Method and Apparatus for Storing and Depleting Energy

• US 20170201113A1
• Filed: 12/19/2016
• Published: 07/13/2017
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Solaredge Technologies Incorporated
• Original Assignee: Solaredge Technologies Incorporated
• Inventors: Gazit, Meir
• Granted Patent: US 10,778,025 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

A method to control storage into and depletion from multiple energy storage devices. The method enables an operative connection between the energy storage devices and respective power converters. The energy storage devices are connectible across respective first terminals of the power converters. At the second terminals of the power converter, a common reference is set which may be a current reference or a voltage reference. An energy storage fraction is determined respectively for the energy storage devices. A voltage conversion ratio is maintained individually based on the energy storage fraction. The energy storage devices are stored individually with multiple variable rates of energy storage through the first terminals. The energy storage is complete for the energy storage devices substantially at a common end time responsive to the common reference.

Claims

1. A method comprising:

setting a common voltage or current reference;

using power converters to individually regulate the storing of energy in energy storage devices with a plurality of variable rates to enable completion of energy storage substantially at a common end time responsive to a common reference; and

using a power converters to individually deplete energy from the energy storage devices with a plurality of variable rates to enable depletion of the energy storage devices substantially at a common end time responsive to the common reference.

2. The method of claim 1, wherein the energy storage devices convert electrical energy to at least one other form of energy.

3. The method of claim 1, wherein said energy storage devices are batteries and storing and depleting energy include charging and discharging the batteries respectively, the method further comprising the steps of:

determining a battery charge fraction respectively for said batteries;

maintaining individually a voltage conversion ratio based on said battery charge fraction;

charging said batteries, wherein said charging is complete for said batteries substantially at a common end time responsive to said common reference;

discharging said batteries individually, wherein said discharging is complete for said batteries substantially at a common end time responsive to said common reference.

4. The method of claim 3, wherein during said charging, maintaining the voltage conversion ratio substantially proportional to the amount of additional charge that may be stored in the respective batteries.

5. The method of claim 3, wherein during said discharging, maintaining said voltage conversion ratio substantially proportional to the remaining available charge in the respective batteries.

6. The method of claim 3, further comprising:

wherein said AC/DC inverter is configured to set said common reference through DC terminals.

7. The method of claim 6, further comprising:

attaching a central controller to said AC/DC inverter to provide a value for said common reference.

8. The method of claim 3, wherein said common reference is selected from a group consisting of:

a current reference and a voltage reference.

9. The method of claim 3, wherein said power converters are serially connected and the common reference is a current reference.

10. The method of claim 3, wherein the power converters are parallel connected and the common reference is a voltage reference.

11. The method of claim 3, wherein the batteries form a first plurality of batteries of a first bank and a second plurality of batteries of a second bank.

12. The method of claim 11, further comprising:

locating said first and said second bank in different geographic locations, wherein said first and said second bank share said common reference.

13. A system operable to charge or discharge a plurality of batteries, the system comprising:

a plurality of power converters each including first terminals and second terminals wherein the first terminals are connectible to the batteries, and the second terminals are connectible to a direct current (DC) source of power and correspond to a common reference wherein each of the power converters includes a controller operatively attached to said power converter, to determine a battery charge fraction of the battery and to to maintain a voltage conversion ratio based on said battery charge fraction, wherein the batteries are fully charged or discharged substantially at a common end time responsive to said common reference.

14. The system of claim 13, wherein said common reference is set as a current reference by a serial connection of said second terminals of said power converters.

15. The system of claim 13, wherein said common reference is set as a voltage reference by a parallel connected of said second terminals of said power converters.

16. The system of claim 13, further comprising:

an AC/DC inverter including AC terminals and DC terminals, wherein said AC terminals are connectible to an AC electrical network source of power, wherein said DC terminals are operatively attached to said second terminals, wherein said AC/DC inverter includes a control portion configured to set the common reference through said DC terminals.

17. The system of claim 16, further comprising a central controller operatively attachable to said AC/DC inverter to provide a value for said common reference.

18. The system of claim 13, wherein the batteries comprise a first plurality of batteries forming a first bank and a second plurality of batteries forming a second bank, located at a different location than the first bank.

19. The system of claim 18, wherein said first and said second bank share the common end times for charging and discharging.

20. A system comprising:

energy storage devices;

a common reference;

an energy gauge configured to determine an energy storage fraction respectively for said energy storage devices;

power converts coupled to the energy storage devices and individually maintaining a voltage conversion ratio, based on the energy storage fraction, wherein energy is stored in the energy storage devices individually with a plurality of variable rates of energy storage and wherein said energy storage is complete for said energy storage devices substantially at a common end time responsive to the common reference and wherein energy is depleted from said energy storage devices individually with a plurality of variable energy depletion rates substantially at a common end time for each energy storage device responsive to said common reference.