Energy storage apparatus and related method

• US 20060221516A1
• Filed: 04/04/2005
• Published: 10/05/2006
• Est. Priority Date: 04/04/2005
• Status: Active Grant

• Current Assignee: Aerovironment
• Original Assignee: Aerovironment
• Inventors: Daboussi, Zaher
• Granted Patent: US 7,436,150 B2
• Time in Patent Office: Days
• US Class Current: 361/18
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence

Abstract

An apparatus including an energy storage device and a power processing unit that is coupled to the energy storage device. The energy storage device is configured to deliver electrical energy to a load. The energy storage device also is configured to receive electrical energy from a source. The power processing unit is configured to control a fluctuation in voltage across the energy storage device while electrical energy is received by the energy storage device, or while electrical energy is delivered from the energy storage device to the load.

Claims

1. An apparatus comprising:

a. an energy storage device configured to deliver electrical energy to a load, and configured to receive electrical energy from a source; and

b. a power processing unit coupled to the energy storage device;

c. wherein the power processing unit is configured to control a fluctuation in voltage across the energy storage device while electrical energy is received by the energy storage device, or while electrical energy is delivered from the energy storage device to the load.

2. The apparatus according to claim 1, further comprising an energy management unit coupled to the energy storage device.

3. The apparatus according to claim 2, wherein the energy management unit includes a balancing element coupled to the energy storage device.

4. The apparatus according to claim 3, wherein the balancing element is a resistor or a resistor coupled to a switch.

5. The apparatus according to claim 3, wherein the energy management unit further comprises:

a. an amplifier having an input coupled to the balancing element, and an output; and

b. a controller having an input coupled to the output of the amplifier, and an output coupled to the power processing unit.

6. The apparatus according to claim 1, wherein the energy storage device is a capacitor.

7. The apparatus according to claim 6, wherein the capacitor is an ultracapacitor.

8. The apparatus according to claim 6, wherein:

a. the capacitor includes a first lead and a second lead;

b. the power processing unit includes a first terminal and a second terminal; and

c. the power processing unit includes a switching module comprising;

i. an inductor having a first lead and a second lead,

ii. a first switch that is coupled between the inductor'"'"'s first lead and the capacitor'"'"'s first lead,

iii. a second switch that is coupled between the inductor'"'"'s first lead and the capacitor'"'"'s second lead,

iv. a third switch that is coupled between the inductor'"'"'s second lead and the power processing unit'"'"'s first terminal, and

v. a fourth switch that is coupled between the inductor'"'"'s second lead and the power processing unit'"'"'s second terminal.

9. The apparatus according to claim 8, wherein the power processing unit further includes a control module that is coupled to the switching module, the control module comprising:

a. a first adder having a first input, a second input, and an output;

b. a voltage regulator having an input that is coupled to the first adder'"'"'s output, and an output;

c. a second adder having a first input that is coupled to the voltage regulator'"'"'s output, a second input, and an output;

d. a current regulator having an input that is coupled to the second adder'"'"'s output, and an output; and

e. a pulse generator having an input that is coupled to the current regulator'"'"'s output, and a first output, a second output, a third output, and a fourth output.

10. The apparatus according to claim 9, wherein:

a. a reference voltage is coupled into the first adder'"'"'s first input;

b. a voltage that corresponds to the voltage measured across the power processing unit'"'"'s first and second terminals is coupled into the first adder'"'"'s second input; and

c. a voltage that corresponds to an amount of current flowing through the inductor is coupled into the second adder'"'"'s second input.

11. The apparatus according to claim 9, wherein:

a. the pulse generator'"'"'s first output is coupled to the first switch;

b. the pulse generator'"'"'s second output is coupled to the second switch;

c. the pulse generator'"'"'s third output is coupled to the third switch; and

d. the pulse generator'"'"'s fourth output is coupled to the fourth switch.

12. The apparatus according to claim 11, wherein:

a. the pulse generator generates a switch control signal that is coupled into one switch of the first, second, third, and fourth switches; and

b. the switch control signal enables the flow of a current through the one switch.

13. A power processing unit configured to control a fluctuation in voltage across an energy storage device as electrical energy is received by the energy storage device, or as electrical energy is delivered from the energy storage device to a load, the power processing unit comprising:

a. a switching module including;

i. an inductor, and

ii. a plurality of switches coupled to the inductor; and

b. a control module including a pulse generator that is coupled to the plurality of switches.

14. The power processing unit according to claim 13, wherein the energy storage device is a capacitor.

15. The power processing unit according to claim 14, wherein the capacitor is an ultracapacitor.

16. The power processing unit according to claim 14, further comprising a dissipative element coupled in parallel with the capacitor.

17. The power processing unit according to claim 14, wherein:

a. the capacitor includes a first lead and a second lead;

b. the power processing unit includes a first terminal and a second terminal;

c. the inductor includes a first lead and a second lead; and

d. the plurality of switches includes;

i. a first switch that is coupled between the inductor'"'"'s first lead and the capacitor'"'"'s first lead,

ii. a second switch that is coupled between the inductor'"'"'s first lead and the capacitor'"'"'s second lead,

iii. a third switch that is coupled between the inductor'"'"'s second lead and the power processing unit'"'"'s first terminal, and

iv. a fourth switch that is coupled between the inductor'"'"'s second lead and the power processing unit'"'"'s second terminal.

18. The power processing unit according to claim 17, wherein the control module includes:

a. a first adder having a first input, a second input, and an output;

b. a voltage regulator having an input that is coupled to the first adder'"'"'s output, and an output;

c. a second adder having a first input that is coupled to the voltage regulator'"'"'s output, a second input, and an output;

d. a current regulator having an input that is coupled to the second adder'"'"'s output, and an output; and

e. a pulse generator having an input that is coupled to the current regulator'"'"'s output, and a first output, second output, third output, and fourth output.

19. The power processing unit according to claim 18, wherein:

a. a references voltage is coupled into the first adder'"'"'s first input;

b. a voltage that corresponds to a voltage measured across the power processing unit'"'"'s first and second terminals is coupled into the first adder'"'"'s second input; and

c. a voltage that corresponds to an amount of current flowing through the inductor is coupled into the second adder'"'"'s second input.

20. The power processing unit according to claim 18, wherein:

a. the pulse generator'"'"'s first output is coupled to the first switch;

b. the pulse generator'"'"'s second output is coupled to the second switch;

c. the pulse generator'"'"'s third output is coupled to the third switch; and

d. the pulse generator'"'"'s fourth output is coupled to the fourth switch.

21. The power processing unit according to claim 20, wherein:

a. the pulse generator generates a switch control signal that is coupled into one switch of the first, second, third, and fourth switches; and

b. the switch control signal enables the flow of a current through the one switch.

22. A method for controlling a fluctuation in voltage across an energy storage device as electrical energy is received by the energy storage device, or as electrical energy is delivered from the energy storage device to a load, the method comprising:

a. providing an energy storage device;

b. providing a power processing unit coupled to the energy storage device; and

c. using the power processing unit to control the fluctuation in voltage across the energy storage device as electrical energy is received by the energy storage device, or as electrical energy is delivered from the energy storage device to a load.

23. The method according to claim 22, wherein the energy storage device is a capacitor.

24. The method according to claim 23, wherein the capacitor is an ultracapacitor.

25. The method according to claim 23, wherein the power processing unit includes:

a. a switching module that is coupled to the capacitor, and includes a plurality of switches; and

b. a control module that is coupled to the switching module.

26. The method according to claim 25, further comprising:

a. using the switching module to generate a switch control signal;

b. coupling the switch control signal into one of the plurality of switches; and

c. using the switch control signal to control the one of the plurality of switches.