Battery heating system and method, power supply system, and electrical apparatus

1. A battery heating system, comprising:

a voltage conversion unit configured to be electrically connected to a power source and to a battery to be heated, to receive a first voltage input by the power source or a second voltage input by the battery to be heated, a charging and discharging frequency of the voltage conversion unit being a maximum switching frequency of the voltage conversion unit; and

a control unit for acquiring the charging and discharging frequency of the voltage conversion unit, determining a charge transfer impedance of the battery to be heated according to the charging and discharging frequency, calculating a safe amplitude current of the battery to be heated according to the charge transfer impedance, and sending a control signal to the voltage conversion unit according to the charging and discharging frequency and the safe amplitude current to cause the voltage conversion unit to perform boost or buck processing of the first voltage or the second voltage according to the control signal.

2. The battery heating system according to claim 1 , further comprising:

a temperature monitoring unit;

wherein:

the temperature monitoring unit is configured to monitor a temperature of the battery to be heated and send the temperature to the control unit; and

the control unit determines the charge transfer impedance of the battery to be heated according to the temperature and the charging and discharging frequency of the voltage conversion unit.

3. The battery heating system according to claim 2 , wherein the control unit is further configured to:

determine the charge transfer impedance of the battery to be heated according to a state of charge of the battery to be heated, the temperature, and the charging and discharging frequency; and

calculate the safe amplitude current of the battery to be heated according to a lithium plating potential of the battery to be heated and the charge transfer impedance.

4. The battery heating system according to claim 2 , wherein:

the control unit pre-stores a mapping table mapping a state of charge of the battery to be heated, a temperature, a charging and discharging frequency, and a safe amplitude current; and

the control unit is further configured to determine the safe amplitude current of the battery to be heated in its current state by searching in the mapping table according to the state of charge of the battery to be heated, the temperature, and the charging and discharging frequency.

5. The battery heating system according to claim 2 , wherein the control unit is further configured to:

send a control signal to the voltage conversion unit in response to the temperature being less than a first preset threshold; and

stop outputting the control signal in response to the temperature being greater than or equal to the first preset threshold.

6. The battery heating system according to claim 5 , further comprising:

an external heating source;

wherein the control unit is further configured to:

start the external heating source to heat the battery to be heated in response to the temperature being less than a second preset threshold; and

turn off the external heating source in response to the temperature being greater than or equal to the second preset threshold, the first preset threshold being less than the second preset threshold.

7. The battery heating system according to claim 1 , wherein the voltage conversion unit is further configured to perform boost or buck processing of the first voltage or the second voltage in a time period so that a charging current received by the battery to be heated is less than the safe amplitude current.

8. The battery heating system according to claim 1 , wherein the voltage conversion unit is further configured to perform boost or buck processing of the first voltage or the second voltage in a time period so that a discharging current output from the battery to be heated is less than the safe amplitude current.

9. A battery heating method for a battery to be heated that is electrically connected to a power source through a voltage conversion unit, the method comprising:

acquiring a charging and discharging frequency of the voltage conversion unit, the charging and discharging frequency of the voltage conversion unit being a maximum switching frequency of the voltage conversion unit;

determining a charge transfer impedance of the battery to be heated according to the charging and discharging frequency;

calculating a safe amplitude current of the battery to be heated according to the charge transfer impedance; and

sending a control signal to the voltage conversion unit according to the safe amplitude current and the charging and discharging frequency, so that the voltage conversion unit regulates a first voltage input by the battery to be heated or a second voltage input by the power source according to the control signal.

10. The battery heating method according to claim 9 , wherein determining the charge transfer impedance of the battery to be heated according to the charging and discharging frequency comprises:

acquiring a temperature of the battery to be heated, and determining the charge transfer impedance of the battery to be heated according to the temperature and the charging and discharging frequency.

11. The battery heating method according to claim 10 , wherein:

determining the charge transfer impedance of the battery to be heated according to the charging and discharging frequency comprises determining the charge transfer impedance of the battery to be heated according to a state of charge of the battery to be heated, the temperature, and the charging and discharging frequency; and

calculating the safe amplitude current of the battery to be heated according to the charge transfer impedance comprises calculating the safe amplitude current of the battery to be heated according to a lithium plating potential of the battery to be heated and the charge transfer impedance.

12. The battery heating method according to claim 10 , wherein calculating the safe amplitude current of the battery to be heated according to the charge transfer impedance comprises:

pre-storing a mapping table mapping a state of charge of the battery to be heated, a temperature, a charging and discharging frequency, and a safe amplitude current; and

determining the safe amplitude current of the battery to be heated in its current state by searching in the mapping table according to the state of charge of the battery to be heated, the temperature, and the charging and discharging frequency.

13. The battery heating method according to claim 9 , wherein regulating the first voltage input by the battery to be heated or the second voltage input by the power source according to the control signal comprises:

performing boost or buck processing of the first voltage or the second voltage in a time period so that a charging current received by the battery to be heated is less than the safe amplitude current.

14. The battery heating method according to claim 9 , wherein regulating the first voltage input by the battery to be heated or the second voltage input by the power source according to the control signal comprises:

performing boost or buck processing of the first voltage or the second voltage in a time period so that a discharging current output from the battery to be heated is less than the safe amplitude current.

15. The battery heating method according to claim 9 , further comprising:

regulating the first voltage input by the battery to be heated or the second voltage input by the power source in response to the temperature being less than a first preset threshold; and

stopping regulating the first voltage input by the battery to be heated or the second voltage input by the power source in response to the temperature being greater than or equal to the first preset threshold.

16. The battery heating method according to claim 15 , further comprising:

starting an external heating source to heat the battery to be heated in response to the temperature being less than a second preset threshold; and

turning off the external heating source in response to the temperature being greater than or equal to the second preset threshold, the first preset threshold being less than the second preset threshold.

17. A power supply system, comprising:

a battery heating system for heating a battery to be heated and comprising:

a voltage conversion unit configured to be electrically connected to a power source and to the battery to be heated, to receive a first voltage input by the power source or a second voltage input by the battery to be heated, a charging and discharging frequency of the voltage conversion unit being a maximum switching frequency of the voltage conversion unit; and

a control unit for acquiring the charging and discharging frequency of the voltage conversion unit, determining a charge transfer impedance of the battery to be heated according to the charging and discharging frequency, calculating a safe amplitude current of the battery to be heated according to the charge transfer impedance, and sending a control signal to the voltage conversion unit according to the charging and discharging frequency and the safe amplitude current to cause the voltage conversion unit to perform boost or buck processing of the first voltage or the second voltage according to the control signal;

wherein the battery to be heated is used for providing power.

18. An electrical apparatus, comprising the power supply system of claim 17 , wherein the power supply system is used for providing power.