art, a DC busbar power supply device of a lithium-ion battery is provided. Figure 1 As shown, including:

[0016] An AC unit 1, one side of the AC unit 1 is connected to a mains 2, and the other side of the AC unit 1 is connected to a plurality of bidirectional inverters 4 via a DC busbar 3, and each bidirectional inverter 4 is respectively connected to a lithium-ion battery 5;

[0017] The AC power of the mains 2 is inverted into DC power by the converter group 1. For each lithium-ion battery 5, when charging, the DC power passes through the DC busbar 3 and is transformed by the bidirectional inverter 4 to charge the lithium-ion battery 5. When discharging, the current of the lithium-ion battery 5 is transformed by the corresponding bidirectional inverter 4 and then flows back to the DC busbar 3 and then flows to other lithium-ion batteries 5 being charged.

[0018] In a preferred embodiment of the present invention, Figure 1 As shown, the AC group 1 includes an AC master 11 and at least one AC slave 12, and each AC slave 11 is connected in parallel with the AC master 12.

[0019] In a preferred embodiment of the present invention, Figure 1As shown, the AC master 11 and the mains 2 as well as each AC slave 12 and the mains 2 are connected via a three-phase five-wire power supply line 6 .

[0020] In a preferred embodiment of the present invention, Figure 1 As shown, a disconnect switch 7 is provided on one side of each bidirectional inverter 4 connected to the DC busbar 3 .

[0021] In a preferred embodiment of the present invention, both the master AC device 11 and the slave AC device 12 are PCS AC devices.

[0022] In a preferred embodiment of the present invention, each bidirectional inverter 4 is a DC / DC bidirectional inverter.

[0023] Specifically, in this embodiment, since 5V direct current is required for charging the lithium-ion battery 5, but the mains 2 is powered by AC380V, a PCS AC device 1 is required to transform, sort, filter, and output DC750V to the DC busbar 3 for flow buffering; in this embodiment, a large-capacity PCS AC device is used to reduce the impact of AC-DC conversion on grid fluctuations, making the grid quality more stable;

[0024] The DC busbar 3 is a conductor connecting the power supply and the electrical appliances, which can store energy and smooth the voltage. The DC busbar 3 generally has one or more capacitors (not shown in the figure), which can buffer the change of current and protect the power supply and the electrical appliances from the impact of the impact of the current.

[0025] Each lithium-ion battery 5 needs to go through a capacity division phase before leaving the factory, and the capacity division phase includes at least one charge and at least one discharge. Figure 1 As shown, the DC busbar 3 can be connected to multiple lithium-ion batteries 5 at the same time. When charging any lithium-ion battery 5, the corresponding isolation switch 7 is closed, and the DC 750V in the DC busbar 3 is converted into DC 5V through the DC / DC bidirectional inverter 4 to charge the lithium-ion battery 5;

[0026] After each lithium-ion battery 5 is charged, it needs to be discharged. The DC5V output by the lithium-ion battery 5 is converted into DC750V by the corresponding DC / DC bidirectional inverter 4 and flows back to the DC busbar 3. When any other lithium-ion battery 5 is charged, it flows to the lithium-ion battery 5.

[0027] It can be seen that in the DC busbar power supply device of the lithium-ion battery provided by the utility model, only one AC to DC conversion is required to convert the AC380V powered by the mains 2 into DC750V, and the discharge current of the lithium-ion battery 5 no longer needs to be converted from DC750V to AC380V to flow back into the mains 2 line, thereby reducing one AC / DC conversion process, greatly reducing energy loss, and improving energy utilization. In addition, the reduction of this conversion process can reduce the discharge current feedback time and improve the discharge feedback efficiency.

[0028] The converter group 1 includes a converter host 11 and a converter slave 12. On the one hand, one more device can be used to convert AC380V-DC750V to increase power. On the other hand, the converter slave 12 can continue to work as a backup machine when the converter host 11 fails, thereby avoiding the situation where the entire system stops working due to the host stopping working and reducing the impact of the failure.

[0029] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A DC busbar power supply device for a lithium-ion battery, characterized in that: include: An AC group, one side of which is connected to the mains, and the other side of which is connected to a plurality of bidirectional inverters via a DC busbar, each of which is connected to a corresponding lithium-ion battery; The alternator group converts the AC current supplied by the mains into DC current, and the current discharged by the lithium-ion battery does not flow back to the mains; The AC group includes an AC master and at least one AC slave, and each of the AC slaves is connected in parallel with the AC master; An isolating switch is provided on one side of each bidirectional inverter connected to the DC busbar.

2. The DC busbar power supply device according to claim 1, characterized in that: The AC host and the mains as well as each of the AC slaves and the mains are connected via a three-phase five-wire power supply line.

3. The DC busbar power supply device according to claim 1, characterized in that: The master switch and the slave switch are both PCS switches.

4. The DC busbar power supply device according to claim 1, characterized in that: Each of the bidirectional inverters is a DC / DC bidirectional inverter.

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