A battery system control PDU and control method for series-parallel conversion

Abstract

The application relates to a battery system control PDU and a control method for series-parallel conversion. The battery system control PDU has independent DC relay control access for the positive and negative interfaces of all the battery pack interface groups, can reduce the use of elements, save costs and reduce the space occupation, is beneficial to the element arrangement of the battery system control PDU, and is further beneficial to the size reduction of the battery system control PDU; the series-parallel conversion between multiple battery packs can be more safely realized, the switching of high-voltage charging and low-voltage discharging of the battery packs can be realized through the battery system control PDU, the charging time of customers can be shortened, the adaptability of multiple uses of the product can be increased, and the unification of charging piles can be realized. In addition, the number of battery packs for realizing series-parallel conversion can be increased by adding the battery pack interface groups and the conversion switch groups of each battery pack interface group according to actual conditions.

Description

Technical Field

[0001] This invention relates to the field of new energy lithium battery control systems, and in particular to a battery system control unit (PDU) and control method for series-parallel conversion. Background Technology

[0002] Currently, charging requirements for pure electric special equipment (such as new energy vehicles) are higher, but the equipment also requires low-voltage discharge. To meet market demand, the battery system control PDU needs to achieve internal high-low voltage switching. During charging, the internal system structure switches to high voltage, and during discharging, the internal system structure switches to low voltage. Solving the high-low switching problem enables the unification of charging piles and shortens the charging time for customers. However, existing battery system control PDUs can only achieve high-voltage charging and discharging or low-voltage charging and discharging. Therefore, there is an urgent need for a battery system control PDU that can simultaneously achieve high-voltage charging and low-voltage discharging. Summary of the Invention

[0003] The purpose of this invention is to address the problem that existing battery system control PDUs can only achieve high-voltage charging and discharging or low-voltage charging and discharging, which affects the charging time during customer use, by providing a battery system control PDU and control method for series-parallel conversion.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A battery system control PDU for series-parallel conversion, wherein the positive main circuit is electrically connected to a positive interface and the negative main circuit is electrically connected to a negative interface; the battery system control PDU includes N battery pack interface groups, a conversion switch group for each battery pack interface group, at least one charging interface group and at least one output interface group, where N is greater than or equal to 1; The positive terminal of the charging interface group and the positive terminal of the output interface group are electrically connected to the positive main circuit, respectively; the negative terminal of the charging interface group and the negative terminal of the output interface group are electrically connected to the negative main circuit, respectively; at least three of the charging positive terminal, the positive terminal of the output, the charging negative terminal and the negative terminal of the output have a DC relay between them and the corresponding positive main circuit or negative main circuit. The positive main circuit and / or the negative main circuit are connected to a protection device; Each of the aforementioned switch groups includes three DC relays. A DC relay of the switch group is respectively installed between the negative interface of the battery pack interface group and the negative main circuit, between the positive interface of the battery pack interface group and the positive main circuit, and between the positive and negative interfaces of the battery pack interface group. When all the DC relays between the positive and negative interfaces of all the battery pack interface groups are closed, a series charging circuit is formed. When all the DC relays between the positive interface and the positive main circuit of each battery pack interface group, and between all the negative interfaces and the negative main circuit, a parallel discharging circuit is formed.

[0006] The protection device is electrically connected to the positive main circuit and / or the negative main circuit to protect the circuit of the battery system control PDU. Each battery pack interface group has one positive interface connected to the positive terminal of the battery pack and one negative interface connected to the negative terminal of the battery pack. The positive and negative terminals of the same battery pack interface group are not connected to the same battery pack. The positive interface directly connected to the positive main circuit and the negative interface directly connected to the negative main circuit are also interfaces used to connect to the corresponding terminals of the battery packs. N+1 battery packs are connected to the positive and negative main circuits. When a charging device is connected to the positive and negative main circuits through the charging interface group, the charging device can charge the battery packs connected to the battery system control PDU. When an external device is connected to the positive and negative main circuits through the output interface group, the battery packs connected to the battery system control PDU can supply power to the external device.

[0007] In this solution, when the battery pack of the pure electric special equipment is being charged, after the charging pile is connected to the positive and negative terminals of the battery system control PDU, the charging interface group connects the positive and negative main circuits. All DC relays between the positive and negative interfaces of all the battery pack interface groups are closed, forming a series circuit of N+1 battery packs. The charging pile provides high-voltage charging to all the battery packs in series, improving charging efficiency and shortening charging time. When an external device connected to the positive and negative output terminals needs power, the output interface group connects the positive and negative main circuits. All DC relays between the positive interface and the positive main circuit, and between the negative interface and the negative main circuit, are closed, forming a parallel circuit of N+1 battery packs. All the battery packs provide low-voltage power to the external device in parallel, saving energy.

[0008] The battery system control PDU using this solution for series-parallel conversion has independent DC relay control access for the positive and negative interfaces of all battery pack interface groups. Firstly, it eliminates the need for diodes to prevent current backflow, thus eliminating the need for cooling equipment to ensure diode operation. This reduces component usage, saves costs and space, and facilitates component arrangement within the battery system control PDU, resulting in a smaller PDU size. Secondly, it enables safer series-parallel conversion between multiple battery packs, allowing for switching between high-voltage charging and low-voltage discharging. This shortens charging time and increases the product's versatility, contributing to the standardization of charging stations. Furthermore, the battery system control PDU includes N battery pack interface groups and a switching group for each group, where N is greater than or equal to 1. This means at least two battery packs can be converted from series to parallel via the PDU. Increasing the number of battery pack interface groups and switching groups allows for more battery packs to be connected in series-parallel conversion, facilitating modifications to the PDU to accommodate different battery packs. Furthermore, the charging positive and charging negative terminals can also serve as output terminals. In other words, four output terminals can exist simultaneously: charging positive, charging negative, output positive, and output negative. These terminals can be selectively connected in series and / or in parallel, and multiple states can coexist, increasing the product's adaptability to various applications.

[0009] Preferably, all of the DC relays, positive interface, negative interface, protection device, charging interface group and output interface group are connected by a busbar; All the battery pack interface groups are distributed longitudinally between the positive interface directly connected to the positive main circuit and the negative interface directly connected to the negative main circuit. All the positive interfaces and all the negative interfaces are arranged vertically and staggered.

[0010] The conductive busbar, such as a copper conductive busbar, possesses a certain degree of rigidity and shape, facilitating installation and fixation. It can withstand higher currents, which is beneficial for the battery pack to perform high-low voltage switching via the battery system control PDU. Furthermore, it allows for the staggered arrangement of all positive and negative interfaces vertically, with the positive interfaces on top and the negative interfaces on the bottom. The positive and negative interfaces connected to the same battery pack are arranged adjacent to each other, which facilitates the identification of positive and negative interfaces and makes battery pack installation easier. It also allows for a more rational arrangement of components, resulting in a more orderly arrangement of the battery system control PDU and reducing space occupation. Simultaneously, this orderly arrangement allows for the quick, convenient, and orderly addition of battery pack interface groups and conversion switch groups for each battery pack interface group between the positive interfaces directly connected to the positive main circuit and the negative interfaces directly connected to the negative main circuit, increasing the number of battery packs that can be connected and improving applicability.

[0011] Preferably, all the positive terminals are located at the same height, all the negative terminals are located at the same height, and the spacing between two adjacent positive terminals is the same, and the spacing between two adjacent negative terminals is the same. This facilitates the installation of the battery pack at the same height, makes connection easier, and improves applicability.

[0012] Preferably, in the circuit of the battery system control PDU, the DC relay between the negative terminal interface and the negative main circuit is the sixth DC relay, the DC relay between the positive terminal interface and the positive main circuit is the fifth DC relay, and the DC relay between the positive terminal interface and the negative terminal interface of the battery pack interface group is the fourth DC relay. In the component structure layout of the battery system control PDU, between the positive and negative interfaces of each battery pack interface group, starting from the nearest battery pack interface group, there are corresponding fourth, sixth, and fifth DC relays arranged sequentially in the horizontal direction; all fourth, fifth, and sixth DC relays are arranged in a vertical column; all fourth, fifth, and sixth DC relays are arranged in a vertical column; the fourth and sixth DC relays are at the same height as the negative interface, and all fifth DC relays are at the same height as the positive interface; the positive terminals of the sixth and fifth DC relays between two adjacent battery pack interface groups face opposite directions to the positive terminal of the fourth DC relay, and the negative terminals of the fourth, sixth, and fifth DC relays between two adjacent battery pack interface groups are arranged side by side in the horizontal direction.

[0013] A fifth, sixth, and fourth DC relay are installed between the positive and negative interfaces of each battery pack interface group. This effectively integrates the DC relays that enable series-parallel switching between the two battery packs into the horizontal arrangement between them, reducing space requirements. Through this structural arrangement, the DC relays and positive and negative interfaces of the entire transfer switch group are arranged in an orderly manner. This allows the negative interface of each battery pack interface group to be directly connected to both the negative terminal of the corresponding sixth DC relay and the positive terminal of the fourth DC relay via a horizontally arranged conductive busbar. Similarly, the positive interface of each battery pack interface group can be directly connected to the positive terminal of the corresponding fifth DC relay via a horizontally arranged conductive busbar. This reduces the number and length of conductive busbars required, thereby reducing space requirements and the size of the chassis housing the battery system control PDU, facilitating installation. Furthermore, this arrangement allows for consistent conductive busbar structures between the battery pack interface groups and the transfer switch groups within each group, simplifying manufacturing, installation, and replacement.

[0014] Preferably, the negative terminals of two adjacent fifth DC relays are connected through a first connecting busbar, and the positive terminals of two adjacent sixth DC relays are connected through a second connecting busbar, with the first connecting busbar located above the corresponding second connecting busbar.

[0015] By using the above connection method, the negative parallel circuit is not directly connected to the negative main circuit, but is indirectly connected to the negative main circuit by connecting to the positive terminal of the adjacent sixth DC relay. This reduces the number and length of the conductors required for the negative parallel circuit, saving costs and space. Similarly, the positive parallel circuit is not directly connected to the positive main circuit, but is indirectly connected to the positive main circuit by connecting to the negative terminal of the adjacent fifth DC relay. This also reduces the number and length of the conductors required for the positive parallel circuit, saving costs and space.

[0016] Preferably, the charging positive terminal, the output positive terminal, and the output negative terminal are each connected to a DC relay between them and the corresponding positive main circuit or negative main circuit, and the charging negative terminal is directly electrically connected to the negative main circuit.

[0017] Not using DC relays for circuit connection control on the negative charging terminal and the main negative circuit has a smaller impact on circuit safety, but it can reduce the number of relays required and lower costs.

[0018] Preferably, the system also includes a control unit, with all the DC relays connected to the control unit. The control unit only needs to collect the voltage state across the contacts of the corresponding DC relay to determine the on / off state of the corresponding DC relay, and then control the external switching state of the corresponding DC relay to achieve series-parallel switching of all battery packs connected to the positive and negative interfaces.

[0019] Preferably, the protection device includes a fuse and a shunt.

[0020] The fuse and the shunt are located on the main circuit of the battery system control PDU. The fuse is a protection device for the entire circuit, and the shunt is a current acquisition unit for the entire circuit, used to acquire current. When the current is too high, it will limit charging or discharging.

[0021] Preferably, the shunt is located in the negative electrode main circuit and the fuse is located in the positive electrode main circuit, which is beneficial for the arrangement and installation of the components of the battery system control PDU in the chassis.

[0022] Preferably, each of the cascaded units has only three of the switching relays, reducing costs.

[0023] A control method for a battery system control PDU for series-parallel conversion, wherein when the charging interface group is detected to be connected, the DC relays between the positive and negative interfaces of all the battery pack interface groups are closed, and the DC relays between all the positive interfaces and the positive main circuit and between all the negative interfaces and the negative main circuit are opened, forming a series charging circuit; When the interface of the output interface group is detected to be connected, the DC relay between the positive interface and the positive main circuit of each battery pack interface group and the DC relay between the negative interface and the negative main circuit are closed, and the DC relay between the positive interface and the negative interface of all battery pack interface groups are opened, forming a parallel discharge circuit.

[0024] The control method of the battery system control unit (PDU) used for series-parallel conversion described above can quickly realize the rapid conversion between series and parallel connection of battery packs, which helps to shorten the charging time for customers and reduce the energy consumption of external devices.

[0025] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The battery system control PDU for series-parallel conversion described in this invention has independent DC relay control access for the positive and negative interfaces of all battery pack interface groups. This reduces the number of components, saves costs, and reduces space occupation, which is beneficial for the component layout of the battery system control PDU and thus helps to reduce its size. Furthermore, it enables safer series-parallel conversion between multiple battery packs, and allows for switching between high-voltage charging and low-voltage discharging of the battery packs through the battery system control PDU. This shortens customer charging time, increases the product's adaptability to various applications, and helps to unify charging piles. In addition, by adding battery pack interface groups and conversion switch groups for each battery pack interface group, the number of battery packs that can achieve series-parallel conversion can be increased, facilitating the modification of the battery system control PDU to accept different battery packs according to actual conditions.

[0026] 2. By using a conductive busbar to connect the circuit, all the positive and negative interfaces can be staggered vertically, with the positive interface on top and the negative interface on the bottom. The positive and negative interfaces connected to the same battery pack are arranged adjacent to each other, which is beneficial for distinguishing the positive and negative interfaces and facilitating the installation of the battery pack. It also allows for a more reasonable arrangement of the components, making the arrangement of the battery system control PDU more orderly and reducing the space occupied.

[0027] 3. Integrating the DC relay that enables series-parallel switching between the two battery packs into the horizontal space between the two battery packs can reduce the space occupied.

[0028] 4. The DC relays and positive and negative interfaces of the entire transfer switch group are arranged in an orderly manner. This allows the negative interface of each battery pack interface group to be directly connected to the negative terminal of the corresponding sixth DC relay and the positive terminal of the fourth DC relay simultaneously via a horizontally arranged conductive busbar. Similarly, the positive interface of each battery pack interface group can be directly connected to the positive terminal of the corresponding fifth DC relay via a horizontally arranged conductive busbar. This reduces the number and length of conductive busbars required, thereby reducing space occupation and the size of the chassis housing the battery system control PDU, which is beneficial for chassis installation. Furthermore, the structure of the conductive busbars between the battery pack interface groups and the transfer switch groups of each battery pack interface group can be made consistent, which facilitates processing, installation, and replacement.

[0029] 5. The control method of the battery system control PDU for series-parallel conversion described in this invention can quickly realize the rapid conversion between series and parallel connection of battery packs, which helps to shorten the charging time of customers and reduce the energy consumption of external devices. Attached Figure Description

[0030] Figure 1This is a circuit diagram of the battery system control PDU for series-parallel conversion described in Example 1; Figure 2 This is a schematic diagram of the battery system control PDU for series-parallel conversion described in Example 1; Figure 3 yes Figure 2 The main view of the battery system control PDU for series-parallel conversion described herein; Figure 4 yes Figure 2 A top view of the battery system control PDU used for series-parallel conversion as described above; Figure 5 yes Figure 2 A bottom view of the battery system control PDU for series-parallel conversion described herein; Figure 6 yes Figure 2 Left view of the battery system control PDU for series-parallel conversion described in the image; Figure 7 yes Figure 2 Right view of the battery system control PDU for series-parallel conversion described in the document; Icons: 1-Positive main circuit; 11-Charging positive terminal; 12-Output positive terminal; 13-Second DC relay; 14-First DC relay; 2-Negative main circuit; 21-Charging negative terminal; 22-Output negative terminal; 23-Third DC relay; 31-Fourth DC relay; 311-Series busbar; 32-Fifth DC relay; 321-First connecting busbar; 33-Sixth DC relay; 331-Second connecting busbar; 34-Positive interface; 35-Negative interface; 36-Battery pack interface group; 4-Fuse; 41-Upstream busbar; 5-Shunt; 61-First positive busbar; 62-Second positive busbar; 63-Third positive busbar; 71-First negative busbar; 72-Second negative busbar; 73-Third negative busbar. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings.

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Example 1 A battery system control PDU for series-parallel conversion, see [link / reference] Figure 1The positive main circuit 1 is electrically connected to a positive interface 34, and the negative main circuit 2 is electrically connected to a negative interface 35; the battery system control PDU includes N battery pack interface groups 36, a changeover switch group for each battery pack interface group 36, at least one charging interface group and at least one output interface group, where N is greater than or equal to 1. The charging positive terminal 11 of the charging interface group and the output positive terminal 12 of the output interface group are respectively electrically connected to the positive main circuit 1; the charging negative terminal 21 of the charging interface group and the output negative terminal 22 of the output interface group are respectively electrically connected to the negative main circuit 2; at least three of the charging positive terminal 11, the output positive terminal 12, the charging negative terminal 21, and the output negative terminal 22 are respectively connected to a DC relay between them and the corresponding positive main circuit 1 or negative main circuit 2; The positive main circuit 1 and / or the negative main circuit 2 are connected to a protection device; Each of the aforementioned switch groups includes three DC relays. A DC relay for each switch group is provided between the negative interface 35 of the battery pack interface group 36 and the negative main circuit 2, between the positive interface 34 of the battery pack interface group 36 and the positive main circuit 1, and between the positive interface 34 and the negative interface 35 of the battery pack interface group 36. When all the DC relays between the positive interfaces 34 and the negative interfaces 35 of all the battery pack interface groups 36 are closed, a series charging circuit is formed. When all the DC relays between the positive interface 34 and the positive main circuit 1 of each battery pack interface group 36, and between all the negative interfaces 35 and the negative main circuit 2, a parallel discharging circuit is formed.

[0034] Each battery pack interface group 36 has a positive terminal interface 34 connected to the positive terminal of the battery pack and a negative terminal interface 35 connected to the negative terminal of the battery pack. The positive and negative terminals of the batteries in the same battery pack interface group 36 are not connected to the same battery pack. For example Figure 1 As shown, BV1- and BV2+ form one battery pack interface group 36, and BV2- and BV3+ form another battery pack interface group 36. However, BV1- and BV1+ are connected to the positive and negative terminals of the same battery pack, BV2+ and BV2- are connected to the positive and negative terminals of the same battery pack, and BV3+ and BV3- are connected to the positive and negative terminals of the same battery pack. The positive interface 34 directly connected to the positive main circuit 1 and the negative interface 35 directly connected to the negative main circuit 2 are also interfaces used to connect the corresponding terminals of the battery pack, such as... Figure 1 BV1+ and BV3- in the model are not controlled by DC relays.

[0035] In this scheme, N+1 battery packs are connected to the positive main circuit 1 and the negative main circuit 2. When the charging device is connected to the positive main circuit 1 and the negative main circuit 2 through the charging interface group, the charging device can charge the battery packs connected to the battery system control PDU. When an external device is connected to the positive main circuit 1 and the negative main circuit 2 through the output interface group, the battery packs connected to the battery system control PDU can supply power to the external device. Figure 1 There are two battery pack interface groups 36 in total, corresponding to the series and parallel connection of 3 battery packs.

[0036] In this solution, the number of charging interface groups and output interface groups can be increased, and the number can be selected according to the actual situation, but there must be at least one group of each. As a preferred implementation, such as... Figure 1 As shown in the circuit diagram, the charging positive terminal 11, the output positive terminal 12, and the output negative terminal 22 are each connected to a DC relay via a corresponding positive main circuit 1 or negative main circuit 2. The charging negative terminal 21 is directly electrically connected to the negative main circuit 2. That is, no DC relays are used for circuit connection control on the charging negative terminal 21 and the negative main circuit 2, which has a smaller impact on circuit safety but reduces the number of relays and lowers costs. Specifically, the charging positive terminal 11 is electrically connected to the positive terminal of the second DC relay 13, the negative terminal of the second DC relay 13 is electrically connected to the positive main circuit 1, and the charging negative terminal 21 is directly electrically connected to the negative main circuit 2. The output positive terminal 12 is electrically connected to the negative terminal of the first DC relay 14, the positive terminal of the first DC relay 14 is electrically connected to the positive main circuit 1, the output negative terminal 22 is electrically connected to the positive terminal of the third DC relay 23, and the negative terminal of the third DC relay 23 is electrically connected to the negative main circuit 2.

[0037] In this embodiment, the protection device is electrically connected to the positive main circuit 1 and / or the negative main circuit 2 to protect the circuit of the battery system control PDU. For example, the protection device includes a fuse 4 and a shunt 5. The fuse 4 and the shunt 5 are located on the main circuit of the battery system control PDU. The fuse 4 is the protection device for the entire circuit, and the shunt 5 is the current acquisition unit for the entire circuit, used to acquire current. When the current is too high, it will limit charging or discharging. As a preferred implementation, such as... Figure 4 As shown, the shunt 5 is located in the negative main circuit 2, and the fuse 4 is located in the positive main circuit 1, which is beneficial for the arrangement and installation of the components of the battery system control PDU in the chassis.

[0038] In this embodiment, the battery system control PDU also includes a control unit, and all the DC relays are respectively connected to the control unit. The control unit only needs to collect the voltage state at both ends of the corresponding DC relay contacts to determine the on / off state of the corresponding DC relay, and then control the external switching state of the corresponding DC relay to realize the series-parallel switching of all battery packs connected to the positive interface 34 and the negative interface 35.

[0039] When charging the battery pack of a pure electric vehicle, after the charging pile is connected to the positive charging terminal 11 and negative charging terminal 21 of the battery system control PDU used for series-parallel conversion, the charging interface group connects the positive main circuit 1 and the negative main circuit 2. All DC relays between the positive interface 34 and negative interface 35 of all battery pack interface groups 36 are closed, forming a series circuit of N+1 battery packs. The charging pile then provides high-voltage series charging to all battery packs, which improves charging efficiency and shortens charging time. Figure 1 Taking the medium circuit as an example, that is Figure 1 Relay B is closed, while Relay A and Relay C are open. Figure 1 When SKA and SKB are closed, PK1-, PK2+, PK2-, and PK3+ are open, forming a series circuit of three battery packs. When an external device connected to the positive output terminal 12 and the negative output terminal 22 requires power, the output interface group connects the positive main circuit 1 and the negative main circuit 2. All DC relays between the positive interface 34 and the positive main circuit 1, and all DC relays between the negative interface 35 and the negative main circuit 2, are closed, forming a parallel circuit of N+1 battery packs. All battery packs provide parallel low-voltage power to the external device, saving energy. Figure 1 Taking the medium circuit as an example, that is Figure 1 Relay B is disconnected, while Relay A and Relay C are closed. Figure 1 When SKA and SKB are disconnected, PK1-, PK2+, PK2- and PK3+ are closed, forming a parallel circuit of three battery packs.

[0040] In this embodiment, all the DC relays, positive interface 34, negative interface 35, protection device, charging interface group and output interface group are connected by conductive busbars; wires can also be used for connection, both of which can realize series-parallel conversion function. Compared with wires, conductive busbars can be copper conductive busbars, etc., which have a certain rigidity and shape, making them easy to install and fix; and can withstand greater current, which is beneficial for the battery pack to use for high and low voltage conversion through the battery system control PDU.

[0041] The battery system control PDU for series-parallel conversion in this embodiment has independent DC relay control access for the positive and negative interfaces 34 and 35 of all battery pack interface groups 36. Firstly, it eliminates the need for diodes to prevent current backflow, thus eliminating the need for cooling equipment to ensure diode operation. This reduces component usage, saves costs and space, and facilitates component arrangement in the battery system control PDU, allowing for smaller PDU size. Secondly, it enables safer series-parallel conversion between multiple battery packs, allowing the battery system control PDU to switch between high-voltage charging and low-voltage discharging, shortening customer charging time, increasing product adaptability for various applications, and contributing to the standardization of charging stations. In addition, the battery system control PDU includes N battery pack interface groups 36 and a switching group for each battery pack interface group 36, where N is greater than or equal to 1. This means that at least two battery packs can be connected in series or parallel via the battery system control PDU. Furthermore, by increasing the number of battery pack interface groups 36 and the switching groups for each battery pack interface group 36, the number of battery packs that can be connected in series or parallel can be increased, facilitating modifications to the battery packs that the battery system control PDU can connect to based on actual needs. Moreover, the charging positive terminal 11 and the charging negative terminal 21 can also serve as output terminals. This means that four output terminals can exist simultaneously: charging positive terminal 11, charging negative terminal 21, output positive terminal 12, and output negative terminal 22. These can be selectively connected in series and / or parallel at different output terminals, and multiple states can coexist, increasing the product's adaptability to various applications.

[0042] Example 2 This embodiment provides a battery system control PDU for series-parallel conversion, which can be exactly the same as the circuit in the embodiment, but this embodiment focuses more on the arrangement of circuit components, such as... Figure 2-7 As shown: To facilitate a clearer and more accurate description of the circuit component layout, some DC relays in the circuit are named as follows: In the battery system control PDU circuit, the DC relay between the negative interface 35 and the negative main circuit 2 is the sixth DC relay 33; the DC relay between the positive interface 34 and the positive main circuit 1 is the fifth DC relay 32; the DC relay between the positive interface 34 and the negative interface 35 of the battery pack interface group 36 is the fourth DC relay 31; the DC relay between the charging positive terminal 11 and the positive main circuit 1 is the second DC relay 13; the DC relay between the output positive terminal 12 and the positive main circuit 1 is the first DC relay 14; and the DC relay between the output negative terminal 22 and the negative main circuit 2 is the third DC relay 23. Except for, such as Figure 4 As shown, the left and right directions are defined as vertical, and the up and down directions are defined as horizontal.

[0043] In this embodiment, all the busbars, DC relays, fuses 4, and shunts 5 are housed inside the chassis. In this embodiment, the DC relays, positive interface 34, negative interface 35, protection devices, charging interface group, and output interface group are all connected via busbars; this allows all the positive interfaces 34 and all the negative interfaces 35 to be staggered longitudinally, i.e.: Figure 3 As shown, all the battery pack interface groups 36 are distributed longitudinally between the positive interface 34 directly connected to the positive main circuit 1 and the negative interface 35 directly connected to the negative main circuit 2. All the positive interfaces 34 and all the negative interfaces 35 are arranged vertically and staggered.

[0044] In this configuration, the positive interface 34 is positioned above the negative interface 35. The adjacent arrangement of the positive and negative interfaces 34 and 35, connected to the same battery pack, facilitates the separation of the positive and negative interfaces 34 and makes battery pack installation easier. It also allows for a more rational arrangement of components, resulting in a more organized layout of the battery system control PDU and reducing space occupancy. Furthermore, this orderly arrangement allows for the quick, convenient, and systematic addition of battery pack interface groups 36 and corresponding switch groups for each group between the positive interface 34 directly connected to the positive main circuit 1 and the negative interface 35 directly connected to the negative main circuit 2. This increases the number of battery packs that can be connected, improving applicability.

[0045] In this embodiment, to facilitate battery pack installation and improve applicability, the battery packs are installed at the same height, and the spacing between the positive and negative terminals of each battery pack is fixed, such as... Figure 3 As shown, all the positive terminals 34 are located at the same height, all the negative terminals 35 are located at the same height, the spacing between two adjacent positive terminals 34 is the same, and the spacing between two adjacent negative terminals 35 is the same. That is, from left to right, there are positive terminals 34 and negative terminals 35 of the three battery packs, so that the three battery packs are arranged in an orderly manner.

[0046] In this embodiment, to ensure an orderly and compact arrangement of DC relays, busbars, etc., and to reduce space occupation, the component structure of the battery system control PDU is arranged such that, between the positive terminal 34 and negative terminal 35 of each battery pack interface group 36, a corresponding fourth DC relay 31, a sixth DC relay 33, and a fifth DC relay 32 are sequentially arranged laterally, starting from the nearest battery pack interface group 36. Generally, each changeover switch group has only one fourth DC relay 31, one sixth DC relay 33, and one fifth DC relay 32, as shown below. Figure 4As shown, between the positive terminal 34 and the negative terminal 35 of each battery pack interface group 36, starting from the nearest battery pack interface group 36, there is a corresponding fourth DC relay 31, a sixth DC relay 33, and a fifth DC relay 32 arranged sequentially in the horizontal direction; all the fourth DC relays 31 are arranged in a vertical column, all the fifth DC relays 32 are arranged in a vertical column, and all the sixth DC relays 33 are arranged in a vertical column. The positive ends are all arranged vertically; the fourth DC relay 31 and the sixth DC relay 33 are at the same height as the negative interface 35, and all the fifth DC relays 32 are at the same height as the positive interface 34; the positive ends of the sixth DC relay 33 and the fifth DC relay 32 between two adjacent battery pack interface groups 36 are oriented opposite to the positive end of the fourth DC relay 31, and the negative ends of the fourth DC relay 31, the positive ends of the sixth DC relay 33 and the negative ends of the fifth DC relay 32 between two adjacent battery pack interface groups 36 are arranged side by side in the horizontal direction.

[0047] like Figure 4 As shown, a fifth DC relay 32, a sixth DC relay 33, and a fourth DC relay 31 are arranged between the positive interface 34 and the negative interface 35 of each battery pack interface group 36. This is equivalent to integrating the DC relays that enable series-parallel switching between the two battery packs into the horizontal arrangement between the two battery packs, which reduces the space occupied. Through the above structural arrangement, the DC relays of the entire conversion switch group are arranged in an orderly manner, and the positive and negative interfaces 34 and 35 are arranged in an orderly manner. This allows the negative interface 35 of each battery pack interface group 36 to be directly connected to the negative terminal of the corresponding sixth DC relay 33 and the positive terminal of the fourth DC relay 31 simultaneously through the horizontally arranged conductive busbar. The positive interface 34 of each battery pack interface group 36 can be directly connected to the positive terminal of the corresponding fifth DC relay 32 through the horizontally arranged conductive busbar. This reduces the number and length of conductive busbars required, thereby reducing the space occupied and the size of the chassis where the battery system control PDU is integrated, which is beneficial for chassis installation. Furthermore, the above arrangement allows the structure of the conductive busbars between the battery pack interface group 36 and the changeover switch group of each battery pack interface group 36 to be consistent, which is beneficial for processing, installation and replacement.

[0048] by Figure 1-7 Taking the battery system control PDU of the three battery packs as an example, Figure 2In the middle, on the left side horizontally, there are positive interface 34 and negative interface 35 arranged vertically and alternately. On the right side horizontally, there is a charging interface group and an output interface group. In the middle horizontally, there are two changeover switch groups, which are vertically aligned. Figure 3 and Figure 1 The component correspondence is as follows: Figure 3 In the middle, the upper left positive terminal 34 is BV1+, the lower left negative terminal 35 is BV1-, the upper middle positive terminal 34 is BV2+, the lower middle negative terminal 35 is BV2-, the upper right positive terminal 34 is BV3+, and the lower right negative terminal 35 is BV3-. Figure 4 In the middle, the vertical direction is horizontal, that is, the two vertical changeover switch groups are located between BV1- and BV2+, and between BV2- and BV3+ respectively. Each changeover switch group, from bottom to top, consists of the fourth DC relay 31, the sixth DC relay 33, and the fifth DC relay 32. The fifth DC relay 32 is higher than the fourth DC relay 31 and the sixth DC relay 33. The fourth DC relay 31 in each changeover switch group has its left end as the positive terminal and its right end as the negative terminal. The sixth DC relay 33 and the fifth DC relay 32 in each changeover switch group both have their left ends as the negative terminals and their right ends as the positive terminals. BV1+ is horizontally connected to the fifth DC relay 32 on the left side through the first positive conductor bus 61. The middle of the first positive conductor bus 61 is connected to the positive main circuit 1 where the fuse 4 is located. BV1- is horizontally connected to the positive terminal of the fourth DC relay 31 and the negative terminal of the sixth DC relay 33 on the left side through the first negative conductor bus 71. BV2+ is horizontally connected to the positive terminal of the fifth DC relay 32 on the left side through the second positive conductor bus 62. BV2- is horizontally connected to the positive terminal of the fourth DC relay 31 and the negative terminal of the sixth DC relay 33 on the right side via the second negative conductor 72. BV3+ is horizontally connected to the positive terminal of the fifth DC relay 32 on the right side via the third positive conductor 63. BV3- is horizontally connected to the negative main circuit 2 where the shunt 5 is located via the third negative conductor 73, and the middle of the third negative conductor 73 is connected to the positive terminal of the sixth DC relay 33 on the right side. The connection extends from the negative terminal of the fourth DC relay 31 on the left side... The second positive conductive bus 62 is connected to the third positive conductive bus 63 via an upwardly vertically bent series conductive bus 311. The negative terminal of the fourth DC relay 31 on the right is connected to the third positive conductive bus 63 via an upwardly vertically bent series conductive bus 311. The positive terminals of the two adjacent sixth DC relays 33 are connected via the second connecting conductive bus 331 to form the negative parallel branch of BV1-. The negative terminals of the two adjacent fifth DC relays 32 are connected via the first connecting conductive bus 321 to form the positive parallel branch of BV3+.

[0049] Figure 2-7The structure of the conductive busbars between the battery pack interface group 36 and the changeover switch group of each battery pack interface group 36 can be set to be consistent, which is beneficial for processing, installation and replacement. Furthermore, a preferred implementation method is adopted, where the negative terminals of two adjacent fifth DC relays 32 are connected through a first connecting conductive busbar 321, and the positive terminals of two adjacent sixth DC relays 33 are connected through a second connecting conductive busbar 331. The first connecting conductive busbar 321 is located above the corresponding second connecting conductive busbar 331. This allows the negative parallel circuit to be indirectly connected to the negative main circuit 2 by connecting the positive terminals of adjacent sixth DC relays 33, rather than directly to the negative main circuit 2. This reduces the number and length of conductive busbars required for the negative parallel circuit, saving costs and space. Similarly, the positive parallel circuit is also indirectly connected to the positive main circuit 1 by connecting the negative terminals of adjacent fifth DC relays 32, rather than directly to the positive main circuit 1. This reduces the number and length of conductive busbars required for the positive parallel circuit, saving costs and space.

[0050] In this embodiment, the two external interface groups connected to the positive main circuit 1 and the negative main circuit 2 also require several conductive busbars. The charging positive terminal 11, the output positive terminal 12, the charging negative terminal 21, and the output negative terminal 22 are all located at the same height, consistent with the height of the positive interface 34. The second DC relay 13, the first DC relay 14, and the third DC relay 23 are all located at the same height, consistent with the height of the fourth DC relay 31. Among them, the positive main circuit 1 has an upward conductive busbar 41, which has an upward inclined structure. The lower end of the upward conductive busbar 41 is connected to the positive terminal of the first DC relay 14, and the upper end is connected to the fuse 4. By setting the upward conductive busbar 41, the positive main circuit 1 is avoided from being set at the same height as the fifth DC relay 32 and the first positive conductive busbar 61, and the number of insulating pillars used to support the positive main circuit 1 can be reduced.

[0051] Example 3 This embodiment provides a control method for a battery system control PDU for series-parallel conversion, as in Embodiment 1 or 2. When the charging interface group is detected to be connected, the DC relays between the positive and negative interfaces 34 and 35 of all battery pack interface groups 36 are closed, and the DC relays between all positive interfaces 34 and the positive main circuit 1 and between all negative interfaces 35 and the negative main circuit 2 are opened, forming a series charging circuit. The series circuit can connect all battery packs connected to all positive interfaces 34 and all negative interfaces 35 in series to the circuit, and charge the battery packs through the charging pile. When the interface of the output interface group is detected to be connected, the DC relay between the positive interface 34 and the positive main circuit 1 of each battery pack interface group 36, and the DC relay between all the negative interfaces 35 and the negative main circuit 2 are closed, and the DC relay between the positive interfaces 34 and the negative interfaces 35 of all battery pack interface groups 36 are opened, forming a parallel discharge circuit. The parallel circuit can be a battery pack whose positive interfaces 34 and negative interfaces 35 of some battery pack interface groups 36, as well as the battery pack whose positive interfaces 34 and negative interfaces 35 are directly connected to the main circuit, are connected in parallel to the main circuit, so that this part of the battery pack can be used to discharge and supply external devices. Alternatively, the parallel circuit can be a battery pack whose positive interfaces 34 and negative interfaces 35 of all battery pack interface groups 36, as well as the battery pack whose positive interfaces 34 and negative interfaces 35 are directly connected to the main circuit, are connected in parallel to the main circuit, so that all battery packs are used to discharge and supply external devices.

[0052] In this embodiment, the opening and closing of all the DC relays are directly controlled by the control unit. When the control unit detects and receives the corresponding electrical signals, it will issue relevant instructions. Through the control method of the battery system control PDU for series-parallel conversion described above, the rapid conversion between series and parallel connection of battery packs can be quickly realized, which helps to shorten the customer's charging time and reduce the energy consumption of external devices.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A battery system control PDU for series-parallel conversion, wherein the positive main circuit (1) is electrically connected to a positive interface (34), and the negative main circuit (2) is electrically connected to a negative interface (35); characterized in that, The battery system control PDU includes N battery pack interface groups (36), a switching group for each of the battery pack interface groups (36), at least one charging interface group and at least one output interface group, where N is greater than or equal to 1. The charging positive terminal (11) of the charging interface group and the output positive terminal (12) of the output interface group are electrically connected to the positive main circuit (1); the charging negative terminal (21) of the charging interface group and the output negative terminal (22) of the output interface group are electrically connected to the negative main circuit (2); at least three of the charging positive terminal (11), the output positive terminal (12), the charging negative terminal (21) and the output negative terminal (22) are connected to a DC relay between each of the corresponding positive main circuit (1) or negative main circuit (2); The positive main circuit (1) and / or the negative main circuit (2) are connected to a protection device; Each of the aforementioned switch groups includes three DC relays. The negative terminal (35) of the battery pack interface group (36) is connected to the negative main circuit (2), the positive terminal (34) of the battery pack interface group (36) is connected to the positive main circuit (1), and the positive terminal (34) and negative terminal (35) of the battery pack interface group (36) are respectively provided with DC relays of the switch group. When all the DC relays between the positive terminal (34) and negative terminal (35) of the battery pack interface group (36) are closed, a series charging circuit is formed. When the DC relays between the positive terminal (34) of each battery pack interface group (36) and the positive main circuit (1) and all the DC relays between the negative terminal (35) and the negative main circuit (2) are closed, a parallel discharge circuit is formed. All the DC relays, positive terminal (34), negative terminal (35), protection devices, charging interface groups and output interface groups are connected by conductive busbars. All the battery pack interface groups (36) are longitudinally distributed between the positive interface (34) directly connected to the positive main circuit (1) and the negative interface (35) directly connected to the negative main circuit (2). All the positive interfaces (34) and all the negative interfaces (35) are arranged vertically and staggered. All the positive interfaces (34) are at the same height, all the negative interfaces (35) are at the same height, the spacing between two adjacent positive interfaces (34) is the same, and the spacing between two adjacent negative interfaces (35) is the same. The DC relay between the negative interface (35) and the negative main circuit (2) is the sixth DC relay (33), the DC relay between the positive interface (34) and the positive main circuit (1) is the fifth DC relay (32), and the DC relay between the positive interface (34) and the negative interface (35) of the battery pack interface group (36) is the fourth DC relay (31). Between the positive terminal (34) and negative terminal (35) of each battery pack interface group (36), a corresponding fourth DC relay (31), a sixth DC relay (33), and a fifth DC relay (32) are arranged sequentially in the horizontal direction, starting from the nearest battery pack interface group (36); all the fourth DC relays (31) are arranged in a vertical column, all the fifth DC relays (32) are arranged in a vertical column, all the sixth DC relays (33) are arranged in a vertical column, and all the fourth DC relays (31), all the fifth DC relays (32), and all the sixth DC relays (33) are arranged in a vertical direction. The fourth DC relay (31) and the sixth DC relay (33) are at the same height as the negative interface (35), and all the fifth DC relays (32) are at the same height as the positive interface (34). The positive terminals of the sixth DC relay (33) and the fifth DC relay (32) between two adjacent battery pack interface groups (36) are opposite to the positive terminal of the fourth DC relay (31). The negative terminals of the fourth DC relay (31), the positive terminals of the sixth DC relay (33) and the negative terminals of the fifth DC relay (32) between two adjacent battery pack interface groups (36) are arranged side by side in the horizontal direction.

2. The battery system control PDU for series-parallel conversion according to claim 1, characterized in that, The negative terminals of two adjacent fifth DC relays (32) are connected through a first connecting busbar (321), and the positive terminals of two adjacent sixth DC relays (33) are connected through a second connecting busbar (331). The first connecting busbar (321) is located above the corresponding second connecting busbar (331).

3. The battery system control PDU for series-parallel conversion according to any one of claims 1-2, characterized in that, The charging positive terminal (11), the output positive terminal (12) and the output negative terminal (22) are connected to a DC relay between the corresponding positive main circuit (1) or negative main circuit (2), and the charging negative terminal (21) is directly electrically connected to the negative main circuit (2).

4. The battery system control PDU for series-parallel conversion according to claim 3, characterized in that, It also includes a control unit, and all the DC relays are respectively connected to the control unit.

5. The battery system control PDU for series-parallel conversion according to any one of claims 1-2, characterized in that, The protection device includes a fuse (4) and a shunt (5).

6. The battery system control PDU for series-parallel conversion according to claim 5, characterized in that, The shunt (5) is located in the negative main circuit (2), and the fuse (4) is located in the positive main circuit (1).

7. A control method for a battery system control PDU for series-parallel conversion as described in any one of claims 1-6, characterized in that, When the charging interface group is detected to be connected, the DC relays between the positive interface (34) and negative interface (35) of all the battery pack interface groups (36) are closed, and the DC relays between all the positive interface (34) and the positive main circuit (1) and between all the negative interface (35) and the negative main circuit (2) are disconnected, forming a series charging circuit; When the interface of the output interface group is detected to be connected, the DC relay between the positive interface (34) and the positive main circuit (1) of each battery pack interface group (36) and the DC relay between all the negative interfaces (35) and the negative main circuit (2) are closed, and the DC relay between the positive interface (34) and the negative interface (35) of all the battery pack interface groups (36) are opened, forming a parallel discharge circuit.

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