CN113696785A

CN113696785A - Control circuit of series power supply pack, charging and discharging method and vehicle

Info

Publication number: CN113696785A
Application number: CN202111039399.0A
Authority: CN
Inventors: 梅俊华; 李志威; 黄后增; 潘俊辉; 张俊
Original assignee: Shagang Technology Shanghai Co ltd
Current assignee: Shagang Technology Shanghai Co ltd
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2021-11-26

Abstract

The embodiment of the application discloses a control circuit of a series power supply pack, a charging and discharging method and a vehicle, wherein the control circuit comprises at least two groups of series power supply packs, a control unit and an inductor; each power supply pack comprises a power supply and a change-over switch; the two ends of the power supply are respectively connected with the change-over switches, and the inductor is arranged between a first public end and a second public end, wherein the first public end is a public end between the power supplies in the adjacent power supply groups, and the second public end is a public end between the change-over switches in the adjacent power supply groups; each change over switch in the power supply package respectively with the control unit is connected, the control unit according to the electric current size that flows through the inductance, control change over switch's disconnection or switching on, and then control the electric quantity transfer between the power supply package, this application embodiment is used for solving the technical problem that reaches the use of bigger among the prior art to the electric quantity of power battery.

Description

Control circuit of series power supply pack, charging and discharging method and vehicle

Technical Field

The embodiment of the application belongs to the technical field of power management, and particularly relates to a control circuit of a series power supply set, a charging and discharging method and a vehicle.

Background

With the popularization of vehicles with power supplies, the demand for high power is more and more pursued, in order to improve efficiency, a mode of connecting a plurality of groups of power batteries in series is generally adopted to achieve low-loss high-power output, potential problems are that the vehicle is not matched with a charger of a single power battery, and when the power of the power battery is inconsistent, the power output of the vehicle is limited to the lowest power battery.

Disclosure of Invention

An embodiment of the present application provides a control circuit of a series power supply set, a charging and discharging method, and a vehicle, so as to solve the technical problem in the prior art that the electric quantity of a power battery is used in a larger manner.

In a first aspect, to achieve the above object, an embodiment of the present application provides a control circuit for a series power supply pack, including at least two series power supply packs, a control unit and an inductor;

each power supply pack comprises a power supply and a change-over switch; the two ends of the power supply are respectively connected with the change-over switches, and the inductor is arranged between a first public end and a second public end, wherein the first public end is a public end between the power supplies in the adjacent power supply groups, and the second public end is a public end between the change-over switches in the adjacent power supply groups;

the change-over switch in each power supply pack is respectively connected with the control unit, and the control unit controls the turn-off or the turn-on of the change-over switch according to the current flowing through the inductor, so as to control the electric quantity transfer between the power supply packs.

Compared with the prior art, this application embodiment is through establishing ties two group batteries, and includes power and change over switch in every group battery, is provided with the inductance between two group batteries, can control the charge-discharge process between the group battery through the electric current size that flows through the inductance, has realized the energy transfer between the group battery, if when charging, through the mutual charging between the control switch control power, if when discharging, can make power battery's electric quantity reach bigger use.

In a second aspect, an embodiment of the present application provides a method for controlling a series power supply pack to perform charging and discharging, including that the method is performed by the control circuit according to any one of the first aspect;

acquiring the current electric quantity of a power supply in each battery pack through a control unit;

judging whether the current electric quantity between the power supplies is different;

if the current exists, the current flowing through the inductor is acquired through the current acquisition unit, and the disconnection or the connection of the related switch is controlled to carry out the charging and discharging process of the power supply.

In a third aspect, embodiments of the present application provide a vehicle comprising a control circuit for a series power pack as claimed in any one of the first aspect.

Compared with the prior art, the beneficial effects of the solutions provided by the second aspect and the third aspect of the present application are the same as those of the first aspect, and are not described herein again.

Drawings

Fig. 1-7 are schematic diagrams illustrating a control circuit structure of a series power pack according to an embodiment of the present application;

fig. 8 is a schematic diagram of a path of a method for controlling a series power supply pack to charge and discharge according to an embodiment of the present disclosure.

Detailed Description

In order to make those skilled in the art better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of protection of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of the invention of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Example 1

As shown in fig. 1, in the embodiment of the present application, two groups of battery packs are included, that is, battery pack 01 and battery pack 02, and battery pack 01 and battery pack 02 are arranged in series, battery pack 01 and battery pack 02 respectively include a power supply and a switch, that is, battery pack 01 includes power supply B1 and switch Q1, battery pack 02 includes power supply B2 and switch Q2, switches Q1 and Q2 may be MOS transistors, the positive pole of power supply B1 is connected to the drain of MOS transistor Q1, the gate of MOS transistor Q1 is connected to control unit 03, and the negative pole of power supply B1 is connected to the source of MOS transistor Q1; similarly, the positive electrode of the power supply B2 is connected to the drain of the MOS transistor Q2, the gate of the MOS transistor Q2 is connected to the control unit 03, the negative electrode of the power supply B2 is connected to the source of the MOS transistor Q2, the inductor L1 is disposed between the first common terminal between the power supplies B1 and B2 and the second common terminal between the switches Q1 and Q2, and the control unit 03 controls the on/off of the switches Q1 and Q2 according to the magnitude of the current flowing through the inductor L1, so as to control the power transfer between the

power supplies

01 and 02. In the embodiment of the application, a diode D1 and a filter circuit C1 are arranged in parallel with the power supply B1, a diode D2 and a filter circuit C2 are arranged in parallel with the power supply B2, wherein the filter circuits C1 and C2 are capacitors, and the diode D1 and the diode D2 play a role of follow current, so that the function of follow current is played for energy stored in parasitic inductance of an external lead during abnormal conditions, and a phenomenon of high-voltage sparking is avoided.

When charging, the switches Q1 and Q2 are turned off, the power supply B1 in the battery pack 01 is selected to be connected with the charger 04 for charging in the present embodiment, of course, the power supply B2 in the battery pack 02 may also be selected for charging, and the present embodiment may select any branch in the whole control circuit to be connected with the fixed voltage node, that is, to ground, in the present embodiment, one branch of the battery pack 01 is selected to be grounded, when the electric quantity of the power supply B1 obtained by the control unit reaches a preset threshold, it indicates that the power supply B1 is fully charged, as shown in fig. 2, at time t0, Lo _ DRV is high, Q1 is turned on, at this time Q1 is turned on to be equivalent to a short-circuit mode, the battery pack 01 starts to charge the inductor L1, the inductor L1 starts to store energy, at time t1, Lo _ DRV is converted to a low level, Q1 is turned off, at this time Q1 is equivalent to an open-circuit mode, the unchangeable characteristic of inductor L1's transient current can release the energy of storage along Q2 direction, opens Q2 this moment, and Q2 switches on the equivalence and is short circuit mode, can reduce the loss to the energy that inductor L1 kept in is higher efficient injects the group battery 02, and so repeatedly, the purpose that reaches the electric quantity of group battery 01 at last and change to group battery 02 realizes the charging process of every group battery, and the risk that misuse the charger and bring can be avoided in the use of single charger.

When discharging, similarly, the power supply B1 and the power supply B2 are discharged simultaneously, but during the discharging process, for example, after the power supply B1 is discharged first, the remaining power in the power supply B2 cannot be used maximally, in order to use the power in B2 completely, it is necessary to transfer part of the power in B2 to B1, so as to maximally use the power in the power supplies B1 and B2 completely, at this time, the switch Q2 is turned on, the switch Q1 is turned off, the battery pack 02 starts to charge the inductor L1, the inductor L1 starts to store energy, when the voltage of Q2 is converted to a low level, Q2 is turned off, at this time, Q2 is cut off to be equivalent to an open circuit mode, the characteristic that the transient current of the inductor L1 is not changed, the stored energy is released along the direction of Q1, at this time, Q1 is turned on, Q1 is equivalent to a short circuit mode, so that the loss can be reduced, and the energy temporarily stored in the inductor L1 can be injected into the battery pack 01 more efficiently, the above steps are repeated, and finally, the purpose of converting the electric quantity of the battery pack 02 into the battery pack 01 is achieved, and the residual electric quantity in the power supply B2 is used to the maximum.

Example 2

As shown in fig. 3, the control circuit further includes a current collecting unit R0, the current collecting unit R0 is connected in series with the inductor L1, in this embodiment, a single-resistor current collecting unit is adopted, the current collecting unit is a resistor R0, the current flowing through the inductor L1 can be collected by a current sensor, if the current collecting unit is a resistor R0, the current flowing through the resistor R0 is calculated by collecting the voltage across the resistor R0, and because of the series circuit, the current flowing through the inductor L1 is the same as the current flowing through the resistor R0, and the current flowing through the inductor L1 is obtained.

In fig. 3, a filter circuit C01 is further disposed in parallel with the resistor R0, and is used for having a low-pass filtering effect and suppressing short-time high-frequency pulse interference, load resistors R01 and R02 are disposed between two ends of the filter circuit C01 and two ends of the resistor R0, respectively, and the load resistors R01 and R02 are used for suppressing short-time high-frequency pulse interference to protect the control unit 03.

When charging is performed, when the current of the inductor L1 is collected to be greater than a preset threshold, it is determined that charging of the battery pack 01 is completed.

Example 3

As shown in fig. 4, on the basis of fig. 3, the control circuit further includes a comparison circuit 05, the comparison circuit 05 is disposed in one-to-one correspondence with the current collecting unit R0, and two input terminals of the comparison circuit 05 are respectively connected to the third common terminal of the loads R01 and R02 connected to the control unit 03, the comparison circuit 05 is configured to compare the current flowing through the current collecting unit R0 with the reference current, so as to implement the charging and discharging processes of the

battery packs

01 and 02 by controlling the switch Q1 and Q2 through the control unit 03, and thus the setting of the comparison circuit 05 makes the whole control process more accurate.

Example 4

As shown in fig. 5, the control circuit of this embodiment is provided with dual-resistor current collection units, which are R1 and R2, respectively, and calculates the currents flowing through the resistors R1 and R2 by collecting the voltages at the two ends of the resistors R1 and R2, the sum of the currents flowing through the resistors R1 and R2 is the current flowing through the inductor L1, and the currents flowing through the resistors R1 and R2 are equal to the current flowing through the switch Q1 and the switch Q2, so if the dual-resistor current collection unit can also monitor the switch Q1 and the switch Q2 at the same time, a short circuit caused by the simultaneous conduction of the switch Q1 and the switch Q2 during software misoperation can be avoided, and the current sampling performed by the dual resistors can perform hardware short circuit and overcurrent protection at the same time.

In the embodiment of the present application, filter circuits C11 and C21 are further connected in parallel with the resistors R1 and R2, and are used for having a low-pass filtering effect and inhibiting transient high-frequency pulse interference, load resistors R11 and R12 are respectively arranged between two ends of the filter circuit C11 and two ends of the resistor R1, load resistors R21 and R22 are respectively arranged between two ends of the filter circuit C21 and two ends of the resistor R2, and the load resistors R11, R12, R21 and R22 are respectively used for inhibiting transient high-frequency pulse interference to protect the control unit 03.

Example 5

As shown in fig. 6, on the basis of fig. 5, a comparison circuit 06 and a comparison circuit 07 are correspondingly disposed for each of the current collection units R1 and R2, two input terminals of the comparison circuit 06 are respectively connected to the third common terminal of the loads R21 and R22 connected to the control unit 03, two input terminals of the comparison circuit 07 are respectively connected to the third common terminal of the loads R11 and R12 connected to the control unit 03, and the

comparison circuits

06 and 07 are used for comparing the currents of the current collection units R1 and R2 with the reference current, so as to control the switching switches Q1 and Q2 through the control unit 03 to realize the charging and discharging processes of the

battery packs

01 and 02, and thus the entire control process is more accurate through the disposition of the comparison circuit 05.

Example 6

As shown in fig. 7, on the basis of fig. 6, a battery pack 03 is added, that is, the control circuit includes three

battery packs

01, 02 and 03, the three

battery packs

01, 02 and 03 are connected in series, each of the current collecting units R1, R2 and R3 is provided with a comparing

circuit

06, 07 and 08, the internal composition of each battery pack is the same as that of the above embodiment, and details are not repeated herein, and similarly, an inductor L1 and an inductor L2 are provided between each battery pack, and the charging and discharging processes of the battery packs are controlled by detecting the current flowing through L1 and L2.

In one embodiment, the

comparison circuits

06, 07 and 08 may be eliminated from the overall control circuit, which is not limited in this application.

Specifically, during charging, if the power source B1 of the battery pack 01 is charged first, and the switches Q1, Q2 and Q3 are turned off, in the embodiment of the present invention, the power source B1 in the battery pack 01 is connected to the charger 04 for charging, of course, the power source B2 in the battery pack 02 may be selected for charging, or the power source B2 in the battery pack 02 is selected for charging, in the embodiment of the present invention, any one of the branches in the entire control circuit may be selected to be connected to a fixed voltage node, that is, to be grounded, in the embodiment of the present invention, one branch of the battery pack 01 is grounded, when the electric quantity of the B1 acquired by the control unit reaches a preset threshold, it is determined that the power source B1 is fully charged, the Q1 is turned on, at this time, the Q1 is turned on to be equivalent to a short-circuit mode, the battery pack 01 starts to charge the inductor L1, the inductor L1 starts to store energy, the Q1 is turned off, at this time, the Q1 is equivalent to be equivalent to an open-circuit mode, the unchangeable characteristic of the transient current of inductor L1 can release the energy of storage along Q2 direction, open Q2 this moment, Q2 switches on the equivalence and is the short circuit mode, can reduce the loss, so that the energy of inductor L1 temporary storage is more efficient to inject group battery 02 into, so repeatedly, finally reach the purpose that the electric quantity of group battery 01 changes to group battery 02, and in the same way, charging to group battery 03 through group battery 02, whole charging process is the same with group battery 01 to group battery 03 charging process, and it is not repeated here.

When discharging, similarly, power B1, power B2 and power B3 are discharged simultaneously, but during the discharging process, for example, after the power of power B1 is discharged first, the remaining power in power B2 and B3 cannot be used maximally, in order to use the power in B2 and B3, B1 is charged by the power larger than the passing power, assuming that the remaining power of B2 is larger than B3, at this time, part of the power in B2 needs to be transferred to B1, so as to maximally use the power in power B2 and B3, at this time, switch Q2 is turned on, switch Q1 is turned off, battery pack 02 starts to charge inductor L1, inductor L1 starts to store energy, when the voltage of Q2 is converted to a low level, Q2 is turned off, at this time, Q2 is blocked equivalently in an open circuit mode, the current of inductor L1 is not changed transiently, and the energy stored in the direction of Q1 is released, at this time, Q1 is turned on, Q1 is turned on to be equivalent to a short-circuit mode, so that loss can be reduced, energy temporarily stored in an inductor L1 can be injected into the battery pack 01 more efficiently, and this is repeated, and finally, the purpose of converting the electric quantity of the battery pack 02 into the battery pack 01 is achieved, the residual electric quantity in the power supply B2 is used to the maximum, when B2 charges B1, if the electric quantity of B2 is less than B3, B3 charges B2 first, and then B2 charges B1, and a specific charging process is the same as the above and is not described herein again.

As shown in fig. 8, an embodiment of the present application provides a method for controlling a series power supply pack to charge and discharge, including that the method is performed by the control circuit according to any one of the first aspect;

step S81, obtaining the current electric quantity of the power supply in each battery pack through the control unit;

step S82, judging whether the current electric quantity between the power supplies is different;

and step S83, if yes, the current flowing through the inductor is acquired through the current acquisition unit, and the relevant change-over switch is controlled to be switched off or switched on to carry out the charging and discharging process of the power supply.

Otherwise, step S84 is executed, and charging and discharging are not required.

Embodiments of the present application provide a vehicle comprising a control circuit for a series power pack as claimed in any one of the first aspect of the present application.

Although the present application has been described in detail herein with reference to specific embodiments and examples, it will be apparent to one skilled in the art that certain changes and modifications can be made therein without departing from the spirit and scope of the invention. Accordingly, such modifications and improvements are intended to be within the scope of this invention as claimed.

Claims

1. A control circuit of a series power supply pack is characterized by comprising at least two groups of series power supply packs, a control unit and an inductor;

2. The control circuit of a series power supply pack according to claim 1, further comprising a current collection unit, wherein the current collection unit is connected in series with the inductor for collecting the current flowing through the inductor, or is connected in series with each of the switches in a one-to-one correspondence, for collecting the current flowing through the inductor and the switch.

3. The control circuit for a series power pack of claim 2, further comprising a second filter circuit, said second filter circuit being disposed in parallel with said current collection unit.

4. The control circuit of a series power pack as claimed in claim 2 or 3, wherein a load is disposed on each of the branches of the current collection unit connected to the control unit.

5. The control circuit of claim 4, further comprising a comparison circuit, wherein the comparison circuit is disposed in one-to-one correspondence with the current collection units, and two input terminals of the comparison circuit are respectively connected to a third common terminal of the load and the control unit.

6. The control circuit of a series power pack of any one of claims 2, 3 or 5, wherein said current collection unit is a resistor.

7. The control circuit for a series power pack of claim 6, wherein a diode is provided in parallel with each of said power supplies in a one-to-one correspondence, and both ends of said diode are connected to both poles of the power supplies, respectively.

8. The control circuit for a series power pack of claim 6, wherein a branch in any power pack or a branch between battery packs in the series is connected to the fixed voltage node.

9. A method of controlling charging and discharging of a series connected power pack, comprising, the method being performed by a control circuit according to any one of claims 1 to 8;

if the current exists, the current flowing through the inductor is acquired through the current acquisition unit, and the relevant change-over switch is controlled to be switched off or switched on to carry out the charging and discharging process of the power supply.

10. A vehicle comprising a control circuit for a series power pack as claimed in claims 1 to 8.