Power battery system and electric vehicle

Abstract

The application provides a power battery system (1000), comprising: a main unit (100), wherein the main unit (100) comprises a power battery (1), a main positive relay (2) connected to a positive electrode of the power battery (1) and a main negative relay (3) connected to a negative electrode of the power battery (1); and an expansion unit (200, 300), wherein the main unit (100) further comprises a first connecting point (71) between the positive electrode of the power battery (1) and the main positive relay (2) and a second connecting point (72) between the negative electrode of the power battery (1) and the main negative relay (3), and the expansion unit (200, 300) is selectively plugged into the main unit (100) and electrically connected between the first connecting point (71) and the second connecting point (72) to access the circuit of the main unit (100). The system can realize the functional expansion and / or update of the power battery system by means of plugging in the expansion unit without changing the structure of the main loop of the power battery.

Description

Technical Field

[0001] This invention relates to a power battery system and an electric vehicle. Background Technology

[0002] Electric vehicles continue to gain popularity and have become one of the mainstream models for civilian transportation. Traditional gasoline vehicles have highly modular engines, abundant aftermarket parts, and allow owners to independently adjust and upgrade them, resulting in strong human-vehicle interaction and a mature modification culture. However, the power battery systems of existing electric vehicles are highly integrated, making modification difficult and resulting in a weak human-vehicle interaction experience. If you want to modify or update the power battery system, you need to redesign the entire electrical circuit, which is a high barrier to entry. Summary of the Invention

[0003] The purpose of this invention is to provide an improved power battery system, which in particular can achieve functional expansion and / or updates of the power battery system without changing the main circuit structure of the power battery.

[0004] According to a first aspect of the present invention, a power battery system is provided, comprising: a main unit, the main unit including a power battery, a main positive relay connected to the positive terminal of the power battery, and a main negative relay connected to the negative terminal of the power battery; and an extension unit, wherein the main unit further includes a first connection point located between the positive terminal of the power battery and the main positive relay and a second connection point located between the negative terminal of the power battery and the main negative relay, and the extension unit selectively plugs into the main unit and is electrically connected between the first connection point and the second connection point to access the circuit of the main unit.

[0005] According to an optional embodiment of the present invention, the main unit includes a first housing and an exposed first plug-in portion and a second plug-in portion disposed on the first housing. The first plug-in portion is electrically connected to a first connection point, and the second plug-in portion is electrically connected to a second connection point. The extension unit includes a second housing and an exposed first plug-in mating portion and a second plug-in mating portion disposed on the second housing. The first plug-in mating portion is interconnected with the first plug-in portion, and the second plug-in mating portion is interconnected with the second plug-in portion to electrically connect the extension unit between the first connection point and the second connection point. In particular, the first plug-in portion and the second plug-in portion are sealed by a sealing member when not occupied.

[0006] According to an optional embodiment of the present invention, the power battery system includes a first expansion unit, the first expansion unit including a capacitor relay, a pre-charge unit and an energy storage unit, the pre-charge unit including a pre-charge relay and a pre-charge resistor connected in series, wherein the pre-charge unit is connected in parallel with the capacitor relay, and the energy storage unit is connected in series with the pre-charge unit and the capacitor relay. In particular, the energy storage unit includes at least one supercapacitor.

[0007] According to an optional embodiment of the invention, the power battery system is configured to: when the first extension unit is plugged into the main unit, in response to a power enhancement demand, particularly in response to a high power mode entry request, close the pre-charge relay and keep the capacitor relay open to charge the energy storage unit through the power battery; and when the voltage of the energy storage unit reaches a set value relative to the voltage of the power battery, open the pre-charge relay and close the capacitor relay to connect the energy storage unit in parallel with the power battery.

[0008] According to an optional embodiment of the present invention, the first expansion unit further includes a discharge unit, which includes a discharge switch and a discharge resistor connected in series, wherein the discharge unit is connected in series with the precharge unit and the capacitor relay, and in parallel with the energy storage unit.

[0009] According to an optional embodiment of the present invention, the power battery system includes a second extension unit, the second extension unit including an inverter and a resonant unit connected downstream of the inverter, the resonant unit including an inductor and a capacitor in series, the inverter, particularly a three-level H-bridge inverter, being configured to controllably change the on / off state of its individual switches based on a PWM signal to generate an excitation current for detecting the electrochemical impedance spectroscopy (EIS) of the power battery via the resonant unit.

[0010] According to an optional embodiment of the present invention, the main unit includes a first cell group, a second cell group, and a battery midpoint. When the second extension unit is plugged into the main unit, the bridge arm midpoint of the inverter is electrically connected to the battery midpoint of the power battery. By controlling the on / off state of each switch of the inverter, electrical energy is transmitted between the first cell group and the second cell group through the resonant unit to generate an excitation current for detecting the electrochemical impedance spectrum of the power battery.

[0011] According to an optional embodiment of the present invention, the main unit includes a first current sensor disposed between a first connection point and the positive electrode of the power battery or disposed between a second connection point and the negative electrode of the power battery. The first current sensor is configured to detect an excitation current generated by a resonant unit for detecting the electrochemical impedance spectrum of the power battery.

[0012] According to an optional embodiment of the present invention, the second extension unit includes a second current sensor disposed in series with the resonant unit downstream of the inverter for detecting the excitation current generated by the resonant unit for detecting the electrochemical impedance spectrum of the power battery.

[0013] According to an optional embodiment of the present invention, the main unit includes a main precharge unit connected in parallel with the main positive relay, the main precharge unit including a main precharge relay and a main precharge resistor connected in series.

[0014] According to an optional embodiment of the present invention, the main unit includes a manual maintenance switch or a high-voltage socket, and a first connection point and a second connection point are integrated into the manual maintenance switch or high-voltage socket.

[0015] According to a second aspect of the invention, an electric vehicle is provided, comprising any of the power battery systems according to the invention, wherein a main unit of the power battery system is fixedly disposed in the electric vehicle, and an extension unit of the power battery system is selectively plugged into the main unit.

[0016] According to certain embodiments of the present invention, a power terminal socket can be provided in the main circuit of the electric vehicle power battery system as an external plug-in interface for connecting external functional expansion units, thereby enabling the modification, upgrading, and / or functional expansion of the power battery system. A variety of external functional plug-ins can be provided for users to choose from, particularly expansion units that include energy storage units to improve vehicle power output performance or enable online electrochemical impedance spectroscopy (EIS) detection of the power battery. This enhances the structural flexibility and modification appeal of the electric vehicle power battery system.

[0017] It is worth noting that the advantages and beneficial effects of the present invention are not limited to those mentioned above. Those skilled in the art can understand other unmentioned advantages and beneficial effects of the present invention through the following specific embodiments and claims. Attached Figure Description

[0018] The invention will now be described in more detail with reference to the accompanying drawings, which will provide a better understanding of its principles, features, and advantages. The drawings include: Figure 1 A circuit diagram of the main unit of an exemplary power battery system according to the present invention is shown; Figure 2 A circuit diagram of the main unit and expansion unit of an exemplary power battery system according to the present invention is shown; Figure 3 A circuit diagram of the main unit and another expansion unit of an exemplary power battery system according to the present invention is shown; and Figure 4 A schematic diagram of the main unit and extension unit of an exemplary power battery system according to the present invention is shown. Detailed Implementation

[0019] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and exemplary embodiments. It should be understood that the specific embodiments described herein are only for explaining the principles of the invention and are not intended to limit the scope of protection of the invention.

[0020] like Figures 1 to 4As shown, the power battery system 1000 according to an embodiment of the present invention includes a main unit 100 and expansion units 200 and 300.

[0021] like Figure 1 As shown, the main unit 100 includes a power battery 1, a main positive relay 2, and a main negative relay 3. The power battery 1 may include multiple battery cells for outputting high-voltage electricity. The main positive relay 2 is connected to the positive terminal of the power battery 1. The main negative relay 3 is connected to the negative terminal of the power battery 1.

[0022] The circuit structure of the main unit 100 includes a high-voltage positive busbar leading from the positive terminal of the power battery 1 and a high-voltage negative busbar leading from the negative terminal of the power battery 1. A main positive relay 2 is connected in series on the high-voltage positive busbar, and a main negative relay 3 is connected in series on the high-voltage negative busbar. The high-voltage positive and negative busbars continue to extend from the power battery 1 after passing through the main positive relay 2 and the main negative relay 3, respectively, to connect various high-voltage electrical units. That is, the high-voltage electrical units are connected between the main positive relay 2 and the main negative relay 3 via the high-voltage positive and negative busbars.

[0023] In the accompanying drawings of this invention, only the power supply circuit structure of the main unit 100 is shown; the high-voltage electrical units connected between the high-voltage positive bus and the high-voltage negative bus after the main positive relay 2 and the main negative relay 3 are not shown.

[0024] Here, the high-voltage electrical unit may include at least one of the vehicle's drive unit, high-voltage power distribution unit, and high-voltage load unit.

[0025] For example, the drive device may include an inverter and a drive motor. The inverter may be configured to controllably adjust the on / off state of its respective arms to output drive current for driving the drive motor to operate, thereby driving the vehicle.

[0026] For example, the high-voltage power distribution device may include a high-voltage distribution unit (PDU) for distributing high-voltage bus power and providing overload protection.

[0027] For example, the high-voltage load unit may include an on-board charger (OBC), a DC-DC converter, an air conditioning heater, and / or an electric air conditioning compressor, etc.

[0028] The aforementioned high-voltage electrical unit can be part of the circuit structure of the main unit 100, meaning the circuit structure of the main unit 100 can itself form a complete circuit. Alternatively, the aforementioned high-voltage electrical unit can be an external unit electrically connected to the circuit structure of the main unit 100. In this case, the main unit 100 can be implemented, for example, as a battery pack, having an output port for electrically connecting the high-voltage electrical unit.

[0029] like Figure 1As shown, the main unit 100 also includes a first connection point 71 located between the positive terminal of the power battery 1 and the main positive relay 2, and a second connection point 72 located between the negative terminal of the power battery 1 and the main negative relay 3. The expansion units 200 and 300 can be selectively plugged into the main unit 100 and electrically connected between the first connection point 71 and the second connection point 72 to access the circuit of the main unit 100.

[0030] Therefore, expansion units capable of performing specific functions can be easily connected to the circuitry of the main unit 100 without modifying its circuit structure. This allows for the modification of the power battery system, including the main unit 100, by connecting external expansion units. Thus, structural flexibility and operability for functional expansion, upgrading, or adjustment of the power battery system are achieved.

[0031] The power battery system 1000 according to an embodiment of the present invention may include at least one expansion unit, and in particular, may provide multiple expansion units capable of performing different functions so that users can select the appropriate or desired expansion unit as needed to plug into the main unit 100.

[0032] In the illustrated embodiment, in the circuit structure of the main unit 100, a first fuse 9 can be provided between the positive terminal of the power battery 1 and the main positive relay 2. The first fuse 9 can be provided between the first connection point 71 and the positive terminal of the power battery 1, or between the first connection point 71 and the main positive relay 2. The first fuse 9 can be used to passively melt and break under conditions such as circuit overcurrent and short circuit to achieve circuit protection.

[0033] Additionally or alternatively, a second fuse 10 may be provided between the negative terminal of the power battery 1 and the main negative relay 3. The second fuse 10 may be located between the second connection point 72 and the negative terminal of the power battery 1, or between the second connection point 72 and the main negative relay 3. The second fuse 10 may be configured to be triggered by the battery management system (BMS) of the electric vehicle to actively disconnect the high-voltage bus in the event of a vehicle collision or battery thermal runaway, thereby achieving high-voltage safety isolation.

[0034] Optionally, the main unit 100 may include a manual maintenance switch or a high-voltage socket 8. The manual maintenance switch is used to physically disconnect the high-voltage circuit of the entire vehicle during maintenance, isolate the high voltage, and discharge residual charge to ensure the safety of personnel operation.

[0035] In an embodiment where a manual maintenance switch is provided in the main unit 100, the first connection point 71 and the second connection point 72 can be integrated into the manual maintenance switch. In this way, the manual maintenance switch can be reused as a plug-in mounting part for the expansion unit.

[0036] In embodiments where a manual maintenance switch is not provided in the main unit 100, the first connection point 71 and the second connection point 72 can be integrated into the high-voltage socket. That is, the positive and negative terminals of the power battery 1 are led out to the outside through the high-voltage socket.

[0037] In the illustrated embodiment, the main unit 100 further includes a main precharge unit 4 connected in parallel with the main positive relay 2. The main precharge unit 4 includes a main precharge relay 5 and a main precharge resistor 6 connected in series.

[0038] When the main unit 100 is implemented as an external unit of the main unit 100, such as a battery pack or a high-voltage electrical unit such as a drive motor, for example Figure 4 As shown, the main unit 100 may include a first housing 110. The circuit structure of the main unit 100 may be disposed within the first housing 110. The main unit 100 may also include an exposed first connector 121 and a second connector 122 disposed on the first housing 110. Inside the first housing 110, the first connector 121 is electrically connected to a first connection point 71, and the second connector 122 is electrically connected to a second connection point 72.

[0039] For example, the first plug-in portion 121 and the second plug-in portion 122 can be implemented as plug interfaces.

[0040] The power battery system 1000 according to the present invention may include or be controlled by a battery management system (BMS) of an electric vehicle. The expansion units 200 and 300 may be configured to be controlled by the BMS when plugged into the main unit 100.

[0041] Figure 2 An exemplary extension unit 200 is shown. This extension unit 200 (which may also be referred to herein as the first extension unit 200 for ease of distinction and description) may be designed to temporarily enhance the power output performance of a vehicle.

[0042] like Figure 2 As shown, the first expansion unit 200 may include a capacitor relay 12, a pre-charge unit 13, and an energy storage unit 19. The pre-charge unit 13 is connected in parallel with the capacitor relay 12. The pre-charge unit 13 includes a pre-charge relay 14 and a pre-charge resistor 15 connected in series. The energy storage unit 19 is connected in series with the pre-charge unit 13 and the capacitor relay 12. The capacitor relay 12 and the pre-charge relay 14 are normally disconnected.

[0043] The energy storage unit 19 may include at least one supercapacitor, and in particular, may include multiple supercapacitors connected in series and / or parallel. In other embodiments not shown, the energy storage unit 19 may include at least one battery (i.e., an external battery).

[0044] In embodiments where the energy storage unit 19 includes at least one battery, when the first expansion unit 200 is connected to the circuit of the main unit 100, the pre-charge relay 14 can be closed first, while the capacitor relay 12 remains open, to eliminate or reduce any potential voltage difference between the energy storage unit 19 and the power battery 1. Once the voltage difference is reduced to a safe range, the pre-charge relay 14 is then opened, and the capacitor relay 12 is closed, connecting the energy storage unit 19 in parallel with the power battery 1. This allows for the expansion of the capacity of the power battery 1.

[0045] In this case, the energy storage unit 19 needs to store electrical energy before being connected to the power battery 1. Therefore, the energy storage unit 19 can be charged externally by a separate charging device, or it can be charged by the charging device of the vehicle's main unit 100, which is equipped with the first expansion unit 200 to be plugged in.

[0046] In embodiments where the energy storage unit 19 includes at least one supercapacitor, when the first extension unit 200 is connected to the circuit of the main unit 100, the power battery 1 can advantageously be used to charge the energy storage unit 19. For this purpose, the pre-charge relay 14 can be closed first, while the capacitor relay 12 remains open, to charge the energy storage unit 19 through the power battery 1. When the voltage of the energy storage unit 19 reaches a set value relative to the voltage of the power battery 1, for example, when the voltage of the energy storage unit 19 is substantially the same as the voltage of the power battery 1 (the voltage difference is within a safe range), the pre-charge relay 14 is opened, and the capacitor relay 12 is closed, to connect the energy storage unit 19 in parallel with the power battery 1.

[0047] During the charging process of the supercapacitor-type energy storage unit 19 by the power battery 1, the power and voltage of the power battery 1 may drop slightly. However, after the supercapacitor completes energy storage, the power battery 1 and the energy storage unit 19 are connected in parallel to output power to the outside. Relying on the high-power discharge characteristics of the supercapacitor, the instantaneous output power of the entire power battery system can be significantly improved, thereby achieving a faster acceleration effect.

[0048] Therefore, in particular, the power battery system 1000 can be configured to connect the energy storage unit 19 in parallel with the power battery 1 when the first extension unit 200 is plugged into the main unit 100, in response to power enhancement requirements, especially in response to a high power mode entry request.

[0049] For example, in an embodiment where the energy storage unit 19 includes at least one supercapacitor, when a vehicle with a main unit 100 connected to the first extension unit 200 has a power enhancement requirement, or when a user selects to enter a high-power mode, the pre-charge relay 14 can be closed first, while the capacitor relay 12 remains open, to charge the energy storage unit 19 through the power battery 1. Then, when the voltage of the energy storage unit 19 reaches a set value relative to the voltage of the power battery 1, the pre-charge relay 14 is opened and the capacitor relay 12 is closed to connect the energy storage unit 19 in parallel with the power battery 1.

[0050] Therefore, the kinetic energy output performance of the power battery system can be improved by plugging the first expansion unit 200 into the circuit of the main unit 100 without changing the original circuit structure of the main unit 100.

[0051] The BMS can send corresponding control commands to the capacitor relay 12 and pre-charge relay 14 inside the first expansion unit 200, which is plugged into and connected to the main unit 100. Furthermore, the BMS can determine whether the voltage difference has been reduced to a safe range by monitoring the terminal voltages of the power battery 1 and the energy storage unit 19, and then control the capacitor relay 12 and pre-charge relay 14 accordingly.

[0052] In addition, the BMS can determine whether the vehicle has a power enhancement requirement based on the vehicle's current driving mode or the driving mode to be entered, or it can receive a high power mode entry request from the user, and then accordingly plug the first expansion unit 200 into the main unit 100 or control the capacitor relay 12 and the precharge relay 14 to perform the above-mentioned expansion steps.

[0053] Furthermore, the first expansion unit 200 may also include a discharge unit 16. The discharge unit 16 includes a discharge switch 17 and a discharge resistor 18 connected in series. The discharge unit 16 is connected in series with the precharge unit 13 and the capacitor relay 12, and in parallel with the energy storage unit 19.

[0054] The discharge unit 16 can be used to release the residual high-voltage charge stored inside the energy storage unit 19. During normal vehicle operation, the discharge switch 17 remains open, the discharge branch is not conductive, it does not consume the electrical energy stored in the energy storage unit 19, and it does not affect the vehicle's power output.

[0055] When the vehicle is powered down, a high-voltage circuit fails and is disconnected, or when it is necessary to separate the first expansion unit 200 from the main unit 100, the discharge switch 17 can be closed in a controlled manner, particularly controlled by the BMS. At this time, the energy storage unit 19, the discharge switch 17, and the discharge resistor 18 can form a complete discharge circuit. The electrical energy stored in the energy storage unit 19 can flow through the discharge resistor 18 and be consumed as heat until the voltage across the energy storage unit 19 drops to a safe low voltage range for the human body. This effectively avoids the electric shock safety hazard caused by the residual high voltage of the energy storage unit 19.

[0056] In addition, the discharge unit 16 can promptly eliminate the static high voltage remaining in the energy storage unit 19, thereby preventing the high voltage from acting on the internal components of the capacitor relay 12 and the pre-charge unit 13 for a long time, slowing down the insulation aging and contact wear of the devices, and extending the service life of the high voltage circuit components.

[0057] like Figure 4 As shown, the first expansion unit 200 may include a second housing 210 and exposed first insertion mating portion 221 and second insertion mating portion 222 disposed on the second housing 210. The first insertion mating portion 221 is interconnected with the first insertion portion 121, and the second insertion mating portion 222 is interconnected with the second insertion portion 122 to electrically connect the first expansion unit 200 between the first connection point 71 and the second connection point 72.

[0058] For example, the mating part 220 can be implemented as a pin.

[0059] Figure 3 Another exemplary extension unit 300 is shown (which may also be referred to herein as the second extension unit 300 for ease of distinction and description). The second extension unit 300 is designed to enable online electrochemical impedance spectroscopy (EIS) detection of the power battery 1.

[0060] like Figure 3 As shown, the second expansion unit 300 may include an inverter 23 and a resonant unit 20 connected downstream of the inverter 23. The resonant unit 20 may include an inductor 21 and a capacitor 22 connected in series. The inverter 23 may be configured to controllably change the on / off state of its individual bridge arm switches based on a PWM signal to generate an excitation current for detecting the EIS of the power battery 1 via the resonant unit 20.

[0061] Inverter 23 is specifically a three-level H-bridge inverter. Inverter 23 includes a first switch 231, a second switch 232, a third switch 233, and a fourth switch 234 connected in series. Inverter 23 also includes a bridge arm midpoint 235. All switches in inverter 23 are normally open. The switches in inverter 23 are specifically metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0062] The power battery 1 includes a first cell pack 1-1 and a second cell pack 1-2. Each cell pack has the same number of cells. The power battery 1 has a battery midpoint 19.

[0063] When the second extension unit 300 is plugged into the main unit 100, the midpoint 235 of the bridge arm of the inverter 23 is electrically connected to the midpoint 19 of the battery of the power battery 1.

[0064] When the second expansion unit 300 is plugged into the main unit 100, the inverter 23 can controllably close the first switch 231 and the third switch 233 in the first stage, while keeping the second switch 232 and the fourth switch 234 open. At this time, the first cell group 1-1 and the resonant unit 20 form a closed loop, and electrical energy is transferred from the first cell group 1-1 to the resonant unit 20. Afterwards, the inverter 23 can controllably open the first switch 231 and the third switch 233 in the second stage, while closing the second switch 232 and the fourth switch 234. At this time, the second cell group 1-2 and the resonant unit 20 form a closed loop, and electrical energy is transferred from the resonant unit 20 to the second cell group 1-2.

[0065] The on / off state of each switching transistor in inverter 23 can be controlled according to the PWM signal. Based on the PWM signal, the first and second stages are executed repeatedly, so that the first cell group 1-1 and the second cell group 1-2 can ultimately obtain excitation currents with the same amplitude but opposite directions. During this process, at different excitation frequencies, by collecting the excitation current and the voltage of each cell in the power battery 1, the electrochemical impedance spectrum corresponding to each cell can be obtained.

[0066] The PWM signal can be generated by the BMS and sent to the inverter 23. EIS measurement can be performed, for example, when the vehicle is stopped. Thus, the second expansion unit 300 can be optionally connected to the main unit 100 only after confirming that the vehicle is stopped.

[0067] The main unit 100 includes a first current sensor 11 disposed between the first connection point 71 and the positive terminal of the power battery 1, or disposed between the second connection point 72 and the negative terminal of the power battery 1. The first current sensor 11 is configured to detect the excitation current generated by the resonant unit 20 for detecting the electrochemical impedance spectroscopy (EIS) of the power battery 1. In this way, the excitation current for EIS measurement can be detected using the current sensor 11 originally disposed in the circuit of the main unit 100.

[0068] Additionally or alternatively, the second extension unit 300 may include a second current sensor 24 disposed in series with the resonant unit 20 downstream of the inverter 23 for detecting the excitation current generated by the resonant unit 20 for detecting the electrochemical impedance spectroscopy (EIS) of the power battery 1. That is, a separate current sensor can be provided in the second extension unit 300 to detect the excitation current. Since the second current sensor 24 is positioned closer to the resonant unit 20, detecting the excitation current using the second current sensor 24 allows for more accurate and flexible detection.

[0069] like Figure 4 As shown, the second expansion unit 300 may include a second housing 310 and exposed first mating portion 321 and second mating portion 322 disposed on the second housing 310. The first mating portion 321 is interconnected with the first mating portion 121, and the second mating portion 322 is interconnected with the second mating portion 122 to electrically connect the second expansion unit 300 between the first connection point 71 and the second connection point 72. Exemplarily, the mating portion 320 may be implemented as a pin.

[0070] The main unit 100 may include an exposed auxiliary connector 123 disposed on the first housing 110, which is electrically connected inside the first housing 110 to the battery midpoint 19 of the power battery 1. The second expansion unit 300 also includes an exposed auxiliary connector 330 disposed on the second housing 310, which is electrically connected inside the second housing 310 to the bridge arm midpoint 235 of the inverter 23.

[0071] Therefore, when the second extension unit 300 is plugged into the main unit 100, the auxiliary plug-in part 123 and the auxiliary plug-in mating part 330 are connected to each other to electrically connect the midpoint 235 of the bridge arm of the inverter 23 to the midpoint 19 of the battery.

[0072] For example, the auxiliary plug-in portion 123 can be implemented as a pin, and the auxiliary plug-in mating portion 330 can be implemented as a plug interface. The auxiliary plug-in portion 123 may differ from the plug-in portions 121 and 122 in structure, appearance, and / or positioning, so as to facilitate differentiation.

[0073] When the first plug-in portion 121, the second plug-in portion 122, and the auxiliary plug-in portion 123 are not connected to the first plug-in mating portions 221 and 321, the second plug-in mating portions 222 and 322, and the auxiliary plug-in mating portion 330, they can be sealed by the sealing member 130. This ensures the sealed state of the power battery 1.

[0074] To accommodate multiple expansion units, the first housing 110 of the main unit 100 may be provided with a first plug-in portion 121, a second plug-in portion 122, and an auxiliary plug-in portion 123. When the first expansion unit 200, which is intended to temporarily enhance the power output performance of the vehicle, is plugged into the main unit 100, the auxiliary plug-in portion 123 is idle and remains sealed by the sealing member 130.

[0075] Various expansion units can be automatically plugged into and detached from the main unit 100. For example, the vehicle may be equipped with an actuator that can be controlled, particularly controlled by the BMS, to plug into the main unit 100 with expansion units 200 or 300 required to complete the task to be performed next, and optionally to detach the plugged-in expansion units 200 or 300 from the main unit 100 after the corresponding task has been completed.

[0076] For example, a first extension unit 200 designed to temporarily enhance the vehicle's power output performance can be plugged into the main unit 100 when there is a power enhancement requirement or in response to a high-power mode entry request, and disconnected from the main unit 100 after exiting the high-power mode. A second extension unit 300 designed to monitor the battery's EIS online can be plugged into the main unit 100 in response to an EIS monitoring request or permanently, and disconnected from the main unit 100 when there is a power enhancement requirement or in response to a high-power mode entry request to allow the first extension unit 200 to connect to the main unit 100.

[0077] In addition, expansion units can be selected for the power battery system based on the type of electric vehicle.

[0078] Therefore, users can choose from a variety of expansion units that perform different functions according to their needs or preferences, so that the functions of their vehicle's power battery system can be continuously expanded and / or updated.

[0079] The present invention also relates to an electric vehicle comprising a power battery system 1000 according to any of the present invention. The main unit 100 of the power battery system 1000 is particularly fixedly disposed in the vehicle, and the extension units 200, 300 of the power battery system 1000 are selectively plugged into the main unit 100.

[0080] It should be understood that the terms "first," "second," etc., used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may expressly or implicitly indicate that at least one of those features is included.

[0081] Although specific embodiments of the invention are described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the invention. The illustrative examples of features provided in this disclosure are intended to be exemplary and not limiting, unless otherwise stated. In practice, multiple features may be combined with each other as needed and where technically feasible. Various substitutions, alterations, and modifications can be conceived without departing from the spirit and scope of the invention.

Claims

1. A power battery system (1000), comprising: Main unit (100), the main unit (100) includes a power battery (1), a main positive relay (2) connected to the positive terminal of the power battery (1), and a main negative relay (3) connected to the negative terminal of the power battery (1); and Extended units (200, 300). The main unit (100) also includes a first connection point (71) between the positive terminal of the power battery (1) and the main positive relay (2) and a second connection point (72) between the negative terminal of the power battery (1) and the main negative relay (3). The expansion units (200, 300) are selectively plugged into the main unit (100) and electrically connected between the first connection point (71) and the second connection point (72) to access the circuitry of the main unit (100).

2. The power battery system (1000) according to claim 1, characterized in that, The main unit (100) includes a first housing (110) and an exposed first plug-in portion (121) and a second plug-in portion (122) disposed on the first housing (110). The first plug-in portion (121) is electrically connected to a first connection point (71), and the second plug-in portion (122) is electrically connected to a second connection point (72). The expansion units (200, 300) include a second housing (210, 310) and an exposed first plug-in mating part (221, 321) and a second plug-in mating part (222, 322) arranged on the second housing (210, 310). The first mating parts (221, 321) are connected to the first mating part (121), and the second mating parts (222, 322) are connected to the second mating part (122) to electrically connect the expansion units (200, 300) between the first connection point (71) and the second connection point (72). Specifically, the first plug portion (121) and the second plug portion (122) are sealed by a plug (130) when not occupied.

3. The power battery system (1000) according to claim 1 or 2, characterized in that, The power battery system (1000) includes a first expansion unit (200), which includes a capacitor relay (12), a pre-charge unit (13), and an energy storage unit (19). The pre-charge unit (13) includes a pre-charge relay (14) and a pre-charge resistor (15) connected in series. The pre-charge unit (13) is connected in parallel with the capacitor relay (12), and the energy storage unit (19) is connected in series with the pre-charge unit (13) and the capacitor relay (12). Specifically, the energy storage unit (19) includes at least one supercapacitor.

4. The power battery system (1000) according to claim 3, characterized in that, The power battery system is configured to be able to: When the first extension unit (200) is plugged into the main unit (100), in response to a power enhancement demand, particularly a high-power mode entry request, the pre-charge relay (14) is closed, while the capacitor relay (12) remains open, so that the energy storage unit (19) can be charged via the power battery (1); and When the voltage of the energy storage unit (19) reaches a set value relative to the voltage of the power battery (1), the precharge relay (14) is disconnected and the capacitor relay (12) is closed to connect the energy storage unit (19) in parallel with the power battery (1).

5. The power battery system (1000) according to claim 3 or 4, characterized in that, The first expansion unit (200) also includes a discharge unit (16), which includes a discharge switch (17) and a discharge resistor (18) connected in series. The discharge unit (16) is connected in series with the precharge unit (13) and the capacitor relay (12), and in parallel with the energy storage unit (19).

6. The power battery system (1000) according to any one of claims 1-5, characterized in that, The power battery system (1000) includes a second expansion unit (300), which includes an inverter (23) and a resonant unit (20) connected downstream of the inverter (23). The resonant unit (20) includes an inductor (21) and a capacitor (22) connected in series. The inverter (23), particularly the three-level H-bridge inverter, is configured to controllably change the on / off state of its individual switches based on a PWM signal to generate an excitation current for detecting the electrochemical impedance spectroscopy (EIS) of the power battery (1) by means of a resonant unit (20).

7. The power battery system (1000) according to claim 6, characterized in that, The main unit (100) includes a first cell group (1-1), a second cell group (1-2) and a battery midpoint (19). When the second extension unit (300) is plugged into the main unit (100), the bridge arm midpoint (235) of the inverter (23) is electrically connected to the battery midpoint (19) of the power battery (1). By controlling the on / off state of each switch of the inverter (23), electrical energy is transmitted between the first cell group (1-1) and the second cell group (1-2) through the resonant unit (20) to generate an excitation current for detecting the electrochemical impedance spectrum of the power battery (1).

8. The power battery system (1000) according to claim 6 or 7, characterized in that, The main unit (100) includes a first current sensor (11) disposed between the first connection point (71) and the positive electrode of the power battery (1) or disposed between the second connection point (72) and the negative electrode of the power battery (1). The first current sensor (11) is configured to detect the excitation current generated by the resonant unit (20) for detecting the electrochemical impedance spectrum of the power battery (1); and / or The second extension unit (300) includes a second current sensor (24) disposed in series with the resonant unit (20) downstream of the inverter (23) for detecting the excitation current generated by the resonant unit (20) for detecting the electrochemical impedance spectrum of the power battery (1).

9. The power battery system (1000) according to any one of claims 1-8, characterized in that, The main unit (100) includes a main precharge unit (4) connected in parallel with the main positive relay (2), the main precharge unit (4) including a main precharge relay (5) and a main precharge resistor (6) connected in series; and / or The main unit (100) includes a manual maintenance switch or high-voltage socket (8), with a first connection point (71) and a second connection point (72) integrated into the manual maintenance switch or high-voltage socket (8).

10. An electric vehicle comprising a power battery system (1000) according to any one of claims 1-9. in, The main unit (100) of the power battery system (1000) is fixedly installed in the electric vehicle, and the extension units (200, 300) of the power battery system (1000) are selectively plugged into the main unit (100).

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