Voltage equalizer apparatus and method thereof

• US 6,586,910 B2
• Filed: 10/18/2001
• Issued: 07/01/2003
• Est. Priority Date: 10/19/2000
• Status: Expired due to Fees

• Current Assignee: Nagano Japan Radio Co. (HK) Ltd. (Japan Radio Company Limited), Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Nagano Japan Radio Co. (HK) Ltd. (Japan Radio Company Limited), Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Nishizawa, Hiroshi, Ishii, Mitsunori, Anzawa, Seiichi, Matsui, Fujio
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/983,013
• Publication Number:
  US 20020074985A1
• Time in Patent Office: 621 Days
• Field of Search: 320/122, 320/118, 320/130, 320/132, 307/43, 307/77, 361/88
• US Class Current: 320/122
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

In such a voltage equalizer circuit in which each of plural windings P1 to Pn electromagnetically coupled to each other, each of plural storage elements E1 to En series-connected to each other, and each of plural first switching elements S1 to Sn are connected to each other in a series connecting manner so as to constitute a plurality of closed circuits, this voltage equalizer apparatus is featured by that a reference voltage winding Pp electromagnetically coupled to the plurality of windings is provided; both a DC power supply Ep and a second switching element Sp are series-connected to the second winding; and all of the plural first switching elements and the second switching element are turned ON/OFF in a synchronous manner.

Claims

1. A voltage equalizer comprising:

a plurality of first windings electromagnetically coupled to each other;

a plurality of storage elements series-connected to each other;

a plurality of first switching elements, each connected to one of the first windings and one of the storage elements to constitute a closed circuit;

a second winding electromagnetically coupled to the first windings;

a second switching element series-connected to the second winding; and

a DC power supply series-connected to the second winding and the second switching element, the DC power supply for applying reference voltage to the second winding,

wherein all of the first switching elements and the second switching element are turned ON/OFF in synchronous.

2. The voltage equalizer as claimed in claim 1, wherein the storage elements are series-connected to the DC power supply.

3. The voltage equalizer as claimed in claim 2, wherein the DC power supply supplies electric power to the storage elements, and absorbs electric power supplied from the storage elements.

4. The voltage equalizer as claimed in claim 1 wherein the DC power supply is variable in voltage.

5. The voltage equalizer as claimed in claim 1, further comprising a voltage detecting section for detecting voltages among the storage elements, the voltage detecting section for calculating an averaged terminal-to-terminal voltage of the storage elements,

wherein the DC power supply sets output voltage according to the averaged terminal-to-terminal voltage.

6. The voltage equalizer as claimed in claim 1, wherein the DC power supply outputs voltage between an allowable maximum voltage and an allowable minimum voltage both determined based upon material of the storage elements.

7. The voltage equalizer as claimed in claim 1, wherein the storage elements and/or the voltage monitoring storage element are electric double layer capacitors.

8. The voltage equalizer as claimed in claim 1, wherein each of the plurality of storage elements includes a plurality of internal storage elements having charging/discharging characteristics different from each other and being connected in parallel.

9. A voltage equalizer comprising:

a plurality of first windings electromagnetically coupled to each other;

a plurality of storage elements series-connected to each other;

a plurality of first switching elements, each connected to one of the first windings and one of the storage elements to constitute a closed circuit;

a second winding electromagnetically coupled to the first windings;

a second switching element series-connected to the second winding;

a DC power supply series-connected to the second winding and the second switching element, the DC power supply for applying reference voltage to the second winding;

a monitoring storage element connected between the second winding and the second switching element; and

a third switching element connected between the DC power supply and the monitoring storage element,

wherein all of the first switching elements and the second switching element are turned ON/OFF in synchronous; and

the third switching element is turned OFF when voltage between terminals of the monitoring storage element is monitored.

10. The voltage equalizer as claimed in claim 9, wherein the storage elements are series-connected to the DC power supply.

11. The voltage equalizer as claimed in claim 10, wherein the DC power supply supplies electric power to the storage elements, and absorbs electric power supplied from the storage elements.

12. The voltage equalizer as claimed in claim 9, wherein the DC power supply is variable in voltage.

13. The voltage equalizer as claimed in claim 9, further comprising a voltage detecting section for detecting a monitored voltage between the terminals of the monitoring storage element, the voltage detecting section obtains an averaged terminal-to-terminal voltage of the storage elements according to the monitored voltage,

wherein the DC power supply sets output voltage according to the averaged terminal-to-terminal voltage of the storage elements.

14. The voltage equalizer as claimed in claim 9, wherein the DC power supply outputs voltage between an allowable maximum voltage and an allowable minimum voltage both determined based upon material of the storage elements.

15. The voltage equalizer as claimed in claim 9 wherein an external charging operation with respect to the storage elements is stopped and/or a warning notice is issued, when the voltage between the terminals of the monitoring storage element during OFF time period of the third switching element exceeds a predetermined voltage.

16. The voltage equalizer as claimed in claim 9, wherein ON/OFF operations of the first switching elements and the second switching element are stopped and/or a warning notice is issued, when the voltage between the terminals of the monitoring storage element during OFF time period of the third switching element becomes lower than, or equal to a predetermined voltage.

17. The voltage equalizer as claimed in claim 9, wherein the storage elements and/or the voltage monitoring storage element are electric double layer capacitors.

18. The voltage equalizer as claimed in claim 9, wherein a relay constitutes the third switching element.

19. The voltage equalizer as claimed in claim 9 wherein the DC power supply includes a bidirectional converter having a first input/output terminal connected to the monitoring storage element, and a second input/output terminal connected to a battery.

20. The voltage equalizer as claimed in claim 9, wherein each of the plurality of storage elements includes a plurality of internal storage elements having charging/discharging characteristics different from each other and being connected in parallel.

21. A voltage equalizer comprising:

a plurality of first windings electromagnetically coupled to each other;

a plurality of storage elements series-connected to each other;

a plurality of first switching elements, each connected to one of the first windings and one of the storage elements to constitute a closed circuit;

a second winding electromagnetically coupled to the first windings;

a second switching element series-connected to the second winding;

a DC power supply series-connected to the second winding and the second switching element, the DC power supply for applying reference voltage to the second winding;

a monitoring storage element connected between the second winding and the second switching element; and

a diode biased along a forward direction to supply a current to the second winding if the voltage of the DC power supply is higher than a voltage between terminals of the monitoring storage element;

wherein all of the first switching elements and the second switching element are turned ON/OFF in synchronous.

22. The voltage equalizer as claimed in claim 21, wherein the storage elements are connected in series to the DC power supply.

23. The voltage equalizer as claimed in claim 21 wherein the DC power supply includes a bidirectional converter having a first input/output terminal connected to the monitoring storage element, and a second input/output terminal connected to a battery.

24. The voltage equalizer as claimed in claim 21, wherein each of the plurality of storage elements includes a plurality of internal storage elements having charging/discharging characteristics different from each other and being connected in parallel.

25. A voltage equalizer comprising:

a plurality of first windings electromagnetically coupled to each other;

a plurality of storage elements series-connected to each other;

a plurality of first switching elements, each connected to one of the first windings and one of the storage elements to constitute a closed circuit;

a second winding electromagnetically coupled to the first windings;

a second switching element series-connected to the second winding;

a DC power supply series-connected to the second winding and the second switching element, the DC power supply for applying reference voltage to the second winding; and

a controller for turning ON/OFF all of the first switching elements and the second switching element in synchronous.

26. The voltage equalizer of a storage element as claimed in claim 25, wherein each of the plurality of storage elements includes a plurality of internal storage elements having charging/discharging characteristics different from each other and being connected in a parallel.

27. A voltage equalizing method for a voltage equalizer including a plurality of first windings electromagnetically coupled to each other;

a plurality of storage elements series-connected to each other;

a plurality of first switching elements, each connected to one of the first windings and one of the storage elements to constitute a closed circuit;

a second winding electromagnetically coupled to the first windings;

a second switching element series-connected to the second winding;

a DC power supply series-connected to the second winding and the second switching element, the DC power supply for applying reference voltage to the second winding;

a monitoring storage element connected between the second winding and the second switching element;

and a third switching element connected between the DC power supply and the monitoring storage element, wherein all of the first switching elements and the second switching element are turned ON/OFF in synchronous;

and the third switching element is turned OFF when voltage between terminals of the monitoring storage element is monitored,

the voltage equalizing method comprising;

charging the plurality of storage elements rapidly up to a predetermined charge voltage by a charging operation of an external power supply when a voltage between terminals of the storage elements is different from a target value by a predetermined voltage, or a higher voltage thereof; and

turning both the first switching elements and the second switching element ON/OFF to control a terminal-to-terminal voltage of the storage elements to be equal to the target value.

28. A voltage equalizing method for a voltage equalizer including a plurality of first windings electromagnetically coupled to each other;

a plurality of storage elements series-connected to each other;

a plurality of first switching elements, each connected to one of the first windings and one of the storage elements to constitute a closed circuit;

a second winding electromagnetically coupled to the first windings;

a second switching element series-connected to the second winding;

a DC power supply series-connected to the second winding and the second switching element, the DC power supply for applying reference voltage to the second winding;

a monitoring storage element connected between the second winding and the second switching element; and

a third switching element connected between the DC power supply and the monitoring storage element, wherein all of the first switching elements and the second switching element are turned ON/OFF in synchronous; and

the third switching element is turned OFF when voltage between terminals of the monitoring storage element is monitored,

the voltage equalizing method comprising;

setting the voltage of the DC power supply to a voltage on the side of the target value and in the vicinity of a voltage of the monitoring storage element when a voltage between terminals of the storage element becomes a value different from a target value by a predetermined voltage, or a higher voltage thereof,; and

turning both the first switching elements and the second switching element ON/OFF; and

carrying out a control operation to gradually approximate the voltage of the DC power supply to the target value.