Charging system, protection method for preventing from impact of surge voltage and power adapter

1. A charging control method, comprising:

controlling a first rectification unit to rectify an input alternating current, to output a voltage with a first pulsating waveform;

outputting a control signal to a switch unit to modulate the voltage with the first pulsating waveform, wherein the modulated voltage with the first pulsating waveform is applied to a primary winding of a transformer, and a secondary winding of the transformer outputs a voltage with a second pulsating waveform;

controlling a second rectification unit to rectify the voltage with the second pulsating waveform to output a voltage with a third pulsating waveform, wherein the voltage with the third pulsating waveform is configured to be applied to a battery for charging the battery;

controlling a voltage sampling unit to sample the voltage with the first pulsating waveform to obtain a voltage sampling value; and

controlling a comparator unit to compare the voltage sampling value and a reference voltage value, wherein the comparator unit outputs a comparison signal to the switch unit to control the switch unit to forcibly open when the voltage sampling value is greater than the reference voltage value.

2. The charging control method of claim 1 , further comprising:

controlling a first sampling circuit to sample current and/or voltage output by the second rectification unit, to acquire a first current sampling value and/or a first voltage sampling value; and

adjusting a duty ratio or a frequency of the control signal based on the first current sampling value and/or the first voltage sampling value.

3. The charging control method of claim 1 , wherein an auxiliary winding of the transformer outputs a voltage with a fourth pulsating waveform based on the modulated voltage with the first pulsating waveform, wherein the method further comprises:

controlling a power supply unit to convert the voltage with the fourth pulsating waveform to output a direct current.

4. The charging control method of claim 1 , further comprising:

communicating with a terminal comprising the battery to determine a charging mode, wherein the charging mode comprises a first charging mode and a second charging mode, and a charging speed of the first charging mode is less than that of the second charging mode.

5. The charging control method of claim 4 , further comprising:

obtaining a charging current and/or a charging voltage corresponding to the first charging mode according to status information of the terminal when it is determined that the charging mode is the first charging mode; and

adjusting a duty ratio of the control signal according to the charging current and/or the charging voltage.

6. The charging control method of claim 5 , wherein the status information of the terminal comprises an electric quantity of the battery, a temperature of the battery, a voltage/current of the terminal, interface information of the terminal and information on path impedance of the terminal.

7. The charging control method of claim 6 , further comprising:

switching the first charging mode to the second charging mode, when the temperature of the battery is greater than a first preset temperature threshold, or the temperature of the battery is less than a second preset temperature threshold, wherein the first preset temperature threshold is greater than the second preset temperature threshold.

8. The charging control method of claim 6 , further comprising:

controlling the switch unit to switch off when the temperature of the battery is greater than a preset high-temperature protection threshold or when temperature of a first charging interface of the terminal is greater than a preset protection temperature.

9. The charging control method of claim 4 , further comprising:

controlling a controllable switch to switch on when determining that a charging mode is a first charging mode; wherein the controllable switch and a filtering unit are in series, and the controllable switch and the filtering unit in series are coupled to an output end of the second rectification unit; and

controlling the controllable switch to switch off when determining that the charging mode is the second charging mode.

10. The charging control method of claim 3 , further comprising:

controlling a first voltage detecting unit to detect the voltage with the fourth pulsating waveform to output a voltage detecting value; and

adjusting a duty ratio of the control signal according to the voltage detecting value.

11. A charging control device, comprising:

a processor; and

a memory, configured to store a computer program;

wherein when the computer program is executed by the processor, the processor is configured to:

control a first rectification unit to rectify an input alternating current, to output a voltage with a first pulsating waveform;

output a control signal to a switch unit to modulate the voltage with the first pulsating waveform, wherein the modulated voltage with the first pulsating waveform is applied to a primary winding of a transformer, and a secondary winding of the transformer outputs a voltage with a second pulsating waveform;

control a second rectification unit to rectify the voltage with the second pulsating waveform, to output a voltage with a third pulsating waveform, wherein the voltage with the third pulsating waveform is configured to be applied to a battery for charging the battery;

control a voltage sampling unit to sample the voltage with the first pulsating waveform to obtain a voltage sampling value; and

control a comparator unit to compare the voltage sampling value and a reference voltage value, wherein the comparator unit outputs a comparison signal to the switch unit to control the switch unit to forcibly open when the voltage sampling value is greater than the reference voltage value.

12. The charging control device of claim 11 , wherein the processor is further configured to:

control a first sampling circuit to sample current and/or voltage output by the second rectification unit, to acquire a first current sampling value and/or a first voltage sampling value; and

adjust a duty ratio or a frequency of the control signal based on the first current sampling value and/or the first voltage sampling value.

13. The charging control device of claim 11 , an auxiliary winding of the transformer outputs a voltage with a fourth pulsating waveform based on the modulated voltage with the first pulsating waveform, and

the processor is further configured to control a power supply unit to convert the voltage with the fourth pulsating waveform to output a direct current.

14. The charging control device of claim 11 , wherein the processor is further configured to communicate with the terminal comprising the battery to determine a charging mode, in which the charging mode comprises a first charging mode and a second charging mode, and a charging speed of the first charging mode is less than that of the second charging mode.

15. The charging control device of claim 14 , wherein the processor is further configured to:

obtain a charging current and/or a charging voltage corresponding to the first charging mode according to status information of the terminal when it is determined that the charging mode is the first charging mode; and

adjust a duty ratio of the control signal according to the charging current and/or the charging voltage.

16. The charging control device of claim 15 , wherein the status information of the terminal comprises an electric quantity of the battery, a temperature of the battery, a voltage/current of the terminal, interface information of the terminal and information on path impedance of the terminal.

17. The charging control device of claim 16 , wherein the processor is further configured to:

switch the first charging mode to the second charging mode, when the temperature of the battery is greater than a first preset temperature threshold, or the temperature of the battery is less than a second preset temperature threshold, in which the first preset temperature threshold is greater than the second preset temperature threshold.

18. The charging control device of claim 16 , wherein the processor is configured to:

control the switch unit to switch off when the temperature of the battery is greater than a preset high-temperature protection threshold or when temperature of a first charging interface of the terminal is greater than a preset protection temperature.

19. The charging control device of claim 14 , wherein the processor is further configured to:

control a controllable switch to switch on when determining that a charging mode is a first charging mode; wherein the controllable switch and a filtering unit are in series, and the controllable switch and the filtering unit in series are coupled to an output end of the second rectification unit; and

control the controllable switch to switch off when determining that the charging mode is the second charging mode.

20. A non-transitory computer readable storage medium having stored therein program instructions, wherein the instructions are configured to be invoked by a charging device to realize acts of:

controlling a first rectification unit to rectify an input alternating current, to output a voltage with a first pulsating waveform;

outputting a control signal to a switch unit to modulate the voltage with the first pulsating waveform, wherein the modulated voltage with the first pulsating waveform is applied to a primary winding of a transformer, and a secondary winding of the transformer outputs a voltage with a second pulsating waveform;

controlling a second rectification unit to rectify the voltage with the second pulsating waveform to output a voltage with a third pulsating waveform, wherein the voltage with the third pulsating waveform is configured to be applied to a battery for charging the battery;

controlling a voltage sampling unit to sample the voltage with the first pulsating waveform to obtain a voltage sampling value; and

controlling a comparator unit to compare the voltage sampling value and a reference voltage value, wherein the comparator unit outputs a comparison signal to the switch unit to control the switch unit to forcibly open when the voltage sampling value is greater than the reference voltage value.