A new energy vehicle power battery and a new energy vehicle

Abstract

The application relates to a new energy automobile power battery and a new energy automobile, and relates to the technical field of new energy automobiles. The power battery comprises a high-voltage power supply battery pack group, a low-voltage power supply battery pack group, a first DCDC converter and a first control switch. The first end of the high-voltage power supply battery pack group is connected with a high-voltage positive power supply node, and the second end of the high-voltage power supply battery pack group is connected with the first end of the low-voltage power supply battery pack group. The input end of the first DCDC converter is connected with the first end of the high-voltage power supply battery pack group through the first control switch, and the output end of the first DCDC converter is connected with the first end of the low-voltage power supply battery pack group. The first end of the low-voltage power supply battery pack group is connected with a low-voltage positive power supply node, and the second end of the low-voltage power supply battery pack group is connected with a high-voltage negative power supply node and a negative low-voltage power supply node. The power battery can supply power to a vehicle-mounted high-voltage load power supply circuit and a vehicle-mounted low-voltage load power supply circuit, and a separate low-voltage power supply does not need to be configured for the new energy automobile, so that the vehicle weight and the vehicle cost are reduced.

Description

Technical Field

[0001] This utility model relates to the field of new energy vehicle technology, specifically to a new energy vehicle power battery and a new energy vehicle. Background Technology

[0002] For new energy vehicles, the power source is a high-voltage battery. The high-voltage battery drives the motor to run the vehicle; at the same time, the high-voltage battery also converts the high-voltage DC to low-voltage DC through a DC-DC converter, and connects in parallel with the 12V battery to supply power to the low-voltage load of the entire vehicle.

[0003] Currently, the voltage power supply scheme for new energy vehicles all adopts a parallel connection of high-voltage DC-DC converters and 12V batteries. In this scheme, the 12V battery is mostly a lead-acid battery. Lead-acid batteries have low energy density, large size, heavy weight, and short lifespan, affecting the vehicle's range and user experience. In the aftermarket, 12V lithium battery solutions have emerged to replace lead-acid batteries. Although they have advantages such as small size, light weight, and long lifespan, their higher cost limits their application to higher-priced models, preventing widespread adoption. Utility Model Content

[0004] In view of this, the present invention provides a power battery for a new energy vehicle and a new energy vehicle, so as to provide a low-cost on-board low-voltage load power supply solution.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A power battery for new energy vehicles, comprising:

[0007] High-voltage power supply battery pack, low-voltage power supply battery pack, first DC-DC converter and first control switch;

[0008] The first end of the high-voltage power supply battery pack is connected to the high-voltage positive power supply node, and the second end of the high-voltage power supply battery pack is connected to the first end of the low-voltage power supply battery pack.

[0009] The input terminal of the first DC-DC converter is connected to the first terminal of the high-voltage power supply battery pack via the first control switch, and the output terminal of the first DC-DC converter is connected to the first terminal of the low-voltage power supply battery pack.

[0010] The first end of the low-voltage power supply battery pack is connected to the low-voltage positive power supply node, and the second end of the low-voltage power supply battery pack is connected to the high-voltage negative power supply node and the negative low-voltage power supply node.

[0011] Optionally, the aforementioned new energy vehicle power battery also includes: a second DC-DC converter;

[0012] The input terminal of the second DC-DC converter is connected to the first terminal of the high-voltage power supply battery pack;

[0013] The output of the second DC-DC converter is connected to the first end of the low-voltage power supply battery pack.

[0014] Optionally, the aforementioned new energy vehicle power battery further includes: the output power of the first DC-DC converter is greater than the output power of the second DC-DC converter.

[0015] Optionally, the aforementioned new energy vehicle power battery also includes: a second control switch;

[0016] The second control switch is located between the output terminal of the first DC-DC converter, the output terminal of the second DC-DC converter, and the first terminal of the low-voltage power supply battery pack.

[0017] Optionally, the aforementioned new energy vehicle power battery also includes: a third control switch;

[0018] The third control switch is located between the second end of the high-voltage power supply battery pack and the first end of the low-voltage power supply battery pack.

[0019] Optionally, in the aforementioned new energy vehicle power battery, the cells in the high-voltage power supply battery pack and the low-voltage power supply battery pack are lithium cells, and the lithium cells are lithium iron phosphate cells or ternary lithium cells.

[0020] Optionally, in the above-mentioned new energy vehicle power battery, the number of cells in the high-voltage power supply battery pack is greater than the number of cells in the low-voltage power supply battery pack.

[0021] Optionally, the aforementioned new energy vehicle power batteries may also include:

[0022] A diode is disposed between the first terminal of the low-voltage power supply battery pack and the low-voltage positive power supply node.

[0023] A new energy vehicle includes: any of the above-mentioned new energy vehicle power batteries, and a controller for controlling various control switches in the new energy vehicle power battery.

[0024] Optionally, the aforementioned new energy vehicles also include:

[0025] First voltage sensor, second voltage sensor;

[0026] The first voltage sensor is used to detect the terminal voltage of the high-voltage power supply battery pack;

[0027] The second voltage sensor is used to detect the terminal voltage of the low-voltage power supply battery pack;

[0028] The output terminals of the first voltage sensor and the second voltage sensor are connected to the acquisition signal input terminal of the controller.

[0029] Based on the above technical solution, in the solution provided by this utility model embodiment, the high-voltage power supply battery pack B and the low-voltage power supply battery pack A are connected in series, and the high-voltage power supply battery pack B and the low-voltage power supply battery pack A jointly supply power to the vehicle high-voltage load power supply circuit HV. When the first control switch is closed, in addition to supplying power to the vehicle high-voltage load power supply circuit HV (which can be a 400V, 800V, or other high-voltage power supply circuits), the high-voltage power supply battery pack B can also supply power to the vehicle low-voltage load power supply circuit LV (which can be 12V, 24V, etc.) through the first DC-DC converter DC1. In this system, the high-voltage battery pack supplies power to various low-voltage power supply circuits (such as 48V, etc.). The high-voltage battery pack provides input to the first DC-DC converter, which converts the voltage to low voltage to power the vehicle's low-voltage load power supply circuit LV. Simultaneously, the low-voltage battery pack also powers the vehicle's low-voltage load power supply circuit LV. The terminal voltage of the low-voltage battery pack matches the input voltage of the vehicle's low-voltage load power supply circuit LV. Therefore, the input power to the vehicle's low-voltage load power supply circuit LV includes both the first DC-DC converter and the low-voltage battery pack. Thus, in this solution, the power battery of the new energy vehicle can power both the vehicle's high-voltage load power supply circuit and the vehicle's low-voltage load power supply circuit LV, eliminating the need for a separate low-voltage power supply for the new energy vehicle and reducing overall vehicle weight and cost. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of a power battery for a new energy vehicle provided in an embodiment of this application;

[0032] Figure 2 This is a schematic diagram of the structure of a new energy vehicle power battery provided in another embodiment of this application. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] The technical solution provided by this utility model takes into account the overall high and low voltage power supply system of the vehicle. Based on the requirements of low voltage power supply in terms of small size, light weight, long life and low cost, a new high and low voltage power supply solution is proposed. In this solution, the power battery of the new energy vehicle can provide high voltage power supply to the vehicle and low voltage power supply to the vehicle's low voltage load at the same time. Therefore, there is no need to configure a separate low voltage battery for the vehicle, which reduces the vehicle cost. Moreover, the lifespan of the low voltage battery is the same as that of the power battery, so users do not need to replace the low voltage battery frequently.

[0035] For details, see Figure 1 This application discloses a new energy vehicle power battery, which includes:

[0036] High-voltage power supply battery pack B, low-voltage power supply battery pack A, first DC-DC converter DC1 and first control switch S1;

[0037] Both the high-voltage power supply battery pack B and the low-voltage power supply battery pack A are composed of multiple cells connected in series and parallel. The cells in both packs can be lithium-ion cells, such as lithium iron phosphate (LiFePO4), ternary lithium (NCM / NCA), or lithium cobalt oxide (LiCoO2). The number of cells connected in series and parallel in both packs can be configured according to design requirements. To ensure the low-voltage power supply battery pack A can safely supply power to the low-voltage load power supply circuit LV, the terminal voltage of pack A must not exceed the maximum required voltage of the low-voltage load power supply circuit LV. Therefore, the number of cells connected in series and parallel in pack A can be configured based on this condition. Furthermore, since the power supply voltage of the vehicle-mounted high-voltage load power supply circuit HV in this scheme is mainly provided by the high-voltage power supply battery pack B, the terminal voltage of the high-voltage power supply battery pack B is greater than the terminal voltage of the low-voltage power supply battery pack A, and the number of cells connected in series and parallel in the high-voltage power supply battery pack B is greater than the number of cells connected in series and parallel in the low-voltage power supply battery pack A.

[0038] The first terminal of the high-voltage power supply battery pack B is connected to the high-voltage positive power supply node HV+, and the second terminal of the high-voltage power supply battery pack B is connected to the first terminal of the low-voltage power supply battery pack A. The high-voltage positive power supply node HV+ is connected to the vehicle-mounted high-voltage load power supply circuit HV. The high voltage at the first terminal of the high-voltage power supply battery pack B can be applied to the vehicle-mounted high-voltage load power supply circuit HV, which is connected to a high-voltage load on the new energy vehicle, such as a permanent magnet synchronous motor, a high-voltage power distribution unit (PDU), an electric compressor, a PTC heater, etc.

[0039] The input terminal of the first DC-DC converter DC1 is connected to the first terminal of the high-voltage power supply battery pack B through the first control switch S1, and the output terminal of the first DC-DC converter DC1 is connected to the first terminal / low-voltage positive power supply node LV+ of the low-voltage power supply battery pack A. The first control switch S1 is a high-voltage pull-in relay switch. When the first control switch S1 is closed, the high-voltage power supply battery pack B supplies power to the input terminal of the first DC-DC converter DC1. The first DC-DC converter DC1 is used to convert the high-voltage DC power output from the first terminal of the high-voltage power supply battery pack B into a low-voltage DC power of a target amplitude, and apply the low-voltage DC power to the vehicle low-voltage load power supply circuit LV. The vehicle low-voltage load power supply circuit LV is equipped with low-voltage loads, such as headlights, signal lights, interior lights, instrument panel, and audio system. The number of low-voltage loads in operation varies, and the voltage requirements of the vehicle low-voltage load power supply circuit LV vary. In order for the first DC-DC converter DC1 to input a voltage value that matches the required voltage on the vehicle low-voltage load power supply circuit LV, the target amplitude can be automatically adjusted according to the required voltage on the vehicle low-voltage load power supply circuit LV.

[0040] The first end of the low-voltage power supply battery pack A is connected to the low-voltage positive power supply node LV+ and the first end of the high-voltage power supply battery pack B through the first control switch S1. The second end of the low-voltage power supply battery pack A is connected to the high-voltage negative power supply node HV- and the negative low-voltage power supply node LV-. The high-voltage negative power supply node and the negative low-voltage power supply node are respectively connected to the low-voltage circuits of the vehicle high-voltage load power supply circuit HV and the vehicle low-voltage load power supply circuit LV.

[0041] In the above scheme, the high-voltage power supply battery pack B and the low-voltage power supply battery pack A are connected in series. When the power battery is working, the high-voltage power supply battery pack B and the low-voltage power supply battery pack A jointly supply power to the vehicle high-voltage load power supply circuit HV. When the first control switch S1 is closed, in addition to supplying power to the vehicle high-voltage load power supply circuit HV (which can be a high-voltage power supply circuit of various levels such as 400V or 800V), the high-voltage power supply battery pack B can also supply power to the vehicle low-voltage load power supply circuit LV (which can be a high-voltage power supply circuit of various levels such as 12V, 24V, or 48V) through the first DC-DC converter DC1. The high-voltage battery pack B supplies power to the input of the first DC-DC converter DC1, which converts the voltage to low voltage to power the vehicle's low-voltage load power supply circuit LV. Simultaneously, the low-voltage battery pack A also supplies power to the vehicle's low-voltage load power supply circuit LV. The terminal voltage of the low-voltage battery pack A matches the input voltage of the vehicle's low-voltage load power supply circuit LV. Therefore, the input power to the vehicle's low-voltage load power supply circuit LV includes the first DC-DC converter DC1 and the low-voltage battery pack A. Thus, in this solution, the power battery of the new energy vehicle can supply power to both the vehicle's high-voltage load power supply circuit and the vehicle's low-voltage load power supply circuit LV, eliminating the need for a separate low-voltage power supply for the new energy vehicle and reducing the overall vehicle weight and cost.

[0042] In the technical solution disclosed in this embodiment, considering that when the energy consumption of the power battery of the new energy vehicle is too high, the terminal voltage of the high-voltage power supply battery pack B and the low-voltage power supply battery pack A will be too low, and consequently, the output voltage provided by the first DC-DC converter DC1 and the low-voltage power supply battery pack A to the vehicle low-voltage load power supply circuit LV will also be too low. Therefore, the new energy vehicle power battery may be unable to provide the target voltage to the vehicle low-voltage load power supply circuit LV. Therefore, see... Figure 2 In this embodiment, the new energy vehicle power battery may further include a second DC-DC converter DC2; the input terminal of the second DC-DC converter DC2 is connected to the first terminal of the high-voltage power supply battery pack; the output terminal of the second DC-DC converter DC2 is connected to the low-voltage positive power supply node LV+. When the output capacity of the first DC-DC converter DC1 and the low-voltage power supply battery pack A is insufficient to provide the target voltage to the vehicle low-voltage load power supply circuit LV, the second DC-DC converter DC2 can be activated to compensate for the insufficient portion. The second DC-DC converter DC2 can also be a DC-DC converter with adjustable output voltage.

[0043] In the technical solution disclosed in this embodiment, the types of the first DC-DC converter DC1 and the second DC-DC converter DC2 can be selected according to design requirements. For example, the first DC-DC converter DC1 and the second DC-DC converter DC2 can be buck converters.

[0044] In the technical solution disclosed in this embodiment, the first DC-DC converter DC1 is a high-power DC-DC conversion circuit, and its output power as the main output DC-DC converter is greater than the output power of the second DC-DC converter DC2. In this solution, the output power of the first DC-DC converter DC1 and the second DC-DC converter DC2 can be selected according to design requirements. Both the output power of the first DC-DC converter DC1 and the second DC-DC converter DC2 can be fixed or adjustable. For example, the output power of the first DC-DC converter DC1 can be in the kilowatt (kW) range, and the first DC-DC converter DC1 serves as the main discharge DC-DC converter. The second DC-DC converter DC2 is a low-power DC-DC conversion circuit, and its output power can be selected according to design requirements. For example, the output power of the second DC-DC converter DC2 can be in the hectowatt (W) range, serving as an auxiliary discharge DC-DC converter.

[0045] In the technical solution disclosed in this embodiment, considering that the vehicle load requires a lower voltage when the vehicle enters a power-down sleep mode, the first DC-DC converter DC1 does not need to operate. At this time, the first control switch S1 can be opened, de-energizing the vehicle's high-voltage load power supply circuit HV, while the vehicle's low-voltage load power supply circuit LV is powered by the second DC-DC converter DC2. The first control switch S1 can respond to the vehicle entering the power-down sleep mode; that is, when the vehicle control system detects that the vehicle has entered the power-down sleep mode, it generates a control signal to open the first control switch S1. Therefore, when the vehicle enters the power-down sleep mode, the vehicle's low-voltage load power supply circuit LV is only powered by the second DC-DC converter DC2. At this time, it is also necessary to monitor the power demand of the entire vehicle load on the vehicle's low-voltage load power supply circuit LV. When the control system detects that the power demand of the entire vehicle load on the vehicle's low-voltage load power supply circuit LV exceeds the output capacity of the second DC-DC converter DC2, it generates a control signal to close the first control switch S1. At this time, the vehicle's low-voltage load power supply circuit LV is powered through the parallel connection of the first DC-DC converter DC1 and the second DC-DC converter DC2.

[0046] In the technical solution disclosed in this embodiment, a control switch for controlling whether the low-voltage battery pack A supplies power to the vehicle low-voltage load circuit LV can be provided between the low-voltage battery pack A and the low-voltage positive power supply node LV+. In this case, the user can choose whether to control the low-voltage battery pack A to supply power to the vehicle low-voltage load circuit LV according to their needs. For example, if the outputs of the first DC-DC converter DC1 and the second DC-DC converter DC2 can meet the needs of the vehicle low-voltage load circuit LV, the control switch is opened, and at this time, the low-voltage battery pack A does not need to supply power to the vehicle low-voltage load circuit LV. If the outputs of the first DC-DC converter DC1 and the second DC-DC converter DC2 cannot meet the needs of the vehicle low-voltage load circuit LV, the control switch is closed, and at this time, the first DC-DC converter DC1, the second DC-DC converter DC2, and the low-voltage battery pack A jointly supply power to the vehicle low-voltage load circuit LV.

[0047] In the technical solution disclosed in this embodiment, the above-mentioned new energy vehicle power battery further includes: a second control switch S2; the second control switch S2 is an output control switch for the first DC-DC converter DC1 and the second DC-DC converter DC2, and the second control switch S2 is disposed between the output terminal of the first DC-DC converter DC1, the output terminal of the second DC-DC converter DC2 and the first terminal of the low-voltage power supply battery pack A. The second control switch S2 can control whether the first DC-DC converter DC1 and the second DC-DC converter DC2 power the low-voltage load power supply circuit LV. When it is not necessary for the first DC-DC converter DC1 and the second DC-DC converter DC2 to power the low-voltage load power supply circuit LV, the second control switch S2 can be turned off.

[0048] In the technical solution disclosed in this embodiment, when the outputs of the first DC-DC converter DC1 and the second DC-DC converter DC2 cannot meet the requirements of the vehicle low-voltage load power supply circuit LV, the low-voltage power supply battery pack A can be controlled to discharge the low-voltage load power supply circuit LV. After the low-voltage power supply battery pack A discharges the low-voltage load power supply circuit LV, the discharge current on the low-voltage load power supply circuit LV is continuously monitored. When the discharge current on the low-voltage load power supply circuit LV is detected to be too large, the first DC-DC converter DC1 and the second DC-DC converter DC2 can be stopped from discharging the low-voltage load power supply circuit LV. That is, the external discharge of the second control switch S2 can be turned off, or the first control switch S1 can be turned off to stop the external discharge of the first DC-DC converter DC1. On the basis of providing sufficient power to the low-voltage load power supply circuit LV, the current on the low-voltage load power supply circuit LV is kept within a safe threshold range, thereby improving the power supply reliability of the low-voltage load power supply circuit LV.

[0049] In the above scheme, the first DC-DC converter DC1 and the second DC-DC converter DC2 can also balance the terminal voltages of the high-voltage battery pack B and the low-voltage battery pack A. For example, when the discharge capacity of the new energy vehicle's power battery decreases, the terminal voltages of both the high-voltage battery pack B and the low-voltage battery pack A decrease, resulting in a decrease in the voltage supplied to the vehicle's high-voltage load power supply circuit. If the difference between the high-voltage battery pack B and the low-voltage battery pack A meets the requirements, the first DC-DC converter DC1 and the second DC-DC converter DC2 do not need to provide additional charging for the low-voltage battery pack A. When the terminal voltage of the low-voltage battery pack A is lower than the terminal voltage of the high-voltage battery pack B, and the difference requirement is not met, the first DC-DC converter DC1 and the second DC-DC converter DC2 provide additional charging for the low-voltage battery pack A. If the terminal voltage of the low-voltage power supply battery pack A is higher than the terminal voltage of the high-voltage power supply battery pack B, and the difference requirement is not met, and the terminal voltage of the low-voltage power supply battery pack A is higher than the DC-DC output voltage (the voltage at the first terminal of the low-voltage power supply battery pack A is the voltage at the output of the first DC-DC converter DC1 and the second DC-DC converter DC2 connected in parallel), in order to maintain the terminal voltages of the low-voltage power supply battery pack A and the high-voltage power supply battery pack B being consistent, the second control switch S2 can be disconnected. At this time, the low-voltage power supply battery pack A is controlled to supply power to the low-voltage load power supply circuit LV alone. In addition to supplying the vehicle's high-voltage load power supply circuit HV in series with the high-voltage power supply battery pack B, the low-voltage power supply battery pack A also supplies power to the low-voltage load power supply circuit LV independently. This causes the terminal voltage of the low-voltage power supply battery pack A to drop rapidly until the terminal voltages of the high-voltage power supply battery pack B and the low-voltage power supply battery pack A meet the difference requirement, or the terminal voltage of the low-voltage power supply battery pack A is not higher than the DC-DC output voltage. At this point, the first DC-DC converter DC1 and the second DC-DC converter DC2 are controlled to participate in the low-voltage load power supply circuit LV.

[0050] In the technical solution disclosed in this embodiment, see [link to relevant documentation]. Figure 2 The new energy vehicle power battery also includes a third control switch S3, which is located between the second terminal of the high-voltage power supply battery pack B and the first terminal of the low-voltage power supply battery pack A. The high-voltage power supply battery pack B is connected in series with the low-voltage power supply battery pack A through the third control switch S3. When the high-voltage power supply battery pack B fails, the third control switch S3 can be controlled to disconnect. At this time, only the low-voltage power supply battery pack A discharges to maintain the low-voltage power supply of the low-voltage load power supply circuit LV, so that the low-voltage load power supply circuit LV can support the vehicle to park in its own lane, park on the side of the road, or drive to an after-sales service point for repair.

[0051] In the technical solution disclosed in this embodiment, in order to ensure that the vehicle has sufficient power to drive slowly when the third control switch S3 is turned off, the first DC-DC converter DC1 and the second DC-DC converter DC2 can be bidirectional DC-DC converters. When the third control switch S3 is turned off, the input and output terminals of the first DC-DC converter DC1 and the second DC-DC converter DC2 are switched. The first DC-DC converter DC1 and the second DC-DC converter DC2 boost the output voltage of the low-voltage power supply battery pack A and output the boosted voltage to the high-voltage positive power supply node HV+ for use by the vehicle motor, thereby enabling the vehicle to continue to drive slowly.

[0052] In the technical solution disclosed in this embodiment, to prevent the current in the low-voltage load power supply circuit LV from flowing back into the low-voltage power supply battery pack A, the above solution may further include a diode D1. The diode D1 is disposed between the first terminal of the low-voltage power supply battery pack A, the output terminals of the first DC-DC converter DC1 and the second DC-DC converter DC2, and the low-voltage positive power supply node LV+. The cathode of the diode D1 faces the low-voltage positive power supply node LV+, and the anode of the diode D1 faces the first terminal of the low-voltage power supply battery pack A. In this case, the reverse current in the low-voltage load power supply circuit LV will be cut off by the diode D1.

[0053] The outputs of the first DC-DC converter (DC1) and the second DC-DC converter (DC2) also act on the first terminal of the low-voltage battery pack A. If the output voltage of the first DC-DC converter (DC1) and the second DC-DC converter (DC2) is greater than the terminal voltage of the low-voltage battery pack A, the first DC-DC converter (DC1) and the second DC-DC converter (DC2) will charge the low-voltage battery pack A. This prevents a large difference in terminal voltage between the high-voltage battery pack B and the low-voltage battery pack A, which could lead to cell aging. Alternatively, if charging of the low-voltage battery pack A by the first DC-DC converter (DC1) and the second DC-DC converter (DC2) is not desired, a diode can be placed between the output terminals of the first DC-DC converter (DC1) and the second DC-DC converter (DC2) and the first terminal of the low-voltage battery pack A. The anode of the diode faces the first terminal of the low-voltage battery pack A, and the cathode of the diode faces the output terminals of the first DC-DC converter (DC1) and the second DC-DC converter (DC2).

[0054] In the technical solution disclosed in this embodiment, both the first DC-DC converter DC1 and the second DC-DC converter DC2 can be DC-DC converters with adjustable output. Users can automatically adjust the output of the first DC-DC converter DC1 and the second DC-DC converter according to the requirements of the vehicle low-voltage load power supply circuit LV.

[0055] This embodiment also discloses a new energy vehicle, including: any of the above-mentioned new energy vehicle power batteries, and a controller for controlling various control switches in the new energy vehicle power battery. The controller is used to control the conduction state of the first control switch S1, the second control switch S2, the third control switch S3 in the new energy vehicle power battery, and the control switch provided at the first end of the low-voltage power supply battery pack A, based on preset control logic.

[0056] In the technical solution disclosed in this embodiment, in order to facilitate the controller in understanding the terminal voltage of the high-voltage power supply battery pack B and the terminal voltage of the low-voltage power supply battery pack A, the above solution may further include a first voltage sensor and a second voltage sensor. The first voltage sensor and the second voltage sensor may be disposed inside the power battery. The first voltage sensor is used to detect the terminal voltage of the high-voltage power supply battery pack B; the second voltage sensor is used to detect the terminal voltage of the low-voltage power supply battery pack A; the output terminals of the first voltage sensor and the second voltage sensor are led out through the output node on the power battery and connected to the acquisition signal input terminal of the controller.

[0057] As can be seen from the above solutions, the high-voltage load power supply circuit HV and the low-voltage load power supply circuit LV share the same power battery, which does not increase the cost of the power battery, does not reduce the capacity of the power battery, and eliminates the need to configure a separate low-voltage battery for the vehicle. This can meet various application scenarios of low-voltage power supply, increase the interior space, reduce the weight and cost of the vehicle, improve the life of the low-voltage battery, and enhance the user experience.

[0058] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. Components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0059] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0060] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power battery for new energy vehicles, characterized in that, include: High-voltage power supply battery pack, low-voltage power supply battery pack, first DC-DC converter and first control switch; The first end of the high-voltage power supply battery pack is connected to the high-voltage positive power supply node, and the second end of the high-voltage power supply battery pack is connected to the first end of the low-voltage power supply battery pack. The input terminal of the first DC-DC converter is connected to the first terminal of the high-voltage power supply battery pack via the first control switch, and the output terminal of the first DC-DC converter is connected to the first terminal of the low-voltage power supply battery pack. The first end of the low-voltage power supply battery pack is connected to the low-voltage positive power supply node, and the second end of the low-voltage power supply battery pack is connected to the high-voltage negative power supply node and the negative low-voltage power supply node.

2. The new energy vehicle power battery according to claim 1, characterized in that, Also includes: Second DC-DC converter; The input terminal of the second DC-DC converter is connected to the first terminal of the high-voltage power supply battery pack; The output of the second DC-DC converter is connected to the low-voltage positive power supply node.

3. The new energy vehicle power battery according to claim 2, characterized in that, include: The output power of the first DC-DC converter is greater than that of the second DC-DC converter.

4. The new energy vehicle power battery according to claim 2, characterized in that, Also includes: Second control switch; The second control switch is located between the output terminal of the first DC-DC converter, the output terminal of the second DC-DC converter, and the first terminal of the low-voltage power supply battery pack.

5. The new energy vehicle power battery according to claim 1, characterized in that, Also includes: Third control switch; The third control switch is located between the second end of the high-voltage power supply battery pack and the first end of the low-voltage power supply battery pack.

6. The new energy vehicle power battery according to claim 1, characterized in that, The cells in the high-voltage power supply battery pack and the low-voltage power supply battery pack are lithium cells, which are either lithium iron phosphate cells or ternary lithium cells.

7. The new energy vehicle power battery according to claim 1, characterized in that, The number of cells in the high-voltage power supply battery pack is greater than the number of cells in the low-voltage power supply battery pack.

8. The new energy vehicle power battery according to claim 1, characterized in that, Also includes: A diode is disposed between the first terminal of the low-voltage power supply battery pack and the low-voltage positive power supply node.

9. A new energy vehicle, characterized in that, include: The new energy vehicle power battery according to any one of claims 1-8, and the controller for controlling each control switch in the new energy vehicle power battery.

10. The new energy vehicle according to claim 9, characterized in that, Also includes: First voltage sensor, second voltage sensor; The first voltage sensor is used to detect the terminal voltage of the high-voltage power supply battery pack; The second voltage sensor is used to detect the terminal voltage of the low-voltage power supply battery pack; The output terminals of the first voltage sensor and the second voltage sensor are connected to the acquisition signal input terminal of the controller.

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