CHARGERS WITH VOLTAGE AMPLITUDE MODULATION

• US 20200052580A1
• Filed: 08/27/2019
• Published: 02/13/2020
• Est. Priority Date: 10/18/2016
• Status: Active Grant

• Current Assignee: StoreDot Ltd.
• Original Assignee: StoreDot Ltd.
• Inventors: SPINDLER, Leonid, DARHOVSKY, Yegal, ARONOV, Daniel
• Granted Patent: US 10,644,587 B2
• Time in Patent Office: Days
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 1/4233 using a bridge converter comprising active switches
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

Chargers and methods are provided which increase the charging efficiency of the chargers by implementing voltage amplitude modulation (VAM) instead of voltage frequency modulation. The charging voltage amplitude is modulated using feedback from at least one energy storage device that is being charged by the charger, while maintaining a charging voltage frequency constant at a LLC resonance frequency of the charger. A buck/boost configuration may be used to reduce maximal voltage levels and further optimize the charger'"'"'s design.

Claims

1. A charger for charging an energy storage device from an AC (alternating current) power source, the charger comprising:

a first rectifier configured to rectify AC power from the AC power source into rectified DC (direct current),

a PFC (power factor correction) unit configured to receive the rectified DC from the first rectifier and to deliver amplitude-modulated DC,

a DC-to-AC converter comprising a LLC circuit, wherein the DC-to-AC converter is configured to operate at a LLC resonance frequency f_s of the LLC circuit and convert the amplitude-modulated DC into amplitude modulated AC, and

a second rectifier configured to rectify the amplitude-modulated AC into charger output DC which is used to charge the energy storage device,

wherein the charger is further configured to receive feedback from the energy storage device that is being charged—

and to carry out the amplitude modulation at an output of the PFC unit with respect to the delivered feedback.

2. The charger of claim 1,

wherein a modulated voltage amplitude of the amplitude modulated DC is lower than a maximal voltage received from the AC power source, and

wherein the PFC unit is configured in a buck/boost configuration to derive the modulated voltage amplitude from the higher maximal voltage received from the AC power source.

3. The charger of claim 1, further comprising a bypass of the PFC unit which is applied when an input voltage to the charger is equal to the modulated voltage.

4. The charger of claim 1, configured to charge at least one fast charging lithium ion battery as the energy storage device.

5. A method of increasing a charging efficiency of a charger for charging an energy storage device from an AC (alternating current) power source, the method comprising:

rectifying AC power from the AC power source into rectified DC (direct current),

deriving amplitude-modulated DC from the rectified DC by a PFC (power factor correction) unit, wherein the amplitude modulation is determined according to feedback received from the energy storage device that is being charged by the charger,

converting the derived amplitude-modulated DC into amplitude-modulated AC by a DC-to-AC converter that comprises a LLC circuit, wherein the converting is carried out at a LLC resonance frequency f_s of the LLC circuit, and

rectifying the amplitude-modulated AC into charger output DC which is used to charge the energy storage device.

6. The method of claim 5,

wherein a modulated voltage amplitude of the amplitude-modulated DC is lower than a maximal voltage received from the AC power source, and

wherein the method further comprises configuring the PFC unit in a buck/boost configuration to derive the modulated voltage amplitude from the higher maximal voltage received from the AC power source.

7. The method of claim 5, further comprising implementing a bypass of the PFC unit when an input voltage to the charger is equal to the modulated voltage.

8. The method of claim 5, wherein the at least one energy storage device comprises at least one fast charging lithium ion battery.

9. A charger for an energy storage device, comprising:

a PFC (power factor correction) unit configured to implement amplitude modulation at an output of the PFC unit, with respect to received rectified DC and according to feedback from the energy storage device that is being charged, and

a DC-to-AC converter configured to convert the amplitude-modulated DC into amplitude modulated AC, at a LLC resonance frequency of an LLC circuit thereof,

wherein the amplitude modulated AC is rectified and used to charge the energy storage device.

10. The charger of claim 9,

wherein a modulated voltage amplitude of the amplitude-modulated DC is lower than a maximal voltage of the received rectified DC, and

wherein the PFC unit is configured in a buck/boost configuration to derive the amplitude-modulated DC from the higher maximal voltage of the received rectified DC.

11. The charger of claim 9, further comprising a bypass of the PFC unit which is applied when the received rectified DC is equal to the amplitude-modulated DC.

12. The charger of claim 9, configured to charge at least one fast charging lithium ion battery as the energy storage device.

13. The charger of claim 9, further comprising:

a first rectifier configures to rectify AC power from an AC power source into rectified DC, and

a second rectifier configured to rectify the amplitude-modulated AC into charger output DC which is used to charge the energy storage device.