CN117081190A

CN117081190A - Parallel battery charger

Info

Publication number: CN117081190A
Application number: CN202310551431.6A
Authority: CN
Inventors: 约翰·L·梅兰森; 埃里克·J·金
Original assignee: Cirrus Logic International Semiconductor Ltd
Current assignee: Cirrus Logic International Semiconductor Ltd
Priority date: 2022-05-16
Filing date: 2023-05-16
Publication date: 2023-11-17

Abstract

The battery charging system may include a first current source for charging the battery and a second current source for charging the battery, the first current source providing direct current for charging the battery and the second current source providing electrical energy to a system load of the battery during discharge of the battery. Further, the battery charging system may include a first current source for charging the battery and a second current source for charging the battery, the first current source providing direct current for charging the battery and the second current source providing alternating current at a frequency of at least 5KHz to charge the battery.

Description

Parallel battery charger

RELATED APPLICATIONS

The present disclosure claims priority from U.S. provisional patent application Ser. No. 63/342,178 filed 5/16 at 2022, which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates generally to circuits for electronic devices, including but not limited to personal audio devices such as wireless telephones and media players, and more particularly to battery charging systems that include parallel Direct Current (DC) and Alternating Current (AC) charging paths.

Background

Portable electronic devices, including wireless telephones (such as mobile/cellular telephones), tablet computers, cordless telephones, mp3 players, smart watches, health monitors, and other consumer devices, are in widespread use. Such portable electronic devices may include a battery (e.g., a lithium ion battery) for powering components of the portable electronic device. Typically, such batteries used in portable electronic devices are rechargeable such that when charged, the battery converts electrical energy to chemical energy, which can then be converted back to electrical energy for powering components of the portable electronic device.

It is desirable for a battery charging system to be able to charge a battery quickly while maximizing power efficiency during charging.

Disclosure of Invention

One or more drawbacks and problems associated with existing battery charging methods may be reduced or eliminated in accordance with the teachings of the present disclosure.

According to an embodiment of the present disclosure, a battery charging system may include a first current source for charging a battery and a second current source for charging the battery, the first current source providing direct current for charging the battery and the second current source providing electrical energy for operation of a system load of the battery during discharge of the battery.

In accordance with these and other embodiments of the present disclosure, a battery charging system may include a first current source for charging a battery and a second current source for charging the battery, the first current source providing direct current for charging the battery and the second current source providing alternating current at a frequency of at least 5KHz to charge the battery.

In accordance with these and other embodiments of the present disclosure, a method may include charging a battery with a first current source that provides direct current for charging the battery and charging the battery with a second current source that provides alternating current for charging the battery and provides electrical energy for operation of a system load of the battery during discharge of the battery.

In accordance with these and other embodiments of the present disclosure, a method may include charging a battery with a first current source that provides direct current for charging the battery and charging the battery with a second current source that provides alternating current at a frequency of at least 5KHz to charge the battery.

Technical advantages of the present disclosure may be readily apparent to one skilled in the art from the figures, descriptions, and claims included herein. The objects and advantages of the embodiments will be realized and attained by means of the elements, features, and combinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claims as set forth in this disclosure.

Drawings

A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:

FIG. 1 illustrates an example block diagram of selected components of a system for charging a battery of an electronic device, according to an embodiment of this disclosure; and

fig. 2 illustrates example waveforms of currents output from each of the DC charging path and the AC charging path in the system depicted in fig. 1, according to an embodiment of the present disclosure.

Detailed Description

Fig. 1 illustrates an example block diagram of selected components of a system 100 for charging a battery 104 of an electronic device 102, according to an embodiment of this disclosure. The electronic device 102 may include any suitable electronic device including, but not limited to, a mobile phone, a smart phone, a tablet, a laptop/notebook, a media player, a handheld device, a smart watch, a game controller, a power tool, a power toothbrush, a flashlight, and the like.

As shown in fig. 1, the electronic device 102 may include a DC charging path 106 coupled between a DC input of the electronic device 102 and the battery 104, and an AC charging path 108 coupled between the battery 104 and the energy storage device 110. The electronic device 102 may also include a system load 112 coupled to one or more of the DC input, the battery 104, and the energy storage device 110, such that the system load 112 may be powered by one or more of the DC input, the battery 104, and the energy storage device 110.

The battery 104 may include any system, device, or apparatus configured to convert chemical energy stored within the battery 104 into electrical energy. For example, in some embodiments, the battery 104 may be integrated into the device 102, and the battery 104 may be configured to deliver electrical energy to the system load 112, the energy storage device 110, and other components of the device 102. In addition, the battery 104 may also be configured to be recharged, wherein the battery 104 may convert electrical energy received by the battery 104 from either or both of the DC charging path 106 and the AC charging path 108 to chemical energy to be stored for later conversion back to electrical energy. For example, in some embodiments, the battery 104 may comprise a lithium ion battery. The battery 104 may comprise a single battery, a plurality of batteries in series, a plurality of batteries in parallel, or a combination of a plurality of batteries in series and parallel.

The DC charging path 106 may include a wired power port configured to receive electrical energy from an external source (e.g., a wall charger) via a power cable. The DC charging path 106 may additionally or alternatively include a wireless power port configured to receive power from an external wireless charger. The DC charging path 106 may include any suitable system, device, or apparatus configured to receive energy from a DC input and transmit such energy to the battery 104 to charge the battery 104. The dc charging path 106 may be implemented by any suitable dc power source including, but not limited to, buck converters, other power converters, and linear current sources.

The AC charging path 108 may include any suitable system, device, or apparatus configured to transfer electrical energy back and forth between the battery 104 and the energy storage device 110 using AC current. For example, in some embodiments, AC charging path 108 may include a switching converter that is operated as a boost converter when transferring energy from battery 104 to energy storage device 110 and as a buck converter when transferring energy from energy storage device 110 to battery 104. In these and other embodiments, the AC charging path 108 may include an inductor-based switch-mode power converter.

The energy storage device 110 may include any suitable system, apparatus, or device configured to store electrical energy. For example, in some embodiments, the energy storage device 110 may include a capacitor. In other embodiments, the energy storage device 110 may include a battery.

The system load 112 may include a plurality of electrical and electronic components configured to perform the functions of the device 102, including but not limited to microphones, speakers, radio antennas, haptic actuators, display devices, lights, motors, etc., and the system load 112 may be configured to be powered by the DC charging path 106 and/or the AC charging path 108 when charging of the battery 104 is disabled and may optionally be powered by the DC charging path 106 and/or the AC charging path 108 when charging of the battery 104 is enabled. In some embodiments, the system load 112 may be powered directly from the battery 104, from the DC charging path 106, from the AC charging path 108, from the DC input, and/or from the energy storage device 110.

The system 100 may also include a controller 114, the controller 114 being configured to control operation of the DC charging path 106, the AC charging path 108, and/or other components of the system 100. For example, the controller 114 may control the operation of the DC charging path 106 and the AC charging path 108 by controlling the commutation of the switches inside the DC charging path 106 and the AC charging path 108.

The system 100 may also include a temperature sensor 116. The temperature sensor 116 may include any system, device, or apparatus (e.g., a thermistor or other temperature-dependent circuit element) configured to generate a signal that is a function of the actual temperature of the battery 104 or the proximity battery 104.

In operation, during active charging of battery 104, controller 114 may cause two current sources to charge battery 104, charging: a DC current source implemented primarily through DC charging path 106 and an AC current source implemented primarily through AC charging path 108. FIG. 2 illustrates a DC current I output from DC charging path 106 in accordance with an embodiment of the present disclosure _DC And an AC current I output from the AC charging path 108 _AC Is an example waveform of (a). AC current I _AC May be an approximation of a sine wave, an approximation of a rectangular wave, an approximation of a triangular wave, or other harmonics. In some embodiments, during a charging period (e.g., a period of 100 seconds), the AC current I _AC The waveform of (a) may vary, for example, from rectangular to sinusoidal, such that at a first time during the charging cycle the AC current I _AC May have a first waveform (e.g., sinusoidal, rectangular, triangular) shape, and an AC current I at a second time during the charging cycle _AC May have a second waveform shape. In these and other embodiments, the AC current I _AC May have a frequency between 1KHz and 100 KHz. In these and other embodiments, a combination of waveforms may be used. Further, the AC charging path 108 may mix and match signals having any zero DC average.

In some embodiments, the controller 114 may be configured to control the AC charging path 108 such that the AC current I _AC May have a frequency greater than 5KHz. Such operation may be advantageous because the chemical time constant of the battery 104 may be 1 millisecond or higher. Operating at frequencies above 5kHz can avoid chemical reactions that may occur in the anode material (e.g., graphite) of a lithium ion battery. During charging, lithium ions may intercalate into (or combine with) electrons in the lattice structure of the graphite particles in the anode material of the lithium ion battery. The ease of this process is affected by a variety of factors such as temperature, the amount of lithium particles already present in the graphite particles, and the location of the graphite particles relative to the separator and current collector of the anode terminal. The time constant that such an embedding process has can be measured and modeled to be much slower than 5kHz. Thus, the application of an AC waveform above 5kHz can avoid interaction with the embedding process.

Among these and the sameIn other embodiments, the controller 114 may be configured to modulate the AC current I _AC To adjust the temperature of the battery 104 (e.g., as measured by the temperature sensor 116) or to approximate the temperature of the battery 104.

The AC charging path 108 may have an efficiency of less than 100% due to the undesirable loss of energy converted to heat during the transfer of energy from the battery 104 to the energy storage device 110 or from the energy storage device 100 to the battery 104. Thus, the AC charging path 108 necessarily generates some DC current associated with losses. It is desirable to minimize this loss and keep most of the current generated by the AC charging path 108 AC. Can increase DC current I _DC To account for undesirable losses in the AC charging path 108. DC current I _DC May be used to minimize such undesirable currents. When the loss of the AC charging path 108 increases, the DC current I _DC May be increased and as the loss of the AC charging path 108 decreases, the DC current I _DC Can be reduced.

It may be advantageous to simultaneously deliver a DC charging current and an AC charging stimulus to the battery 104. DC current I _DC The charge of the battery 104 can be replenished while the AC current I _AC The quality of charging can be improved. Thus, the waveforms generated by DC charging path 106 and AC charging path 108 may allow for more flexible charging waveforms, faster charging times, and improved battery life. Furthermore, the selection of the waveform or waveforms used may allow for optimization of charging.

As used herein, when two or more elements are referred to as being "coupled" to each other, the term indicates that the two or more elements are in electronic or mechanical communication (as applicable), whether connected indirectly or directly, with or without intervening elements.

The present disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that one of ordinary skill would understand. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person of ordinary skill in the art would understand. Furthermore, in the appended claims, reference to a device or system or component of a device or system being adapted, arranged, capable of being, configured, enabled, operable, or operative to perform a particular function includes the device, system, or component whether or not it or that particular function is activated, turned on, or unlocked, so long as the device or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Accordingly, modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, components of the systems and devices may be integrated or separated. Moreover, the operations of the systems and apparatus disclosed herein may be performed by more, fewer, or other components, and the described methods may include more, fewer, or other steps. Furthermore, the steps may be performed in any suitable order. As used in this document, "each" refers to each member of a collection or each member of a subset of a collection.

Although exemplary embodiments are illustrated in the accompanying drawings and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should not be limited in any way to the exemplary embodiments and techniques illustrated in the drawings and described above.

The items depicted in the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the disclosure and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and scope of the present disclosure.

Although specific advantages have been enumerated above, various embodiments may include some, none, or all of the enumerated advantages. Further technical advantages may become readily apparent to one of ordinary skill in the art after review of the above figures and description.

To assist the patent office and any readers of any patent issued in accordance with the present application in interpreting the claims appended hereto, the applicant wishes to note that they do not intend for any claim or claim element appended to refer to 35u.s.c. ≡112 (f) unless "means for … …" or "steps for … …" are explicitly used in a particular claim.

Claims

1. A battery charging system, comprising:

a first current source for charging a battery that provides direct current for charging the battery; and

a second current source for charging the battery, providing alternating current for charging the battery, and providing electrical energy for operation of a system load of the battery during discharge of the battery.

2. The battery charging system of claim 1, wherein the second current source comprises a switch-mode converter.

3. The battery charging system of claim 2, further comprising an energy storage device, and wherein:

the switch-mode converter is coupled between the battery and the energy storage device and is configured to transfer electrical energy from the battery to the energy storage device and vice versa.

4. A battery charging system according to claim 3, wherein the energy storage device is a capacitor.

5. The battery charging system according to any one of claims 1-4, wherein said first current source comprises a switch mode converter.

6. The battery charging system according to any one of claims 1-5, wherein said battery comprises a lithium ion battery.

7. The battery charging system according to any one of claims 1-6, wherein, during a charging cycle of the battery, the waveform of the alternating current has a first waveform shape at a first time during the charging cycle and a second waveform shape at a second time during the charging cycle.

8. The battery charging system of claim 7, wherein one of the first waveform and the second waveform is one of the following waveforms: rectangular waves, triangular waves, and sinusoidal waves.

9. The battery charging system according to claim 7 or 8, wherein at least one of the first waveform and the second waveform has zero direct current.

10. The battery charging system according to any one of claims 1-9, wherein said alternating current has a frequency between 1KHz and 100 KHz.

11. The battery charging system according to any one of claims 1-9, wherein said alternating current has a frequency of at least 5KHz.

12. The battery charging system according to any one of claims 1-11, wherein said direct current is dependent on an amount of power loss of said second current source.

13. The battery charging system according to any one of claims 1-12, wherein the frequency of the alternating current is modulated to regulate a temperature associated with the battery.

14. A battery charging system, comprising:

and a second current source for charging the battery, which provides an alternating current of at least 5KHz frequency for charging the battery.

15. The battery charging system of claim 14, wherein the second current source comprises a switch-mode converter.

16. The battery charging system of claim 15, further comprising an energy storage device, and wherein:

17. The battery charging system of claim 16, wherein the energy storage device is a capacitor.

18. The battery charging system according to any one of claims 14-17, wherein said first current source comprises a switch mode converter.

19. The battery charging system according to any one of claims 14-18, wherein said battery comprises a lithium ion battery.

20. The battery charging system according to any one of claims 14-19, wherein, during a charging cycle of said battery, the waveform of said alternating current has a first waveform shape at a first time during said charging cycle and a second waveform shape at a second time during said charging cycle.

21. The battery charging system of claim 20, wherein one of the first waveform and the second waveform is a rectangular wave.

22. The battery charging system according to claim 20 or 21, wherein one of the first waveform and the second waveform is one of the following waveforms: rectangular waves, triangular waves, and sinusoidal waves.

23. The battery charging system according to any one of claims 14-22, wherein said alternating current has a frequency between 1KHz and 100 KHz.

24. The battery charging system according to any one of claims 14-22, wherein said alternating current has a frequency of at least 5KHz.

25. The battery charging system according to any one of claims 14-24, wherein said direct current is dependent on an amount of power loss of said second current source.

26. The battery charging system according to any one of claims 14-25, wherein the frequency of the alternating current is modulated to regulate a temperature associated with the battery.

27. The battery charging system according to any one of claims 14-26, wherein at least one of said first and second current sources is configured to provide electrical energy to a system load of a device housing said battery.

28. A method, comprising:

charging a battery with a first current source, the first current source providing direct current for charging the battery; and

the battery is charged with a second current source, the second current providing alternating current for charging the battery and providing electrical energy for operation of a system load of the battery during discharge of the battery.

29. The method of claim 28, further comprising transferring electrical energy from the battery to an energy storage device and vice versa, wherein the second current source is coupled between the battery and the energy storage device.

30. The method of claim 28 or 29, wherein, during a charging cycle of the battery, the waveform of the alternating current has a first waveform shape at a first time during the charging cycle and a second waveform shape at a second time during the charging cycle.

31. The method of claim 30, wherein one of the first waveform and the second waveform is one of the following waveforms: rectangular waves, triangular waves, and sinusoidal waves.

32. The method of claim 30 or 31, wherein at least one of the first waveform and the second waveform has zero direct current.

33. The method of any of claims 28-32, wherein the alternating current has a frequency between 1KHz and 100 KHz.

34. The method of any of claims 28-32, wherein the alternating current has a frequency of at least 5KHz.

35. The method of any of claims 28-34, wherein the direct current is dependent on an amount of power loss of the second current source.

36. The method of any of claims 28-35, wherein the frequency of the alternating current is modulated to regulate a temperature associated with the battery.

37. A method, comprising:

the battery is charged with a second current source that provides an alternating current of at least 5KHz frequency for charging the battery.

38. The method of claim 37, further comprising transferring electrical energy from the battery to an energy storage device and vice versa, wherein the second current source is coupled between the battery and the energy storage device.

39. The method of claim 37 or 38, wherein, during a charging cycle of the battery, the waveform of the alternating current has a first waveform shape at a first time during the charging cycle and a second waveform shape at a second time during the charging cycle.

40. The method of claim 39, wherein one of the first waveform and the second waveform is one of the following waveforms: rectangular waves, triangular waves, and sinusoidal waves.

41. The method of claim 39 or 40, wherein at least one of the first waveform and the second waveform has zero direct current.

42. A method as claimed in any one of claims 37 to 41, wherein the alternating current has a frequency between 1KHz and 100 KHz.

43. A method according to any one of claims 37 to 41 wherein the alternating current has a frequency of at least 5KHz.

44. The method of any of claims 37-43, wherein the direct current is dependent on an amount of power loss of the second current source.

45. The method of any of claims 37-44, wherein the frequency of the alternating current is modulated to regulate a temperature associated with the battery.

46. The method of any of claims 37-45, wherein at least one of the first current source and the second current source is configured to provide electrical energy to a system load of a device housing the battery.