SYSTEMS AND METHODS OF ENERGY SAVING IN A BATTERY CHARGING SYSTEM

• US 20150207343A1
• Filed: 01/15/2015
• Published: 07/23/2015
• Est. Priority Date: 01/17/2014
• Status: Active Grant

• Current Assignee: SG Micro Limited
• Original Assignee: Grenotek Integrated, Inc.
• Inventors: Zhai, Jerry Zhijun
• Granted Patent: US 9,806,612 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 7/0032 disconnection of loads if battery is not under charge, e.g. in vehicle if engine is not running
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

Systems and methods of implementing battery charging and energy saving systems in computers, computerized devices, medical devices, industrial devices, wearable devices, wireless charging devices, or any other suitable battery-operable devices. The systems and methods can control output voltages of battery charging systems during multiple charging/discharging periods, including a pre-charging period, a current-controlled charging period, a voltage-controlled charging period, a discharging period, as well as an additional period during which battery packs are removed or otherwise absent from the battery-operable devices or testing is being performed. The systems and methods also provide multiple energy saving modes for the battery-operable devices, allowing transitions between the respective energy saving modes both during operation of the battery-operable devices and during charging of the battery packs within the battery-operable devices.

Claims

1. A method of implementing a plurality of energy saving modes in a battery charging system, the battery charging system including an alternating current (AC) adapter input port and a pulse width modulation (PWM) power stage, the battery charging system being operable to receive an AC adapter current from the AC adapter input port, and the PWM power stage being operable to switch two or more active switch elements at a PWM switching frequency to generate an output current for charging a battery pack, the method comprising:

operating the battery charging system in a zeroth energy saving mode;

monitoring a reduction in the AC adapter current from the AC adapter input port until the AC adapter current reaches a predetermined current level;

upon reaching the predetermined current level of the AC adapter current, transitioning operation of the battery charging system from the zeroth energy saving mode to a first energy saving mode;

monitoring a reduction in the PWM switching frequency of the PWM power stage until the PWM switching frequency reaches a predetermined frequency threshold, the reduction in the PWM switching frequency being in response to the reduction in the AC adapter current; and

upon reaching the predetermined frequency threshold of the PWM switching frequency, transitioning operation of the battery charging system from the first energy saving mode to a second energy saving mode.

2. The method of claim 1 wherein the battery pack is absent from the battery charging system, and wherein the method further comprises:

while operating the battery charging system in the zeroth energy saving mode, regulating an output voltage of the PWM power stage to be equal to a predetermined voltage level.

3. The method of claim 1 wherein the battery pack is present within the battery charging system, and wherein the method further comprises:

while operating the battery charging system in the zeroth energy saving mode, regulating an output voltage of the PWM power stage to be equal to a sum of a target voltage of the battery pack and a predetermined voltage level.

4. The method of claim 1 wherein the PWM power stage includes a first high-side switch element and a second high-side switch element connected in parallel on a high side of a buck converter switch, and a first low-side switch element and a second low-side switch element connected in parallel on a low side of the buck converter switch, the first high-side switch element being connected in series with the first low-side switch element, and the second high-side switch element being connected in series with the second low-side switch element, and wherein the method further comprises:

while operating the battery charging system in the zeroth energy saving mode, actuating the first and second high-side switch elements of the buck converter switch substantially simultaneously.

5. The method of claim 4 further comprising:

while operating the battery charging system in the first energy saving mode;

deactivating the second high-side switch element and the second low-side switch element of the buck converter switch; and

actuating the first high-side switch element and the first low-side switch element of the buck converter switch in PWM cycles.

6. The method of claim 4 further comprising:

while operating the battery charging system in the second energy saving mode;

deactivating the second high-side switch element and the second low-side switch element of the buck converter switch; and

actuating the first high-side switch element and the first low-side switch element of the buck converter switch in PWM cycles.

7. The method of claim 5 further comprising:

while operating the battery charging system in the second energy saving mode;

regulating an output voltage of the PWM power stage to be equal to a voltage ramping up from a predetermined minimum voltage level to a predetermined maximum voltage level; and

performing switching of the PWM power stage in continuous PWM pulses until the output voltage of the PWM power stage reaches the predetermined maximum voltage level.

8. The method of claim 7 wherein the second energy saving mode includes a sleep period, and wherein the method further comprises:

upon reaching the predetermined maximum voltage level of the output voltage, entering the sleep period of the second energy saving mode.

9. The method of claim 8 further comprising:

during the sleep period of the second energy saving mode, performing one of terminating switching of the PWM power stage, and performing switching of the PWM power stage at a reduced PWM switching frequency.

10. The method of claim 8 further comprising:

during the sleep period of the second energy saving mode, regulating the output voltage of the PWM power stage to be equal to a voltage ramping down from the predetermined maximum voltage level to the predetermined minimum voltage level.

11. The method of claim 10 further comprising:

upon reaching the predetermined minimum voltage level of the output voltage, resuming switching of the PWM power stage at the PWM switching frequency.

12. The method of claim 8 wherein a duration of the sleep period is reduced as the output current of the PWM power stage is increased, and wherein the method further comprises:

monitoring a reduction in the duration of the sleep period until the sleep period reaches a predetermined minimum sleep period.

13. The method of claim 12 further comprising:

upon reaching the predetermined minimum sleep period, transitioning operation of the battery charging system from the second energy saving mode to the zeroth energy saving mode.

14. The method of claim 1 further comprising:

generating the output current for charging the battery pack; and

while charging the battery pack, regulating an output voltage of the PWM power stage to be equal to a target voltage of the battery pack.

15. The method of claim 14 further comprising:

upon reaching the predetermined current level of the AC adapter current;

transitioning operation of the battery charging system from the zeroth energy saving mode to the first energy saving mode; and

completing the charging of the battery pack.

16. The method of claim 15 further comprising:

upon completion of the charging of the battery pack, transitioning operation of the battery charging system from the first energy saving mode to the zeroth energy saving mode.

17. A battery charging system for delivering battery power to a battery-operable device, comprising:

a battery charging controller including a digital core circuit, a charger mode control circuit component, and an energy saving circuit component;

an alternating current (AC) adapter input port;

a battery pack; and

a pulse width modulation (PWM) power stage including a plurality of active switch elements for implementing, at a PWM switching frequency, a PWM switching scheme to provide a battery charging output to the battery pack,

wherein the digital core circuit is operative;

to regulate the battery charging output during at least a pre-charging period, a current-controlled charging period, and a voltage-controlled charging period of the battery pack;

during one or both of the current-controlled charging period and the voltage-controlled charging period of the battery pack, to control the charger mode control circuit component to operate the energy saving circuit component in a zeroth energy saving mode of the battery charging system;

to monitor a reduction in an AC adapter current from the AC adapter input port until the AC adapter current reaches a predetermined current level;

upon reaching the predetermined current level of the AC adapter current, to control the charger mode control circuit component to transition the energy saving circuit component from operating in the zeroth energy saving mode to a first energy saving mode of the battery charging system;

to monitor a reduction in the PWM switching frequency of the PWM power stage until the PWM switching frequency reaches a predetermined frequency threshold, the reduction in the PWM switching frequency being in response to the reduction in the AC adapter current; and

upon reaching the predetermined frequency threshold of the PWM switching frequency, to control the charger mode control circuit component to transition the energy saving circuit component from operating in the first energy saving mode to a second energy saving mode of the battery charging system.

18. The battery charging system of claim 17 wherein the digital core circuit is further operative, during the pre-charging period of the battery pack, to control the charger mode control circuit component to operate the energy saving circuit component in the first energy saving mode of the battery charging system.

19. The battery charging system of claim 17 wherein the battery-operable device is configured to operate in a system standby mode, and wherein the digital core circuit is further operative, while the battery-operable device operates in the system standby mode, to control the charger mode control circuit component to operate the energy saving circuit component in the second energy saving mode of the battery charging system.

20. A method of a battery charging system for delivering battery power to a battery-operable device, comprising:

regulating, by a digital core circuit within a battery charging controller, a battery charging output of a pulse width modulation (PWM) power stage during at least a current-controlled charging period and a voltage-controlled charging period of a battery pack, the battery charging controller including a charger mode control circuit component and an energy saving circuit component;

during one or both of the current-controlled charging period and the voltage-controlled charging period of the battery pack, controlling the charger mode control circuit component to operate the energy saving circuit component in a zeroth energy saving mode of the battery charging system;

monitoring, by the digital core circuit, a reduction in an AC adapter current from an AC adapter input port of the battery charging system until the AC adapter current reaches a predetermined current level;

upon reaching the predetermined current level of the AC adapter current, controlling the charger mode control circuit component to transition the energy saving circuit component from operating in the zeroth energy saving mode to a first energy saving mode of the battery charging system;

monitoring, by the digital core circuit, a reduction in a PWM switching frequency of the PWM power stage until the PWM switching frequency reaches a predetermined frequency threshold, the reduction in the PWM switching frequency being in response to the reduction in the AC adapter current; and

upon reaching the predetermined frequency threshold of the PWM switching frequency, controlling the charger mode control circuit component to transition the energy saving circuit component from operating in the first energy saving mode to a second energy saving mode of the battery charging system.

21. The method of claim 20 further comprising, while the battery-operable device operates in a system standby mode of operation, controlling the charger mode control circuit component to operate the energy saving circuit component in the second energy saving mode of the battery charging system.