Patent Description:
A battery pack is an important part of an electric vehicle. A battery pack is multiple cells connected in series. While a battery is in use, the difference between the cells in the battery pack gradually increases, resulting in poor consistency between the battery cells. Due to the short stave effect of the battery, the capacity of a battery pack cannot be brought into full play, thereby decreasing the overall capacity of the battery pack. Therefore, managing equalization of the battery pack of an electric vehicle effectively is helpful to improve the consistency between the cells in the battery pack, reduce the capacity loss of the battery, and extend the battery life and the mileage of the electric vehicle, and is of great significance.

In the practical application of related equalization technologies, main operations in a battery charging and discharging process are to collect battery information, determine whether equalization needs to be enabled for the battery and whether equalization processing needs to be performed for the battery, in which equalization efficiency is low and equalization time is long.

<CIT> relates to a battery pack including: a plurality of cell modules including a plurality of battery cells; and a battery management system for transmitting a control signal on charging to at least one of the plurality of cell modules based on state information of a battery cell transmitted by the cell modules, and controlling a current supplied to the cell modules by an external charger based on the state information, wherein the cell modules are charged to a predetermined capacity of the battery cell in connection with the external charger, and are charged to full capacity of the battery cell individually according to the control signal so the battery pack is fully charged very quickly without a cell balancing process. <CIT> concerns a vehicle battery-pack equalization system, in which a equalization processing time of each of a plurality of cells is based on the ratio of the difference between the currents discharged by each of the cells with respect to the equalization discharging current. <CIT> discloses a battery-powered system of cleaning devices each powered by a battery pack which is interchangeable among the devices.

Provided are a battery equalization system, a battery equalization method and a vehicle according to the independent claims. Dependent claims relate to preferred embodiments. The objective of the present application is to provide a battery equalization system, a vehicle, a battery equalization method, and a storage medium to resolve the technical problem of low equalization efficiency of a battery equalization system in the related art.

To achieve the above objective, the present application provides a power supply circuit of a battery equalization system, including:.

The charging branch circuit is connected to a high-voltage direct current output terminal of the charging device, and the first power supply branch circuit is connected to a low-voltage direct current output terminal of the charging device.

Optionally, a first switch controlled by the controller is disposed on the first power supply branch circuit, one side of the first switch is connected to the low-voltage direct current output terminal of the charging device, and the other side of the first switch is connected to the controller.

Optionally, the battery equalization system further includes a second power supply branch circuit, one end of the second power supply branch circuit is connected to the controller, and the other end of the second power supply branch circuit is connected to the collection circuit and the equalization circuit.

Optionally, a second switch controlled by the controller is disposed on the second power supply branch circuit, and the second switch keeps connected under the control of the controller.

Optionally, a second switch controlled by the controller is disposed on the second power supply branch circuit; when the equalization circuit performs equalization processing on the cell that needs enabling of equalization, the second switch changes from a connected state to a disconnected state under the control of the controller, so that the battery pack supplies power to the equalization circuit and the collection circuit.

Optionally, after the second switch is disconnected, the controller periodically gets into a sleep mode; when the controller exits the sleep mode, the controller controls the second switch to get connected to obtain the parameter information of the cells in the battery pack and a remaining duration of equalization processing still to be performed by the equalization circuit on the cell that needs enabling of equalization.

Optionally, the controller is respectively connected through two channels to the collection circuit and the equalization circuit that correspond to a same cell.

Optionally, the controller includes a control chip, and the control chip is respectively connected through two pins to the collection circuit and the equalization circuit that correspond to the same cell, the two pins are in one-to-one correspondence to the two channels, one of the two pins is connected to the equalization circuit through one of the two channels, and the other of the two pins is connected to the collection circuit through the other of the two channels.

Optionally, the controller is connected through one channel to the collection circuit and the equalization circuit that correspond to a same cell, and the collection circuit and the equalization circuit multiplex the channel in a time division manner.

Optionally, the controller includes a control chip, the control chip is connected through one pin to the collection circuit and the equalization circuit that correspond to the same cell, and the pin is connected to the equalization circuit and the collection circuit through the channel.

Optionally, the controller is further configured to: when it is determined, according to the parameter information of the battery pack, that a cell in the battery pack needs enabling of equalization, obtain a target equalization duration of the cell that needs enabling of equalization, and control, according to the target equalization duration of the cell that needs enabling of equalization, the equalization circuit to perform equalization processing on the cell that needs enabling of equalization.

Optionally, the controller controls, according to the target equalization duration and an equalization duty cycle, the equalization circuit to perform equalization processing on the cell that needs enabling of equalization, the equalization duty cycle is a ratio of an equalization period of the cell that needs enabling of equalization to a unit cycle, and the unit cycle includes the equalization period and a collection period.

The present application further provides a vehicle, including the battery equalization system.

The present application further provides a battery equalization method, applied to a vehicle including the battery equalization system, where the method includes:.

In this case, the method further includes:
controlling, by the controller, the second power supply branch circuit to change from a connected state to a disconnected state, so that the battery pack supplies power to the equalization circuit and the collection circuit.

Optionally, after the second power supply branch circuit is disconnected, the method further includes:.

In this case, the determining that a cell in the battery pack needs enabling of equalization includes:.

The present application further provides a computer-readable storage medium, on which a computer program instruction is stored. When executed by a processor, the program instruction implements the battery equalization method.

The technical solutions provided in the embodiments of the present application may include the following beneficial effects:
The present application improves the electrical connection structure of the battery equalization system. When the state-of-charge of the battery pack of the charging device is full and a cell in the battery pack needs enabling of equalization, by controlling the first power supply branch circuit to stay in the connected state, the present application enables the charging device to supply power to the controller through the first power supply branch circuit. Further, the controller can continue to control the equalization circuit to perform equalization processing on the cell that needs enabling of equalization, thereby extending the battery equalization time, improving the battery equalization effect, and resolving the technical problem of low equalization efficiency of the battery equalization system in the related art.

Other features and advantages of the present application will be described in detail in the following detailed description.

The accompanying drawings are used to provide a further understanding of the present application, constitute a part of the specification, are used to explain the present application together with the following specific implementations, but do not constitute a limitation on the present application. In the accompanying drawings:.

The specific implementations of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that, the specific implementations described herein are only used to illustrate and explain the present application, and are not intended to limit the present application.

<FIG> is a block diagram of a battery equalization system according to an exemplary embodiment; and <FIG> is a schematic diagram of a power supply branch circuit in a battery equalization system according to an exemplary embodiment. As shown in <FIG>, the battery equalization system includes a collection circuit <NUM>, an equalization circuit <NUM>, a controller <NUM>, a charging branch circuit (not shown in the drawing), a first power supply branch circuit <NUM>, and a second power supply branch circuit <NUM>.

As shown in <FIG>, the charging branch circuit is connected to a charging device <NUM> and a battery pack <NUM>, and is configured to charge the battery pack <NUM>. The battery pack <NUM> is a power battery pack, and is multiple cells <NUM> connected in series, and is configured to provide a driving power for an entire vehicle. The charging device <NUM> includes a low-voltage direct current output terminal <NUM> and a high-voltage direct current output terminal <NUM>.

To charge the battery pack <NUM>, one side of the charging branch circuit is connected to the high-voltage direct current output terminal <NUM> of the charging device <NUM>, and the other side of the charging branch circuit is connected to the battery pack <NUM>. As shown in <FIG>, the charging device <NUM> may be a vehicle-mounted charger. When the vehicle-mounted charger is connected to a charging pile <NUM>, an alternating current mains supply output by the charging pile <NUM> charges the battery pack through the vehicle-mounted charger and the charging branch circuit. When a state-of-charge of the battery pack is full, the charging branch circuit is disconnected.

In <FIG>, the controller <NUM> is respectively connected through two channels <NUM>, <NUM> to the collection circuit <NUM> and the equalization circuit <NUM> that correspond to the same cell <NUM>. The controller <NUM> includes a control chip, and the control chip is respectively connected through two pins to the collection circuit <NUM> and the equalization circuit <NUM> that correspond to the same cell <NUM>. The two pins are in one-to-one correspondence to the two channels <NUM>, <NUM>. One of the two pins is connected to the equalization circuit <NUM> through the channel <NUM>, and the other of the two pins is connected to the collection circuit <NUM> through the channel <NUM>.

As shown in <FIG>, the collection circuit <NUM> is configured to collect parameter information of the cell <NUM> in the battery pack <NUM>, and transmit the collected parameter information of the battery pack to the controller <NUM>. The cell <NUM> in the battery pack <NUM> is in one-to-one correspondence to the collection circuit <NUM>. The parameter information includes information such as battery voltage and temperature. By connecting the channel <NUM>, the controller <NUM> controls the collection circuit <NUM> to collect the parameter information of the battery pack <NUM>.

As shown in <FIG>, the equalization circuit <NUM> is configured to perform equalization processing on the cell <NUM> in the battery pack <NUM>, and the cell <NUM> in the battery pack <NUM> is in one-to-one correspondence to the equalization circuit <NUM>. When a cell <NUM> in the battery pack <NUM> needs to be equalized, the channel <NUM> between the equalization circuit <NUM> and the controller <NUM> is connected, so that the equalization circuit <NUM> can perform equalization processing on the cell <NUM> that needs to be equalized.

As shown in <FIG>, the controller <NUM> is configured to: when it is determined, according to the parameter information of the cell <NUM> in the battery pack <NUM>, that a cell <NUM> in the battery pack <NUM> needs enabling of equalization, connect the corresponding channel <NUM>, and control the equalization circuit <NUM> to perform equalization processing on the cell <NUM> that needs to be equalized.

When the battery pack <NUM> stops being charged, the charging branch circuit is disconnected. If a cell <NUM> in the battery pack <NUM> needs enabling of equalization, there is no power supply to support the battery equalization system to perform equalization processing. To enable continuous equalization on the battery pack <NUM> after the battery pack <NUM> stops being charged, referring to <FIG>, the battery equalization system includes a first power supply branch circuit <NUM>. One side of the first power supply branch circuit <NUM> is connected to the charging device <NUM>, and the other side of the first power supply branch circuit <NUM> is connected to the battery equalization system. In <FIG>, one side of the first power supply branch circuit <NUM> is connected to a low-voltage direct current output terminal <NUM> of the charging device <NUM>, and the other side is connected to the controller <NUM>.

As shown in <FIG>, the first power supply branch circuit <NUM> is controlled by the controller <NUM>. When the charging device <NUM> is connected to the charging pile <NUM> and the state-of-charge of the battery pack <NUM> is full, the charging branch circuit is disconnected. If a cell <NUM> in the battery pack <NUM> needs enabling of equalization, because the controller <NUM> controls the first power supply branch circuit <NUM> to keep connected, the alternating current mains supply output by the charging pile <NUM> at this time continues to supply power to the controller <NUM> through the charging device <NUM> and the first power supply branch circuit <NUM> to maintain the power required for operation of the controller <NUM>. Because both the collection circuit <NUM> and the equalization circuit <NUM> are connected to the controller <NUM>, when the charging pile <NUM> supplies power to the controller <NUM>, the charging pile <NUM> can also supply power to the collection circuit <NUM> and the equalization circuit <NUM>.

Optionally, when the charging device <NUM> is connected to the charging pile <NUM> and the battery pack <NUM> is being charged, if the controller <NUM> determines, according to the parameter information of the cell <NUM> in the battery pack <NUM>, that a cell <NUM> in the battery pack <NUM> needs enabling of equalization, the controller <NUM> may also control the first power supply branch circuit <NUM> to stay in a connected state. Further, the alternating current mains supply output by the charging pile <NUM> supplies power to the controller <NUM> through the charging device <NUM> and the first power supply branch circuit <NUM> to maintain the power required for operation of the controller <NUM>.

As shown in <FIG>, when the battery equalization system performs equalization processing on the cell in a passive equalization manner, that is, discharges the cell that needs enabling of equalization, the controller <NUM> may determine, in the following way, the cell <NUM> that needs enabling of equalization:.

First, according to the voltage value of each cell <NUM> in the battery pack <NUM> that is collected by the collection circuit <NUM>, the smallest voltage value among the voltage values of the cells <NUM> in the battery pack <NUM> is used as a reference voltage value.

Then, according to a voltage difference between the voltage value of each cell <NUM> in the battery pack <NUM> and the reference voltage value, it is determined that the cell <NUM> whose voltage difference is greater than or equal to a preset voltage difference threshold is the cell <NUM> that needs enabling of equalization.

Certainly, in other embodiments, the cell that needs enabling of equalization may also be determined according to other parameter information of the battery pack. For example, when the battery equalization system performs equalization processing on the cell in an active equalization manner, that is, charges the cell that needs enabling of equalization, the greatest voltage value among the voltage values of the cells in the battery pack is used as a reference voltage value.

Optionally, when the controller <NUM> determines, according to the parameter information of the cell <NUM> in the battery pack <NUM>, that a cell <NUM> in the battery pack <NUM> needs enabling of equalization, for example, according to the voltage value of the cell <NUM> that needs enabling of equalization and the reference voltage value, obtains a target equalization duration of the cell <NUM> that needs enabling of equalization, and according to the target equalization duration of the cell <NUM> that needs enabling of equalization, controls the equalization circuit <NUM> to perform equalization processing on the cell <NUM> that needs enabling of equalization.

Further, the controller <NUM> controls, according to the target equalization duration and an equalization duty cycle, the equalization circuit <NUM> to perform equalization processing on the cell <NUM> that needs enabling of equalization. The equalization duty cycle is a ratio of an equalization period of the cell <NUM> that needs enabling of equalization to a unit cycle. The unit cycle includes the equalization period and a collection period. In the collection period, the collection circuit <NUM> collects the parameter information of the battery pack <NUM>; and in the equalization period, the equalization circuit <NUM> performs equalization processing on the cell <NUM> to be equalized in the battery pack <NUM>.

For example, as shown in <FIG>, the smallest voltage value among the voltage values of the cells <NUM> in the battery pack <NUM> may be used as the reference voltage value, and the preset voltage difference threshold may be <NUM> mV (or another value). First, the controller <NUM> obtains the smallest voltage value Vmin among the cells <NUM> through comparison, and determines whether the difference between the voltage value of each cell <NUM> in the battery pack <NUM> and Vmin is less than <NUM> mV. If the difference is less than <NUM> mV, the battery pack <NUM> is very consistent in equalization and needs no more equalization; if the difference is greater than <NUM> mV, the cell <NUM> with a difference between its voltage value and Vmin being greater than <NUM> mV is used as the cell <NUM> that needs enabling of equalization. At this time, if the charging device <NUM> is connected to the charging pile <NUM> and the state-of-charge of the battery pack <NUM> is full, the controller <NUM> controls the first power supply branch circuit <NUM> to get connected. Further, the alternating current mains supply output by the charging pile <NUM> continues to supply power to the controller <NUM> through the charging device <NUM> and the first power supply branch circuit <NUM>. Subsequently, the controller <NUM> controls the equalization circuit <NUM> to discharge the cell <NUM> that needs enabling of equalization.

In the discharging process, the controller <NUM> may keep reading voltage information of the cell <NUM> that needs enabling of equalization, and determine whether the difference between Vmin and the voltage of the cell is less than <NUM> mV. If the difference is less than <NUM> mV, the discharge stops, and the equalization is ended. The controller <NUM> controls the first power supply branch circuit <NUM> to stay in the disconnected state, so that the controller <NUM> is powered off. If the difference is still greater than <NUM> mV, the controller continues to cyclically read the voltage information of the cell <NUM> that needs enabling of equalization until the difference between Vmin and the voltage of the cell is less than <NUM> mV. Thereafter the discharge stops, and the equalization is ended. The controller <NUM> controls the first power supply branch circuit <NUM> to stay in the disconnected state, so that the controller <NUM> is powered off.

After the cell <NUM> that needs enabling of equalization is determined, a target equalization duration of the cell <NUM> that needs enabling of equalization may also be calculated according to the voltage value of the cell <NUM> that needs enabling of equalization and Vmin. Further, after the discharge starts, a discharge duration of the cell <NUM> that needs enabling of equalization is counted. When the difference between the discharge duration of the cell <NUM> and the target equalization duration falls within a threshold range, the discharge stops, and the equalization ends. The controller <NUM> controls the first power supply branch circuit <NUM> to stay in the disconnected state, so that the controller <NUM> is powered off.

The present application improves the electrical connection structure of the battery equalization system. When the charging device is connected to the charging pile, the state-of-charge of the battery pack is full, and a cell in the battery pack needs enabling of equalization, by controlling the first power supply branch circuit to keep connected, the charging pile is enabled to supply power to the controller through the charging device and the first power supply branch circuit. Further, the controller can continue to control the equalization circuit to perform equalization processing on the cell that needs enabling of equalization, thereby extending the battery equalization time, improving the battery equalization effect, and resolving the technical problem of low equalization efficiency of the battery equalization system in the related art.

Referring to <FIG>, a first switch <NUM> controlled by the controller <NUM> is disposed on the first power supply branch circuit <NUM>. One side of the first switch <NUM> is connected to the low-voltage direct current output terminal <NUM>, and the other side of the first switch <NUM> is connected to the controller <NUM>.

Optionally, the first switch <NUM> may be a relay switch, and the controller <NUM> controls the first switch <NUM> by outputting a control signal. When the charging device <NUM> is connected to the charging pile <NUM>, the state-of-charge of the battery pack <NUM> is full, and a cell <NUM> in the battery pack <NUM> needs enabling of equalization, the controller <NUM> outputs a control signal to the first switch <NUM>. After receiving the control signal, the first switch <NUM> changes to a connected state. That is, the first power supply branch circuit <NUM> is connected. At this time, the alternating current mains supply output by the charging pile <NUM> continues to supply power to the controller <NUM> through the charging device <NUM> and the first power supply branch circuit <NUM> to maintain the power required for operation of the controller <NUM>.

After the charging device <NUM> is connected to the charging pile <NUM>, the state-of-charge of the battery pack <NUM> is full, and the equalization circuit <NUM> finishes the equalization processing on the cell that needs enabling of equalization, the controller <NUM> outputs a control signal to the first switch <NUM>. After receiving the control signal, the first switch <NUM> changes to a disconnected state. That is, the first power supply branch <NUM> is in the disconnected state, and the controller <NUM> is powered off.

Optionally, after the vehicle is powered on, the controller <NUM> controls the first switch <NUM> to keep connected all the time. When the charging device <NUM> is connected to the charging pile <NUM>, the state-of-charge of the battery pack <NUM> is full, and the equalization circuit <NUM> finishes the equalization processing on the cell that needs enabling of equalization, the controller <NUM> controls the first switch <NUM> to disconnect.

As shown in <FIG>, the battery equalization system further includes a second power supply branch circuit <NUM>. One end of the second power supply branch circuit <NUM> is connected to the controller <NUM>, and the other end of the second power supply branch circuit <NUM> is connected to a collection circuit <NUM> and the equalization circuit <NUM>. In <FIG>, the second power supply branch circuit <NUM> keeps connected. Because the second power supply branch circuit <NUM> keeps connected all the time, when the alternating current mains supply output by the charging pile <NUM> supplies power to the controller <NUM> through the charging device <NUM> and the first power supply branch circuit <NUM>, the mains alternating current can also be supplied to the collection circuit <NUM> and the equalization circuit <NUM> through the second power supply branch circuit <NUM>.

As shown in <FIG> is a schematic diagram of another power supply branch circuit in a battery equalization system according to an exemplary embodiment. A second switch <NUM> controlled by the controller <NUM> is disposed on the second power supply branch circuit <NUM>. One side of the second switch <NUM> is connected to the controller <NUM>, and the other side of the second switch <NUM> is connected to the collection circuit <NUM> and the equalization circuit <NUM>. The second switch <NUM> keeps connected under the control of the controller <NUM>.

Optionally, as shown in <FIG> and <FIG>, when the equalization circuit <NUM> performs equalization processing on the cell that needs enabling of equalization, the second switch <NUM> changes from a connected state to a disconnected state under the control of the controller <NUM>, so that the battery pack <NUM> supplies power to the equalization circuit <NUM> and the collection circuit <NUM>.

As shown in <FIG> and <FIG>, after determining, according to the parameter information of the cell <NUM> in the battery pack <NUM>, that a cell <NUM> in the battery pack <NUM> needs enabling of equalization and determining a target equalization duration of the cell <NUM> that needs enabling of equalization, the controller <NUM> transmits an equalization instruction to the equalization circuit <NUM> to indicate the cell <NUM> that needs enabling of equalization in the battery pack <NUM>, and the target equalization duration of the cell <NUM>. After the equalization circuit <NUM> receives the equalization instruction, the second switch <NUM> changes from the connected state to a disconnected state under the control of the controller <NUM>. That is, when the equalization circuit <NUM> performs equalization processing on the cell that needs enabling of equalization, the controller <NUM> controls the second switch <NUM> to change from the connected state to the disconnected state. Because the cell <NUM> in the battery pack <NUM> is connected to the collection circuit <NUM> and the equalization circuit <NUM> in a one-to-one correspondence, after the second switch <NUM> is disconnected, operating power supplies of the collection circuit <NUM> and the equalization circuit <NUM> receive power from the cell <NUM> in the battery pack <NUM>, and the controller <NUM> operates normally.

Still referring to <FIG> and <FIG>, after the second switch <NUM> is disconnected, the controller <NUM> periodically (for example, every <NUM>, <NUM> or at other intervals) gets into a sleep mode. In the sleep mode, the controller <NUM> is in an operating state with a low power consumption. When the controller <NUM> exits the sleep mode, the controller <NUM> controls the second switch <NUM> to get connected to obtain the parameter information of the cells <NUM> in the battery pack <NUM> and a remaining duration of equalization processing still to be performed by the equalization circuit <NUM> on the cell <NUM> that needs enabling of equalization. Further, the controller <NUM> may adjust, in real time, the equalization processing on the cell <NUM> that needs enabling of equalization.

<FIG> is another block diagram of a battery equalization system according to an exemplary embodiment. As shown in <FIG>, and <FIG>, the battery equalization system includes a collection circuit <NUM>, an equalization circuit <NUM>, a controller <NUM>, a charging branch circuit, a first power supply branch circuit <NUM>, and a second power supply branch circuit <NUM>. The battery pack <NUM> is multiple cells <NUM> connected in series. The difference from the battery equalization system in <FIG> lies in that the controller <NUM> in the battery equalization system in <FIG> is connected through a channel <NUM> to the collection circuit <NUM> and the equalization circuit <NUM> that correspond to the same cell <NUM>.

When the controller <NUM> determines that the cell <NUM> needs no equalization, the controller <NUM> is connected through the channel <NUM> to the corresponding collection circuit <NUM>; or, when the controller <NUM> determines that the cell <NUM> needs equalization, the collection circuit <NUM> and the equalization circuit <NUM> that correspond to the cell <NUM> multiplex the channel <NUM> in a time division manner. That is, the control module <NUM> is connected through the channel <NUM> to the corresponding collection module <NUM> and equalization module <NUM> in a time division manner. The controller <NUM> includes a control chip, the control chip is connected through one pin to the collection circuit <NUM> and the equalization circuit <NUM> that correspond to the same cell <NUM>, and the pin is connected to the equalization circuit <NUM> and the collection circuit <NUM> through the channel <NUM>.

Optionally, as shown in <FIG>, the controller <NUM> controls, according to the target equalization duration and an equalization duty cycle, the equalization circuit <NUM> to perform equalization processing on the cell <NUM> that needs enabling of equalization, the equalization duty cycle is a ratio of an equalization period of the cell <NUM> that needs enabling of equalization to a unit cycle, and the unit cycle includes the equalization period and a collection period. In <FIG>, the equalization duty cycle may also be a ratio of a duration for which the equalization circuit <NUM> occupies the channel <NUM> to a total duration for which the channel <NUM> is occupied. The total duration for which the channel <NUM> is occupied includes the duration for which the equalization circuit <NUM> occupies the channel <NUM> and a duration for which the collection circuit <NUM> occupies the channel <NUM>.

As shown in <FIG> and <FIG>, first, the controller <NUM> connects the channel <NUM> to the collection circuit <NUM>, and further can control the collection circuit <NUM> to collect the parameter information of the battery pack <NUM>. Then, the controller <NUM> is configured to: when it is determined, according to the parameter information of the cell <NUM> in the battery pack <NUM>, a cell <NUM> in the battery pack <NUM> needs enabling of equalization, obtain the target equalization duration and the equalization duty cycle of the cell <NUM> that needs enabling of equalization, and connect the channel <NUM> to the equalization circuit <NUM> corresponding to the cell <NUM> that needs enabling of equalization. Then, the controller <NUM> controls the equalization circuit <NUM> to connect the cell <NUM> that needs enabling of equalization to a power generator <NUM> or a storage battery <NUM> according to the target equalization duration and the equalization duty cycle of the cell <NUM> that needs enabling of equalization. That is, the controller <NUM> can control the connection time of the first switch <NUM> in <FIG> or the second switch <NUM> in <FIG> according to the target equalization duration and the equalization duty cycle.

Optionally, the controller <NUM> determines an equalization period and a collection period according to the target equalization duration and the equalization duty cycle. A sum of the equalization period and the collection period is equal to the total duration for which the channel <NUM> is occupied. In the collection period, the channel <NUM> is connected to the collection circuit <NUM>, so that the collection circuit <NUM> collects the parameter information of the battery pack <NUM>. In the equalization period, the channel <NUM> is connected to the equalization circuit <NUM> that needs to perform equalization processing, and the equalization circuit <NUM> is connected, so that the equalization circuit <NUM> performs equalization processing on the cell <NUM> to be equalized in the battery pack <NUM>.

Because the controller in the present application multiplexes one channel in a time division manner with a voltage sampling circuit of each cell and the equalization circuit, the required quantity of channels of the controller is reduced, and hardware cost is reduced. In addition, because battery sampling is separated from equalization, equalization of current does not affect the battery voltage, thereby improving precision of battery voltage sampling.

The sampling circuit and the equalization circuit in the present application may be a sampling circuit and an equalization circuit commonly used in this field.

The present application further provides a vehicle, including the battery equalization system described above. Specific operation manners of each circuit have been described in detail in the embodiments related to the system, and will not be described in detail here.

<FIG> is a flowchart of a battery equalization method according to an exemplary embodiment. As shown in <FIG>, the battery equalization method is applied to a vehicle including the battery equalization system, and the method includes the following steps:.

<FIG> is another flowchart of a battery equalization method according to an exemplary embodiment. As shown in <FIG>, the battery equalization system further includes a second power supply branch circuit. One end of the second power supply branch circuit is connected to the controller, and the other end of the second power supply branch circuit is connected to a collection circuit and the equalization circuit. The method may include the following steps:.

<FIG> is another flowchart of a battery equalization method according to an exemplary embodiment. As shown in <FIG>, the controller is connected through one channel to the collection circuit and the equalization circuit that correspond to a same cell, and the collection circuit and the equalization circuit multiplex the channel in a time division manner. The method may include the following steps:.

Detailed implementation of each step in the battery equalization method in the foregoing embodiment has been described in detail in the embodiment related to the battery equalization system, and will not be described in detail here.

The preferred implementations of the present application have been described in detail above with reference to the accompanying drawings, but the present application is not limited to the specific details in the above implementations. The protection scope is defined by the appended claims.

Claim 1:
A battery equalization system, comprising:
a collection circuit (<NUM>), configured to collect parameter information of cells in a battery pack (<NUM>);
a controller (<NUM>), connected to the collection circuit (<NUM>);
a charging branch circuit, connected to a charging device and the battery pack (<NUM>), and configured to charge the battery pack (<NUM>); and
a first power supply branch circuit (<NUM>), connected to the charging device and the battery equalization system, and configured to supply power to the battery equalization system;
wherein the charging branch circuit is connected to a high-voltage direct current output terminal of the charging device, and the first power supply branch circuit (<NUM>) is connected to a low-voltage direct current output terminal of the charging device; and
the battery equalization system comprises an equalization circuit (<NUM>), configured to perform equalization processing on the cells (<NUM>) in the battery pack (<NUM>); wherein
the controller (<NUM>) is connected to the equalization circuit (<NUM>), and configured to: when it is determined, according to the parameter information of the cells in the battery pack (<NUM>), that a cell in the battery pack (<NUM>) needs enabling of equalization, control the equalization circuit (<NUM>) to perform equalization processing on the cell that needs enabling of equalization; wherein
when a state-of-charge of the battery pack (<NUM>) is full and a cell in the battery pack (<NUM>) needs enabling of equalization, the controller (<NUM>) controls the charging branch circuit to disconnect, and controls the first power supply branch circuit (<NUM>) to keep connected, so that the equalization circuit (<NUM>) performs equalization processing on the cell that needs enabling of equalization; wherein
the equalization processing on the cell that needs enabling of equalization is performed in a passive equalization manner by discharging the cell that needs enabling of equalization.