WO2019042353A1

WO2019042353A1 - Battery equalization system, vehicle, battery equalization method, and storage medium

Info

Publication number: WO2019042353A1
Application number: PCT/CN2018/103246
Authority: WO
Inventors: 罗红斌; 王超; 沈晓峰; 曾求勇
Original assignee: 比亚迪股份有限公司
Priority date: 2017-08-31
Filing date: 2018-08-30
Publication date: 2019-03-07
Also published as: CN110015130B; CN110015130A

Abstract

A battery equalization system, comprising acquisition circuits (12), equalization circuits (13), and controllers (14). Each controller (14) is connected, by means of one control channel (140), to the acquisition circuit (12) and the equalization circuit (13) corresponding to the same cell in a battery pack, and the control channel (140) is multiplexed by the acquisition circuit (12) and the equalization circuit (13) by time; when the acquisition circuits (12) need to acquire parameter information of the cells in the battery pack, the equalization circuits (13) are in an ON state; when the equalization circuits (13) need to equalize the cells in the battery pack, the acquisition circuits (12) are in a short-circuit state. One channel is multiplexed by the controller (14) and the voltage sampling circuit and the equalization circuit of each cell by time, so as to reduce the requirements for the number of channels of the controller, thereby reducing hardware costs; moreover, because battery sampling and equalization are performed separately, equalizing current does not affect a battery voltage, thereby improving battery voltage sampling precision. Also provided are a vehicle, a battery equalization method, and a storage medium.

Description

Battery equalization system, vehicle, battery equalization method and storage medium

Cross-reference to related applications

The present disclosure claims the priority of the Chinese patent application No. "201710776103.0" filed on August 31, 2017 by BYD Co., Ltd., entitled "Battery equalization system, vehicle, battery equalization method and storage medium".

Technical field

The present disclosure relates to the field of battery pack equalization, and in particular to a battery equalization system, a vehicle, a battery equalization method, and a storage medium.

Background technique

In electric vehicles, battery packs are an important part of it. Since the battery pack is formed by connecting a plurality of single cells in series, the difference between the cells in the battery pack gradually increases with the use of the battery, resulting in poor consistency between the battery cells. Due to the short board effect of the battery, the battery pack capacity cannot be fully utilized, resulting in a decrease in the overall capacity of the battery pack. Therefore, effective balancing management of the battery pack of the electric vehicle is beneficial to improving the consistency of each unit battery in the battery pack, reducing the capacity loss of the battery, prolonging the service life of the battery and the driving range of the electric vehicle. significance.

In the related equalization technology, the battery equalization system generally includes: a battery management controller and a plurality of battery information collectors, wherein each battery information collector includes three modules: a control unit, a battery sampling circuit, and a battery equalization circuit. And the battery sampling circuit and the battery equalization circuit respectively apply different channels. Each cell of the battery pack is provided with a battery detection circuit channel and a battery equalization circuit channel. The workflow is as follows: the battery sampling circuit is responsible for real-time sampling of the battery voltage information, the control unit of the battery information collector sends battery sampling information to the battery management controller, and the battery management controller determines whether it is necessary to turn on the equalization, and then to the battery information collector. The control unit sends an equalization command, and the control unit of the battery information collector controls the battery equalization circuit to turn on the equalization.

In the practical application of the related equalization technology, since a control channel is required between the control unit and the voltage sampling circuit and the equalization circuit of each unit cell, the number of channels of the controller is increased, resulting in high hardware cost; Since battery sampling and equalization are performed simultaneously, the equalization current affects the battery voltage, which affects the accuracy of battery voltage sampling.

Summary of the invention

An object of the present disclosure is to provide a battery equalization system, a vehicle, a battery equalization method, and a storage medium for solving the technical problem of high hardware cost of the battery equalization system in the related art.

In order to achieve the above object, the present disclosure provides a battery equalization system including an acquisition circuit, an equalization circuit, and a controller; wherein the controller passes through a control channel and an acquisition circuit and an equalization circuit corresponding to the same single cell in the battery pack. Connecting, the collecting circuit and the equalizing circuit time-multiplexing the control channel;

The collecting circuit is configured to collect parameter information of the single battery in the battery group; when the collecting circuit needs to collect parameter information of the single battery in the battery group, the equalizing circuit is in an on state;

The equalization circuit is configured to perform equalization processing on the single cells in the battery pack; when the equalization circuit needs to perform equalization processing on the single cells in the battery pack, the acquisition circuit is in a short circuit state;

The controller is configured to control the equalization circuit to perform equalization processing on the single-cell that needs to be turned on when determining that a single battery in the battery pack needs to be turned on according to parameter information of the battery pack.

Optionally, the equalization circuit is respectively connected to the corresponding single cell through the first equalization branch and the second equalization branch, and one ends of the first equalization branch and the second equalization branch are respectively connected to the Two poles of the single battery; the first equalizing branch and the other end of the second equalizing branch are connected between the collecting circuit and the equalizing circuit;

When the collecting circuit needs to collect parameter information of the single battery in the battery pack, the first equalizing branch is disconnected and the second equalizing branch is turned on;

When the equalization circuit needs to perform equalization processing on the single cells in the battery pack, the first equalization branch and the second equalization branch corresponding to the single battery are turned on.

Optionally, the second equalization branch is maintained in an on state, and the first equalization branch is provided with a first switch; when the collection circuit needs to collect parameter information of a single battery in the battery group, the A switch is turned off; when the equalization circuit performs equalization processing on the single cell that needs to be turned on, the first switch of the first equalization branch corresponding to the single cell is closed.

Optionally, the controller is further configured to control, according to the target equalization duration and the equalization duty ratio of the unit that needs to be turned on by the parameter information of the battery pack, to control the equalization circuit to open the required The equalized single cell performs equalization processing, and the equalization duty ratio is a ratio of a duration occupied by the equalization circuit occupying the control channel to a total duration occupied by the control channel.

Optionally, the controller is further configured to determine an equalization period and an acquisition period according to the target equalization duration and the equalization duty ratio, where the sum of the equalization period and the collection period is equal to the control The total duration of the channel being occupied; in the equalization period, the control channel is connected to the equalization circuit, so that the equalization circuit performs equalization processing on the single cells in the battery pack; during the acquisition period The control channel is connected to the acquisition circuit, so that the acquisition circuit collects parameter information of the battery pack.

Optionally, the controller is configured to obtain, by using the following manner, a target equalization duration of the single battery that needs to be turned on:

Determining, according to the parameter information of the battery pack collected by the collecting circuit, whether a single battery needs to be turned on in the battery pack;

When it is determined that a single battery in the battery pack needs to be turned on, the target equalization time of the single battery that needs to be turned on is calculated according to the parameter information of the battery.

Optionally, when the single battery in the battery pack does not need to perform equalization processing, the collecting circuit of the single battery is connected to the controller through the corresponding control channel.

Optionally, the controller is further configured to control the equalization circuit to discharge the single battery when a difference between a cell voltage and a minimum voltage in each of the cells is greater than a preset voltage difference threshold.

Optionally, the controller is further configured to control the equalization circuit to charge the single battery when a difference between a voltage of the single battery and a maximum voltage in each of the single cells is greater than a preset voltage difference threshold.

Optionally, the controller includes a control chip, and the control chip is connected to an acquisition module and an equalization module corresponding to the same single cell through a pin, and the pin passes through the control channel and the equalization circuit and The acquisition circuit is connected.

Optionally, the equalization circuit includes an equalization resistor in parallel with the single cell.

The present disclosure also provides a vehicle including the battery equalization system described above.

The present disclosure also provides a battery equalization method for a battery equalization system, the battery equalization system including a controller, an acquisition circuit, and an equalization circuit; wherein the controller passes through a control channel and corresponds to the same single in the battery pack The acquisition circuit of the body battery is connected to the equalization circuit, and the acquisition circuit and the equalization circuit time-multiplex the control channel;

The method includes:

Connecting the control channel to the acquisition circuit, and controlling the equalization circuit to be in an on state;

Collecting parameter information of the single battery in the battery group by using the collecting circuit;

Determining, by the controller, that a single battery in the battery pack needs to be turned on according to parameter information of the battery pack;

Connecting the control channel to the equalization circuit corresponding to the unit cell that needs to be turned on, and controlling the acquisition circuit to be in a short circuit state;

The equalization circuit is controlled by the controller to perform equalization processing on the single battery that needs to be turned on.

The controlling the equalization circuit is in an on state, including:

Disconnecting the first equalization branch and turning on the second equalization branch;

The controlling the acquisition circuit is in a short circuit state, including:

The first equalization branch and the second equalization branch corresponding to the single battery are turned on.

Optionally, the determining, by the controller, that the single battery in the battery pack needs to be turned on according to the parameter information of the battery group, includes:

Determining, by the controller, the target equalization time and the equalization duty ratio of the single cell that needs to be turned on, the cell that needs to be turned on, and the equalization duty according to the parameter information of the battery. The ratio of the duration of the control channel to the total duration of the control channel being occupied by the equalization circuit;

And controlling, by the controller, the equalization circuit to perform equalization processing on the single-cell that needs to be turned on, including:

The equalization circuit controls the equalization circuit to perform equalization processing on the unit cells that need to be turned on by the controller according to the target equalization duration and the equalization duty ratio of the unit cells that are required to be turned on.

Optionally, the method further includes:

Determining, according to the target equalization duration and the equalization duty ratio, an equalization period and an acquisition period, where a sum of the equalization period and the collection period is equal to a total duration of the control channel being occupied;

The connecting the control channel to the acquisition circuit includes:

Connecting the control channel to the acquisition circuit during the acquisition period;

The equalizing circuit corresponding to the single-cell battery that needs to be turned on and equalized by the control channel includes:

During the equalization period, the control channel is connected to the equalization circuit corresponding to the single cell that needs to be turned on.

Optionally, the determining, according to the parameter information of the battery group, the target equalization duration of the single-cell that needs to be turned on, including:

Determining, according to the collected parameter information of the battery pack, whether a single battery in the battery pack needs to be balanced;

When it is determined that there is a single cell in the battery pack that needs to be turned on, the target equalization time of the single cell that needs to be turned on is calculated.

Optionally, when the single battery in the battery pack does not need to be equalized, the method further includes:

The acquisition circuit of the single cell is connected to the controller through the corresponding control channel.

Optionally, the controlling, by the controller, the equalization circuit to perform equalization processing on the single-cell that needs to be turned on, including:

The equalization circuit is controlled by the controller to perform equalization discharge on the unit cells that need to be turned on.

The equalization circuit is controlled by the controller to perform equalization charging on the single battery that needs to be turned on.

The present disclosure also provides a computer readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the battery equalization method described above.

The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects:

Since the controller in the present disclosure and the voltage sampling circuit and the equalization circuit of each unit cell are time-multiplexed one channel, the number of channels of the controller is reduced, thereby reducing the hardware cost; and due to battery sampling and equalization Separate, the equalization current does not affect the battery voltage, which improves the accuracy of the battery voltage sampling.

Other features and advantages of the present disclosure will be described in detail in the detailed description which follows.

DRAWINGS

The drawings are intended to provide a further understanding of the disclosure, and are in the In the drawing:

FIG. 1 is a block diagram of a battery equalization system, according to an exemplary embodiment.

FIG. 2 is a schematic diagram of an equalization circuit of a battery equalization system according to an exemplary embodiment.

FIG. 3 is another block diagram of a battery equalization system, according to an exemplary embodiment.

FIG. 4 is a flow chart showing a battery equalization method according to an exemplary embodiment.

FIG. 5 is another flow chart of a battery equalization method according to an exemplary embodiment.

FIG. 6 is a flowchart of determining, in a step included in a battery equalization method, a unit cell that needs to turn on equalization and a target equalization duration thereof, according to an exemplary embodiment.

FIG. 7 is another flow chart of a battery equalization method according to an exemplary embodiment.

FIG. 8 is another flow chart of a battery equalization method according to an exemplary embodiment.

Detailed ways

The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are not to be construed

FIG. 1 is a block diagram of a battery equalization system, according to an exemplary embodiment. As shown in FIG. 1 , the battery equalization system includes an acquisition circuit 12 , an equalization circuit 13 , and a controller 14 , wherein the battery 11 is formed by connecting a plurality of single cells 111 in series.

In FIG. 1, the controller 14 is connected to an acquisition circuit 12 and an equalization circuit 13 corresponding to the same single cell 111 through a control channel 140. The acquisition circuit 12 and the equalization circuit 13 time-multiplex the control channels. 140. The controller 14 includes a control chip connected to the acquisition circuit 12 and the equalization circuit 13 corresponding to the same single cell 111 through a pin, and the pin passes through the control channel 140 and the equalization circuit. 13 is connected to the acquisition circuit 12.

The present disclosure corresponds to a control circuit 140 of the same unit cell 111 and the equalization circuit 13 sharing a control channel 140 of the controller 14, such that the number of channels required for the controller 14 is reduced, thereby reducing the number of channels required for the controller 14.

For example, when the existing acquisition circuit and the equalization circuit are respectively connected to the controller through one control channel, the N single cells correspond to 2N control channels. The acquisition circuit and the equalization circuit of the same single battery share the control channel and the controller, and the N single cells correspond to N control channels, thereby reducing the number of control channels and reducing the cost of the controller.

When the existing acquisition circuit and the equalization circuit are respectively connected to the controller through a control channel, the N single cells correspond to 2N control channels, and 2N control channels need to be controlled. The acquisition circuit and the equalization circuit of the same single battery share the control channel of the controller, so that the N single cells correspond to the N control channels, and only the N control channels need to be controlled, which simplifies the control flow and reduces The misoperation rate of the controller.

When the existing acquisition circuit and the equalization circuit are respectively connected to the controller through a control channel, the N single cells correspond to 2N control channels, and the pass rate of the controller through the control channel is qualified by 2N control channels. Decide. The acquisition circuit and the equalization circuit of the same single battery share a control channel of the controller, and the N single cells correspond to N control channels, and the pass rate of the controller through the control channel is determined by the pass rate of the N control channels. In this way, the total pass rate of the plurality of single cells in the whole system through the control channel to the controller can be improved, thereby improving the pass rate of the battery equalization system.

The control channel or channel refers to a transmission path of a control command of the control module to the execution end (acquisition module and equalization module).

As shown in FIG. 1 , the collecting circuit 12 is configured to collect parameter information of the single battery 111 in the battery pack 11 , and send the collected parameter information of the battery pack to the controller 14 , the battery pack 11 . The unit cells 111 in the one-to-one correspondence with the acquisition circuit 12. The parameter information includes information such as a battery voltage and a temperature. The controller 14 controls the acquisition circuit 12 to collect parameter information of the battery pack 11 by connecting the control channel 140 to the acquisition circuit 12. When the controller 14 controls the acquisition circuit 12 to collect the parameter information of the single battery 111 in the battery pack 11, the equalization circuit 13 is in an on state. It should be noted that, when the collecting circuit 12 collects the parameter information of the battery pack 11, the equalizing circuit 13 is in the conducting state, and does not mean that the equalizing circuit 13 performs equalization processing on the single battery, but refers to the collecting circuit 12 and When the unit cells 111 are connected, the equalization circuit 13 corresponding to the unit cells 111 corresponds to a part of the acquisition circuit 12.

For example, referring to FIG. 2, the equalization circuit 13 may be an equalization resistor 130 including a parallel connection to the unit cell 111. As shown in FIG. 2 and FIG. 3, FIG. 3 is another block diagram of a battery equalization system, which is controlled by the controller 14 to collect the battery pack 11 in accordance with an exemplary embodiment. When the parameter information of the body battery 111 is used, the branch where the collecting circuit 12 is located is in an on state, and the second equalizing branch 132 where the equalizing circuit 13 is located may also be in an on state, and the first equalizing branch 131 is in a state of being Disconnected state. At this time, the collecting circuit 12 and the equalizing resistor 130 are connected in series in a branch, and both ends of the branch are respectively connected to two stages of the single cell 111, that is, when the collecting circuit 12 is connected to the single cell 111. The equalization resistor 130 included in the equalization circuit 13 can be used as part of the acquisition circuit 12.

As shown in FIG. 1, the equalization circuit 13 is connected to the corresponding single cell 111 through the first equalization branch 131 and the second equalization branch 132, respectively, and the second equalization branch 132 and the first equalization branch One end of the path 131 is connected to the two poles of the single cell 111, and the other end of the first equalization branch 131 and the second equalization branch 132 is connected between the collecting circuit 12 and the equalizing circuit 13. In FIG. 1, the first equalization branch 131 is connected to the anode of the unit cell 111, and the second equalization branch 132 is connected to the cathode of the unit cell 111.

As shown in FIG. 1, when the acquisition circuit 12 needs to collect parameter information of the single battery in the battery pack, the controller 14 can control the first equalization branch 131 to be disconnected, and control the equalization. The second equalizing branch 132 where the circuit 13 is located and the branch where the collecting circuit 12 is located are turned on. At this time, the equalizing circuit 13 can be in a conducting state together with the branch where the collecting circuit 12 is located.

As shown in FIG. 1 , the equalization circuit 13 is configured to perform equalization processing on the single cells 111 in the battery pack 11 , and the single cells 111 in the battery pack 11 are in one-to-one correspondence with the equalization circuit 13 . When there is a unit cell 111 in the battery pack 11 that needs to be equalized, the controller 14 controls the equalization circuit 13 to the unit that needs to be equalized by connecting the control channel 140 to the equalization circuit 13. The battery 111 performs equalization processing. When the equalization circuit 13 performs equalization processing on the single cells 111 in the battery pack 11, the controller 14 may control the first equalization branch 131 and the second equalization branch 132 to be turned on. Further, the equalization circuit 13 is in an on state, and the acquisition circuit 12 is in a short circuit state.

Optionally, when the single cell 111 in the battery pack 11 does not need to be equalized, the collecting circuit 12 corresponding to the single cell 111 is connected to the controller 14 through a corresponding control channel 140. That is, when the controller 14 determines that the unit cell 111 ends the equalization, the controller 14 disconnects the equalization circuit 13 corresponding to the unit cell 111 from the control channel 140, and controls the corresponding collection of the unit cell 111. Circuit 12 is in communication with control channel 140.

As shown in FIG. 1, the controller 14 is connected to the acquisition circuit 12 and the equalization circuit 13. The controller 14 is configured to receive parameter information of the battery pack 11 when the control channel 140 is communicated with the acquisition circuit 12. The controller 14 connects the control channel 140 to the equalization circuit when determining, according to the parameter information of the battery pack 11, that there is a unit cell 111 in the multi-cell unit 111 that needs to be equalized. 13. The equalization circuit 13 performs equalization processing on the unit cell 111.

The equalization circuit 13 may be an equalization processing method for discharging the unit cells 111 that need to be equalized. For example, in FIG. 2 and FIG. 3, the two ends of the unit cells 111 that need to be balanced are connected in parallel. An equalization resistor 130. The equalization circuit 13 may also be an equalization processing method for charging the single-cell battery 111 that needs to be equalized. For example, the unit cell 111 that needs to be balanced is connected to a generator or a battery of the vehicle, and then passes through the The generator or the battery charges the unit cell 111 that needs to be equalized.

Optionally, the controller 14 may further control, according to the target equalization duration of the unit battery 111 that needs to be turned on, determined by the parameter information of the battery pack 11, to control the equalization circuit 13 to open the equalization. The unit cell 111 is subjected to equalization processing. The controller 14 can obtain the target equalization duration of the unit cell 111 that needs to be turned on by the following method: determining the battery pack 11 according to the parameter information of the battery pack 11 collected by the acquisition circuit 12 Whether the single battery 111 needs to be turned on and equalized; when it is determined that the single battery 111 needs to be turned on in the battery pack 11, the target of the unit cell 111 that needs to be turned on is calculated according to the parameter information of the battery pack 11. Equilibrium duration.

As shown in FIG. 1 , when the battery equalization system performs equalization processing on the single battery in a passive equalization manner, that is, when the single-cell battery 111 that needs to be turned on is discharged, the controller 14 can be determined by the following manner. The unit cell 111 that needs to be turned on is balanced:

First, according to the voltage value of each of the single cells 111 in the battery pack 11 collected by the collecting circuit 12, the minimum voltage value among the voltage values of the single cells 111 in the battery pack 11 is used as a reference voltage value. ;

Then, according to the voltage difference between the voltage value of each of the unit cells 111 in the battery pack 11 and the reference voltage value, the unit cell 111 having a voltage difference greater than or equal to the preset voltage difference threshold is determined as It is described that the balanced unit cell 111 needs to be turned on.

Of course, in other embodiments, the single-cell battery that needs to be turned on can be determined by other parameter information of the battery pack. For example, when the battery equalization system adopts an active equalization method to equalize the single-cell battery, that is, When the unit cells that need to be turned on are charged, the maximum voltage value among the voltage values of the individual cells in the battery pack is used as a reference voltage value.

For example, the minimum voltage value among the voltage values of the individual cells 111 of the battery pack 11 may be used as the reference voltage value, and the preset voltage difference threshold may be 5 mV (or other value). First, the controller 14 connects the control channel 140 to the acquisition circuit 12, thereby controlling the acquisition circuit 12 to collect the voltage values of the individual cells 111 of the battery pack 11; meanwhile, the controller 14 controls the The first equalization branch 131 is turned off.

Next, the controller 14 compares the minimum voltage value Vmin in each of the single cells 111, and determines whether the difference between the voltage value of each of the single cells 111 of the battery pack 11 and Vmin is less than 5 mV. If so, the battery pack 11 has a good uniformity and does not need to be equalized; if it is greater than 5 mV, the single-cell battery 111 having a difference from Vmin of more than 5 mV is used as the single-cell battery 111 that needs to be turned on.

Then, after determining the cell 111 that needs to be turned on, the voltage value and Vmin of the balanced cell 111 can be turned on according to the need, and the target equalization time of the cell 111 that needs to be turned on is calculated. Further, the controller 14 connects the control channel 140 to the equalization circuit 13, and at the same time, the controller 14 can control the first equalization branch 131 and the second equalization branch 132 to be turned on. Further, the controller 14 controls the equalization circuit 13 to discharge the unit cell 111 that needs to be turned on according to the target equalization duration of the unit cell 111 that needs to be turned on.

Then, after the start of the discharge, the controller 14 counts the discharge duration of the equalization circuit 13 for the unit cell 111 that needs to be turned on, and the difference between the discharge duration of the unit cell 111 and the target equalization period. When the value is within the threshold range, the discharge is stopped and the equalization ends. The controller 14 disconnects the equalization circuit 13 corresponding to the unit cell 111 from the control channel 140, and controls the acquisition circuit 12 corresponding to the unit cell 111 to communicate with the control channel 140.

Referring to FIG. 1 , the second equalization branch 132 can be kept in an on state, and the first equalization branch 131 is provided with a first switch K1 . The first switch K1 is controlled by the controller 14. Optionally, the first switch K1 may be a relay switch, and the controller 14 controls the first switch K1 to be in an open state or a closed state by outputting a control signal.

When the acquisition circuit 12 needs to collect the parameter information of the single battery 111 in the battery pack 11, the controller 14 controls the first switch K1 to be turned off. When the equalization circuit 13 performs equalization processing on the unit cell 111 that needs to be turned on, the controller 14 controls the first switch K1 on the first equalization branch 131 corresponding to the unit cell 111 to be closed.

Optionally, as shown in FIG. 1 , the controller 14 may further control, according to the target equalization duration and the equalization duty ratio, the equalization circuit 13 to perform equalization processing on the single-cell battery 111 that needs to be turned on. The equalization duty ratio is a ratio of the duration of the equalization circuit 13 occupying the control channel 140 to the total duration occupied by the control channel 140; wherein the total duration occupied by the control channel 140 includes the equalization circuit 13 consuming the length of the control channel 140 and the duration of the acquisition circuit 12 occupying the control channel 140.

As shown in FIG. 1, first, the controller 14 connects the control channel 140 to the acquisition circuit 12, and further controls the acquisition circuit 12 to collect parameter information of the battery pack 11; meanwhile, the controller 14 controls The first switch K1 is turned off.

Then, the controller 14 obtains the single-cell battery 111 that needs to be turned on and balanced when it is determined that the single-cell battery 111 needs to be turned on in the battery pack 11 according to the parameter information of the single-cell battery 111 in the battery pack 11. The target equalization duration and the equalization duty ratio, and the control channel 140 is connected to the equalization circuit 13 corresponding to the unit cell 111 that needs to be turned on. Meanwhile, the controller 14 can control the first switch. K1 is closed.

Then, the controller 14 controls the equalization circuit 13 to perform equalization processing on the unit cells 111 that need to be turned on, according to the target equalization duration and the equalization duty ratio of the unit cells 111 that need to be turned on.

Optionally, the controller 14 determines an equalization period and an acquisition period according to the target equalization duration and the equalization duty, and the sum of the equalization period and the acquisition period is equal to the control channel 140. The controller 14 controls the control channel 140 to communicate with the acquisition circuit 12 to enable the acquisition circuit 12 to collect parameter information of the battery pack 11 at the same time. The controller 14 controls the first switch K1 to be turned off; during the equalization period, the controller 14 controls the control channel 140 to communicate with an equalization circuit 13 that needs to perform equalization processing, and the controller 14 can control The first switch K1 is closed, so that the equalization circuit 13 performs equalization processing on the unit cells 111 in the battery pack 11 that need to be equalized.

The disclosure provides a first switch on the first equalization branch, and when the parameter information of the battery pack needs to be collected, the control channel is connected to the acquisition circuit, the first switch is turned off; and when the balance is needed, the control channel is controlled. Connected to the equalization circuit, the first switch is closed, and a control channel is realized by time division multiplexing, which reduces the number of channels required for the controller, thereby reducing the hardware cost; and because the battery sampling and equalization are separately performed, the equalization current is not Will affect the battery voltage, which improves the accuracy of battery voltage sampling.

Optionally, a control switch may be disposed on the control channel 140. When the collecting circuit 12 is required to collect the parameter information of the battery pack 11, that is, during the collecting period, the controller 14 controls the control switch to be connected to the collecting circuit 12 to connect the control channel 140. The acquisition circuit 12. When the equalization circuit 13 is required to perform equalization processing on the single cells 111 in the battery pack 11, that is, in the equalization period, the controller 14 controls the control switch to be connected to the equalization circuit 13 So that the control channel 140 is connected to the equalization circuit 13.

The present disclosure provides a control switch between the controller and the acquisition circuit and the equalization circuit. The controller can adjust the state of the switch to achieve the function of acquisition and equalization, and can achieve no sampling during equalization, and is unbalanced during sampling. The effect of equalizing the current does not affect the battery voltage, thereby improving the accuracy of the battery voltage sampling.

When the existing acquisition circuit and the equalization circuit are respectively connected to the controller through a control channel, each single cell corresponds to two control channels, and each control channel corresponds to one pin of the control chip, that is, N single cells. Corresponds to 2N pins. The acquisition circuit and the equalization circuit of the same single battery share the control channel and the controller, and one control channel corresponds to one pin, that is, N single cells correspond to N control channels, corresponding to N pins, so that Reducing the need for control chip pins, based on the prior art, can reduce the number of pins by half, effectively reducing the cost of the control chip.

Optionally, the controller includes a first control unit disposed in the battery information collector and a second control unit disposed in the battery management controller. Optionally, the collecting circuit sends the parameter information of the single battery in the collected battery group to the second control unit by using the first control unit; wherein the acquisition circuit and the equalization circuit of the same single battery correspond to the first A connection channel of a control unit.

The first control unit may be connected to the acquisition circuit by controlling the connection channel, thereby controlling the collection circuit to collect parameter information of the single battery in the battery group. The second control unit may also send an acquisition instruction to the first control unit through the communication unit to control the connection channel to be connected to the acquisition circuit by the first control unit.

The first control unit may be connected to the equalization circuit by controlling the connection channel, thereby controlling the equalization circuit to perform equalization processing on the single battery that needs to be turned on and equalized. The first control unit may send parameter information of the battery pack collected by the acquisition circuit to the second control unit, and the second control unit determines, according to parameter information of the battery pack, a single battery that needs to be turned on, and And transmitting, by the communication unit, an equalization instruction to the first control unit, to control, by the first control unit, the connection channel to be connected to the equalization circuit.

When the acquisition circuit in the battery equalization system sends the parameter information of the single battery in the collected battery pack to the second control unit through the first control unit, the acquisition circuit and the equalization circuit of the same single battery correspond to the first control unit. A connection channel reduces the number of channels required by the first control unit.

The first control unit of the battery information collector and the second control unit of the battery management controller can selectively perform equalization control on the unit cells that need to be equalized. That is, the first control unit may control the equalization circuit to perform equalization processing on the single cells that need to be equalized, and the second control unit may also control the equalization circuit to perform equalization processing on the single cells that need to be equalized. The first control unit or the second control unit determines the unit cells that need to be equalized according to the parameter information of the battery pack collected by the acquisition circuit.

When the battery information collector does not receive the equalization command sent by the battery management controller, the first control unit receives the parameter information of the battery pack, and determines according to the parameter information of the battery group. When a single battery in the battery pack needs to be turned on, the control equalization circuit performs equalization processing on the single battery that needs to be turned on.

When the battery information collector receives an instruction for instructing the battery information collector to perform equalization processing, the first control unit receives parameter information of the battery pack, and determines, according to parameter information of the battery pack, When a single battery in the battery pack needs to be turned on, the control equalization circuit performs equalization processing on the single battery that needs to be turned on.

When the battery information collector receives the battery management controller failure message, the first control unit receives the parameter information of the battery group, and determines, according to the parameter information of the battery group, that the battery group has a single When the battery needs to be turned on, the control equalization circuit equalizes the single cells that need to be turned on.

The battery information collector and the battery management controller can selectively control the equalization system through the first control unit and the second control unit, respectively, so that one of the battery information collector and the battery management controller can be disabled or malfunctioned. In this case, the normal operation of the battery equalization system is still guaranteed.

Regarding the vehicle in the above embodiment, the battery equalization system included in the vehicle is described in detail in the embodiment of the above battery equalization system, and will not be described in detail herein.

FIG. 4 is a flow chart showing a battery equalization method according to an exemplary embodiment. As shown in FIG. 4, the battery equalization method is applied to a battery equalization system, where the battery equalization system includes a controller, an acquisition circuit, and an equalization circuit; wherein the controller passes through a control channel and corresponds to the same single in the battery pack. The acquisition circuit of the body battery is connected to the equalization circuit, and the acquisition circuit and the equalization circuit time-multiplex the control channel; the method comprises the following steps.

Step S21, the control channel is connected to the acquisition circuit, and the equalization circuit is controlled to be in an on state.

Step S22, collecting parameter information of the single battery in the battery group by using the collecting circuit.

Step S23, the controller determines, according to the parameter information of the battery pack, that a single battery in the battery pack needs to be turned on.

Step S24, the control channel is connected to the equalization circuit corresponding to the unit cell that needs to be turned on, and the acquisition circuit is controlled to be in a short circuit state.

In step S25, the equalizing circuit is controlled by the controller to perform equalization processing on the single battery that needs to be turned on.

FIG. 5 is another flow chart of a battery equalization method according to an exemplary embodiment. As shown in FIG. 5, the equalization circuit is respectively connected to the corresponding single cell through the first equalization branch and the second equalization branch, and one ends of the first equalization branch and the second equalization branch are respectively connected. The two ends of the single cell; the first equalizing branch and the other end of the second equalizing branch are connected between the collecting circuit and the equalizing circuit; the method comprises the following steps.

Step S31, the control channel is connected to the acquisition circuit, the first equalization branch is disconnected, and the second equalization branch is turned on.

Step S32, collecting parameter information of the single battery in the battery group by using the collecting circuit.

Step S33, the controller determines, according to the parameter information of the battery pack, a target equalization time and an equalization duty ratio of the single-cell that needs to be turned on, and the unit that needs to be turned on, and the balance is occupied. The air ratio is the ratio of the duration that the equalization circuit occupies the control channel to the total duration that the control channel is occupied.

Step S34, the control channel is connected to the equalization circuit corresponding to the unit cell that needs to be turned on, and the first equalization branch and the second equalization branch corresponding to the unit cell are turned on.

Step S35: The equalization circuit controls the equalization circuit to perform equalization processing on the single-cell that needs to be turned on by the controller according to the target equalization duration and the equalization duty ratio of the unit cell that needs to be turned on.

Optionally, as shown in FIG. 6 , the determining, according to the parameter information of the battery group, the target equalization duration of the single-cell that needs to be turned on, including:

Step S331, the controller determines, according to the collected parameter information of the battery pack, whether a single battery needs to be turned on in the battery pack;

Step S332, when it is determined that a single battery in the battery pack needs to be turned on, the controller calculates a target equalization time length of the single battery that needs to be turned on according to parameter information of the battery pack.

Optionally, the method further includes: determining, by the controller, an equalization period and an acquisition period according to the target equalization duration and the equalization duty ratio, where the sum of the equalization period and the collection period is equal to The total length of time that the control channel is occupied;

The connecting the control channel to the collecting circuit includes: connecting the control channel to the collecting circuit during the collecting period;

The equalizing circuit corresponding to the single-cell battery that needs to be turned on and equalized by the control channel includes: in the equalizing period, the control channel is connected to the equalization corresponding to the single-cell battery that needs to be turned on and equalized Circuit.

FIG. 7 is another flow chart of a battery equalization method according to an exemplary embodiment. As shown in Figure 7, the method includes the following steps.

Step S51, the control channel is connected to the acquisition circuit, the first equalization branch is disconnected, and the second equalization branch is turned on.

Step S52, collecting parameter information of the single battery in the battery pack through the collecting circuit.

Step S53, determining, by the controller, that a single battery in the battery pack needs to be turned on according to parameter information of the battery pack.

Step S54, the control channel is connected to the equalization circuit corresponding to the unit cell that needs to be turned on, and the first equalization branch and the second equalization branch corresponding to the unit cell are turned on.

Step S55, the equalizing circuit is controlled by the controller to discharge the single cell that needs to be turned on.

Step S56, when the single cells in the battery pack do not need to be equalized, the collecting circuit of the single cells is connected to the controller through the corresponding control channel.

FIG. 8 is another flow chart of a battery equalization method according to an exemplary embodiment. As shown in Figure 8, the method includes the following steps.

Step S61, the control channel is connected to the acquisition circuit, the first equalization branch is disconnected, and the second equalization branch is turned on.

Step S62, collecting parameter information of the single battery in the battery pack through the collecting circuit.

Step S63, the controller determines, according to the parameter information of the battery pack, that a single battery in the battery pack needs to be turned on.

Step S64, the control channel is connected to the equalization circuit corresponding to the unit cell that needs to be turned on, and the first equalization branch and the second equalization branch corresponding to the single battery are turned on.

Step S65, the equalizing circuit is controlled by the controller to charge the single battery that needs to be turned on.

Step S66, when the single cells in the battery pack do not need to be equalized, the collecting circuit of the single cells is connected to the controller through the corresponding control channel.

Regarding the battery equalization method in the above embodiment, the specific manner of each step has been described in detail in the embodiment relating to the battery letter equalization system, and will not be described in detail herein.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solutions of the present disclosure within the scope of the technical idea of the present disclosure. These simple variations are all within the scope of the disclosure.

It should be further noted that the specific technical features described in the above specific embodiments may be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not be further described in various possible combinations.

In addition, any combination of various embodiments of the present disclosure may be made as long as it does not deviate from the idea of the present disclosure, and should also be regarded as the disclosure of the present disclosure.

Claims

A battery equalization system, comprising: an acquisition circuit, an equalization circuit, and a controller; wherein the controller is connected to an acquisition circuit and an equalization circuit corresponding to the same single cell in the battery pack through a control channel, the collection The circuit and the equalization circuit time-multiplex the control channel;

The collecting circuit is configured to collect parameter information of the single battery in the battery group; when the collecting circuit needs to collect parameter information of the single battery in the battery group, the equalizing circuit is in an on state;

The equalization circuit is configured to perform equalization processing on the single cells in the battery pack; when the equalization circuit needs to perform equalization processing on the single cells in the battery pack, the acquisition circuit is in a short circuit state;

The controller is configured to control the equalization circuit to perform equalization processing on the single-cell that needs to be turned on when determining that a single battery in the battery pack needs to be turned on according to parameter information of the battery pack.
The battery equalization system according to claim 1, wherein the equalization circuit is connected to a corresponding single cell through a first equalization branch and a second equalization branch, respectively, the first equalization branch and the One end of the second equalization branch is respectively connected to two poles of the single cell; the other end of the first equalization branch and the second equalization branch are connected between the acquisition circuit and the equalization circuit;

When the collecting circuit needs to collect parameter information of the single battery in the battery pack, the first equalizing branch is disconnected and the second equalizing branch is turned on;

When the equalization circuit needs to perform equalization processing on the single cells in the battery pack, the first equalization branch and the second equalization branch corresponding to the single battery are turned on.
The battery equalization system according to claim 2, wherein the second equalization branch is maintained in an on state, the first equalization branch is provided with a first switch; and when the acquisition circuit needs to collect a battery pack When the parameter information of the single battery is used, the first switch is turned off; when the equalization circuit performs equalization processing on the single cell that needs to be turned on, the first balanced branch on the single battery corresponds to the first The switch is closed.
The battery equalization system according to any one of claims 1 to 3, wherein the controller is further configured to perform target equalization of the balanced unit cells according to the need to obtain the parameter information of the battery pack. The equalization period and the equalization duty ratio control the equalization circuit to perform equalization processing on the single cell that needs to be turned on, and the equalization duty ratio is that the equalization circuit occupies the control channel and the control channel is occupied. The ratio of total time.
The battery equalization system according to claim 4, wherein the controller is further configured to determine an equalization period and an acquisition period according to the target equalization duration and the equalization duty ratio, the equalization period and The sum of the acquisition periods is equal to the total duration of the control channel being occupied; in the equalization period, the control channel is connected to the equalization circuit, so that the equalization circuit pairs the cells in the battery pack The battery performs an equalization process; the control channel is connected to the acquisition circuit during the acquisition period, so that the acquisition circuit collects parameter information of the battery pack.
The battery equalization system according to claim 4, wherein the controller is configured to acquire a target equalization duration of the single battery that needs to be turned on by:

Determining, according to the parameter information of the battery pack collected by the collecting circuit, whether a single battery needs to be turned on in the battery pack;

When it is determined that a single battery in the battery pack needs to be turned on, the target equalization time of the single battery that needs to be turned on is calculated according to the parameter information of the battery.
The battery equalization system according to any one of claims 1 to 6, wherein when the single cells in the battery pack do not need to be equalized, the acquisition circuit of the single cells passes the corresponding control A channel is connected to the controller.
The battery equalization system according to any one of claims 1 to 7, wherein the controller is further configured to: the difference between the cell voltage and the minimum voltage in each of the cells is greater than a preset voltage difference threshold The equalization circuit is controlled to discharge the single cell.
The battery equalization system according to any one of claims 1-8, wherein the controller is further configured to: the difference between the voltage of the single battery and the maximum voltage of each of the single cells is greater than a preset voltage difference The threshold circuit controls the equalization circuit to charge the single battery.
The battery equalization system according to any one of claims 1 to 9, wherein the controller comprises a control chip, and the control chip is connected to an acquisition circuit and an equalization circuit corresponding to the same single cell through a pin. The pin is connected to the equalization circuit and the acquisition circuit through the control channel.
A battery equalization system according to any one of claims 1 to 10, wherein the equalization circuit comprises an equalization resistor in parallel with the unit cell.
A vehicle characterized by comprising the battery equalization system of any one of claims 1-11.
A battery equalization method is applied to a battery equalization system, wherein the battery equalization system includes a controller, an acquisition circuit, and an equalization circuit; wherein the controller passes through a control channel and corresponds to the same cell in the battery pack The acquisition circuit of the battery is connected to the equalization circuit, and the acquisition circuit and the equalization circuit time-multiplex the control channel;

The method includes:

Connecting the control channel to the acquisition circuit, and controlling the equalization circuit to be in an on state;

Collecting parameter information of the single battery in the battery group by using the collecting circuit;

Determining, by the controller, that a single battery in the battery pack needs to be turned on according to parameter information of the battery pack;

Connecting the control channel to the equalization circuit corresponding to the unit cell that needs to be turned on, and controlling the acquisition circuit to be in a short circuit state;

The equalization circuit is controlled by the controller to perform equalization processing on the single battery that needs to be turned on.
The method according to claim 13, wherein the equalization circuit is connected to the corresponding single cell through the first equalization branch and the second equalization branch, respectively, the first equalization branch and the second One end of the equalization branch is respectively connected to two poles of the single cell; the other end of the first equalization branch and the second equalization branch are connected between the acquisition circuit and the equalization circuit;

The controlling the equalization circuit is in an on state, including:

Disconnecting the first equalization branch and turning on the second equalization branch;

The controlling the acquisition circuit is in a short circuit state, including:

The first equalization branch and the second equalization branch corresponding to the single battery are turned on.
The method according to claim 13 or claim 14, wherein the determining, by the controller, that the single battery in the battery pack needs to be turned on according to the parameter information of the battery pack comprises:

Determining, by the controller, the target equalization time and the equalization duty ratio of the single cell that needs to be turned on, the cell that needs to be turned on, and the equalization duty according to the parameter information of the battery. The ratio of the duration of the control channel to the total duration of the control channel being occupied by the equalization circuit;

And controlling, by the controller, the equalization circuit to perform equalization processing on the single-cell that needs to be turned on, including:

The equalization circuit controls the equalization circuit to perform equalization processing on the unit cells that need to be turned on by the controller according to the target equalization duration and the equalization duty ratio of the unit cells that are required to be turned on.
The method of claim 15 further comprising:

Determining, according to the target equalization duration and the equalization duty ratio, an equalization period and an acquisition period, where a sum of the equalization period and the collection period is equal to a total duration of the control channel being occupied;

The connecting the control channel to the acquisition circuit includes:

Connecting the control channel to the acquisition circuit during the acquisition period;

The equalizing circuit corresponding to the single-cell battery that needs to be turned on and equalized by the control channel includes:

During the equalization period, the control channel is connected to the equalization circuit corresponding to the single cell that needs to be turned on.
The method according to claim 15 or 16, wherein the determining, according to the parameter information of the battery pack, the target equalization duration of the single-cell battery that needs to be turned on, includes:

Determining, according to the collected parameter information of the battery pack, whether a single battery in the battery pack needs to be balanced;

When it is determined that there is a single cell in the battery pack that needs to be turned on, the target equalization time of the single cell that needs to be turned on is calculated.
The method according to any one of claims 13-17, wherein when the individual cells in the battery pack do not need to be equalized, the method further comprises:

The acquisition circuit of the single cell is connected to the controller through the corresponding control channel.
The method according to any one of claims 13 to 18, wherein the controlling, by the controller, the equalization circuit to perform equalization processing on the single-cells that need to be turned on, including:

The equalization circuit is controlled by the controller to perform equalization discharge on the unit cells that need to be turned on.
The method according to any one of claims 13 to 19, wherein the controlling, by the controller, the equalization circuit to perform equalization processing on the single cell that needs to be turned on, comprising:

The equalization circuit is controlled by the controller to perform equalization charging on the single battery that needs to be turned on.
A computer readable storage medium having stored thereon computer program instructions, wherein the computer program instructions are executed by a processor to implement the battery equalization method of any one of claims 13-20.