阅读说明：本技术 车辆供电系统、方法和车辆 (Vehicle power supply system and method and vehicle ) 是由 王超 闫磊 张俊伟 陈定树 黄伟 于 2020-03-31 设计创作，主要内容包括：本申请公开了一种车辆供电系统、方法和车辆,其中,车辆供电系统包括：多个电池组,每个电池组包括串联的多个单体电芯；多个电压控制模块,每个电压控制模块与每个电池组一一对应连接,每个电压控制模块将与其对应连接的电池组的输出电压转化成第一目标电压,其中,每个电压控制模块的输入端与其对应的电池组的输出端连接,每个电压控制模块的输出端按照预设需求并联连接输出第二目标电压。该系统可以确保所有电芯均作为电压控制模块的输入来源,避免造成电芯一致性差异,将一个动力电池分成多个电池组,每个电池组串联一个电压控制模块,并将所有电压控制模块设计成并联输出结构,可以有效提升输出功率,满足多种负载功率需求。(The application discloses vehicle power supply system, method and vehicle, wherein, vehicle power supply system includes: a plurality of battery packs, each battery pack including a plurality of unit cells connected in series; the voltage control device comprises a plurality of voltage control modules, wherein each voltage control module is connected with each battery pack in a one-to-one correspondence mode, each voltage control module converts the output voltage of the battery pack connected correspondingly to the voltage control module into a first target voltage, the input end of each voltage control module is connected with the output end of the battery pack corresponding to the voltage control module, and the output end of each voltage control module is connected in parallel to output a second target voltage according to preset requirements. The system can ensure that all the battery cells are used as input sources of the voltage control modules, the consistency difference of the battery cells is avoided, one power battery is divided into a plurality of battery packs, each battery pack is connected with one voltage control module in series, all the voltage control modules are designed into a parallel output structure, the output power can be effectively improved, and the power requirements of various loads are met.)

1. A vehicle power supply system, characterized by comprising:

a plurality of battery packs, each of the battery packs including a plurality of unit cells connected in series;

the voltage control module is connected with each battery pack in a one-to-one correspondence mode, the voltage control module converts the output voltage of the battery pack connected with the voltage control module into a first target voltage, the input end of the voltage control module is connected with the output end of the battery pack corresponding to the voltage control module, and the output end of the voltage control module is connected in parallel to output a second target voltage according to a preset requirement.

2. The vehicle power supply system of claim 1, wherein the voltage control module comprises:

the battery cell sampling unit is respectively connected with the plurality of monomer battery cells and is used for respectively sampling the voltage of the plurality of monomer battery cells;

the input end of the high-low voltage conversion unit is connected with the output end of the corresponding battery pack, and the high-low voltage conversion unit is used for converting the output voltage of the battery pack correspondingly connected with the high-low voltage conversion unit into a first target voltage.

3. The vehicle power supply system of claim 2, wherein the voltage control module further comprises:

the control unit is respectively connected with the electric core sampling unit and the high-low voltage conversion unit, and is used for controlling the electric core sampling unit and the high-low voltage conversion unit.

4. The vehicle power supply system according to claim 2, characterized by further comprising:

the control module is respectively connected with the cell sampling unit and the high-low voltage conversion unit in each voltage control module, and the control module is used for respectively controlling the cell sampling unit and the high-low voltage conversion unit in each voltage control module.

5. The vehicle power supply system according to any one of claims 2 to 4, wherein the high-low voltage conversion unit is an isolated conversion unit or a non-isolated conversion unit.

6. The vehicle power supply system according to any one of claim 5, wherein the isolated conversion unit includes: a transformer, a first power switch tube and a second power switch tube, wherein,

the first power switch tube is connected in series between the input end of the transformer and the output end of the battery pack correspondingly connected with the isolated conversion unit, and the second power switch tube is connected in series between the output end of the transformer and the input end of the low-voltage system of the whole vehicle.

7. A control method for use on a vehicle electric power supply system according to any one of claims 1 to 6, characterized by comprising:

detecting the parallel output voltage of the voltage control module in real time;

calculating a first difference between the detected parallel output voltage and a second target voltage;

and performing closed-loop control on a first power switch tube and a second power switch tube in a high-low voltage conversion unit in the voltage control module according to the first difference value so as to adjust the parallel output voltage of the voltage control module.

8. The method of claim 7, wherein performing closed-loop control on a first power switch tube and a second power switch tube in a high-low voltage conversion unit in the voltage control module according to the first difference value to adjust the parallel output voltage of the voltage control module comprises:

and if the absolute value of the first difference is larger than a first threshold, adjusting the duty ratio and/or the switching frequency of a first power switching tube and a second power switching tube in a high-low voltage conversion unit in the voltage control module to adjust the parallel output voltage of the voltage control module.

9. The method of claim 7, further comprising:

acquiring the voltage of a monomer battery cell in each battery pack in real time;

calculating the average voltage value of each battery pack according to the voltage of the single battery cells in each battery pack;

and if the absolute value of the difference between the voltage of the monomer electric core in each battery pack and the voltage average value of each battery pack is greater than a second threshold, determining that the monomer electric core corresponding to the difference is capacity attenuation, and performing power-limited charging and discharging protection on the capacity-attenuated monomer electric core.

10. The method of claim 7, further comprising:

when a plurality of battery packs provide low-voltage power supply for a whole vehicle low-voltage system, if the cell sampling unit detects that the voltage of the single cell is less than a third target voltage, the high-low voltage conversion unit, where the cell of which the voltage is less than the third target voltage is located, is correspondingly connected to the battery packs, so as to reduce the discharge output power of the battery packs.

11. A vehicle, characterized by comprising: the vehicle power supply system according to any one of claims 1 to 6.

Technical Field

The application relates to the technical field of vehicles, in particular to a vehicle power supply system, a vehicle power supply method and a vehicle.

Background

With the popularization of new energy vehicles (mainly hybrid electric vehicles and pure electric vehicles with the working voltage of B-level voltage), the economy and reliability of the new energy vehicles are more and more emphasized. When the new energy vehicle is placed for a long time, the electricity shortage of the low-voltage power supply storage battery in the vehicle is a common fault, so that the whole vehicle is easily broken down, and the user experience is reduced; in addition, after the vehicle is started, low voltage needs to be provided through the high-low voltage conversion unit, and in the process that the module converts high voltage into low voltage (such as 12-14V), the loss of the battery pack is large, so that the weight of the whole vehicle system is increased, and the power density of the whole high voltage system is reduced.

In the related technology, in order to reduce the weight of the whole vehicle, increase the endurance mileage and improve the power density of the whole vehicle, the first mode is to remove the low-voltage power supply battery of the vehicle and supply power to the low-voltage control system circuit through a simple high-voltage to low-voltage low-power-consumption voltage reduction and voltage stabilization circuit module, namely, low-voltage equipment supplies power through a high-voltage and low-voltage conversion unit; the second mode is that a high-voltage battery pack in a vehicle power supply system is formed by sequentially connecting a plurality of single batteries in series, a 48V voltage tap and a 12V voltage tap are arranged between the single batteries, and a relay is controlled according to load requirements to get electricity.

However, the first method has the problems that the difference between the input voltage and the output voltage of the high-low voltage conversion unit is too large, the input voltage exceeds the B-level safety voltage, the transformer has large volume, poor efficiency, high loss and large static power consumption, and the service life of the power battery and the service life of the direct-current power supply can be reduced after long-time use; in the second mode, all the battery cells cannot be guaranteed to be used for load power supply, imbalance of the single battery cells can be caused after long-time use, the service life of the power battery is influenced, and potential safety hazards easily exist in the charging and discharging processes of the power battery; moreover, if the relay module for controlling the load to supply power is sintered in the use process, part of power batteries supply power for the load for a long time, the consistency of local battery cores is easy to deteriorate, and if the load needs a higher voltage platform, the electric shock risk is easy to occur.

Disclosure of Invention

The object of the present application is to solve at least to some extent one of the above mentioned technical problems.

Therefore, a first objective of the present application is to provide a vehicle power supply system, which can ensure that all battery cells are used as input sources of voltage control modules, avoid causing a difference in battery cell consistency, divide a power battery into a plurality of battery packs, connect each battery pack in series with one voltage control module, and design all voltage control modules into a parallel output structure, so as to effectively improve output power and meet various load power requirements.

A second object of the present application is to propose a control method for a vehicle electrical supply system.

A third object of the present application is to propose a vehicle.

To achieve the above object, an embodiment of a first aspect of the present application provides a vehicle power supply system, including: a plurality of battery packs, each of the battery packs including a plurality of unit cells connected in series; the voltage control module is connected with each battery pack in a one-to-one correspondence mode, the voltage control module converts the output voltage of the battery pack connected with the voltage control module into a first target voltage, the input end of the voltage control module is connected with the output end of the battery pack corresponding to the voltage control module, and the output end of the voltage control module is connected in parallel to output a second target voltage according to a preset requirement.

According to the vehicle power supply system, a plurality of battery packs are arranged, and each battery pack comprises a plurality of monomer battery cores which are connected in series; the system comprises a plurality of voltage control modules, a plurality of battery packs and a plurality of battery packs, wherein the voltage control modules are connected with the battery packs in a one-to-one correspondence manner, each voltage control module converts the output voltage of the battery pack correspondingly connected with the voltage control module into a first target voltage, the input end of each voltage control module is connected with the output end of the battery pack correspondingly connected with the voltage control module, and the output end of each voltage control module is connected with a second target voltage (such as a low voltage) in parallel according to a preset requirement; in addition, one power battery is divided into a plurality of battery packs, each battery pack is connected with one voltage control module in series, and all the voltage control modules are designed into a parallel output structure, so that the output power can be effectively improved, and various load power requirements are met.

To achieve the above object, a second embodiment of the present application provides a control method for a vehicle power supply system according to the first embodiment of the present application, the method including: detecting the parallel output voltage of the voltage control module in real time; calculating a first difference between the detected parallel output voltage and a second target voltage; and performing closed-loop control on a first power switch tube and a second power switch tube in a high-low voltage conversion unit in the voltage control module according to the first difference value so as to adjust the parallel output voltage of the voltage control module.

According to the control method for the vehicle power supply system, the parallel output voltage of the voltage control module is detected in real time; calculating a first difference between the detected parallel output voltage and a second target voltage; according to the first difference value, the first power switch tube and the second power switch tube in the high-low voltage conversion unit in the voltage control module are subjected to closed-loop control to adjust the parallel output voltage of the voltage control modules, the method detects the parallel output voltage of the voltage control modules in real time, compares the output voltage with a target voltage, and adjusts the parallel output voltage of the voltage control modules according to a comparison result, so that the parallel output voltage of the voltage control modules can be effectively adjusted, the output voltage of each voltage control module can be controlled within a certain range, the discharge capacity of the battery cell of the battery pack can be kept consistent, and the consistency difference of the battery cells is avoided.

To achieve the above object, an embodiment of a third aspect of the present application proposes a vehicle including: the vehicle power supply system of the embodiment of the first aspect of the application.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic block diagram of a vehicle power supply system according to one embodiment of the present application;

FIG. 2 is an enlarged view of a portion of FIG. 1;

FIG. 3 is a schematic structural diagram of an isolated conversion unit according to an embodiment of the present application;

fig. 4 is a flowchart illustrating a control method for a vehicle power supply system according to an embodiment of the present application.

Reference numerals:

100: a vehicle power supply system; 110: a battery pack; 120: a voltage control module; 111: the output positive electrode of the high-voltage power battery; 112: the output negative electrode of the high-voltage power battery; 121: all the voltage control modules output positive poles; 122: all low-voltage systems output negative electrodes; 200: a voltage control module; 201: a cell sampling unit; 202: a high-low voltage conversion unit; 109: a single cell; 310: a transformer; 320: a first power switch tube; 330: a second power switch tube; 203: a control unit.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Fig. 1 is a schematic structural diagram of a vehicle power supply system according to an embodiment of the present application.

As shown in fig. 1, the vehicle power supply system 100 may include: a plurality of battery packs 110 and a plurality of voltage control modules 120. Each battery pack 110 may include a plurality of unit cells connected in series. Each voltage control module 120 is connected to each battery pack 110 in a one-to-one correspondence manner, wherein an input end of each voltage control module 120 is connected to an output end of the corresponding battery pack 110, each voltage control module 120 can convert an output voltage of the corresponding battery pack 110 into a first target voltage, an input end of each voltage control module 120 is connected to an output end of the corresponding battery pack 110, and an output end of each voltage control module 120 can be connected in parallel to output a second target voltage according to a preset requirement.

As an example, the voltage control module implements the purpose of converting the high voltage output by the battery pack into the low voltage to supply power to the low-voltage system of the whole vehicle. For example, the second target voltage may be a low voltage, for example, the output ends of the plurality of voltage control modules may be connected in parallel to the input end of the entire vehicle low-voltage system according to a preset requirement, so as to output the second target voltage to the entire vehicle low-voltage system, so as to implement power supply of the entire vehicle low-voltage system based on the voltage control modules through the high-voltage power battery, and a low-voltage power supply battery does not need to be configured in the vehicle.

In the embodiment of the present application, the power battery formed by the plurality of battery packs 110 may be a high voltage power battery. The high-voltage power battery is divided into a plurality of battery packs, each battery pack is connected with one voltage control module 120 in series, the voltage control modules convert the output voltage of the battery packs 110 connected with the voltage control modules in series into low voltage, and the output ends of all the voltage control modules 120 are connected to a low-voltage system of the whole vehicle in parallel to supply power. Wherein 111 in fig. 1 can be an output positive electrode of the power battery, and 112 is an output negative electrode of the power battery; 121 may be the positive output of all voltage control modules 120 and 122 the negative output of all voltage control modules. Therefore, by adopting a mode of parallel output of a plurality of groups of voltage control modules, the output power of the voltage control modules can be effectively improved, and various load power requirements are met.

It is worth noting that the output ends of all the voltage control modules can be connected to the input end of the whole vehicle low-voltage system in parallel. Or, the output ends of the voltage control modules may be selected according to a preset requirement, for example, the output ends of the voltage control modules to be connected in parallel are connected in parallel to the input end of the low-voltage system of the entire vehicle.

It is understood that the high-voltage power battery serves as a power source of the voltage control module of the new energy automobile. Under the conditions of an OFF gear and a vehicle dormancy of the new energy automobile, the utilization rate of the power battery of the new energy automobile can be increased by reasonably using the energy stored by the power battery, and the power battery has the function of starting the battery at low voltage on the basis of not increasing the cost and lightening the weight.

In one embodiment of the present application, as shown in fig. 2, each voltage control module 200 may include: a cell sampling unit 201 and a high-low voltage conversion unit 202. The cell sampling unit 201 is connected to the plurality of cell 109. The input terminal of the high-low voltage conversion unit 202 is connected to the output terminal of the battery pack 110 corresponding thereto.

Specifically, the cell sampling unit 201 may be configured to perform voltage sampling on a plurality of individual cells 109 respectively; the high-low voltage conversion unit 202 may be used to convert the output voltage of the battery pack 110 connected corresponding thereto into a first target voltage.

That is to say, a plurality of battery cells 109 are connected in series as an input of the voltage control module 200, the cell sampling unit 201 in the voltage control module 200 samples voltages of the plurality of battery cells 109, and an input end of the high-low voltage conversion unit 202 in the voltage control module 200 is connected to an output end of the battery pack corresponding thereto, so as to convert an output voltage of the battery pack connected corresponding thereto into a low voltage. And then, the output ends of all the voltage control modules are connected to the input end of the low-voltage system of the whole vehicle in parallel, so that the low-voltage power consumption requirement of the whole vehicle can be met.

It should be noted that, in the embodiment of the present application, the input voltage level of a single voltage control module may be determined according to the sampling capability of the electrical core sampling unit, which may avoid waste of the sampling interface of the electrical core sampling unit, and save cost. For example, the cell sampling unit has 8 interfaces that can provide single cell sampling, and then 8 single cells can be set to share one low-voltage power supply system, thereby avoiding interface waste. In practical application, the sampling capability of the cell sampling unit, the cost of the high-low voltage conversion unit and the conversion power loss are considered in a balanced manner in consideration of the cost of the high-low voltage conversion unit.

It should be understood that, in fig. 1, the connection line between the positive output pole 111 and the negative output pole 112 of the power battery may represent a high-voltage power line bundle, and the other line is a low-voltage power supply line bundle. If the voltage control module directly gets power from the interior of the power battery, the power battery is converted into low voltage (for example, 500V-12V) through the high-low voltage conversion unit, but the high-low voltage conversion unit directly converts the high voltage of the power battery into the low voltage, so that the input bus voltage (500V) of the power battery exceeds the minimum value of the B-level safety voltage and is not within the safety voltage range. In the embodiment of the application, although the voltage control module obtains electricity inside the power battery, the voltage control module sets a plurality of monomer battery cores to share one battery core sampling unit and one high-low voltage conversion unit according to requirements, the battery core sampling unit is used for respectively sampling the voltage of the plurality of monomer battery cores, the input end of the high-low voltage conversion unit is connected with the output end of a battery pack formed by connecting the plurality of corresponding monomer battery cores in series, and the output voltage of the battery pack is converted into the low voltage, so that the input voltage of each single high-low voltage conversion unit is ensured to be below the level-B safe voltage, for example, the input voltage of the high-low voltage conversion unit is controlled to be below 60V in a direct current environment; for another example, in an ac environment, the input voltage of the high-low voltage conversion unit is controlled below 30V to ensure the safety of the high-low voltage conversion unit. Wherein, the class B voltage generally means that the maximum working voltage is greater than 30Vac and less than or equal to 1000Vac, or greater than 60Vdc and less than or equal to 1500 Vdc.

For example, if the high-low voltage conversion of 500V to 12V is to be realized, that is, 12V low voltage and 150A current need to be output, the present application may directly take electricity from the single battery cells, and set a plurality of single battery cells in each battery pack to share one cell sampling unit and 60V to 12V high-low voltage conversion units, and connect a plurality of 60V to 12V high-low voltage conversion units in parallel, so that the total voltage output by all the single battery cells is 12V and the total current is 150A. Therefore, each single battery cell outputs 30-50V of voltage to the high-low voltage conversion unit, and the input bus voltage is 30-50V, so that all power transmission lines are safe voltage below B level.

It should be noted that the cell sampling unit can monitor the cell voltage in real time and provide the voltage to the high-low voltage conversion unit, the high-low voltage conversion unit performs isolated voltage reduction and voltage stabilization, and the parallel connection of all low-voltage power supply systems is adopted to meet the load power requirement, and meanwhile, all cells are input as the voltage control module, so that the cell consistency difference can be avoided on the premise of realizing isolation of the high-low voltage conversion unit.

In an example of one possible implementation of the present application, the high-low voltage converting unit 202 may be an isolated converting unit. In this embodiment, as shown in fig. 3, the isolated converting unit may include: transformer 310, first power switch tube 320 and second power switch tube 330. The first power switch tube 320 is connected in series between the input end of the transformer 310 and the output end of the battery pack correspondingly connected to the isolated conversion unit, and the second power switch tube 330 is connected in series between the output end of the transformer 310 and the input end of the low voltage system of the whole vehicle. It should be noted that the voltage control module can implement voltage sampling, high-low voltage conversion, and the like. The transformer can be an isolation transformer, and the high-low voltage conversion unit formed by the transformer is the isolation conversion unit. Alternatively, when the transformer is an isolation type transformer, the function of isolating a high-voltage system from a low-voltage system can be realized. It can be understood that the transformer may also be a non-isolated transformer, and the high-low voltage conversion unit formed by the non-isolated transformer is a non-isolated conversion unit.

As an example, the first power switch 320 and the second power switch 330 may be, but are not limited to, Metal-Oxide-Semiconductor Field Effect transistors (MOSFET), Insulated Gate Bipolar Transistors (IGBT), thyristors, and contactors.

In order to optimize the layout space, in this embodiment of the application, a voltage detection circuit of a transformer in the high-low voltage conversion unit may be replaced by a sampling circuit in the battery cell sampling unit, a sampling circuit for a single battery cell inside a battery in the battery cell sampling unit is integrated with the high-low voltage conversion unit, and the battery cell sampling unit and the high-low voltage conversion unit are integrated and then integrally arranged inside the battery pack, so that the layout space may be optimized.

In order to better maintain the normal output of the voltage, in the embodiment of the present application, the voltage control module may be controlled. As an example, as shown in fig. 2, each voltage control module 200 may further include: a control unit 203.

The control unit 203 and the control unit 203 are respectively connected with the cell sampling unit 201 and the high-low voltage conversion unit 202, and the control unit 203 is used for controlling the cell sampling unit 201 and the high-low voltage conversion unit 202.

That is to say, in order to save the whole arrangement space, the cell sampling Unit and the high-low voltage conversion Unit in each voltage control module may share one control Unit, for example, an MCU (micro controller Unit), and a plurality of low-voltage control and power supply circuits such as AD (analog-digital) conversion, crystal oscillator, reset, power supply, and filtering may be omitted.

As another example, the vehicle power supply system may further include: and a control module. The control module is respectively connected with the cell sampling unit and the high-low voltage conversion unit in each voltage control module, and the control module is used for respectively controlling the cell sampling unit and the high-low voltage conversion unit in each voltage control module.

That is to say, under the condition that the processing capacity of the control module can satisfy the control of the cell sampling units and the high-low voltage conversion units in the plurality of voltage control modules, the cell sampling units and the high-low voltage conversion units in the plurality of voltage control modules are connected, and can share one control module for control, thereby being convenient for saving the whole arrangement space.

In the embodiment of the application, the normal output of the voltage is maintained by controlling the operation of the first power switch tube and the second power switch tube, and the new energy power supply system has a lower voltage platform, does not need to adopt a product with higher power and withstand voltage level, has less heat dissipation capacity, and has smaller switching-on and switching-off losses of the power switch tubes under the condition of passing through lower level voltage and current according to withstand voltage and current characteristics of the power switch tubes, so that the system efficiency can be further improved; adopt isolated transformer to realize high low pressure and keep apart, when avoiding power battery high voltage system to appear unusually, can in time protect low voltage system, at present, new forms of energy vehicle most have the insulation monitoring function, if do not adopt isolated transformer product, probably influence the insulation monitoring precision, cause the monitoring result deviation great. If the new energy vehicle has a high-voltage system leakage situation, the insulation monitoring system may not respond in time to process, and thus an electric shock safety risk is caused.

According to the vehicle power supply system, a plurality of battery packs are arranged, and each battery pack comprises a plurality of monomer battery cores which are connected in series; the voltage control module comprises a plurality of voltage control modules, each voltage control module is connected with each battery pack in a one-to-one correspondence mode, each voltage control module converts the output voltage of the battery pack connected correspondingly to the voltage control module into a first target voltage, wherein the input end of each voltage control module is connected with the output end of the corresponding battery pack, and the output end of each voltage control module is connected with a second target voltage (such as a low voltage) in parallel, for example, the output ends of the voltage control modules can be connected with the input end of a low voltage system of the whole vehicle in parallel according to preset requirements. The vehicle power supply system can save a low-voltage starting battery and a high-low voltage (such as 500V-12V) direct current high-power conversion module of a new energy vehicle on the physical structure, reduce high-low voltage conversion loss, well solve the problem of power shortage of the starting battery of the new energy vehicle, greatly reduce cost, place a plurality of high-low voltage conversion units in a power battery, save front cabin space, avoid independently arranging the high-low voltage conversion units, eliminate complex structures such as an assembled metal shell, a connector, a high-voltage wiring harness, a mark and the like, improve the space utilization rate of the new energy vehicle, reduce weight, ensure that all battery cores are used as input sources of a voltage control module, avoid causing battery core consistency difference, bring great convenience and safety for vehicle users, and effectively improve output power by a parallel output structure on the basis of not exceeding a B-level safe voltage level, and various load power requirements are met.

The embodiment of the application also provides a control method of the vehicle power supply system. It should be noted that the control method according to the embodiment of the present application may be applied to the vehicle power supply system according to any one of the embodiments of fig. 1 to 3.

As shown in fig. 4, the specific implementation process is as follows:

step 401, detecting the parallel output voltage of the voltage control module in real time.

In step 402, a first difference between the detected parallel output voltage and a second target voltage is calculated.

In the embodiment of the application, the parallel output voltage of the voltage control module is detected in real time, the detected parallel output voltage is subjected to phase difference with a preset second target voltage, and the difference value is used as a first difference value.

And step 403, performing closed-loop control on a first power switch tube and a second power switch tube in the high-low voltage conversion unit in the voltage control module according to the first difference value to adjust the parallel output voltage of the voltage control module.

Optionally, if the first difference is a positive value and the difference is greater than a first threshold, adjusting duty ratios and/or switching frequencies of first power switching tubes and second power switching tubes in the high-low voltage conversion units in the plurality of voltage control modules to reduce parallel output voltages of the plurality of voltage control modules; if the first difference is a negative value and the absolute value of the difference is greater than the first threshold, the duty ratio and/or the switching frequency of a first power switching tube and a second power switching tube in the high-low voltage conversion unit in the plurality of voltage control modules are adjusted to increase the parallel output voltage of the plurality of voltage control modules. The first threshold is a fault-tolerant value of the fluctuation of the target voltage.

That is, when the first difference is a positive value and the difference is greater than the first threshold, the duty ratio and/or the switching frequency of the first power switching tube and the second power switching tube in the high-low voltage conversion unit in the plurality of voltage control modules are adjusted to reduce the parallel output voltage of the plurality of voltage control modules; when the first difference is a positive value and the difference is less than or equal to the first threshold, the duty ratio and/or the switching frequency of the first power switching tube and the second power switching tube in the high-low voltage conversion unit in the plurality of voltage control modules are not adjusted.

When the first difference is a negative value and the absolute value of the difference is greater than the first threshold, the parallel output voltages of the voltage control modules are increased by adjusting the duty ratios and/or the switching frequencies of the first power switching tube and the second power switching tube in the high-low voltage conversion unit in the voltage control modules. When the first difference is a negative value and the absolute value of the difference is less than or equal to the first threshold, the duty ratios and/or the switching frequencies of the first power switching tube and the second power switching tube in the high-low voltage conversion unit in the plurality of voltage control modules are not adjusted.

Optionally, when a plurality of battery packs are in a charging or discharging working condition, acquiring the voltage of a single battery cell in each battery pack in real time in order to protect the charging and discharging processes of the battery; calculating the average voltage value of each battery pack according to the voltage of the single battery cell in each battery pack; and if the absolute value of the difference between the voltage of the monomer electric core in each battery pack and the average voltage value of each battery pack is greater than a second threshold, determining that the monomer electric core corresponding to the difference is capacity attenuation, and performing power-limited charging and discharging protection on the monomer electric core with the capacity attenuation.

That is to say, when a plurality of battery packs are in a charging or discharging condition, the voltage of a monomer cell in each battery pack can be collected in real time, and the voltage average value of each battery pack (for example, the average value of the voltage of N battery cells) is calculated according to the voltage of the monomer cell in each battery pack, and then, the voltage of the monomer cell in each battery pack is different from the voltage average value of each battery pack, and the difference value is used as a second difference value; and if the second difference is larger than the second threshold, judging that the single battery cell corresponding to the difference is capacity attenuation, and performing power-limited charge-discharge protection on the capacity-attenuated single battery cell.

In an embodiment of this application, when a plurality of groups of batteries provide the low pressure power supply for whole car low voltage system, if the voltage that electric core sampling unit detected monomer electricity core is less than third target voltage, then the regulation voltage is less than the high-low voltage conversion unit that the group of battery that monomer electricity core place of third target voltage corresponds the connection reduces the output of discharging of group of batteries avoids producing the condition that monomer electricity core is overdischarged.

That is to say, in order to ensure that the charging of the battery can achieve the equalizing effect and avoid the occurrence of the overcharge of the single battery cell, in the embodiment of the present application, the battery cell sampling unit performs the voltage equalization processing in the battery voltage sampling process, for example, in the charging process of the power battery, if the battery cell sampling unit detects that the voltage of the single battery cell of the power battery is too high, the charging power of the single battery cell can be limited, and the normal charging of the remaining battery cells can be maintained; if the cell sampling unit detects that the voltage of the single cell or a plurality of cells is too low, the low-voltage control module can change the switching frequency of the loop to reduce the discharge output power of the loop, so that the condition of over-discharge of the single cell is avoided.

According to the control method for the vehicle power supply system, the parallel output voltage of the voltage control module is detected in real time; calculating a first difference between the detected parallel output voltage and a second target voltage; according to the first difference value, performing closed-loop control on a first power switch tube and a second power switch tube in a high-low voltage conversion unit in the voltage control modules to adjust the parallel output voltage of the voltage control modules, detecting the parallel output voltage of the voltage control modules in real time, comparing the output voltage with a target voltage, and adjusting the parallel output voltage of the voltage control modules according to a comparison result, so that the parallel output voltage of the voltage control modules can be effectively adjusted, the output voltage of each voltage control module can be controlled within a certain range, the discharge capacity of the battery cell of the battery pack can be kept consistent, and the consistency difference of the battery cells can be avoided.

In order to implement the above embodiments, the present application also proposes a vehicle, which may include the vehicle power supply system described in the embodiment of fig. 1 to 3.

In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing steps of a custom logic function or process, and alternate implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.

The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.