WO2023207395A1 - 用于加热动力电池的加热系统和电动车 - Google Patents

用于加热动力电池的加热系统和电动车 Download PDF

Info

Publication number
WO2023207395A1
WO2023207395A1 PCT/CN2023/081703 CN2023081703W WO2023207395A1 WO 2023207395 A1 WO2023207395 A1 WO 2023207395A1 CN 2023081703 W CN2023081703 W CN 2023081703W WO 2023207395 A1 WO2023207395 A1 WO 2023207395A1
Authority
WO
WIPO (PCT)
Prior art keywords
measured current
current
value
heating
difference
Prior art date
Application number
PCT/CN2023/081703
Other languages
English (en)
French (fr)
Inventor
张柯
郭姿珠
潘仪
朱燕
孙华军
Original Assignee
比亚迪股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 比亚迪股份有限公司 filed Critical 比亚迪股份有限公司
Publication of WO2023207395A1 publication Critical patent/WO2023207395A1/zh

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/61—Types of temperature control
    • H01M10/615—Heating or keeping warm
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/62—Heating or cooling; Temperature control specially adapted for specific applications
    • H01M10/625—Vehicles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/657—Means for temperature control structurally associated with the cells by electric or electromagnetic means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Definitions

  • the present disclosure relates to the field of vehicle technology, and more specifically, to a heating system for heating a power battery and an electric vehicle.
  • the characteristics of power batteries are significantly affected by ambient temperature. Especially in low-temperature environments, the energy and power characteristics of lithium-ion power batteries will be severely attenuated, so the batteries need to be heated at low temperatures. For the heating method that uses excitation current to self-heat the battery core, how to improve its heating performance has become a key issue.
  • An object of the present disclosure is to provide a new technical solution for a heating system for heating a power battery.
  • Another object of the present disclosure is to provide a new technical solution for an electric vehicle, which includes a power battery and the heating system.
  • the present disclosure provides a heating system for heating a power battery, which can improve heating performance.
  • a heating system for heating a power battery includes a first battery group and a second battery group connected in series, and the electromotive force of the first battery group and the electromotive force of the second battery group are not equal;
  • the heating system includes an inverter, AC motor and first controller;
  • the inverter includes three bridge arms, the positive electrode of the power battery is connected to the upper bridge arm of the inverter, and the negative electrode of the power battery is connected to the upper bridge arm of the inverter.
  • the lower bridge arms are connected; the midpoints of the three bridge arms of the inverter are connected in one-to-one correspondence with the head ends of the three-phase coils of the AC motor, and the ends of the AC motor are connected together to form a neutral point; the The neutral point of the AC motor is connected to a first connection point through a connection line, and the first connection point is the connection point between the first battery core group and the second battery core group; the first controller is used to provide the The inverter inputs a driving signal; the first battery cell group, the second battery cell group, the inverter, the AC motor and the connecting line form an AC self-heating circuit; the first controller It is also used to adjust the driving signal during the self-heating process so that the ratio of the first target difference value to the first difference value is within a preset interval; wherein the first target difference value is the first difference value and the second difference value.
  • the first difference is the difference between the electromotive force of the first cell group and the electromotive force of the second cell group since the heating started.
  • the second difference is the difference between the electromotive force of the first cell group and the electromotive force of the second cell group at the end of self-heating.
  • the preset interval range is (-0.9, +0.9).
  • the first controller adjusts the drive signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: the first control The controller adjusts the duty cycle of the driving signal and/or the timing state of the driving signal during the self-heating process, so that the ratio of the first target difference to the first difference is within the preset interval.
  • the first controller adjusts the drive signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: the first control The device adjusts the driving signal so that the ratio between the second target difference value and the fifth intensity integrated value is within a preset interval.
  • the second target difference is a difference between a fifth intensity integrated value and a sixth intensity integrated value
  • the fifth intensity integrated value is the value flowing through the first battery cell group during the self-heating process.
  • the intensity integrated value of the current, the sixth intensity integrated value is the intensity integrated value of the current flowing through the second battery core group during the self-heating process; wherein the intensity integrated value of the current is the current intensity of the current in time. Points value.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: calculating the first theoretical current and the second theoretical current; correct the first theoretical current and the second theoretical current based on the first preset ratio; set the driving signal based on the corrected first theoretical current and the corrected second theoretical current;
  • the first theoretical current is a theoretical current flowing through the first battery core group
  • the second theoretical current is a theoretical current flowing through the second battery core group.
  • the first preset ratio is determined in advance through a heating test experiment; determining the first preset ratio includes: obtaining a first intensity integrated value of the first experimental current and a third intensity value of the second experimental current. The ratio of an intensity integrated value is used as the second ratio; the first preset ratio is determined, and the first preset ratio is the reciprocal of the second ratio; wherein the first experimental current is the value flowing through the heating test experiment.
  • the measured current of the first battery cell group, the second experimental current is the measured current flowing through the second battery cell group during the heating test experiment; wherein, the first intensity integrated value of the first experimental current is the value from the beginning of the heating test experiment to The intensity integrated value of the first experimental current during the end of the heating test experiment, and the first intensity integrated value of the second experimental current is the intensity integral of the second experimental current from the beginning of the heating test experiment to the end of the heating test experiment. value.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: obtaining the first measured current and a second intensity integrated value of the second measured current; based on the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current, set The driving signal of the next adjustment cycle; wherein, the first measured current is the measured current flowing through the first battery core group, and the second measured current is the measured current flowing through the second battery core group;
  • the second intensity integrated value of the first measured current is the intensity integrated value of the first measured current from the beginning of heating to the end of the current adjustment period
  • the second intensity integrated value of the second measured current is the intensity integrated value of the second measured current from the beginning of heating to the end of the current adjustment period
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: obtaining the first measured current the second intensity integrated value of the second measured current and the second intensity integrated value of the second measured current; obtain the third intensity integrated value of the first measured current and the third intensity integrated value of the second measured current; and obtain the third intensity integrated value of the first measured current based on the first measured current.
  • the second intensity integrated value, the second intensity integrated value of the second measured current, the third intensity integrated value of the first measured current, and the third intensity integrated value of the second measured current set the value of the next adjustment cycle. drive signal;
  • the first measured current is the measured current flowing through the first battery core group
  • the second measured current is the measured current flowing through the second battery core group
  • the second intensity integrated value of the first measured current is the intensity integrated value of the first measured current from the beginning of heating to the end of the current adjustment period
  • the second intensity integrated value of the second measured current is the intensity integral value of the second measured current from the beginning of heating to the end of the current adjustment period
  • the third intensity integral value of the first measured current is the intensity integral value of the first measured current during the current adjustment period
  • the third intensity integral value of the second measured current is the second actual measured intensity value during the current adjustment period. Integrated value of current intensity.
  • setting the drive signal for the next adjustment period includes: setting the duty cycle and/or timing state of the drive signal for the next adjustment period so that the second absolute value is smaller than the first absolute value. value; wherein, the first absolute value is the absolute value of the difference between the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current;
  • the second absolute value is the absolute value of the difference between the fourth intensity integrated value of the first measured current and the fourth intensity integrated value of the second measured current;
  • the fourth intensity integral value of the first measured current is the intensity integral value of the first measured current from the beginning of heating to the end of the next adjustment period
  • the fourth intensity integral value of the second measured current is the intensity integral value of the second measured current. The intensity integrated value of the second measured current from the beginning to the end of the next adjustment period.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: obtaining the first measured current The first effective value and the first effective value of the second measured current; based on the first effective value of the first measured current and the first effective value of the second measured current, set the driving signal of the next adjustment cycle;
  • the first measured current is the measured current flowing through the first battery core group
  • the second measured current is the measured current flowing through the second battery core group
  • the first effective value of the first measured current is the effective value of the first measured current from the start of heating to the end of the current adjustment period
  • the first effective value of the second measured current is the effective value of the first measured current from the start of heating to the end of the current adjustment period. The effective value of the second measured current during the end of the period.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: obtaining the first measured current The first effective value of the first measured current and the first effective value of the second measured current; obtaining the second effective value of the first measured current and the second effective value of the second measured current; based on the first effective value of the first measured current, The first effective value of the second measured current, the second effective value of the first measured current and the second effective value of the second measured current are set to the next A driving signal for an adjustment period;
  • the first measured current is the measured current flowing through the first battery core group
  • the second measured current is the measured current flowing through the second battery core group
  • the first effective value of the first measured current is the effective value of the first measured current from the start of heating to the end of the current adjustment period
  • the first effective value of the second measured current is the effective value of the first measured current from the start of heating to the end of the current adjustment period. The effective value of the second measured current during the end of the period;
  • the second effective value of the first measured current is the effective value of the first measured current during the current adjustment period
  • the second effective value of the second measured current is the effective value of the second measured current during the current adjustment period. value.
  • setting the drive signal of the next adjustment period includes: setting the duty cycle and/or timing state of the drive signal of the next adjustment period so that the fourth absolute value is smaller than the third absolute value. value;
  • the third absolute value is the absolute value of the difference between the first effective value of the first measured current and the first effective value of the second measured current
  • the fourth absolute value is the absolute value of the difference between the third effective value of the first measured current and the third effective value of the second measured current
  • the third effective value of the first measured current is the effective value of the first measured current from the beginning of heating to the end of the next adjustment period
  • the third effective value of the second measured current is the effective value of the second measured current from the beginning of heating to the end of the next adjustment period.
  • the effective value of the second measured current during the end of a regulation period.
  • the adjustment mode of the first controller is a PID adjustment mode.
  • the first controller is also used to synchronously control the on-off states of the three upper bridge arms during the self-heating process, and control the on-off states of the three lower bridge arms. Synchronous control.
  • the first controller is also used to adjust the driving signal during the self-heating process, so that the average effective value of the current flowing through the first battery core group during the entire self-heating period is 0.5C. to 5C, and the average effective value of the current flowing through the second battery core group during the entire self-heating period is between 0.5C and 5C.
  • the first controller is also used to adjust the drive signal during the self-heating process, so that the average effective value of the current flowing through the neutral point of the AC motor during the entire self-heating period is within 1C to 10C.
  • the central section is a curved structure composed of one or more arc-shaped structures, or the central section is a curved structure composed of one or more arc-shaped structures and one or more straight-line structures.
  • an electric vehicle including a power battery and the heating system described in any of the above embodiments.
  • a loop is added based on the original circuit topology of the electric vehicle.
  • the loop is from the neutral point of the AC motor to the connection point between the first battery group and the second battery group. , using this heating system can improve the overall heating performance.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within the preset interval, which can ensure At the end of self-heating, the difference between the charge loss of the first cell group and the charge loss of the second cell group will not be too large, thereby ensuring that the balance between the first cell group and the second cell group is Balance, reducing the negative impact of self-heating on the available power and cruising range of electric vehicles.
  • Figure 1 is a block diagram of a heating system for heating a power battery provided by an embodiment of the present disclosure.
  • Figure 2 is a specific circuit diagram of a heating system for heating a power battery provided by an embodiment of the present disclosure.
  • the first battery cell group 2. The second battery cell group; P-connection point; 3. Inverter; 4. AC motor;
  • the inverter is connected between the power battery and the AC motor.
  • One of the main functions of the inverter is to convert the DC power output by the power battery into AC power to drive the AC motor to rotate, and then drive the wheel end to rotate.
  • the power battery heating solution in the embodiment of the present disclosure utilizes the circuit topology between the power battery, the inverter and the AC motor to achieve heating of the power battery.
  • the power battery includes a first battery group and a second battery group connected in series
  • a heating system for heating the power battery includes an inverter, an AC motor, and a first controller.
  • the inverter includes three bridge arms. The positive electrode of the power battery is connected to the upper bridge arm of the inverter. The negative electrode of the power battery is connected to the lower bridge arm of the inverter. The midpoint of the three bridge arms of the inverter is connected to the AC motor. The head ends of the three-phase coils are connected one to one, and the ends of the AC motor are connected together to form a neutral point.
  • the neutral point of the AC motor is connected to the first connection point through the connection line, and the first connection point is the connection point between the first battery core group and the second battery core group.
  • the first controller is used to input driving signals to the inverter; the first battery cell group, the second battery cell group, the inverter, the AC motor and the connecting lines form an AC self-heating circuit.
  • the first controller is used to input driving signals to the inverter. Under the action of the driving signal, the inverter is controlled to alternately conduct the first battery group and the AC motor, and the second battery group and the AC motor, so that the first battery group and the second battery group alternately charge each other.
  • the heating system and electric vehicle for heating the power battery in the embodiment of the present disclosure add a loop based on the original circuit topology of the electric vehicle.
  • the loop is from the neutral point of the AC motor to the first battery pack and the third battery pack.
  • the connection point between the two battery core groups can use this heating system to improve the overall heating performance.
  • the power battery includes a first battery group 1 and a second battery group 2 connected in series, and the heating system includes an inverter 3, an AC motor 4, and a first controller 6.
  • the AC motor 4 is star-connected, and the three ends of the three-phase coils (coil A, coil B, and coil C) are connected together as a common terminal, and the common terminal is the neutral point N of the AC motor 4 .
  • the inverter 3 includes three bridge arms.
  • the positive electrode of the power battery is connected to the upper bridge arm of the inverter 3.
  • the negative electrode of the power battery is connected to the lower bridge arm of the inverter 3.
  • the inverter 3 includes an IGBT tube T1, an IGBT tube T2, an IGBT tube T3, an IGBT tube T4, an IGBT tube T5 and an IGBT tube T6.
  • the IGBT tubes T1 to T6 constitute 3 A bridge arm.
  • IGBT Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor
  • BJT tube Bipolar Junction Transistor, Bipolar Transistor
  • MOS tube Metal-Oxide-Semiconductor, Insulated Gate Field Effect Transistor
  • Voltage-driven power semiconductor devices combine the advantages of high input impedance of MOSFET field-effect transistors and low conduction voltage drop of GTR (Giant Transistor, power transistor).
  • GTR Gate Transistor, power transistor
  • each IGBT tube is also connected in reverse parallel with a diode, which can play a circuit protection role.
  • IGBT transistors T1 to T6 can also be replaced with MOS transistors respectively.
  • the IGBT transistors T1 to T6 can also be replaced with silicon carbide (SiC) power transistors respectively.
  • the neutral point N of the AC motor is connected to the first connection point P through the connection line S1.
  • the first connection point P is the connection point between the first battery core group and the second battery core group.
  • the first battery pack and the second battery pack belong to the same battery pack, and the battery pack provides a total positive port, a total negative port, and a third port led from the first connection point P.
  • the third port It is connected to the neutral point N of the AC motor through the connecting line S1.
  • the first controller 6 is used to input a driving signal to the inverter 3 to control the inverter 3 to alternately conduct the first cell group 1 and the AC motor 4, the second cell group 2 and the AC motor 4, so that the One battery cell group 1 and the second battery cell group 2 alternately charge each other.
  • the first controller 6 outputs six drive signals Q1 to Q6, where the drive signal Q1 is applied to the IGBT tube T1, the drive signal Q2 is applied to the IGBT tube T2, and the drive signal Q3 is applied to the IGBT tube T1.
  • the driving signal Q4 is applied to the IGBT tube T4
  • the driving signal Q5 is applied to the IGBT tube T5
  • the driving signal Q6 is applied to the IGBT tube T6.
  • the first controller 6 alternately conducts the circuits of the first cell group 1 and the AC motor 4 and the circuits of the second cell group 2 and the AC motor 4 by applying the driving signals Q1 to Q6 to the IGBT tubes T1 to T6, so that the One battery cell group 1 and the second battery cell group 2 alternately charge each other.
  • the first battery cell group 1 discharges, and the inverter 3 converts the DC power output by the first battery cell group 1 into AC power and supplies it to the AC motor 4.
  • the AC motor 4 stores the electric energy in the coil to the second battery cell. Group 2 charging. Afterwards, the second battery cell group 2 discharges, and the inverter 3 converts the DC power output by the second battery cell group 2 into AC power and supplies it to the AC motor 4.
  • the AC motor 4 stores the electric energy in the coil to charge the first battery cell group 1. In a repetitive cycle, the first battery cell group 1 and the second battery cell group 2 alternately charge each other through the AC motor 4, thereby self-heating the battery cells.
  • a switch 5 is provided in the connection line S1.
  • the heating system also includes a second control
  • the second controller 8 is used to control the on-off state of the switch 5 so that the heating circuit and the heating circuit are connected when the power battery needs to be heated and disconnected when the power battery does not need to be heated to ensure the safety of the vehicle and the power battery. safety.
  • the second controller 8 controls the switch 5 to be turned off when the electric vehicle is driving to ensure the safety of the vehicle while it is driving.
  • connection line S1 is provided with a protection circuit 7, such as a fuse, a relay and other protection circuits, to improve the safety of the battery heating process.
  • a protection circuit 7 such as a fuse, a relay and other protection circuits, to improve the safety of the battery heating process.
  • Figure 1 also shows the distribution box of the electric vehicle.
  • the distribution box mainly distributes power according to the electric load of the electric vehicle.
  • the heating system for heating the power battery provided by the embodiment of the present disclosure adds a connection line based on the original circuit topology of the electric vehicle.
  • the connection line is from the neutral point of the AC motor to the first battery pack and the second battery pack.
  • the connection points between the battery packs require little modification to the original circuit of the electric vehicle, and the solution is simple and easy to implement.
  • the heating system for heating the power battery provided by the embodiment of the present disclosure can make greater use of the three inductance coils of the motor to generate alternating pulse current by time-sharing the use of the upper and lower bridge arms in the inverter, thereby being used to heat the two The battery pack heats up quickly.
  • the charging and discharging current that is, the frequency and size of the excitation current are limited by the relevant components.
  • the heating system provided by the embodiments of the present disclosure can make the excitation current less limited, so that the excitation current can be used with a larger It is possible to heat the battery by excitation current.
  • the maximum current of the inverter is limited by the minimum current withstand current of IGBT tubes T1 to T6.
  • the maximum current of the inverter is limited by the sum of the withstand currents of IGBT tubes T1, T2, and T3, and by the sum of the withstand currents of IGBT tubes T4, T5, and T6, which greatly Increased range of available current.
  • the self-heating system in the embodiment of the present disclosure may also include a measurement system and a battery management system (Battery Management System, BMS).
  • BMS Battery Management System
  • relevant data monitored by the measurement system and battery management system will be output and fed back to the first controller in real time.
  • the first controller dynamically adjusts the frequency or amplitude of the excitation current output by the self-heating system according to the preset strategy. .
  • the start of self-heating means that the connection line S1 changes from a disconnected state to a conductive state, and the first battery cell group and the second battery cell group begin to alternately charge each other.
  • the end of self-heating means that the connection line S1 changes from the conductive state to the disconnected state, and the first battery cell group and the second battery cell group no longer charge each other alternately.
  • the electromotive force of the first battery group and the second battery group is unequal, which refers to the voltage difference between the two ends of the first battery group and the voltage between the two ends of the second battery group when self-heating starts. The difference varies.
  • the conditions of the battery cells in the first battery group and the second battery group are different, resulting in unequal electromotive forces in the first battery group and the second battery group.
  • This difference may be a difference in the number of battery units, or a difference in the material of the battery units, or a difference in the model of the battery units.
  • the difference in electromotive force between the first battery core group and the second battery core group may be: the rated electromotive force of the first battery core group is different from the rated electromotive force of the second battery core group.
  • the initial design of the first battery cell group and the second battery cell group is the same, that is to say, the initial electromotive force of the first battery cell group and the second battery cell group is equal, but due to the electromotive force
  • the daily use of the car causes varying degrees of losses in the first battery pack and the second battery pack, resulting in the electromotive force of the first battery pack and the second battery pack. It became a wait.
  • the first cell group and the second cell group belong to the same battery pack
  • the electromotive forces of the first cell group and the second cell group are unequal
  • the first connection point is an unequal potential point
  • the connecting line Connect to the unequal potential points of the battery pack.
  • An unequal potential point indicates that the absolute value of the voltage difference from this point to the total positive port of the battery pack is not equal to the absolute value of the voltage difference from this point to the total negative port of the battery pack.
  • the battery cells included in the first battery group 1 and the battery units included in the second battery group 2 are the same in model but different in quantity. Therefore, the first battery group 1 and the battery units are different in quantity.
  • the electromotive force of the second cell group 2 is different
  • the connection point P is an unequal potential point.
  • the available power of the vehicle is limited to the lowest SOC of each battery unit. Therefore, the charge amount of the first battery group 1 is lost under the self-heating condition. The inconsistency with the charge loss of the second battery cell group 2 will have a negative impact on the available power and cruising range of the electric vehicle.
  • the first controller 6 is also used to adjust the driving signal during the self-heating process so that the ratio between the first target difference and the first difference is within the preset interval.
  • the first target difference is the difference between the first difference and the second difference
  • the first difference is the difference between the electromotive force of the first cell group 1 and the electromotive force of the second cell group 2 since the heating starts.
  • the second difference is the difference between the electromotive force of the first cell group 1 and the electromotive force of the second cell group 2 at the end of self-heating.
  • the ratio of the first target difference to the first difference within the preset interval means that at the end of self-heating, the total charge loss of the first battery group 1 during the entire heating process is equal to the total charge loss of the second battery group 2 during the heating process.
  • the difference between the total loss of charge during the entire heating process is within a certain extent, thereby ensuring the balance between the first battery group 1 and the second battery group 2, and self-heating will have an impact on the available power of the electric vehicle and The adverse effects on cruising range are controlled to a certain extent.
  • the first controller 6 adjusts the drive signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: the first controller 6 adjusts the drive signal , so that the ratio between the second target difference value and the fifth intensity integrated value is within the preset interval.
  • the second target difference is the difference between the fifth intensity integral value and the sixth intensity integral value
  • the fifth intensity integral value is the intensity integral value of the current flowing through the first battery core group 1 during the self-heating process
  • the integrated value is the integrated value of the intensity of the current flowing through the second battery core group 2 during the self-heating process.
  • the integrated value of the intensity of the current is the integrated value of the current intensity in time.
  • the current flowing through the first cell group 1 and the current flowing through the second cell group 2 refer to the theoretical current or the measured current at the same time.
  • the preset interval range is (-0.9, +0.9).
  • the preset interval range is (-0.5, +0.5).
  • the preset interval range is (-0.1, +0.1).
  • the preset interval range is (-0.05, +0.05).
  • the preset interval range is (-0.005, +0.005).
  • different first differences correspond to different preset intervals. That is to say, the difference between the electromotive force of the first cell group 1 and the electromotive force of the second cell group 2 when heating starts will affect Default interval range.
  • the narrower the preset interval range is (for example, the preset interval range is (-0.05, +0.05) ).
  • the mapping relationship between the first difference value and the preset interval range is pre-stored in the electric vehicle.
  • the difference between the electromotive force of the first battery cell group 1 and the electromotive force of the second battery cell group 2 is detected. value, find the corresponding preset interval range according to the pre-stored mapping relationship.
  • the integrated value of the intensity of the current refers to the integrated value of the current intensity in time.
  • Current intensity refers to the size of the current, which is a positive value.
  • Current intensity can represent the amount of charge passing through a conductor per unit time.
  • the theoretical current is a theoretical current determined through non-actual measurement, and can be calculated based on the driving signal.
  • the measured current refers to the current determined by actual measurement.
  • the first controller adjusts the drive signal during the self-heating process so that the ratio of the first target difference to the first difference is within a preset interval, including: the first controller adjusts the drive signal during the self-heating process. Adjust the duty cycle of the drive signal and/or the timing state of the drive signal so that the ratio of the first target difference to the first difference is within the preset interval.
  • the timing status of the driving signal is the timing status of the driving signals Q1-Q3 of the three upper-side arms, or the timing status of the driving signals Q4-Q6 of the three lower-side arms.
  • "1" is used to indicate that an upper bridge arm is turned on.
  • the upper bridge arm is turned on, its corresponding lower bridge arm is disconnected.
  • the upper bridge arm is disconnected, its corresponding lower bridge arm is turned on.
  • timings of the three-phase bridge arms of the inverter that is, there are 8 kinds of timing states of the driving signals, namely U0(000), U1(001), U2(010), U3(011), U4( 100), U5(101), U6(110), U7(111).
  • U1(001), U2(010), U3(011), U4(100), U5(101), and U6(110) are non-zero vectors
  • U0(000) and U7(111) are zero vectors.
  • the first controller adjusts the driving signal during the self-heating process, including: the first controller adjusts the driving signal in a dynamic and real-time manner during the self-heating process. That is to say, the first controller adjusts the driving signal in real time to promptly correct the difference between the charge loss of the first battery group 1 and the charge loss of the second battery group 2 to avoid The excitation current fluctuates greatly.
  • the first preset ratio is determined in advance through a heating test experiment.
  • the heating test experiment can be a heating test performed on the electric vehicle before the vehicle leaves the factory, in which high-precision Hall elements, etc. can be used to accurately measure the excitation current.
  • the process of determining the first preset ratio includes steps S102-S104.
  • Step S102 Obtain the first intensity integral value of the first experimental current and the first intensity product of the second experimental current.
  • the ratio of points is used as the second ratio.
  • the driving signal is set at the beginning of the heating test experiment so that the ratio of the first intensity integrated value of the first theoretical current and the first intensity integrated value of the second theoretical current is 1.
  • the first experimental current and the second theoretical current are obtained.
  • Experimental current The first theoretical current is the theoretical current flowing through the first cell group 1, and the second theoretical current is the theoretical current flowing through the second cell group 2.
  • the first theoretical current and the second theoretical current are determined through non-actual measurement.
  • the current can be calculated based on the driving signal.
  • the first intensity integral value of the first theoretical current is the intensity integral value of the first theoretical current from the beginning of the heating test experiment to the end of the heating test experiment
  • the first intensity integral value of the second theoretical current is the intensity integral value from the beginning of the heating test experiment to the end of the heating test.
  • the intensity integrated value of the second theoretical current during the end of the test experiment.
  • the first experimental current is the measured current flowing through the first cell group 1 in the heating test experiment
  • the second experimental current is the measured current flowing through the second cell group 2 in the heating test experiment.
  • the first experimental current and the second experimental current are obtained through actual measurement.
  • the first intensity integrated value of the first experimental current is the intensity integrated value of the first experimental current from the beginning of the heating test experiment to the end of the heating test experiment.
  • the first intensity integrated value of the second experimental current is the intensity integral value of the second experimental current from the beginning of the heating test experiment to the end of the heating test experiment. Integrated intensity value of the second experimental current during the end period.
  • Step S104 Determine a first preset ratio, which is the reciprocal of the second ratio.
  • the first experimental current and the second experimental current include the influence of electrical control error and motor coil loss.
  • the first intensity integral value of the first experimental current can be reflected in the first theoretical current condition, when the first battery core group 1 is heating.
  • the true degree of loss of charge in the test experiment the first intensity integral value of the second experimental current can reflect the true degree of loss of charge in the second battery core group 2 in the heating test experiment under the second theoretical current.
  • the first preset ratio is 100/99.
  • the first preset ratio corresponding to each type of battery pack must be determined through respective heating test experiments.
  • the first battery pack 1 and the second battery pack 2 are divided in different ways in each battery pack, it is also necessary to determine the corresponding first battery pack for each battery pack through respective heating test experiments. Default ratio.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio between the first target difference and the first difference is within a preset interval, which may include steps S202-S206.
  • Step S202 Calculate the first theoretical current and the second theoretical current during the self-heating process.
  • Step S204 Correct the first theoretical current and the second theoretical current based on the first preset ratio.
  • the ratio of the second intensity integrated value of the first theoretical current to the second intensity integrated value of the second theoretical current is: The first preset ratio.
  • the second intensity integral value of the first theoretical current is the intensity integral value of the first theoretical current during the period from the beginning of heating to the end of self-heating
  • the second intensity integral value of the second theoretical current is the period from the beginning of self-heating to the end of self-heating. The intensity integrated value of the second theoretical current.
  • Step S206 Set the driving signal based on the corrected first theoretical current and the corrected second theoretical current.
  • the first theoretical current calculated based on the drive signal is the above-mentioned corrected first theoretical current, calculated based on the drive signal
  • the second theoretical current obtained is the above-mentioned corrected second theoretical current.
  • control error and charge loss error caused by motor coil loss ensure that the intensity integral value of the first measured current from the beginning of self-heating to the end of self-heating and the intensity integral value of the second measured current from the beginning of self-heating to the end of self-heating are Basically the same.
  • the first adjustment method it can be ensured that the difference between the total loss of charge of the first battery group 1 and the total loss of charge of the second battery group 2 due to self-heating is within a certain extent, thereby ensuring The balance between the first battery cell group 1 and the second battery cell group 2 controls the adverse effects of self-heating on the available power and cruising range of the electric vehicle to a certain extent.
  • the first preset ratio is determined in advance through a heating test experiment.
  • the heating test experiment can be a heating test performed on the electric vehicle before the vehicle leaves the factory, in which high-precision Hall elements, etc. can be used to accurately measure the excitation current.
  • the process of determining the first preset ratio includes steps P102-P104.
  • Step P102 Obtain the ratio of the fourth effective value of the first measured current to the fourth effective value of the second measured current as the second ratio.
  • the effective value of the current is the root mean square value well-known in the industry, which is defined as the heat generated by the current passing through a resistor within a given period of time and the heat generated by the direct current passing through the resistor in the same period of time.
  • the heat is equal, and the DC value is the effective value of the current.
  • the driving signal is set so that the ratio of the first effective value of the first theoretical current to the first effective value of the second theoretical current is 1.
  • the first measured current and the second measured current are obtained.
  • the first theoretical current is the theoretical current flowing through the first cell group 1
  • the second theoretical current is the theoretical current flowing through the second cell group 2.
  • the first theoretical current and the second theoretical current are determined through non-actual measurement.
  • the current can be calculated based on the driving signal.
  • the first effective value of the first theoretical current is the effective value of the first theoretical current from the beginning of the heating test experiment to the end of the heating test experiment
  • the first effective value of the second theoretical current is the effective value of the first theoretical current from the beginning of the heating test experiment to the end of the heating test experiment.
  • the effective value of the second theoretical current during the period.
  • the first measured current is the measured current flowing through the first cell group 1
  • the second measured current is the measured current flowing through the second cell group 2 .
  • the fourth effective value of the first measured current is the effective value of the first measured current from the beginning to the end of the heating test experiment
  • the fourth effective value of the second measured current is the effective value from the beginning to the end of the heating test experiment.
  • the effective value of the second measured current is the effective value of the second measured current.
  • Step P104 Determine a first preset ratio, which is the reciprocal of the second ratio.
  • the first measured current and the second measured current include the influence of electrical control error and motor coil loss.
  • the fourth effective value of the first measured current can be reflected in the first theoretical current condition, when the first battery core group 1 is tested during the heating test.
  • the true degree of charge loss in the experiment and the fourth effective value of the second measured current can be reflected in the true loss degree of the charge of the second battery cell group 2 in the heating test experiment under the second theoretical current.
  • the ratio of the fourth effective value of the first measured current to the fourth effective value of the second measured current is 99/100, Then the first preset ratio is 100/99.
  • the first preset ratio corresponding to each type of battery pack must be determined through respective heating test experiments.
  • the first battery pack 1 and the second battery pack 2 are divided in different ways in each battery pack, it is also necessary to determine the corresponding first battery pack for each battery pack through respective heating test experiments. Default ratio.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio between the first target difference and the first difference is within a preset interval, which may include steps P202-P206.
  • Step P202 Calculate the first theoretical current and the second theoretical current during the self-heating process.
  • Step P204 Correct the first theoretical current and the second theoretical current based on the first preset ratio.
  • the ratio of the second effective value of the first theoretical current to the second effective value of the second theoretical current is the first preset ratio.
  • the second effective value of the first theoretical current is the effective value of the first theoretical current from the beginning of heating to the end of self-heating
  • the second effective value of the second theoretical current is the second effective value of the second theoretical current from the beginning of self-heating to the end of self-heating. The effective value of the theoretical current.
  • Step P206 Set the driving signal based on the corrected first theoretical current and the corrected second theoretical current.
  • the first theoretical current calculated based on the drive signal is the above-mentioned corrected first theoretical current
  • the second theoretical current is the modified second theoretical current mentioned above.
  • control error and charge loss error caused by motor coil loss ensure that the effective value of the first measured current from the beginning of self-heating to the end of self-heating is basically the same as the effective value of the second measured current from the beginning of self-heating to the end of self-heating. of.
  • the first adjustment method it can be ensured that the difference between the total loss of charge of the first battery group 1 and the total loss of charge of the second battery group 2 due to self-heating is within a certain extent, thereby ensuring The balance between the first battery cell group 1 and the second battery cell group 2 controls the adverse effects of self-heating on the available power and cruising range of the electric vehicle to a certain extent.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within the preset interval, including steps S302-304.
  • Step S302 Obtain the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current.
  • the first measured current is the measured current flowing through the first cell group 1
  • the second measured current is the measured current flowing through the second cell group 2
  • the second intensity integral value of the first measured current is the intensity integral value of the first measured current from the beginning of heating to the end of the current adjustment period
  • the second intensity integral value of the second measured current is the intensity integral value of the second actual measured current from the beginning of heating to the end of the current adjustment period.
  • the intensity integrated value of the second measured current during the end period is the intensity integrated value of the second measured current during the end period.
  • Step S304 The second intensity integrated value based on the first measured current and the second intensity product of the second measured current. Score, sets the drive signal for the next adjustment cycle.
  • setting the drive signal for the next adjustment period includes: setting the duty cycle and/or timing state of the drive signal for the next adjustment period so that the second absolute value is smaller than the first absolute value.
  • the first absolute value is the absolute value of the difference between the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current.
  • the second absolute value is the absolute value of the difference between the fourth intensity integrated value of the first measured current and the fourth intensity integrated value of the second measured current.
  • the fourth intensity integral value of the first measured current is the intensity integral value of the first measured current from the beginning of heating to the end of the next adjustment period
  • the fourth intensity integral value of the second measured current is the intensity integral value of the second measured current from the beginning of heating to the end of the next adjustment period. The intensity integrated value of the second measured current during the end of the adjustment period.
  • the second intensity integral value of the first measured current is 90, and the second intensity integral value of the second measured current is 100, then the first absolute value is 10.
  • Set the driving signal for the next adjustment period so that the fourth intensity integral value of the first measured current becomes 95, the fourth intensity integral value of the second measured current becomes 102, and the second absolute value is 7.
  • the second absolute value is smaller than the first absolute value, indicating that at the end of the next cycle, the difference between the total charge loss of the first battery cell group 1 and the total charge loss of the second battery cell group 2 becomes smaller.
  • the driving signal may not be adjusted, and the driving signal of the next adjustment period and The drive signal for the current regulation cycle is the same. If the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current are not within the preset interval, set the duty cycle and/or timing state of the driving signal in the next adjustment period so that the second The absolute value is less than the first absolute value.
  • the first controller adjusts the driving signal in real time, so as to promptly correct the difference between the charge loss of the first cell group 1 and the charge loss of the second cell group 2, This avoids large fluctuations in the excitation current and improves the stability of the self-heating process.
  • Example 2 The first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within the preset interval, including steps S402-S406.
  • Step S402 Obtain the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current.
  • the first measured current is the measured current flowing through the first cell group 1
  • the second measured current is the measured current flowing through the second cell group
  • the second intensity integral value of the first measured current is the intensity integral value of the first measured current from the beginning of heating to the end of the current adjustment period
  • the second intensity integral value of the second measured current is the intensity integral value of the second actual measured current from the beginning of heating to the end of the current adjustment period.
  • the intensity integrated value of the second measured current during the end period is the intensity integrated value of the second measured current during the end period.
  • Step S404 Obtain the third intensity integrated value of the first measured current and the third intensity integrated value of the second measured current.
  • the third intensity integral value of the first measured current is the intensity integral value of the first measured current during the current adjustment period
  • the third intensity integral value of the second measured current is the intensity integral value of the second actual measured current during the current adjustment period. value.
  • Step S406 Based on the second intensity integrated value of the first measured current, the second intensity integrated value of the second measured current, the third intensity integrated value of the first measured current, and the third intensity integrated value of the second measured current, set the following A driving signal that regulates the cycle.
  • setting the drive signal for the next adjustment period includes: setting the duty cycle and/or timing state of the drive signal for the next adjustment period so that the second absolute value is smaller than the first absolute value.
  • the first absolute value is the absolute value of the difference between the second intensity integrated value of the first measured current and the second intensity integrated value of the second measured current.
  • the second absolute value is the absolute value of the difference between the fourth intensity integrated value of the first measured current and the fourth intensity integrated value of the second measured current.
  • the fourth intensity integral value of the first measured current is the intensity integral value of the first measured current from the beginning of heating to the end of the next adjustment period
  • the fourth intensity integral value of the second measured current is the intensity integral value of the second measured current from the beginning of heating to the end of the next adjustment period. The intensity integrated value of the second measured current during the end of the adjustment period.
  • the ratio of the second intensity integrated value of the first measured current to the second intensity integrated value of the second measured current is within the preset interval, and the third intensity integrated value of the first measured current is equal to the second intensity integrated value of the first measured current, The ratio of the third intensity integral value of the actual measured current is also within the preset interval, and the driving signal does not need to be adjusted.
  • the driving signal of the next adjustment period is the same as the driving signal of the current adjustment period. If the ratio of the second intensity integrated value of the first measured current to the second intensity integrated value of the second measured current is not within the preset interval, set the duty cycle and/or timing state of the drive signal in the next adjustment period, such that The second absolute value is less than the first absolute value.
  • the first controller adjusts the driving signal in real time, so as to promptly correct the difference between the charge loss of the first cell group 1 and the charge loss of the second cell group 2, This avoids large fluctuations in the excitation current and improves the stability of the self-heating process.
  • the second intensity integrated value of the first measured current, the second intensity integrated value of the second measured current, the third intensity integrated value of the first measured current and the third intensity integrated value of the second measured current are simultaneously considered. The intensity integrated value can accurately determine the driving signal for the next adjustment period.
  • the first controller adjusts the driving signal during the self-heating process so that the ratio between the first target difference and the first difference is within the preset interval, including steps P302-P304.
  • Step P302 Obtain the first effective value of the first measured current and the first effective value of the second measured current.
  • the first measured current is the measured current flowing through the first cell group 1
  • the second measured current is the measured current flowing through the second cell group 2
  • the first effective value of the first measured current is the effective value of the first measured current from the start of heating to the end of the current adjustment period
  • the first effective value of the second measured current is the effective value of the second actual measured current from the start of heating to the end of the current adjustment period. The effective value of the second measured current.
  • Step P304 Set the driving signal for the next adjustment cycle based on the first effective value of the first measured current and the first effective value of the second measured current.
  • setting the drive signal for the next adjustment period includes: setting the duty cycle and/or timing state of the drive signal for the next adjustment period so that the fourth absolute value is smaller than the third absolute value.
  • the third absolute value is the absolute value of the difference between the first effective value of the first measured current and the first effective value of the second measured current. That , the fourth absolute value is the absolute value of the difference between the third effective value of the first measured current and the third effective value of the second measured current.
  • the third effective value of the first measured current is the effective value of the first measured current from the beginning of heating to the end of the next adjustment cycle
  • the third effective value of the second measured current is the effective value of the second actual measured current from the beginning of heating to the end of the next adjustment cycle. The effective value of the second measured current during the period.
  • the first effective value of the first measured current is 90
  • the first effective value of the second measured current is 100
  • the third absolute value is 10.
  • the driving signal in the next adjustment period is adjusted so that the third effective value of the first measured current becomes 95
  • the third effective value of the second measured current becomes 102
  • the fourth absolute value is 7.
  • the fourth absolute value is smaller than the third absolute value, indicating that at the end of the next cycle, the difference between the total charge loss of the first cell group 1 and the total charge loss of the second cell group 2 becomes smaller.
  • the driving signal in the next adjustment period is not adjusted. If the first effective value of the first measured current and the first effective value of the second measured current are not within the preset interval, adjust the duty cycle of the drive signal and/or the timing status of the drive signal in the next adjustment period, Make the fourth absolute value smaller than the third absolute value.
  • the first controller adjusts the driving signal in real time, so as to promptly correct the difference between the charge loss of the first cell group 1 and the charge loss of the second cell group 2, This avoids large fluctuations in the excitation current and improves the stability of the self-heating process.
  • Example 4 The first controller adjusts the driving signal during the self-heating process so that the ratio of the first target difference to the first difference is within the preset interval, including steps P402-P406.
  • Step P402 Obtain the first effective value of the first measured current and the first effective value of the second measured current.
  • the first measured current is the measured current flowing through the first cell group 1
  • the second measured current is the measured current flowing through the second cell group 2
  • the first effective value of the first measured current is the effective value of the first measured current from the start of heating to the end of the current adjustment period
  • the first effective value of the second measured current is the effective value of the second actual measured current from the start of heating to the end of the current adjustment period. The effective value of the second measured current.
  • Step P404 Obtain the second effective value of the first measured current and the second effective value of the second measured current.
  • the second effective value of the first measured current is the effective value of the first measured current during the current adjustment period
  • the second effective value of the second measured current is the effective value of the second measured current during the current adjustment period
  • Step P406 Based on the first effective value of the first measured current, the first effective value of the second measured current, the second effective value of the first measured current, and the second effective value of the second measured current, set the value of the next adjustment period. driving signal.
  • setting the drive signal for the next adjustment period includes: setting the duty cycle and/or timing state of the drive signal for the next adjustment period so that the fourth absolute value is smaller than the third absolute value.
  • the third absolute value is the absolute value of the difference between the first effective value of the first measured current and the first effective value of the second measured current.
  • the fourth absolute value is the absolute value of the difference between the third effective value of the first measured current and the third effective value of the second measured current.
  • the third effective value of the first measured current is the effective value of the first measured current from the start of heating to the end of the next adjustment cycle
  • the third effective value of the second measured current is the effective value of the second actual measured current from the start of heating to the end of the next adjustment cycle. The effective value of the second measured current during the end of the period.
  • the ratio of the first effective value of the first measured current to the first effective value of the second measured current is within the preset interval, and the ratio of the second effective value of the first measured current to the second effective value of the second measured current The ratio of the second effective value is also within the preset interval, and the driving signal in the next adjustment period is not adjusted. If the ratio of the first effective value of the first measured current to the first effective value of the second measured current is not within the preset interval, the duty cycle of the drive signal and/or the timing status of the drive signal in the next adjustment period are determined. Adjust so that the fourth absolute value is smaller than the third absolute value.
  • the duty cycle of the drive signal and/or the timing status of the drive signal in the next adjustment period are determined. Adjust so that the fourth absolute value is smaller than the third absolute value.
  • the first controller adjusts the driving signal in real time, so as to promptly correct the difference between the charge loss of the first cell group 1 and the charge loss of the second cell group 2, This avoids large fluctuations in the excitation current and improves the stability of the self-heating process.
  • the first effective value of the first measured current, the first effective value of the second measured current, the second effective value of the first measured current and the second effective value of the second measured current are simultaneously considered,
  • the drive signal for the next adjustment cycle can be determined in a refined manner.
  • the control method of the first controller is feedback closed-loop control.
  • the adjustment mode of the first controller is PI (Proportion Integration, proportional-integral control).
  • the adjustment method of the first controller is PID (Proportion Integration Differentiation, proportional-integral-derivative control), which is a composite control that is a superposition of proportional, integral and differential parts.
  • Proportional control is a simple control method based on proportion. Only in proportional control, the system has a steady-state error and cannot completely eliminate fixed disturbances added by the outside world. The main purpose of integral control is to eliminate steady-state errors. The purpose of differential control is to eliminate large fluctuations in the system.
  • the electric control error and the charge loss error caused by the loss of the motor coil still exist, these errors are corrected in time according to the adjustment cycle to ensure that the first measured current from the beginning of self-heating to the end of self-heating is accurate.
  • the intensity integrated value or effective value is substantially the same as the degree integrated value or effective value of the second measured current during the period from the beginning of self-heating to the end of self-heating.
  • the second adjustment method it can be ensured that the difference between the total loss of charge of the first battery group 1 and the total loss of charge of the second battery group 2 due to self-heating is within a certain extent, thereby ensuring The balance between the first battery cell group 1 and the second battery cell group 2 controls the adverse effects of self-heating on the available power and cruising range of the electric vehicle to a certain extent.
  • the battery cells in the battery pack are lithium iron phosphate battery cells or ternary lithium battery cells or batteries of other chemical systems.
  • the capacities of these two batteries under self-heating conditions are obtained in advance based on a large number of tests. After judging the safety boundary range of the retention rate, formulate the following control strategy:
  • the first controller is also used to adjust the driving signal during the self-heating process, so that the average effective value of the current flowing through the first battery core group 1 during the entire self-heating period is between 0.5C and 5C. flows through the second cell
  • the average value of the current effective value of group 2 during the entire self-heating period is between 0.5C and 5C.
  • this requirement can be achieved by adjusting the duty cycle and/or timing state of the drive signal.
  • the current flowing through the first cell group 1 and the current flowing through the second cell group 2 refer to the theoretical current or the measured current at the same time.
  • the first controller is also used to adjust the driving signal during the self-heating process so that the effective value of the current flowing through the neutral point of the AC motor has an average value between 1C and 10C during the entire self-heating period. In one example, this requirement can be achieved by adjusting the duty cycle and/or timing state of the drive signal.
  • the current flowing through the first cell group 1 and the current flowing through the second cell group 2 refer to the theoretical current or the measured current at the same time.
  • the driving signal output by the first controller is a PWM (Pulse width modulation wave, pulse width modulation) driving signal.
  • the first controller uses SVPWM (Space Vector Pulse Width Modulation, Network Space Vector Pulse Width Modulation) modulation method to output the driving signal.
  • SVPWM Space Vector Pulse Width Modulation, Network Space Vector Pulse Width Modulation
  • the battery core can be prevented from being overcharged or overdischarged at low temperatures, thus ensuring the safety of the battery core.
  • the embodiment of the present disclosure takes into account both the temperature-raising efficiency and safety of the self-heating process, and can efficiently heat the power battery while avoiding excessive damage to the battery life, and ensuring the safety of the battery.
  • the above strategies can be implemented in a superimposed manner to achieve better results.
  • the first controller is also used to synchronously control the on-off states of the three upper bridge arms and synchronously control the on-off states of the three lower bridge arms during the self-heating process.
  • the three upper bridge arms are turned on/off at the same time, and correspondingly, the three lower bridge arms are turned off/on at the same time.
  • the first controller of the embodiment of the present disclosure may include a processor and a memory, as well as a program or instructions stored on the memory and executable on the processor. When the program or instructions are executed by the processor, any one of the foregoing embodiments can be implemented. Heating control strategy.
  • An embodiment of the present disclosure provides an electric vehicle, including a power battery and a heating system for heating the power battery according to any of the foregoing embodiments.
  • Embodiments of this specification may be systems, methods, and/or computer program products.
  • a computer program product may include a computer-readable storage medium having computer instructions thereon for causing a processor to implement various aspects of the embodiments of this specification.
  • a computer-readable storage medium may be a medium that can retain and store computations used by a computer instruction execution device Physical equipment for machine instructions.
  • the computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above.
  • Non-exhaustive list of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory), Static Random Access Memory (SRAM), Compact Disk Read Only Memory (CD-ROM), Digital Versatile Disk (DVD), Memory Stick, Floppy Disk, Mechanically encoded device, such as one on which computer instructions are stored Punch cards or raised structures in grooves, and any suitable combination of the above.
  • RAM random access memory
  • ROM read-only memory
  • EPROM erasable programmable read-only memory
  • flash memory Static Random Access Memory
  • CD-ROM Compact Disk Read Only Memory
  • DVD Digital Versatile Disk
  • Memory Stick Memory Stick
  • Mechanically encoded device such as one on which computer instructions are stored Punch cards or raised structures in grooves, and any suitable combination of the above.
  • computer-readable storage media are not to be construed as transient signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or through electrical wires. transmitted electrical signals.
  • the computer instructions described herein may be downloaded from a computer-readable storage medium to various computing/processing devices, or to an external computer or external storage device over a network, such as the Internet, a local area network, a wide area network, and/or a wireless network.
  • the network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and/or edge servers.
  • a network adapter card or network interface in each computing/processing device receives computer instructions from the network and forwards the computer instructions for storage on a computer-readable storage medium in the respective computing/processing device.
  • each block in the flowchart or block diagrams may represent a module, segment, or portion of computer instructions that embody one or more elements for implementing the specified logical function(s). Can execute computer instructions.
  • the functions noted in the block may occur out of the order noted in the figures. For example, two consecutive blocks may actually execute substantially in parallel, or they may sometimes execute in the reverse order, depending on the functionality involved.
  • each block of the block diagram and/or flowchart illustration, and combinations of blocks in the block diagram and/or flowchart illustration can be implemented by special purpose hardware-based systems that perform the specified functions or acts. , or can be implemented using a combination of specialized hardware and computer instructions. It is well known to those skilled in the art that implementation through hardware, implementation through software, and implementation through a combination of software and hardware are all equivalent.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)
  • General Induction Heating (AREA)

Abstract

本公开提供了一种用于加热动力电池的加热系统和电动车。动力电池包括电动势不等且串联的第一电芯组和第二电芯组。该加热系统包括逆变器、交流电动机和第一控制器。逆变器的三个桥臂中点与电动机的三相线圈的头端一一对应连接，电动机的末端连接在一起形成中性点。电动机的中性点与第一连接点通过连接线路连接，第一连接点为第一电芯组和第二电芯组之间的连接点。第一控制器用于向逆变器输入驱动信号第一电芯组、第二电芯组、逆变器、电动机以及连接线路构成交流电自加热回路。

Description

用于加热动力电池的加热系统和电动车
本公开要求于2022年04月28日提交中国专利局的申请号为202210456060.9、申请名称为“动力电池的加热系统和电动车”的中国专利申请的优先权，其全部内容通过引用结合在本公开中。
技术领域
本公开涉及车辆技术领域，更具体地，涉及一种用于加热动力电池的加热系统和电动车。
背景技术
动力电池的特性受环境温度的影响比较显著，特别是在低温环境中，锂离子动力电池的能量和功率特性会出现严重衰减，因此需要在低温情况下对电池进行加热。对于利用激励电流对电芯进行自加热这种加热方式，如何提升其加热性能成为关键问题。
发明内容
本公开的一个目的是提供一种用于加热动力电池的加热系统的新技术方案。
本公开的又一个目的是提供一种电动车的新技术方案，该电动车包括动力电池以及该加热系统。
本公开提供用于加热动力电池的加热系统，可以提升加热性能。
根据本公开的第一方面，提供了用于加热动力电池的加热系统。所述动力电池包括串联的第一电芯组和第二电芯组，所述第一电芯组的电动势和所述第二电芯组的电动势不等；所述加热系统包括逆变器、交流电动机和第一控制器；所述逆变器包括三个桥臂，所述动力电池的正极与所述逆变器的上桥臂连接，所述动力电池的负极与所述逆变器的下桥臂连接；所述逆变器的三个桥臂中点与所述交流电动机的三相线圈的头端一一对应连接，所述交流电动机的末端连接在一起形成中性点；所述交流电动机的中性点与第一连接点通过连接线路连接，所述第一连接点为第一电芯组和第二电芯组之间的连接点；所述第一控制器用于向所述逆变器输入驱动信号；所述第一电芯组、所述第二电芯组、所述逆变器、所述交流电动机以及所述连接线路构成交流电自加热回路；所述第一控制器还用于在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内；其中，所述第一目标差值为第一差值和第二差值的差值，所述第一差值为自加热开始时第一电芯组的电动势与第二电芯组的电动势的 差值，所述第二差值为自加热结束时第一电芯组的电动势与第二电芯组的电动势的差值。
根据本公开的实施例，所述预设区间范围为(-0.9，+0.9)。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：所述第一控制器在自加热过程中调节所述驱动信号的占空比和/或驱动信号的时序状态，以使得所述第一目标差值与所述第一差值的比值在所述预设区间范围内。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：所述第一控制器调节所述驱动信号，以使得第二目标差值在与第五强度积分值之间的比值在预设区间范围内。
根据本公开的实施例，所述第二目标差值为第五强度积分值和第六强度积分值的差值，所述第五强度积分值为自加热过程中流经所述第一电芯组的电流的强度积分值，所述第六强度积分值为自加热过程中流经所述第二电芯组的电流的强度积分值；其中，电流的强度积分值是电流的电流强度在时间上的积分值。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：计算自加热过程中的第一理论电流和第二理论电流；基于第一预设比值修正第一理论电流和第二理论电流；基于修正后的第一理论电流和修正后的第二理论电流设置所述驱动信号；其中，所述第一理论电流为流经所述第一电芯组的理论电流，所述第二理论电流为流经所述第二电芯组的理论电流。
根据本公开的实施例，所述第一预设比值预先通过加热测试实验确定；所述确定第一预设比值，包括：获取第一实验电流的第一强度积分值和第二实验电流的第一强度积分值的比值作为第二比值；确定所述第一预设比值，所述第一预设比值为第二比值的倒数；其中，所述第一实验电流为加热测试实验中流经所述第一电芯组的实测电流，第二实验电流为加热测试实验中流经所述第二电芯组的实测电流；其中，所述第一实验电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的所述第一实验电流的强度积分值，所述第二实验电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的所述第二实验电流的强度积分值。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：获取第一实测电流的第二强度积分值和第二实测电流的第二强度积分值；基于所述第一实测电流的所述第二强度积分值和所述第二实测电流的所述第二强度积分值，设置下一个调节周期的驱动信号；其中，所述第一实测电流为流经所述第一电芯组的实测电流，所述第二实测电流为流经所述第二电芯组的实测电流；
其中，所述第一实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第一实测电流的强度积分值，所述第二实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第二实测电流的强度积分值。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：获取第一实测电流的第二强度积分值和第二实测电流的第二强度积分值；获取第一实测电流的第三强度积分值和第二实测电流的第三强度积分值；基于所述第一实测电流的第二强度积分值、所述第二实测电流的第二强度积分值、所述第一实测电流的第三强度积分值以及所述第二实测电流的第三强度积分值，设置下一个调节周期的驱动信号；
其中，所述第一实测电流为流经所述第一电芯组的实测电流，所述第二实测电流为流经所述第二电芯组的实测电流；
其中，所述第一实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第一实测电流的强度积分值，所述第二实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第二实测电流的强度积分值；
其中，所述第一实测电流的第三强度积分值是当前调节周期期间的第一实测电流的强度积分值，所述第二实测电流的第三强度积分值是当前调节周期期间的第二实测电流的强度积分值。
根据本公开的实施例，所述设置下一个调节周期的驱动信号，包括：设置所述下一个调节周期的驱动信号的占空比和/或时序状态，以使得第二绝对值小于第一绝对值；其中，所述第一绝对值是所述第一实测电流的第二强度积分值和所述第二实测电流的第二强度积分值的差值的绝对值；
其中，所述第二绝对值是所述第一实测电流的第四强度积分值和所述第二实测电流的第四强度积分值的差值的绝对值；
其中，所述第一实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第一实测电流的强度积分值，所述第二实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第二实测电流的强度积分值。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：获取第一实测电流的第一有效值和第二实测电流的第一有效值；基于所述第一实测电流的第一有效值和所述第二实测电流的第一有效值，设置下一个调节周期的驱动信号；
其中，所述第一实测电流为流经所述第一电芯组的实测电流，所述第二实测电流为流经所述第二电芯组的实测电流；
其中，所述第一实测电流的第一有效值是自加热开始至当前调节周期结束期间的第一实测电流的有效值，所述第二实测电流的第一有效值是自加热开始至当前调节周期结束期间的第二实测电流的有效值。
根据本公开的实施例，所述第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：获取第一实测电流的第一有效值和第二实测电流的第一有效值；获取第一实测电流的第二有效值和第二实测电流的第二有效值；基于所述第一实测电流的第一有效值、所述第二实测电流的第一有效值、所述第一实测电流的第二有效值以及所述第二实测电流的第二有效值，设置下一 个调节周期的驱动信号；
其中，所述第一实测电流为流经所述第一电芯组的实测电流，所述第二实测电流为流经所述第二电芯组的实测电流；
其中，所述第一实测电流的第一有效值是自加热开始至当前调节周期结束期间的第一实测电流的有效值，所述第二实测电流的第一有效值是自加热开始至当前调节周期结束期间的第二实测电流的有效值；
其中，所述第一实测电流的第二有效值是当前调节周期期间的第一实测电流的有效值，所述第二实测电流的第二有效值是当前调节周期期间的第二实测电流的有效值。
根据本公开的实施例，所述设置下一个调节周期的驱动信号，包括：设置所述下一个调节周期的驱动信号的占空比和/或时序状态，以使得第四绝对值小于第三绝对值；
其中，所述第三绝对值是所述第一实测电流的第一有效值和所述第二实测电流的第一有效值的差值的绝对值；
其中，所述第四绝对值是所述第一实测电流的第三有效值和所述第二实测电流的第三有效值的差值的绝对值；
其中，所述第一实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第一实测电流的有效值，所述第二实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第二实测电流的有效值。
根据本公开的实施例，所述第一控制器的调节方式为PID调节方式。
根据本公开的实施例，所述第一控制器还用于在自加热过程中对所述三个上桥臂的通断状态进行同步控制，对所述三个下桥臂的通断状态进行同步控制。
根据本公开的实施例，所述第一控制器还用于在自加热过程中调节驱动信号，使得流经所述第一电芯组的电流有效值在整个自加热期间的平均值在0.5C到5C之间，流经所述第二电芯组的电流有效值在整个自加热期间的平均值在0.5C到5C之间。
根据本公开的实施例，所述第一控制器还用于在自加热过程中调节驱动信号，使得流经所述交流电动机的中性点的电流有效值在整个自加热期间的平均值在1C到10C之间。
根据本公开的实施例，所述中心段为由一段或多段弧形结构组成的曲线结构，或者所述中心段为由一段或多段弧形结构与一段或多段直线结构组成的曲线结构。
根据本公开的第二方面，提供了一种电动车，包括动力电池以及上述任一实施例所述的加热系统。
根据本公开的一个实施例，在电动车原有电路拓扑结构的基础上增加一条回路，该回路是从交流电动机的中性点至第一电芯组和第二电芯组之间的连接点，利用这一加热系统可以在整体上提升加热性能。本公开的用于加热动力电池的加热系统和电动车，第一控制器在自加热过程中调节驱动信号，使得第一目标差值与第一差值的比值在预设区间范围内，可以保证在自加热结束时，第一电芯组的电荷量损失和第二电芯组电荷量的损失之间的差异不会过大，从而保证第一电芯组和第二电芯组之间的均衡性，降低自加热对电动车的可用电量和续航里程产生的不良影响。
通过以下参照附图对本公开的示例性实施例的详细描述，本公开的其它特征及其优点将会变得清楚。
附图说明
被结合在说明书中并构成说明书的一部分的附图示出了本公开的实施例，并且连同其说明一起用于解释本公开的原理。
图1是本公开实施例提供的用于加热动力电池的加热系统的框图。
图2是本公开实施例提供的用于加热动力电池的加热系统的具体电路图。
附图标记说明：
1、第一电芯组；2、第二电芯组；P-连接点；3、逆变器；4、交流电动机；
N-中性点；5、开关；6、第一控制器；7、保护电路；8、第二控制器；
S1、连接线路。
具体实施方式
现在将参照附图来详细描述本说明书的各种示例性实施例。
以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本说明书实施例及其应用或使用的任何限制。
应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步讨论。
在电动车中，逆变器连接在动力电池和交流电动机之间，逆变器的主要作用之一是将动力电池输出的直流电转变为交流电以驱动交流电动机转动，进而带动轮端转动。本公开实施例的动力电池加热方案，利用了动力电池、逆变器和交流电动机之间的电路拓扑结构，实现对动力电池的加热升温。
本公开实施例中，动力电池包括串联的第一电芯组和第二电芯组，用于加热动力电池的加热系统包括逆变器、交流电动机和第一控制器。逆变器包括三个桥臂，动力电池的正极与逆变器的上桥臂连接，动力电池的负极与逆变器的下桥臂连接，逆变器的三个桥臂中点与交流电动机的三相线圈的头端一一对应连接，交流电动机的末端连接在一起形成中性点。交流电动机的中性点与第一连接点通过连接线路连接，第一连接点为第一电芯组和第二电芯组之间的连接点。第一控制器用于向逆变器输入驱动信号；第一电芯组、第二电芯组、逆变器、交流电动机以及连接线路构成交流电自加热回路。第一控制器用于向逆变器输入驱动信号。在驱动信号的作用下，控制逆变器交替导通第一电芯组和交流电动机、第二电芯组和交流电动机，以使得第一电芯组和第二电芯组交替互相充电。
本公开实施例的用于加热动力电池的加热系统和电动车，在电动车原有电路拓扑结构的基础上增加一条回路，该回路是从交流电动机的中性点至第一电芯组和第二电芯组之间的连接点，利用这一加热系统可以在整体上提升加热性能。下面结合各实施 例进行说明。
参见图1-2所示，说明本公开实施例提供的用于加热动力电池的加热系统。
参见图1-2所示，动力电池包括串联的第一电芯组1和第二电芯组2，加热系统包括逆变器3、交流电动机4、第一控制器6。
交流电动机4为星形连接，三相线圈(线圈A、线圈B、线圈C)的3个末端连接在一起作为公共端，公共端即为交流电动机4的中性点N。
逆变器3包括三个桥臂，动力电池的正极与逆变器3的上桥臂连接，动力电池的负极与逆变器3的下桥臂连接，逆变器3的三个桥臂中点与交流电动机4的三相线圈的头端一一对应连接。在一个例子中，参见图1和图2所示，逆变器3包括IGBT管T1、IGBT管T2、IGBT管T3、IGBT管T4、IGBT管T5以及IGBT管T6，IGBT管T1～T6构成3个桥臂。IGBT(Insulated Gate Bipolar Transistor，绝缘栅双极型晶体管)，是由BJT管(Bipolar Junction Transistor，双极型三极管)和MOS管(Meial-Oxide-Semiconductor，绝缘栅型场效应管)组成的复合型电压驱动式功率半导体器件，兼有MOSFET场效应晶体管的高输入阻抗和GTR(Giant Transistor，电力晶体管)的低导通压降两方面的优点。参见图2所示，在逆变器3中，每个IGBT管还反向并联有二极管，该二极管可以起电路保护作用。在另一个实施例中，IGBT管T1～T6也可以分别替换为MOS管。在另一个实施例中，IGBT管T1～T6也可以分别替换为碳化硅(SiC)功率管。交流电动机的中性点N与第一连接点P通过连接线路S1连接，第一连接点P为第一电芯组和第二电芯组之间的连接点。
在一个例子中，第一电芯组和第二电芯组属于同一个电池包，电池包对外提供总正端口、总负端口以及从第一连接点P处引出的第三端口，第三端口与交流电动机的中性点N之间通过连接线路S1连接。
第一控制器6用于向逆变器3输入驱动信号，以控制逆变器3交替导通第一电芯组1和交流电动机4、第二电芯组2和交流电动机4，以使得第一电芯组1和第二电芯组2交替互相充电。在一个例子中，参见图2所示，第一控制器6输出六路驱动信号Q1～Q6，其中驱动信号Q1施加在IGBT管T1上，驱动信号Q2施加在IGBT管T2上，驱动信号Q3施加在IGBT管T3上，驱动信号Q4施加在IGBT管T4上，驱动信号Q5施加在IGBT管T5上，驱动信号Q6施加在IGBT管T6上。第一控制器6通过向IGBT管T1～T6施加驱动信号Q1～Q6，交替导通第一电芯组1和交流电动机4的回路、第二电芯组2和交流电动机4的回路，使得第一电芯组1和第二电芯组2交替性地给对方充电。在一个例子中，第一电芯组1放电，逆变器3把第一电芯组1输出的直流电转换为交流电输入给交流电动机4，交流电动机4将电能储存在线圈中给第二电芯组2充电。之后，第二电芯组2放电，逆变器3把第二电芯组2输出的直流电转换为交流电输入给交流电动机4，交流电动机4将电能储存在线圈给第一电芯组1充电。循环往复，第一电芯组1和第二电芯组2通过交流电动机4交替给对方充电，从而对电芯进行自加热。
参见图1和图2所示，连接线路S1中设有开关5。该加热系统还包括第二控制 器8，第二控制器8用于控制开关5的通断状态，使得加热线路和加热线路在动力电池需要加热时导通，在动力电池不需要加热时断开，以保证车辆和动力电池的安全性。例如，第二控制器8在电动车行驶状态下控制开关5断开，以保证车辆行驶过的安全性。
参见图1和图2所示，连接线路S1中设有保护电路7，例如设有保险丝、继电器等保护电路，以提升电池加热过程的安全性。
图1中还示出了电动车的配电箱，配电箱主要根据电动车用电负载的情况进行配电。
本公开实施例提供的用于加热动力电池的加热系统，在电动车原有电路拓扑结构的基础上增加连接线路，该连接线路是从交流电动机的中性点至第一电芯组和第二电芯组之间的连接点，对电动车原有电路的改动小，方案简单容易实现。
本公开实施例提供的用于加热动力电池的加热系统，通过分时利用逆变器中的上下桥臂从而可以更大限度利用电动机的三个电感线圈产生交变脉冲电流，从而用于对两组电芯快速加热。
在动力电池自加热过程中，充放电电流，也就是激励电流的频率和大小受限于相关元器件，本公开实施例提供的加热系统可以使得激励电流的受限程度较小，使得以较大激励电流对电池进行加热成为可能。传统电池包在自加热工况下，逆变器的最大电流受限于IGBT管T1～T6耐受电流的最小电流。而在本公开实施例中，逆变器的最大电流受限于IGBT管T1、T2、T3的耐受电流之和，以及受限于IGBT管T4、T5、T6的耐受电流之和，大大提高了可利用电流的范围。
本公开实施例的自加热系统包括还可以包括测量系统、电池管理系统(Battery Management System，BMS)。在自加热过程中，测量系统、电池管理系统监测到的相关数据会实时输出反馈到第一控制器中，第一控制器根据预设策略动态调整自加热系统输出的激励电流的频率或幅值。
本公开实施例中，自加热开始是指连接线路S1从断开状态变为导通状态、第一电芯组和第二电芯组开始交替互相充电。自加热结束是指连接线路S1从导通状态变为断开状态，第一电芯组和第二电芯组不再交替互相充电。
本公开实施例中，第一电芯组和第二电芯组的电动势不等，是指在自加热开始时，第一电芯组的两端的电压差和第二电芯组的两端的电压差不等。
在一个例子中，第一电芯组和第二电芯组中的电芯单元的情况存在区别，导致第一电芯组和第二电芯组的电动势不等。这种区别可能是电芯单元的数量上的区别，或者电芯单元的材质上的区别，或者电芯单元的型号上的区别。在一个例子中，第一电芯组和第二电芯组的电动势不等可以是：第一电芯组的额定电动势和所述第二电芯组的额定电动势不等。
在一个例子中，第一电芯组和第二电芯组在初始设计上是一样的，也就是说，第一电芯组和第二电芯组的初始的电动势是相等的，但由于电动车日常使用造成了第一电芯组和第二电芯组出现了不同程度的损耗，导致第一电芯组和第二电芯组的电动势 变成了不等。
在一个例子中，第一电芯组和第二电芯组属于同一个电池包，第一电芯组和第二电芯组的电动势不等，第一连接点为不等势点，连接线路连接在电池包的不等势点上。不等势点表明该点到电池包总正端口的电压差值绝对值与该点到电池包总负端口的电压差值绝对值不相等。如图2所示，第一电芯组1中包含的电芯单元和第二电芯组2中包含的电芯单元，在型号上相同，在数量上不同，因此第一电芯组1和第二电芯组2的电动势不同，连接点P为不等势点。
传统方案中，由于逆变器中的功率电子开关切换时具有误差、交流电动机的线圈在大电流震荡时具有损耗、以及测量用的霍尔元件在测量时具有误差，导致流过第一电芯组1的电流的功耗与流过第二电芯组2的功耗无法保持，两者之间存在一定误差。这会导致在长期的自加热工况下，第一电芯组1的电荷量的损失和第二电芯组2的电荷量的损失不一致(出现电荷量损失误差)，从而导致第一电芯组1中的电芯单元的SOC(State of Charge，剩余电荷量)和第二电芯组2中的电芯单元的SOC存在差异。
由于动力电池中的电芯单元为串联连接，整车可用电量受限于各电芯单元的SOC中的最低的一个，因此，自加热工况下的第一电芯组1的电荷量的损失和第二电芯组2的电荷量的损失的不一致，会对电动车的可用电量和续航里程产生不良影响。
本公开实施例中，为了解决这一问题，第一控制器6还用于在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内。其中，第一目标差值为第一差值和第二差值的差值，第一差值为自加热开始时第一电芯组1的电动势与第二电芯组2的电动势的差值，第二差值为自加热结束时第一电芯组1的电动势与第二电芯组2的电动势的差值。第一目标差值与第一差值的比值在预设区间范围内意味着在自加热结束时，第一电芯组1在整个加热过程期间的电荷量总损失和第二电芯组2在整个加热过程期间的电荷量的总损失之间的差异在一定程度内，从而保证第一电芯组1和第二电芯组2之间的均衡性，将自加热对电动车的可用电量和续航里程产生的不良影响控制在一定程度内。
在一个例子中，第一控制器6在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：第一控制器6调节驱动信号，以使得第二目标差值在与第五强度积分值之间的比值在预设区间范围内。其中，第二目标差值为第五强度积分值和第六强度积分值的差值，第五强度积分值为自加热过程中流经第一电芯组1的电流的强度积分值，第六强度积分值为自加热过程中流经第二电芯组2的电流的强度积分值。其中，电流的强度积分值是电流的电流强度在时间上的积分值。在这一例子中，流经第一电芯组1的电流和流经第二电芯组2的电流同时是指理论电流或者同时是指实测电流。
在一个例子中，所述预设区间范围为(-0.9，+0.9)。
在一个例子中，所述预设区间范围为(-0.5，+0.5)。
在一个例子中，所述预设区间范围为(-0.1，+0.1)。
在一个例子中，所述预设区间范围为(-0.05，+0.05)。
在一个例子中，所述预设区间范围为(-0.005，+0.005)。
在一个例子中，不同的第一差值对应有不同的预设区间范围，也就是说，自加热开始时第一电芯组1的电动势与第二电芯组2的电动势的差值将影响预设区间范围。在一个例子中，自加热开始时第一电芯组1的电动势与第二电芯组2的电动势的差值越小，则预设区间范围可以越宽(例如，预设区间范围为(-0.9，+0.9))。自加热开始时第一电芯组1的电动势与第二电芯组2的电动势的差值越大，则预设区间范围为越窄(例如，预设区间范围为(-0.05，+0.05))。在一个例子中，电动车中预先存储第一差值和预设区间范围的映射关系，在需要进行自加热时，检测第一电芯组1的电动势与第二电芯组2的电动势的差值，根据预先存储的映射关系查找与对应的预设区间范围。
本公开实施例中，电流的强度积分值是指电流的电流强度在时间上的积分值。电流强度是指电流的大小，为正值。电流强度可以表征单位时间内通过导体的电荷量的情况。
本公开实施例中，理论电流是通过非实测方式确定的理论上的电流，可以根据驱动信号计算得到。实测电流是指通过实测方式确定的电流。
在一个例子中，第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：第一控制器在自加热过程中调节驱动信号的占空比和/或驱动信号的时序状态，以使得第一目标差值与第一差值的比值在所述预设区间范围内。
本公开实施例中，驱动信号的时序状态是三个上桥臂的驱动信号Q1-Q3的时序状态，或三个下桥臂的驱动信号Q4-Q6的时序状态。假设用“1”表示一个上桥臂导通，上桥臂导通时其对应的下桥臂断开。用“0”表示一个上桥臂断开，上桥臂断开时其对应的下桥臂导通。则逆变器的三相桥臂的时序有8种，也就是驱动信号的时序状态有8种，分别为U0(000)、U1(001)、U2(010)、U3(011)、U4(100)、U5(101)、U6(110)、U7(111)。其中，U1(001)、U2(010)、U3(011)、U4(100)、U5(101)、U6(110)为非零矢量，U0(000)和U7(111)为零矢量。
在一个例子中，第一控制器在自加热过程中调节驱动信号，包括：第一控制器在自加热过程中以动态实时的方式调节驱动信号。也就是说，第一控制器对驱动信号的调节是实时的，以便于及时修正第一电芯组1的电荷量损失和第二电芯组2的电荷量的损失之间的差异，避免出现激励电流出现大幅波动情况。
下面说明调节驱动信号的第一种方式：
例子1：
首先，预先通过加热测试实验确定第一预设比值。加热测试实验可以是在整车出厂前对电动车进行的加热测试，其中可以利用高精度的霍尔元件等精确测量激励电流的情况。
在一个例子中，确定第一预设比值的过程包括步骤S102-S104。
步骤S102、获取第一实验电流的第一强度积分值和第二实验电流的第一强度积 分值的比值作为第二比值。
在加热测试实验开始时设置驱动信号，使得第一理论电流的第一强度积分值和第二理论电流的第一强度积分值的比值为1，在此情况下，获取第一实验电流和第二实验电流。第一理论电流为流经第一电芯组1的理论电流，第二理论电流为流经第二电芯组2的理论电流，第一理论电流和第二理论电流是通过非实测方式确定的电流，可以根据驱动信号计算得到。其中，第一理论电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的第一理论电流的强度积分值，第二理论电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的第二理论电流的强度积分值。
第一实验电流为加热测试实验中流经第一电芯组1的实测电流，第二实验电流为加热测试实验中流经第二电芯组2的实测电流。在加热测试实验过程中，通过实测方式获取第一实验电流和第二实验电流。第一实验电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的第一实验电流的强度积分值，第二实验电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的第二实验电流的强度积分值。
步骤S104、确定第一预设比值，第一预设比值为第二比值的倒数。
第一实验电流和第二实验电流包含了电控误差和电机线圈损耗造成的影响，第一实验电流的第一强度积分值可以体现在第一理论电流情况下、第一电芯组1在加热测试实验中电荷量的真实损耗程度，第二实验电流的第一强度积分值可以体现在第二理论电流情况下、第二电芯组2在加热测试实验中电荷量的真实损耗程度。
例如，第一实验电流的第一强度积分值和第二实验电流的第一强度积分值的比值为99/100，则第一预设比值为100/99。
对于不同型号的电池包，要通过各自的加热测试实验确定每种型号的电池包各自对应的第一预设比值。对于同一型号的多个电池包，如果各个电池包中划分第一电芯组1和第二电芯组2的方式不同，也需要通过各自的加热测试实验确定每个电池包各自对应的第一预设比值。
第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，可以包括步骤S202-S206。
步骤S202、计算自加热过程中的第一理论电流和第二理论电流。
步骤S204、基于第一预设比值修正第一理论电流和第二理论电流。
在一个例子中，在基于第一预设比值对第一理论电流和第二理论电流进行修正后，第一理论电流的第二强度积分值和第二理论电流的第二强度积分值的比值为第一预设比值。其中，第一理论电流的第二强度积分值是自加热开始至自加热结束期间的第一理论电流的强度积分值，第二理论电流的第二强度积分值是自加热开始至自加热结束期间的第二理论电流的强度积分值。
步骤S206、基于修正后的第一理论电流和修正后的第二理论电流设置驱动信号。
在基于修正后的第一理论电流和修正后的第二理论电流设置驱动信号以后，根据驱动信号计算出的第一理论电流即为上述修正后的第一理论电流，根据驱动信号计算 出的第二理论电流即为上述修正后的第二理论电流。
按照这种调节方式，虽然电控误差和电机线圈损耗造成的电荷量损失误差依然存在，但由于驱动信号是基于修正后的第一理论电流和修正后的第二理论电流设置的，可以弥补电控误差和电机线圈损耗造成的电荷量损失误差，保证自加热开始至自加热结束期间的第一实测电流的强度积分值与自加热开始至自加热结束期间的第二实测电流的强度积分值是基本相同的。通过第一种调节方式，可以保证由于自加热造成的第一电芯组1的电荷量的总损失和第二电芯组2的电荷量的总损失之间的差异在一定程度内，进而保证第一电芯组1和第二电芯组2之间的均衡性，将自加热对电动车的可用电量和续航里程产生的不良影响控制在一定程度内。
例子2：
首先，预先通过加热测试实验确定第一预设比值。加热测试实验可以是在整车出厂前对电动车进行的加热测试，其中可以利用高精度的霍尔元件等精确测量激励电流的情况。
在一个例子中，确定第一预设比值的过程包括步骤P102-P104。
步骤P102、获取第一实测电流的第四有效值和第二实测电流的第四有效值的比值作为第二比值。
本公开实施例中，电流有效值即为行业所公知的均方根值，其定义为在一段给定时间内，电流通过某电阻，所产生的热量与直流电通过该电阻在同样时间内产生的热量相等，此直流电值即为该电流电的有效值。
在加热测试实验开始时设置驱动信号，使得第一理论电流的第一有效值和第二理论电流的第一有效值的比值为1，在此情况下，获取第一实测电流和第二实测电流。第一理论电流为流经第一电芯组1的理论电流，第二理论电流为流经第二电芯组2的理论电流，第一理论电流和第二理论电流是通过非实测方式确定的电流，可以根据驱动信号计算得到。其中，第一理论电流的第一有效值是加热测试实验开始至加热测试实验结束期间的第一理论电流的有效值，第二理论电流的第一有效值是加热测试实验开始至加热测试实验结束期间的第二理论电流的有效值。
第一实测电流为流经第一电芯组1的实测电流，第二实测电流为的流经第二电芯组2的实测电流。在加热测试实验过程中，通过实测方式获取第一实测电流和第二实测电流。第一实测电流的第四有效值是加热测试实验开始至加热测试实验结束期间的第一实测电流的有效值，第二实测电流的第四有效值是加热测试实验开始至加热测试实验结束期间的第二实测电流的有效值。
步骤P104、确定第一预设比值，第一预设比值为第二比值的倒数。
第一实测电流和第二实测电流包含了电控误差和电机线圈损耗造成的影响，第一实测电流的第四有效值可以体现在第一理论电流情况下、第一电芯组1在加热测试实验中电荷量的真实损耗程度，第二实测电流的第四有效值可以体现在第二理论电流情况下、第二电芯组2在加热测试实验中电荷量的真实损耗程度。
例如，第一实测电流的第四有效值和第二实测电流的第四有效值的比值为99/100， 则第一预设比值为100/99。
对于不同型号的电池包，要通过各自的加热测试实验确定每种型号的电池包各自对应的第一预设比值。对于同一型号的多个电池包，如果各个电池包中划分第一电芯组1和第二电芯组2的方式不同，也需要通过各自的加热测试实验确定每个电池包各自对应的第一预设比值。
第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，可以包括步骤P202-P206。
步骤P202、计算自加热过程中的第一理论电流和第二理论电流。
步骤P204、基于第一预设比值修正第一理论电流和第二理论电流。
在基于第一预设比值对第一理论电流和第二理论电流进行修正后，第一理论电流的第二有效值和第二理论电流的第二有效值的比值为第一预设比值。其中，第一理论电流的第二有效值是自加热开始至自加热结束期间的第一理论电流的有效值，第二理论电流的第二有效值是自加热开始至自加热结束期间的第二理论电流的有效值。
步骤P206、基于修正后的第一理论电流和修正后的第二理论电流设置驱动信号。
在基于修正后的第一理论电流和修正后的第二理论电流设置驱动信号以后，根据驱动信号计算出的第一理论电流即为上述修正后的第一理论电流，根据驱动信号计算出的第二理论电流即为上述修正后的第二理论电流。
按照这种调节方式，虽然电控误差和电机线圈损耗造成的电荷量损失误差依然存在，但由于驱动信号是基于修正后的第一理论电流和修正后的第二理论电流设置的，可以弥补电控误差和电机线圈损耗造成的电荷量损失误差，保证自加热开始至自加热结束期间的第一实测电流的有效值与自加热开始至自加热结束期间的第二实测电流的有效值是基本相同的。通过第一种调节方式，可以保证由于自加热造成的第一电芯组1的电荷量的总损失和第二电芯组2的电荷量的总损失之间的差异在一定程度内，进而保证第一电芯组1和第二电芯组2之间的均衡性，将自加热对电动车的可用电量和续航里程产生的不良影响控制在一定程度内。
下面说明调节驱动信号的第二种方式：
例子1：
第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括步骤S302-304。
步骤S302、获取第一实测电流的第二强度积分值和第二实测电流的第二强度积分值。
其中，第一实测电流为流经第一电芯组1的实测电流，第二实测电流为流经第二电芯组2的实测电流；
其中，第一实测电流的第二强度积分值是自加热开始至当前调节周期结束期间的第一实测电流的强度积分值，第二实测电流的第二强度积分值是自加热开始至当前调节周期结束期间的第二实测电流的强度积分值。
步骤S304、基于第一实测电流的第二强度积分值和第二实测电流的第二强度积 分值，设置下一个调节周期的驱动信号。
在一个例子中，设置下一个调节周期的驱动信号，包括：设置下一个调节周期的驱动信号的占空比和/或时序状态，以使得第二绝对值小于第一绝对值。其中，第一绝对值是第一实测电流的第二强度积分值和第二实测电流的第二强度积分值的差值的绝对值。其中，第二绝对值是第一实测电流的第四强度积分值和第二实测电流的第四强度积分值的差值的绝对值。其中，第一实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第一实测电流的强度积分值，第二实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第二实测电流的强度积分值。
例如：第一实测电流的第二强度积分值为90，第二实测电流的第二强度积分值为100，则第一绝对值为10。设置下一个调节周期的驱动信号，使得第一实测电流的第四强度积分值变为95，第二实测电流的第四强度积分值变为102，则第二绝对值为7。第二绝对值小于第一绝对值，说明在下一个周期结束时，第一电芯组1的电荷量总损失和第二电芯组2的电荷量总损失的差异情况变小。
在一个例子中，如果第一实测电流的第二强度积分值和第二实测电流的第二强度积分值的比值在预设区间范围内，可以不调节驱动信号，下一个调节周期的驱动信号和当前调节周期的驱动信号是相同的。如果第一实测电流的第二强度积分值和第二实测电流的第二强度积分值不在预设区间范围内，设置下一个调节周期的驱动信号的占空比和/或时序状态，使得第二绝对值小于第一绝对值。
在这一例子中，第一控制器对驱动信号的调节是实时的，以便于及时修正第一电芯组1的电荷量损失和第二电芯组2的电荷量的损失之间的差异，避免出现激励电流出现大幅波动情况，提升自加热过程的平稳性。
例子2：第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括步骤S402-S406。
步骤S402、获取第一实测电流的第二强度积分值和第二实测电流的第二强度积分值。
其中，第一实测电流为流经第一电芯组1的实测电流，第二实测电流为流经第二电芯组的实测电流；
其中，第一实测电流的第二强度积分值是自加热开始至当前调节周期结束期间的第一实测电流的强度积分值，第二实测电流的第二强度积分值是自加热开始至当前调节周期结束期间的第二实测电流的强度积分值。
步骤S404：获取第一实测电流的第三强度积分值和第二实测电流的第三强度积分值。
其中，第一实测电流的第三强度积分值是当前调节周期期间的第一实测电流的强度积分值，第二实测电流的第三强度积分值是当前调节周期期间的第二实测电流的强度积分值。
步骤S406，基于第一实测电流的第二强度积分值、第二实测电流的第二强度积分值、第一实测电流的第三强度积分值以及第二实测电流的第三强度积分值，设置下 一个调节周期的驱动信号。
在一个例子中，设置下一个调节周期的驱动信号，包括：设置下一个调节周期的驱动信号的占空比和/或时序状态，以使得第二绝对值小于第一绝对值。其中，第一绝对值是第一实测电流的第二强度积分值和第二实测电流的第二强度积分值的差值的绝对值。其中，第二绝对值是第一实测电流的第四强度积分值和第二实测电流的第四强度积分值的差值的绝对值。其中，第一实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第一实测电流的强度积分值，第二实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第二实测电流的强度积分值。
在一个例子中，如果第一实测电流的第二强度积分值和第二实测电流的第二强度积分值的比值在预设区间范围内、并且第一实测电流的第三强度积分值和第二实测电流的第三强度积分值的比值也在预设区间范围内，可以不调节驱动信号，下一个调节周期的驱动信号和当前调节周期的驱动信号是相同的。如果第一实测电流的第二强度积分值和第二实测电流的第二强度积分值的比值不在预设区间范围内，设置下一个调节周期的驱动信号的占空比和/或时序状态，使得第二绝对值小于第一绝对值。如果第一实测电流的第三强度积分值和第二实测电流的第三强度积分值的比值不在预设区间范围内，设置下一个调节周期的驱动信号的占空比和/或时序状态，使得第二绝对值小于第一绝对值。
在这一例子中，第一控制器对驱动信号的调节是实时的，以便于及时修正第一电芯组1的电荷量损失和第二电芯组2的电荷量的损失之间的差异，避免出现激励电流出现大幅波动情况，提升自加热过程的平稳性。并且，在调节驱动信号时，同时考虑第一实测电流的第二强度积分值、第二实测电流的第二强度积分值、第一实测电流的第三强度积分值以及第二实测电流的第三强度积分值，可以精细化的确定下一个调节周期的驱动信号。
例子3：
第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括步骤P302-P304。
步骤P302、获取第一实测电流的第一有效值和第二实测电流的第一有效值。
其中，第一实测电流为流经第一电芯组1的实测电流，第二实测电流为流经第二电芯组2的实测电流；
其中，第一实测电流的第一有效值是自加热开始至当前调节周期结束期间的第一实测电流的有效值，第二实测电流的第一有效值是自加热开始至当前调节周期结束期间的第二实测电流的有效值。
步骤P304、基于第一实测电流的第一有效值和第二实测电流的第一有效值，设置下一个调节周期的驱动信号。
在一个例子中，设置下一个调节周期的驱动信号，包括：设置下一个调节周期的驱动信号的占空比和/或时序状态，以使得第四绝对值小于第三绝对值。其中，第三绝对值是第一实测电流的第一有效值和第二实测电流的第一有效值的差值的绝对值。其 中，第四绝对值是第一实测电流的第三有效值和第二实测电流的第三有效值的差值的绝对值。其中，第一实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第一实测电流的有效值，第二实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第二实测电流的有效值。
例如：第一实测电流的第一有效值为90，第二实测电流的第一有效值为100，则第三绝对值为10。对下一个调节周期的驱动信号进行调节，使得第一实测电流的第三有效值变为95，第二实测电流的第三有效值变为102，则第四绝对值为7。第四绝对值小于第三绝对值，说明在下一个周期结束时，第一电芯组1的电荷量总损失和第二电芯组2的电荷量总损失的差异情况变小。
在一个例子中，如果第一实测电流的第一有效值和第二实测电流的第一有效值的比值在预设区间范围内，不对下一个调节周期的驱动信号进行调节。如果第一实测电流的第一有效值和第二实测电流的第一有效值不在预设区间范围内，对下一个调节周期的驱动信号的占空比和/或驱动信号的时序状态进行调节，使得第四绝对值小于第三绝对值。
在这一例子中，第一控制器对驱动信号的调节是实时的，以便于及时修正第一电芯组1的电荷量损失和第二电芯组2的电荷量的损失之间的差异，避免出现激励电流出现大幅波动情况，提升自加热过程的平稳性。
例子4：第一控制器在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括步骤P402-P406。
步骤P402、获取第一实测电流的第一有效值和第二实测电流的第一有效值。
其中，第一实测电流为流经第一电芯组1的实测电流，第二实测电流为流经第二电芯组2的实测电流；
其中，第一实测电流的第一有效值是自加热开始至当前调节周期结束期间的第一实测电流的有效值，第二实测电流的第一有效值是自加热开始至当前调节周期结束期间的第二实测电流的有效值。
步骤P404：获取第一实测电流的第二有效值和第二实测电流的第二有效值。
其中，第一实测电流的第二有效值是当前调节周期期间的第一实测电流的有效值，第二实测电流的第二有效值是当前调节周期期间的第二实测电流的有效值。
步骤P406，基于第一实测电流的第一有效值、第二实测电流的第一有效值、第一实测电流的第二有效值以及第二实测电流的第二有效值，设置下一个调节周期的驱动信号。
在一个例子中，设置下一个调节周期的驱动信号，包括：设置下一个调节周期的驱动信号的占空比和/或时序状态，以使得第四绝对值小于第三绝对值。其中，第三绝对值是第一实测电流的第一有效值和第二实测电流的第一有效值的差值的绝对值。其中，第四绝对值是第一实测电流的第三有效值和第二实测电流的第三有效值的差值的绝对值。其中，第一实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第一实测电流的有效值，第二实测电流的第三有效值是自加热开始至下一个调节周 期结束期间的第二实测电流的有效值。
在一个例子中，如果第一实测电流的第一有效值和第二实测电流的第一有效值的比值在预设区间范围内、并且第一实测电流的第二有效值和第二实测电流的第二有效值的比值也在预设区间范围内，不对下一个调节周期的驱动信号进行调节。如果第一实测电流的第一有效值和第二实测电流的第一有效值的比值不在预设区间范围内，对下一个调节周期的驱动信号的占空比和/或驱动信号的时序状态进行调节，使得第四绝对值小于第三绝对值。如果第一实测电流的第二有效值和第二实测电流的第二有效值的比值不在预设区间范围内，对下一个调节周期的驱动信号的占空比和/或驱动信号的时序状态进行调节，使得第四绝对值小于第三绝对值。
在这一例子中，第一控制器对驱动信号的调节是实时的，以便于及时修正第一电芯组1的电荷量损失和第二电芯组2的电荷量的损失之间的差异，避免出现激励电流出现大幅波动情况，提升自加热过程的平稳性。并且，在调节驱动信号时，同时考虑第一实测电流的第一有效值、第二实测电流的第一有效值、第一实测电流的第二有效值以及第二实测电流的第二有效值，可以精细化的确定下一个调节周期的驱动信号。
在第二种调节方式中，第一控制器的控制方式为反馈闭环控制。在一个例子中，第一控制器的调节方式为PI(Proportion Integration，比例-积分控制)。在一个例子中，第一控制器的调节方式为PID(Proportion Integration Differentiation，比例-积分-微分控制)，也就是比例、积分和微分三部分作用的叠加的复合控制。比例控制是按比例的简单控制方式，仅有比例控制时系统存在稳态误差，无法完全消除外界所加入的固定扰动。积分控制的主要目的在于消除稳态误差。微分控制的目的，是消除系统的大幅波动。
按照第二种调节方式，虽然电控误差和电机线圈损耗造成的电荷量损失误差依然存在，但按照调节周期及时进行修正弥补这些误差，保证自加热开始至自加热结束期间的第一实测电流的强度积分值或有效值与自加热开始至自加热结束期间的第二实测电流的度积分值或有效值是基本相同的。通过第二种调节方式，可以保证由于自加热造成的第一电芯组1的电荷量的总损失和第二电芯组2的电荷量的总损失之间的差异在一定程度内，进而保证第一电芯组1和第二电芯组2之间的均衡性，将自加热对电动车的可用电量和续航里程产生的不良影响控制在一定程度内。
在动力电池自加热过程中，对激励电流的控制是非常关键的。发明人经研究发现，在较大的激励电流的作用下，动力电池的升温速度较快，但随着激励电流的增大，加热过程对电池容量造成的不利影响也会变大，因此在自加热过程中要同时考虑到这两种因素。
在本公开实施例中，电芯组中的电芯单元为磷酸铁锂电芯单元或三元锂电芯单元或者其他化学体系的电池，预先根据大量测试得到这两种电池在自加热条件下的容量保持率判断其安全边界范围后，制定以下控制策略：
在一个例子中，第一控制器还用于在自加热过程中调节驱动信号，使得流经第一电芯组1的电流有效值在整个自加热期间的平均值在0.5C到5C之间，流经第二电芯 组2的电流有效值在整个自加热期间的平均值在0.5C到5C之间。在一个例子中，可以通过调节驱动信号的占空比和/或时序状态实现这一要求。在这一例子中，流经第一电芯组1的电流和流经第二电芯组2的电流同时是指理论电流或者同时是指实测电流。
在一个例子中，第一控制器还用于在自加热过程中调节驱动信号，使得流经交流电动机的中性点的电流有效值在整个自加热期间的平均值在1C到10C之间。在一个例子中，可以通过调节驱动信号的占空比和/或时序状态实现这一要求。在这一例子中，流经第一电芯组1的电流和流经第二电芯组2的电流同时是指理论电流或者同时是指实测电流。
在一个例子中，第一控制器输出的驱动信号为PWM(Pulse width modulation wave，脉冲宽度调制)驱动信号。在一个例子中，第一控制器采用SVPWM(Space Vector Pulse Width Modulation，网络空间矢量脉宽调制)调制方式输出驱动信号。通过调节驱动信号的占空比、时序等，IGBT管可以实时输出不同频率和幅值的电流信号。
通过上述控制策略，可以防止电芯在低温下发生过充或者过放，从而保证电芯的安全性。本公开实施例通过上述自加热策略，兼顾自加热过程的升温效率和安全性，可以高效率地对动力电池进行加热同时避免对电池的寿命造成过大损伤，并且保证电池的安全性。在本公开实施例中，上述策略可以叠加实施，以取得更好的效果。
在一个例子中，第一控制器还用于在自加热过程中对三个上桥臂的通断状态进行同步控制，对三个下桥臂的通断状态进行同步控制。也就是说，三个上桥臂同时导通/同时断开，对应的，三个下桥臂同时断开/同时导通。这种方式可以充分利用功率电子开关的性能，增强自加热的效果。
本公开实施例的第一控制器可以包括处理器和存储器，以及存储在存储器上并可在处理器上运行的程序或指令，程序或指令被处理器执行时实现如前述实施例的任一项加热控制策略。
本公开实施例提供了一种电动车，包括动力电池以及前述任一实施例的用于加热动力电池的加热系统。
本说明书中的各个实施例均采用递进的方式描述，各个实施例之间相同相似的部分互相参见即可，每个实施例重点说明的都是与其他实施例的不同之处。对于电动车实施例而言，其相关之处参见加热系统实施例的部分说明即可。
上述对本说明书特定实施例进行了描述。其它实施例在所附权利要求书的范围内。在一些情况下，在权利要求书中记载的动作或步骤可以按照不同于实施例中的顺序来执行并且仍然可以实现期望的结果。另外，在附图中描绘的过程不一定要求示出的特定顺序或者连续顺序才能实现期望的结果。在某些实施方式中，多任务处理和并行处理也是可以的或者可能是有利的。
本说明书的实施例可以是系统、方法和/或计算机程序产品。计算机程序产品可以包括计算机可读存储介质，其上载有用于使处理器实现本说明书实施例的各个方面的计算机指令。
计算机可读存储介质可以是可以保持和存储由计算机指令执行设备使用的计算 机指令的有形设备。计算机可读存储介质例如可以是――但不限于――电存储设备、磁存储设备、光存储设备、电磁存储设备、半导体存储设备或者上述的任意合适的组合。计算机可读存储介质的更具体的例子(非穷举的列表)包括：便携式计算机盘、硬盘、随机存取存储器(RAM)、只读存储器(ROM)、可擦式可编程只读存储器(EPROM或闪存)、静态随机存取存储器(SRAM)、便携式压缩盘只读存储器(CD-ROM)、数字多功能盘(DVD)、记忆棒、软盘、机械编码设备、例如其上存储有计算机指令的打孔卡或凹槽内凸起结构、以及上述的任意合适的组合。这里所使用的计算机可读存储介质不被解释为瞬时信号本身，诸如无线电波或者其他自由传播的电磁波、通过波导或其他传输媒介传播的电磁波(例如，通过光纤电缆的光脉冲)、或者通过电线传输的电信号。
这里所描述的计算机指令可以从计算机可读存储介质下载到各个计算/处理设备，或者通过网络、例如因特网、局域网、广域网和/或无线网下载到外部计算机或外部存储设备。网络可以包括铜传输电缆、光纤传输、无线传输、路由器、防火墙、交换机、网关计算机和/或边缘服务器。每个计算/处理设备中的网络适配卡或者网络接口从网络接收计算机指令，并转发该计算机指令，以供存储在各个计算/处理设备中的计算机可读存储介质中。
附图中的流程图和框图显示了根据本说明书的多个实施例的系统、方法和计算机程序产品的可能实现的体系架构、功能和操作。在这点上，流程图或框图中的每个方框可以代表一个模块、程序段或计算机指令的一部分，模块、程序段或计算机指令的一部分包含一个或多个用于实现规定的逻辑功能的可执行计算机指令。在有些作为替换的实现中，方框中所标注的功能也可以以不同于附图中所标注的顺序发生。例如，两个连续的方框实际上可以基本并行地执行，它们有时也可以按相反的顺序执行，这依所涉及的功能而定。也要注意的是，框图和/或流程图中的每个方框、以及框图和/或流程图中的方框的组合，可以用执行规定的功能或动作的专用的基于硬件的系统来实现，或者可以用专用硬件与计算机指令的组合来实现。对于本领域技术人员来说公知的是，通过硬件方式实现、通过软件方式实现以及通过软件和硬件结合的方式实现都是等价的。
以上已经描述了本说明书的各实施例，上述说明是示例性的，并非穷尽性的，并且也不限于所披露的各实施例。在不偏离所说明的各实施例的范围的情况下，对于本技术领域的普通技术人员来说许多修改和变更都是显而易见的。本文中所用术语的选择，旨在最好地解释各实施例的原理、实际应用或对市场中的技术的改进，或者使本技术领域的其它普通技术人员能理解本文披露的各实施例。

Claims (17)

  1. 一种用于加热动力电池的加热系统，其特征在于，所述动力电池包括串联的第一电芯组(1)和第二电芯组(2)，所述第一电芯组(1)的电动势和所述第二电芯组(2)的电动势不等；
    所述加热系统包括逆变器(3)、交流电动机(4)和第一控制器(5)；
    所述逆变器(3)包括三个桥臂，所述动力电池的正极与所述逆变器的(3)上桥臂连接，所述动力电池的负极与所述逆变器(3)的下桥臂连接；所述逆变器(3)的三个桥臂中点与所述交流电动机的三相线圈的头端一一对应连接，所述交流电动机的末端连接在一起形成中性点(N)；
    所述交流电动机的中性点(N)与第一连接点通过连接线路(S1)连接，所述第一连接点为所述第一电芯组(1)和所述第二电芯组(2)之间的连接点(P)；
    所述第一控制器(6)用于向所述逆变器(3)输入驱动信号；所述第一电芯组(1)、所述第二电芯组(2)、所述逆变器(3)、所述交流电动机(4)以及所述连接线路(S1)构成交流电自加热回路；
    所述第一控制器(6)还用于在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内；
    其中，所述第一目标差值为第一差值和第二差值的差值，所述第一差值为自加热开始时所述第一电芯组(1)的电动势与所述第二电芯组(2)的电动势的差值，所述第二差值为自加热结束时所述第一电芯组(1)的电动势与所述第二电芯组(2)的电动势的差值。
  2. 根据权利要求1所述的加热系统，其特征在于，所述预设区间范围为(-0.9，+0.9)。
  3. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：
    所述第一控制器(6)在自加热过程中调节所述驱动信号的占空比和/或驱动信号的时序状态，以使得所述第一目标差值与所述第一差值的比值在所述预设区间范围内。
  4. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)在自加 热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：
    所述第一控制器(6)调节所述驱动信号，以使得第二目标差值在与第五强度积分值之间的比值在预设区间范围内；
    其中，所述第二目标差值为第五强度积分值和第六强度积分值的差值，所述第五强度积分值为自加热过程中流经所述第一电芯组(1)的电流的强度积分值，所述第六强度积分值为自加热过程中流经所述第二电芯组(2)的电流的强度积分值；其中，电流的强度积分值是电流的电流强度在时间上的积分值。
  5. 根据权利要求1-4任一项所述的加热系统，其特征在于，所述第一控制器(6)在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：
    计算自加热过程中的第一理论电流和第二理论电流；
    基于第一预设比值修正第一理论电流和第二理论电流；
    基于修正后的第一理论电流和修正后的第二理论电流设置所述驱动信号；
    其中，所述第一理论电流为流经所述第一电芯组(1)的理论电流，所述第二理论电流为流经所述第二电芯组(2)的理论电流。
  6. 根据权利要求5所述的加热系统，其特征在于，所述第一预设比值预先通过加热测试实验确定；
    所述确定第一预设比值，包括：
    获取第一实验电流的第一强度积分值和第二实验电流的第一强度积分值的比值作为第二比值；
    确定所述第一预设比值，所述第一预设比值为第二比值的倒数；
    其中，所述第一实验电流为加热测试实验中流经所述第一电芯组(1)的实测电流，第二实验电流为加热测试实验中流经所述第二电芯组(2)的实测电流；
    其中，所述第一实验电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的所述第一实验电流的强度积分值，所述第二实验电流的第一强度积分值是加热测试实验开始至加热测试实验结束期间的所述第二实验电流的强度积分值。
  7. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内， 包括：
    获取第一实测电流的第二强度积分值和第二实测电流的第二强度积分值；
    基于所述第一实测电流的所述第二强度积分值和所述第二实测电流的所述第二强度积分值，设置下一个调节周期的驱动信号；
    其中，所述第一实测电流为流经所述第一电芯组的实测电流，所述第二实测电流为流经所述第二电芯组的实测电流；
    其中，所述第一实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第一实测电流的强度积分值，所述第二实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第二实测电流的强度积分值。
  8. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：
    获取第一实测电流的第二强度积分值和第二实测电流的第二强度积分值；
    获取第一实测电流的第三强度积分值和第二实测电流的第三强度积分值；
    基于所述第一实测电流的第二强度积分值、所述第二实测电流的第二强度积分值、所述第一实测电流的第三强度积分值以及所述第二实测电流的第三强度积分值，设置下一个调节周期的驱动信号；
    其中，所述第一实测电流为流经所述第一电芯组(1)的实测电流，所述第二实测电流为流经所述第二电芯组(2)的实测电流；
    其中，所述第一实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第一实测电流的强度积分值，所述第二实测电流的所述第二强度积分值是自加热开始至当前调节周期结束期间的第二实测电流的强度积分值；
    其中，所述第一实测电流的第三强度积分值是当前调节周期期间的第一实测电流的强度积分值，所述第二实测电流的第三强度积分值是当前调节周期期间的第二实测电流的强度积分值。
  9. 根据权利要求7或8任一项所述的加热系统，其特征在于，所述设置下一个调节周期的驱动信号，包括：
    设置所述下一个调节周期的驱动信号的占空比和/或时序状态，以使得第二绝对值小于第一绝对值；
    其中，所述第一绝对值是所述第一实测电流的第二强度积分值和所述第二实测电流的第二强度积分值的差值的绝对值；
    其中，所述第二绝对值是所述第一实测电流的第四强度积分值和所述第二实测电流的第四强度积分值的差值的绝对值；
    其中，所述第一实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第一实测电流的强度积分值，所述第二实测电流的第四强度积分值是自加热开始至下一个调节周期结束期间的第二实测电流的强度积分值。
  10. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：
    获取第一实测电流的第一有效值和第二实测电流的第一有效值；
    基于所述第一实测电流的第一有效值和所述第二实测电流的第一有效值，设置下一个调节周期的驱动信号；
    其中，所述第一实测电流为流经所述第一电芯组(1)的实测电流，所述第二实测电流为流经所述第二电芯组(2)的实测电流；
    其中，所述第一实测电流的第一有效值是自加热开始至当前调节周期结束期间的第一实测电流的有效值，所述第二实测电流的第一有效值是自加热开始至当前调节周期结束期间的第二实测电流的有效值。
  11. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)在自加热过程中调节驱动信号，以使得第一目标差值与第一差值的比值在预设区间范围内，包括：
    获取第一实测电流的第一有效值和第二实测电流的第一有效值；
    获取第一实测电流的第二有效值和第二实测电流的第二有效值；
    基于所述第一实测电流的第一有效值、所述第二实测电流的第一有效值、所述第一实测电流的第二有效值以及所述第二实测电流的第二有效值，设置下一个调节周期的驱动信号；
    其中，所述第一实测电流为流经所述第一电芯组(1)的实测电流，所述第二实测电流为流经所述第二电芯组(2)的实测电流；
    其中，所述第一实测电流的第一有效值是自加热开始至当前调节周期结束期间的 第一实测电流的有效值，所述第二实测电流的第一有效值是自加热开始至当前调节周期结束期间的第二实测电流的有效值；
    其中，所述第一实测电流的第二有效值是当前调节周期期间的第一实测电流的有效值，所述第二实测电流的第二有效值是当前调节周期期间的第二实测电流的有效值。
  12. 根据权利要求10或11任一项所述的加热系统，其特征在于，所述设置下一个调节周期的驱动信号，包括：
    设置所述下一个调节周期的驱动信号的占空比和/或时序状态，以使得第四绝对值小于第三绝对值；
    其中，所述第三绝对值是所述第一实测电流的第一有效值和所述第二实测电流的第一有效值的差值的绝对值；
    其中，所述第四绝对值是所述第一实测电流的第三有效值和所述第二实测电流的第三有效值的差值的绝对值；
    其中，所述第一实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第一实测电流的有效值，所述第二实测电流的第三有效值是自加热开始至下一个调节周期结束期间的第二实测电流的有效值。
  13. 根据权利要求7、8、10或11所述的加热系统，其特征在于，所述第一控制器(6)的调节方式为PID调节方式。
  14. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)还用于在自加热过程中对所述三个上桥臂的通断状态进行同步控制，对所述三个下桥臂的通断状态进行同步控制。
  15. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)还用于在自加热过程中调节驱动信号，使得流经所述第一电芯组(1)的电流有效值在整个自加热期间的平均值在0.5C到5C之间，流经所述第二电芯组(2)的电流有效值在整个自加热期间的平均值在0.5C到5C之间。
  16. 根据权利要求1所述的加热系统，其特征在于，所述第一控制器(6)还用于在自加热过程中调节驱动信号，使得流经所述交流电动机的中性点(N)的电流有效值在整个自加热期间的平均值在1C到10C之间。
  17. 一种电动车，其特征在于，包括动力电池以及如权利要求1-16任一项所述的加热系统。
PCT/CN2023/081703 2022-04-28 2023-03-15 用于加热动力电池的加热系统和电动车 WO2023207395A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210456060.9A CN114566740B (zh) 2022-04-28 2022-04-28 动力电池的加热系统和电动车
CN202210456060.9 2022-04-28

Publications (1)

Publication Number Publication Date
WO2023207395A1 true WO2023207395A1 (zh) 2023-11-02

Family

ID=81721106

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/081703 WO2023207395A1 (zh) 2022-04-28 2023-03-15 用于加热动力电池的加热系统和电动车

Country Status (2)

Country Link
CN (1) CN114566740B (zh)
WO (1) WO2023207395A1 (zh)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE112020004731T5 (de) * 2019-10-03 2022-06-15 Denso Corporation Leistungswandler
CN116552335A (zh) * 2022-01-29 2023-08-08 比亚迪股份有限公司 动力电池的加热电路和电动车
CN114566740B (zh) * 2022-04-28 2022-08-09 比亚迪股份有限公司 动力电池的加热系统和电动车
CN216980691U (zh) * 2022-04-28 2022-07-15 比亚迪股份有限公司 动力电池的加热系统和电动车
CN117013144A (zh) * 2022-04-29 2023-11-07 比亚迪股份有限公司 电池自加热控制方法、控制系统及电动交通工具
CN115051078B (zh) * 2022-08-03 2024-03-29 广汽埃安新能源汽车有限公司 电池交流加热电路和电动车
WO2024082155A1 (zh) * 2022-10-19 2024-04-25 宁德时代新能源科技股份有限公司 电池自加热系统、用电设备及车辆

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003272712A (ja) * 2002-03-18 2003-09-26 Mitsubishi Motors Corp バッテリ制御装置
CN105762434A (zh) * 2016-05-16 2016-07-13 北京理工大学 一种具有自加热功能的电源系统和车辆
CN110116653A (zh) * 2019-04-19 2019-08-13 清华大学 电动汽车驱动系统、驱动电路及电动汽车电池加热方法
CN113348616A (zh) * 2019-01-24 2021-09-03 株式会社综研 电力转换装置
CN113752875A (zh) * 2020-06-04 2021-12-07 比亚迪股份有限公司 车辆电池加热装置和方法、车辆
CN114566740A (zh) * 2022-04-28 2022-05-31 比亚迪股份有限公司 动力电池的加热系统和电动车

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010035392A (ja) * 2008-07-31 2010-02-12 Panasonic Corp 不均衡低減回路、電源装置、及び不均衡低減方法
JP2012023901A (ja) * 2010-07-15 2012-02-02 Aisin Aw Co Ltd 回転電機制御装置
CN109995102B (zh) * 2019-03-01 2022-04-01 中国第一汽车股份有限公司 一种电动汽车用动力电池均衡系统及控制方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003272712A (ja) * 2002-03-18 2003-09-26 Mitsubishi Motors Corp バッテリ制御装置
CN105762434A (zh) * 2016-05-16 2016-07-13 北京理工大学 一种具有自加热功能的电源系统和车辆
CN113348616A (zh) * 2019-01-24 2021-09-03 株式会社综研 电力转换装置
CN110116653A (zh) * 2019-04-19 2019-08-13 清华大学 电动汽车驱动系统、驱动电路及电动汽车电池加热方法
CN113752875A (zh) * 2020-06-04 2021-12-07 比亚迪股份有限公司 车辆电池加热装置和方法、车辆
CN114566740A (zh) * 2022-04-28 2022-05-31 比亚迪股份有限公司 动力电池的加热系统和电动车

Also Published As

Publication number Publication date
CN114566740A (zh) 2022-05-31
CN114566740B (zh) 2022-08-09

Similar Documents

Publication Publication Date Title
WO2023207395A1 (zh) 用于加热动力电池的加热系统和电动车
US11876197B2 (en) Vehicle and power battery heating apparatus and method thereof
JP4582168B2 (ja) 回転機の制御装置、及び回転機の制御システム
JP4458174B2 (ja) 回転機の制御装置、及び回転機の制御システム
CN112977173B (zh) 一种电动汽车及其动力电池脉冲加热系统和加热方法
US20230327596A1 (en) Power conversion apparatus
JP7488288B2 (ja) 電池パック加熱方法、電池加熱システム及び電力消費装置
CN102811013B (zh) 交流传动控制系统和方法及其逆变器电压误差测量方法
Ishida et al. Fundamental characteristics of five-level double converters with adjustable DC voltages for induction motor drives
WO2017033673A1 (ja) パワー半導体素子の駆動回路、電力変換ユニットおよび電力変換装置
CN104539220A (zh) 一种三相四开关逆变器自适应脉宽调制方法
KR20190119780A (ko) 차량용 인버터 시스템 및 그 제어방법
CN113733988A (zh) 电动汽车的动力电池加热方法、装置以及汽车
JP2020137408A (ja) 電動機駆動装置
Puls et al. Lifetime calculation for capacitors in industrial micro dc grids
CN111371301A (zh) 一种两电平牵引逆变器igbt结温控制方法及系统
US11916504B2 (en) Energy conversion device and vehicle
US20230130303A1 (en) Control method, device, power system and electric vehicle
CN115549454A (zh) 变换器桥臂结温均衡方法、装置、电子设备及存储介质
Malidarreh et al. Capacitor voltage imbalance reduction in flying capacitor modular multilevel converters by using model predictive control
Li et al. Junction temperature post-fault analysis of single IGBT short-circuit for double-side cooling inverter used for electric vehicle
Puls et al. Dimensioning and Lifespan Estimation of Electrolytic Capacitors in Industrial DC micro Grids
US11418143B2 (en) Control method and apparatus, power system, and electric vehicle
Hong et al. Research on Power Cycling for IGBT Module under Motor Operating Condition Simulation
Masic et al. Model of the Stand-Alone Self-Excited Induction Generator With Saturation Effects and Terminal Voltage Regulation

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23794831

Country of ref document: EP

Kind code of ref document: A1