Minibus battery pack BDU high-voltage electrical framework

Abstract

The utility model relates to the technical field of electric vehicle battery management, in particular to a miniature bus battery pack BDU high-voltage electrical framework which comprises a discharging loop, a pre-charging loop, a fast charging loop, a heating loop and a three-in-one loop which are arranged in parallel. The discharge loop comprises a main positive relay, one end of the main positive relay is connected with the anode of the battery, and the other end is connected with a discharge interface; the heating loop and the main positive relay are connected in parallel or in series; the pre-charging loop comprises a pre-charging relay and a pre-charging resistor; the pre-charging relay and the pre-charging resistor are connected in series and then are connected in parallel with the main positive relay; the fast charging loop comprises a fast charging relay, the fast charging relay and the main positive relay are arranged in parallel, one end of the fast charging relay is connected with the positive electrode of the battery, and the other end of the fast charging relay is connected with a fast charging interface. According to the utility model, the technical problems of poor universality, difficult maintenance, high production cost and low production efficiency caused by high customization of the existing miniature bus BDU can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicle battery management, in particular to a high-voltage electrical architecture of a battery pack BDU for a minivan. Background Technique

[0002] The full name of BDU is Battery Disconnect Unit, which is an important accessory in the high-voltage circuit of new energy vehicles. It was initially derived from the Power Distribution Unit (PDU) in the power system. BDU is directly connected to the power battery through a high-voltage plug-in, controlling the charging and discharging process of electric vehicles, and is a crucial component in the high-voltage circuit. In the field of new energy battery packs, BDU is closely related to vehicle models, customer requirements, etc. Our company has conducted research on multiple minivans on the market and found the following technical problems in the existing high-voltage electrical architecture of minivan BDU:

[0003] 1. High customization leads to increased costs and complexity: Due to the inconsistent specific requirements of different vehicle manufacturers for the high-voltage electrical architecture of the battery pack, the battery pack design requires high customization, which increases the design cost, manufacturing cost, and the complexity of supply chain management;

[0004] 2. Poor compatibility and universality: The diversity of the types and quantities of electrical components makes it difficult to standardize the production of the battery pack, and the replacement and upgrade of components become difficult, restricting the efficiency of after-sales service and cost control;

[0005] 3. Difficult maintenance and upgrade: The diverse electrical architectures require technicians to master multiple maintenance skills, resulting in high training costs and making it difficult to achieve rapid fault detection and repair.

[0006] Based on this, this application provides a high-voltage electrical architecture of a battery pack BDU for a minivan, aiming to improve the universality and platform design of BDU products, enabling the high-voltage electrical architecture of BDU to meet the technical route requirements of multiple minivan battery packs, significantly reducing production costs, improving production efficiency, and reducing the difficulty of maintenance. Content of the Utility Model

[0007] The utility model provides a high-voltage electrical architecture of a battery pack BDU for a minivan, which can solve the technical problems of poor universality, difficult maintenance, high production cost, and low production efficiency of the existing minivan BDU due to high customization.

[0008] This application provides the following technical solutions:

[0009] A high-voltage electrical architecture for a minivan battery pack BDU, including a discharge circuit, a pre-charge circuit, a fast-charge circuit, a heating circuit, and a three-in-one circuit. The discharge circuit, the pre-charge circuit, the fast-charge circuit, and the three-in-one circuit are arranged in parallel. The discharge circuit includes a main positive relay. One end of the main positive relay is connected to the positive electrode of the battery, and the other end is connected to the positive electrode of the discharge interface. The heating circuit is arranged in parallel or in series with the main positive relay. The pre-charge circuit includes a pre-charge relay and a pre-charge resistor. The pre-charge relay and the pre-charge resistor are connected in series and then connected in parallel with the main positive relay. The fast-charge circuit includes a fast-charge relay. The fast-charge relay is connected in parallel with the main positive relay. One end of the fast-charge relay is connected to the positive electrode of the battery, and the other end is connected to the positive electrode of the fast-charge interface.

[0010] Beneficial effects:

[0011] 1. In the traditional BDU electrical design, the fast-charge relay is set after the main positive relay (series design). In this way, when controlling, it is necessary to close the main positive relay first and then the fast-charge relay. However, with the increase of the fast-charge rate and the current-carrying performance, higher performance requirements are put forward for the fast-charge relay. At the same time, higher performance requirements are also needed for the main positive relay, which will cause an increase in the cost of the battery pack and an increase in space requirements. In this application, by designing the main circuit (discharge circuit) in parallel with the fast-charge circuit, independent control of the main positive relay and the fast-charge relay can be realized. The main positive relay only needs to meet the current-carrying and performance requirements of the discharge circuit, while the fast-charge relay independently meets the charging requirements. In this way, the cost of the main positive relay can be reduced, and the space requirement of the battery pack can also be reduced.

[0012] 2. Modular design improves versatility: The architecture of this application includes a discharge circuit, a pre-charge circuit, a fast-charge circuit, a heating circuit, and a three-in-one circuit. The layout of each circuit arranged in parallel reflects the modular design concept, which is convenient for system maintenance and upgrade. And the series and parallel relationships of each circuit can be adjusted according to the electrical architecture defined by the whole vehicle. The main feature of this architecture is that it can independently control the discharge, pre-charge, and fast-charge processes, improving the flexibility of charging and energy release, adapting to different usage scenarios, and enhancing versatility. In addition, the modular design simplifies the integration process of the battery pack, shortens the design cycle, improves production efficiency, reduces the development of BDU molds, enhances the reusability of product design schemes, and reduces the DV performance verification carried out due to repeated redevelopment, reducing waste of resources.

[0013] 3. Integrated design: The electrical architecture of the three-in-one circuit integrates multiple functions, reduces the system volume and weight, and optimizes space utilization. Finally, the modular and integrated circuit layout is convenient for technicians to locate faults, perform rapid repairs, reduce vehicle downtime, and reduce maintenance costs.

[0014] Further, the heating circuit includes a positive circuit and a negative circuit. A heating fuse and a heating positive relay are serially arranged on the positive circuit. One end of the heating positive relay is connected in parallel or in series with the main positive relay. One end of the heating fuse is connected to the positive pole of the heating output plug. One end of the negative circuit is connected to the negative pole of the heating output plug.

[0015] Beneficial effects: The main function of the heating circuit is to maintain the battery pack within an appropriate operating temperature range. Especially in low-temperature environments, the battery pack is heated through the heating circuit to ensure that it can quickly reach the optimal operating temperature in cold weather, thereby guaranteeing the power performance and driving range of the electric vehicle.

[0016] Further, the heating positive relay is a ceramic relay.

[0017] Beneficial effects: Since heating relays are usually closed and opened under load, which has a greater impact on the relay life. To improve the reliability of the electrical architecture and reduce the relay adhesion failure rate, this architecture abandons the previous epoxy resin relays and adopts ceramic relays.

[0018] Further, the discharge circuit further includes a main fuse. One end of the main fuse is connected to the positive pole of the battery, and the other end is connected to the main positive relay. A parallel node is provided between the main fuse and the main positive relay. The pre-charge circuit, the fast-charge circuit, and the three-in-one circuit branch at the parallel node.

[0019] Beneficial effects:

[0020] 1. Enhance system safety: As a primary protection component, the main fuse is set at the battery positive pole outlet. It can quickly cut off the power supply of the entire high-voltage circuit in case of severe short circuit or overcurrent, preventing excessive current from damaging the battery pack or causing a fire, thus enhancing system safety. Moreover, the position of the main fuse is convenient for quick positioning and replacement. Compared with protection components integrated in complex circuits, it reduces the maintenance difficulty and time, improving the vehicle's usability.

[0021] 2. Facilitate modular design and upgrade: This layout facilitates considering the main fuse, the main positive relay, and each circuit as relatively independent modules. In the future, if it is necessary to upgrade a certain part or replace components of different specifications (such as more efficient fast-charge technology), adjustments can be made more easily without affecting the basic architecture of the entire system, enhancing the system's flexibility and scalability.

[0022] Further, the other end of the three-in-one circuit is connected to a three-in-one interface, and the three-in-one interface is connected to the three-in-one controller at the vehicle end.

[0023] Beneficial effects: The three-in-one circuit mainly powers the vehicle's three-in-one PDU, including OBC, DC / AC, and DC / DC, and completes the AC charging function of the vehicle, the high-voltage to low-voltage power supply function of the vehicle, and the DC to AC inversion function; specifically, it can provide slow charging, AC inversion, power supply for the vehicle's air conditioner AC compressor, and conversion of the vehicle's DC power supply; in addition, by integrating multiple power components, the efficiency can be improved, the volume and weight can be reduced, and the cost can be optimized.

[0024] Furthermore, the discharge circuit further includes an MSD, a shunt, and a main negative relay connected in series in sequence. One end of the MSD is connected to the negative electrode of the battery, and one end of the main negative relay is respectively connected to the negative electrode of the discharge interface, the negative electrode of the three-in-one interface, and the negative electrode of the fast charging interface.

[0025] Beneficial effects:

[0026] 1. Enhance maintenance safety and have a dual protection mechanism: An MSD (manual service disconnect) is set at the negative electrode, allowing operators to manually disconnect the negative electrode of the entire high-voltage circuit during maintenance or in an emergency, providing a clear safety disconnect point and ensuring the safety of personnel during electrical maintenance or inspection; the presence of the MSD completely isolates the high-voltage system in the non-operating state, reducing the risk of accidental electric shock. A fuse is set at the positive electrode of the main circuit and an MSD is set at the negative electrode, forming dual protection for the positive and negative electrodes; the fuse mainly deals with instantaneous large current overload and short-circuit situations, quickly disconnecting the power supply to avoid system damage; while the MSD provides safety isolation when manual intervention is required. The combination of the two provides a comprehensive protection strategy for the battery pack and the entire high-voltage system, enhancing the reliability and safety of the system.

[0027] 2. Setting a shunt can monitor the discharge current of the battery pack in real time, which is crucial for the battery management system (BMS); by accurately measuring the current, the BMS can more accurately monitor the battery state, predict the remaining power, optimize the charge and discharge strategy, extend the battery life, and promptly detect abnormal current situations, improving the overall stability and efficiency of the system.

[0028] Furthermore, the discharge circuit further includes a current sensor, one end of the current sensor is connected to the positive electrode of the battery, and the other end is connected to the main fuse.

[0029] Beneficial effects: Installing the current sensor between the positive electrode of the battery and the main fuse can monitor the discharge current flowing through the battery pack in real time and accurately; strengthening the real-time monitoring ability of the battery system is conducive to improving the safety, reliability, and economy of the system, and is an important measure to optimize the high-voltage electrical architecture of the battery pack BDU of a mini-van. Brief Description of the Drawings

[0030] Figure 1This is the circuit connection diagram of the BDU high-voltage electrical architecture of the present utility model. Detailed implementation manners

[0031] The following is a further detailed description through specific implementation manners:

[0032] The markings in the attached drawings of the specification include: battery 1, parallel node 10, main positive relay 11, main fuse 12, current sensor 13, MSD 14, shunt 15, main negative relay 16, discharge interface 17, pre-charge relay 21, pre-charge resistor 22, fast charge relay 3, fast charge interface 31, three-in-one circuit 4, three-in-one interface 41, heating positive relay 51, heating fuse 52, heating output plug 53.

[0033] As Figure 1 shown, a BDU high-voltage electrical architecture for a minivan battery pack includes a discharge circuit, a pre-charge circuit, a fast charge circuit, a heating circuit, and a three-in-one circuit 4. The discharge circuit, the pre-charge circuit, the fast charge circuit, and the three-in-one circuit 4 are arranged in parallel. The discharge circuit is also called the main circuit and includes a positive electrode circuit and a negative electrode circuit. The positive electrode circuit includes a current sensor 13, a main fuse 12, and a main positive relay 11 connected in series in sequence. In this embodiment, a parallel node 10 is provided between the main fuse 12 and the main positive relay 11. The pre-charge circuit, the fast charge circuit, and the three-in-one circuit 4 branch at the parallel node 10.

[0034] Among them, the connection point of the heating circuit can be adjusted to after the main positive relay 11 according to the architecture requirements and is designed in series with the main positive relay 11; or, as shown in this embodiment, the connection point of the heating circuit is set before the main positive relay 11 and is arranged in parallel with the main positive relay 11.

[0035] Specifically, in this embodiment, the current sensor 13 uses a Hall sensor. One end of the Hall sensor is connected to the positive electrode of the battery 1 through a wire, and one end of the main positive relay 11 is connected to the positive electrode of the discharge interface 17. The negative electrode circuit includes an MSD 14 (manual service switch), a shunt 15, and a main negative relay 16 connected in series in sequence; among them, one end of the MSD 14 is connected to the negative electrode of the battery 1 through a wire, and one end of the main negative relay 16 branches through a wire and is respectively connected to the negative electrode of the discharge interface 17, the negative electrode of the three-in-one interface 41, and the negative electrode of the fast charge interface 31; in other embodiments other than this embodiment, the MSD 14 on the negative electrode circuit can also be replaced with a fuse.

[0036] The pre-charge circuit includes a pre-charge relay 21 and a pre-charge resistor 22. The pre-charge relay 21 and the pre-charge resistor 22 are connected in series and then connected in parallel with the main positive relay 11. The pre-charge relay 21 and the pre-charge resistor 22 play a role in protecting the circuit. Without the pre-charge relay 21 and the pre-charge resistor 22, due to the capacitive load in the power supply circuit of the electric vehicle, when the circuit is turned on, the high-voltage system relay will suddenly close. At this time, the charge of the capacitor is zero. According to the transient characteristics of the circuit, the capacitor is equivalent to a short circuit, and the circuit resistance is about dozens of milliohms. Therefore, the transient current of the high-voltage system becomes very large, resulting in a large current impact of several thousand amperes. If effective protection measures are not taken, this transient impact current will not only burn out the main and negative relays, but also cause serious damage to the entire power supply circuit and other electrical equipment, and at the same time, it is also entirely possible to endanger the personal safety of the driver and passengers.

[0037] In this embodiment, the pre-charger can meet various differentiated pre-charge requirements of the 400V voltage platform of the minivan model in terms of specification selection. By selecting pre-charge relays 21 and pre-charge resistors 22 with high compatibility, it can meet the requirements of different manufacturers and different specifications of BMS for the pre-charge voltage difference judgment value of 5V to 20V, as well as the requirements of different pre-charge durations of 100mS to 500mS for the whole vehicle, and the range requirements of the X capacitor of 100uF to 1000uF for the whole vehicle, so as to meet the pre-charge function requirements of the whole vehicle. Specifically, the pre-charge resistor 22 can be compatibly selected with a power of 10W to 100W and a resistance range of 10Ω to 250Ω, and the pre-charge relay 21 selects a 20A relay.

[0038] The fast-charge circuit includes a fast-charge relay 3. The fast-charge relay 3 is arranged in parallel with the main positive relay 11. One end of the fast-charge relay 3 is connected to the parallel node 10 on the discharge circuit, and the other end is connected to the positive pole of the fast-charge interface 31. In this application, by designing the main circuit (discharge circuit) and the fast-charge circuit in parallel, the separate control of the main positive relay 11 and the fast-charge relay 3 can be realized. The main positive relay 11 only needs to meet the current-carrying and performance requirements of the discharge circuit, while the fast-charge relay 3 separately meets the charging requirements. This can reduce the cost of the main positive relay 11 and also reduce the required space of the battery pack.

[0039] The heating circuit includes a heating fuse 52 and a heating positive relay 51 connected in series in sequence; in this embodiment, one end of the heating positive relay 51 is connected to the parallel node 10 on the discharge circuit. The heating positive relay 51 is located before the main positive relay 11 and is arranged in parallel with the main positive relay 11. One end of the heating fuse 52 is connected to the positive terminal of the heating output plug 53; one end of the negative circuit of the heating circuit is connected to the negative terminal of the heating output plug 53, and the other end is connected to the main negative circuit, and the connection point is located at the rear end of the main negative relay 16; wherein, the heating output plug 53 is a connecting component connecting the BDU and the battery pack heating film. Specifically, when in use, the heating output plug 53 and the heating film are connected through a high-voltage wire.

[0040] Specifically, in this embodiment, the heating positive relay 51 adopts a ceramic-type relay. The heating circuit is used to maintain the battery pack within a suitable operating temperature range. Especially in a low-temperature environment, the battery pack is heated through the heating circuit to ensure that it can quickly reach the optimal operating temperature in cold weather, thereby ensuring the power performance and cruising range of the electric vehicle. In the electrical architecture provided by this application, the heating circuit can be selected according to the actual vehicle model. The following are specifically three cases of heating methods:

[0041] Case 1: When the BMS is awakened and needs to control the battery pack to discharge or charge externally, the BMS will detect the temperature situation inside the battery pack and check whether the battery cells are within a healthy temperature range. If the temperature is too low and affects the charging or discharging ability of the battery cells, the BMS will first close the heating positive relay 51 to make the heating film of the battery pack start to work. After the battery pack temperature is heated to the normal temperature range, the main positive relay 11 will be closed, and then the battery pack can be charged or discharged externally.

[0042] Case 2: If a liquid cooling and heating solution is adopted, the battery pack has no heating film. The BMS communicates with the vehicle controller, and the PTC of the vehicle heats the cooling water to provide heat for the battery pack, and all devices of the heating circuit are not required for the BDU of the battery pack; while the heating circuit of this application is an independent circuit, and its existence or non-existence has no impact on the design of the BDU.

[0043] Case 3: The heating circuit is connected by a high-voltage wire, and this wire can be connected before or after the main positive relay 11, with flexible selection. If the heating positive high-voltage wire is connected after the main positive relay 11, when the vehicle needs to be charged and the BMS detects that the battery pack temperature is low, it will first close the heating positive relay 51 to make the heating film inside the battery pack start to heat. After the heating is completed, the fast charging relay 3 will be closed again to make the battery pack start to charge.

[0044] In summary, the above three scenarios can meet the performance requirements of battery packs for different regions and different customer groups. Currently, there are also differences in the heating strategy requirements of electric vehicle models. In the northern region, the battery pack is required to be able to achieve independent heating. In the southern region, PTC heating is not required, and liquid heating is adopted. Some customers also require the charging pile to heat the entire pack first and then charge. The architecture of the present application can be selected according to the needs of customers during use, with high flexibility, which can effectively reduce the development cost and shorten the development cycle.

[0045] One end of the three-in-one circuit 4 is connected to the parallel node 10 on the main circuit, and the other end is connected to a three-in-one interface 41, which is connected to the three-in-one controller at the vehicle end. Specifically, the three-in-one circuit 4 mainly supplies power to the vehicle three-in-one PDU, including OBC, DC / AC, and DC / DC, to complete the AC charging function of the vehicle, the high-voltage to low-voltage power supply function of the vehicle, and the DC-to-AC inversion function. Specifically, it can provide slow charging, AC inversion, power supply for the vehicle air conditioner AC air compressor, and conversion of the vehicle DC power supply for the vehicle.

[0046] The above are only the embodiments of the present invention. The present invention is not limited to the fields involved in this embodiment. Common knowledge such as the specific structures and characteristics known in the solutions is not described in detail here. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by the present application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A mini van battery pack BDU high voltage electrical architecture, characterized in that: It includes a discharge circuit, a pre-charge circuit, a fast-charge circuit, a heating circuit and a three-in-one circuit, and the discharge circuit, pre-charge circuit, fast-charge circuit and three-in-one circuit are arranged in parallel; the discharge circuit includes a main positive relay, one end of the main positive relay is connected to the positive electrode of the battery, and the other end is connected to the positive electrode of the discharge interface; the heating circuit is arranged in parallel or in series with the main positive relay; the pre-charge circuit includes a pre-charge relay and a pre-charge resistor, the pre-charge relay is connected in series with the pre-charge resistor and then connected in parallel with the main positive relay; the fast-charge circuit includes a fast-charge relay, the fast-charge relay is arranged in parallel with the main positive relay, one end of the fast-charge relay is connected to the positive electrode of the battery, and the other end is connected to the positive electrode of the fast-charge interface.

2. A mini van battery pack BDU high voltage electrical architecture according to claim 1, characterized in that: The heating circuit includes a positive circuit and a negative circuit. A heating fuse and a heating positive relay are arranged in series on the positive circuit. One end of the heating positive relay is connected in parallel or in series with the main positive relay. One end of the heating fuse is connected to the positive pole of the heating output plug-in; one end of the negative circuit is connected to the negative pole of the heating output plug-in.

3. A mini van battery pack BDU high voltage electrical architecture according to claim 2, characterized in that: The heating positive relay is a ceramic type relay.

4. A mini van battery pack BDU high voltage electrical architecture according to claim 3, characterized in that: The discharge circuit also includes a main fuse, one end of which is connected to the positive electrode of the battery, and the other end is connected to the main positive relay. A parallel node is set between the main fuse and the main positive relay; the pre-charging circuit, the fast charging circuit, and the three-in-one circuit are branched at the parallel node.

5. A mini van battery pack BDU high voltage electrical architecture according to claim 4, characterized in that: The other end of the three-in-one circuit is connected to a three-in-one interface, and the three-in-one interface is connected to a three-in-one controller at the vehicle end.

6. A mini van battery pack BDU high voltage electrical architecture according to claim 5, characterized in that: The discharge circuit also includes an MSD, a shunt and a main negative relay connected in series in sequence, one end of the MSD is connected to the negative electrode of the battery, and one end of the main negative relay is respectively connected to the negative electrode of the discharge interface, the negative electrode of the three-in-one interface, and the negative electrode of the fast charging interface.

7. A mini van battery pack BDU high voltage electrical architecture according to claim 6, characterized in that: The discharge circuit also includes a current sensor, one end of which is connected to the positive electrode of the battery, and the other end of which is connected to the main fuse.

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