Capacitor charging method and capacitor charger

• US 6,661,205 B1
• Filed: 07/30/2002
• Issued: 12/09/2003
• Est. Priority Date: 03/27/2001
• Status: Active Grant

• Current Assignee: Origin Pty Limited (Origin Energy Limited)
• Original Assignee: Origin Electric Company Limited
• Inventors: Honma, Yuji, Muraki, Saori, Yamamoto, Makoto, Shinohara, Shinichi
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/208,256
• Time in Patent Office: 497 Days
• Field of Search: 320/139, 320/141, 320/145, 320/148, 320/161, 320/162, 320/166
• US Class Current: 320/166
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A capacitor charger is provided that can control charging voltage with high accuracy, and repeat a process of increasing it to a target charging voltage at high speed. In a first step, an ac voltage is generated in a resonant type inverter section by fixed frequency driving pulses, the ac voltage is converted to a dc voltage, a load capacitor is charged by the dc voltage, a calculation pulse in the driving pulse has a predetermined, fixed driving pulse width, and the load capacitor is charged by ΔVn each pulse. In a second step, when the charging voltage V1 of the load capacitor and the target voltage V2 satisfy an inequality relationship “V2>V1>V2−ΔVn”, charging is performed by a single or a plurality of final pulses having a driving pulse width W2 (W1>W2) as required to step up the voltage by “V2−V1”.

Claims

1. A capacitor charging method in which a resonant type inverter section is operated by driving pulses at a fixed frequency to generate an ac voltage, the ac voltage is converted to a dc voltage, and a capacitor is charged using the dc voltage, comprising the steps of:

a first step where a first type of driving pulse of the driving pulses has a fixed driving pulse width W1 determined in advance, which charges the capacitor by a boost voltage Δ

Vn (n is a natural number, Δ

V1, Δ

V2, . . . ) at each input of the first type of driving pulse; and

a second step which charges the capacitor by a single or a plurality of a second type of driving pulse having a controlled driving pulse width W2 (W1>

W2) as required to increase the voltage of the capacitor by a voltage [V2−

V1] when a charging voltage V1 of the capacitor reaches a value that satisfies [V2>

V1>

V2−

V1<

Δ

Vn] for a target voltage value V2.

5. A capacitor charging method according to claim 1, wherein at the start of charging of the first step, the capacitor is charged by a fixed driving pulse width smaller than the fixed driving pulse width W1, or a soft start driving pulse with a gradually increasing driving pulse width.

2. A capacitor charging method in which a resonant type inverter section is operated by driving pulses at a fixed frequency to generate an ac voltage, the ac voltage is converted to a dc voltage, and a capacitor is charged using the dc voltage, comprising the steps of:

a first step where a first type of driving pulse of the driving pulses has a fixed driving pulse width W1 determined in advance, which charges the capacitor by a boost voltage Δ

Vn (n is a natural number, Δ

V1, Δ

V2, . . . ) at each input of the first type of driving pulse; and

a second step which charges the capacitor by a plurality of a second type of driving pulse having a fixed driving pulse width W3 (W1>

W3) in order to boost the voltage by [V2−

V1] when a relationship between a charging voltage V1 of the capacitor and a target voltage value V2 is [V2−

V1<

Δ

Vk+ . . . +Δ

Vn (k is a natural number, and k<

n), or [V2−

V1<

Δ

Vn].

3. A capacitor charging method according to claim 2, wherein only the last driving pulse among a plurality of the second type of driving pulses in the second step has a controlled driving pulse width.

6. A capacitor charging method according to claim 2, wherein at the start of charging of the first step, the capacitor is charged by a fixed driving pulse width smaller than the fixed driving pulse width W1, or a soft start driving pulse with a gradually increasing driving pulse width.

7. A capacitor charging method according to claim 3, wherein at the start of charging of the first step, the capacitor is charged by a fixed driving pulse width smaller than the fixed driving pulse width W1, or a soft start driving pulse with a gradually increasing driving pulse width.

4. A capacitor charging method in which a resonant type inverter section is operated by driving pulses at a fixed frequency to generate an ac voltage, the ac voltage is converted to a dc voltage, and a capacitor is charged using the dc voltage, comprising the steps of:

a first step where a first type of driving pulse of the driving pulses has a fixed driving pulse width W1 determined in advance, which charges the capacitor by a boost voltage Δ

Vn (n is a natural number, Δ

V1, Δ

V2, . . . ) at each input of the first type of driving pulse;

a second step which when a charging voltage V1 of the capacitor is a midpoint preset voltage value V3 that is lower than a target voltage value V2, charges by a boost voltage Δ

Vm (m is a natural number), by using a second type of driving pulse with a new, fixed driving pulse width W4 obtained with consideration of a change of input voltage to the resonant type inverter section; and

a third step which charges by a third type of driving pulse having a controlled driving pulse width W5 (W5<

W4) as required to boost the voltage by [V2−

V1<

Δ

Vm].

8. A capacitor charging method according to claim 4, wherein at the start of charging of the first step, the capacitor is charged by a fixed driving pulse width smaller than the fixed driving pulse width W1, or a soft start driving pulse with a gradually increasing driving pulse width.

9. A capacitor charger in which a resonant type inverter section is switched by driving pulses at a fixed frequency to generate an ac voltage, the ac voltage is converted to a dc voltage by a rectifier, and a capacitor is charged using the dc voltage, comprising:

a control section that controls such that the voltage of the capacitor is increased by a boost voltage Δ

Vn (n is a natural number, Δ

V1, Δ

V2, . . . ) at each input to the resonant type inverter section of a first type of driving pulse with a predetermined, fixed driving pulse width W1, calculates an n^th first type of driving pulse with the fixed driving pulse width W1 when a relationship between a charging voltage V1 of the capacitor and a target voltage value V2 satisfies [V2>

V1>

V2−

V1<

Δ

Vn] (n is a natural number), calculates at least one of a required adjusted driving pulse width and the number of driving pulses, of a second type of driving pulse that is supplied in order to increase the voltage of the capacitor by [V2−

V1] when a relationship [V2−

V1<

Δ

Vn] is satisfied, drives the resonant type inverter section by the first type of driving pulse until the relationship [V2−

V1<

Δ

Vn] is satisfied for the charging voltage V1, drives the resonant type inverter section by the second type of driving pulse when the relationship [V2−

V1<

Δ

Vn] is satisfied, and charges the capacitor to the target voltage value V2.

12. A capacitor charger according to claim 9, wherein the control section calculates the driving pulse width using a predetermined equation based on an input voltage value input to the capacitor charger, a voltage value of charging voltage V1, and a current value supplied to the capacitor.

15. A capacitor charger according to claim 9, wherein the control section reads out from a lookup table showing a relationship between detected values of input voltage input to the capacitor charger, voltage values of the charging voltage V1, and current values supplied to the capacitor, and values of the driving pulse width, a driving pulse width value corresponding to these detected values, to thereby calculate the driving pulse width.

18. A capacitor charger according to claim 9, wherein the control section reads out from a lookup table showing a relationship between detected values of input voltage input to the capacitor charger and the charging voltage V1, and values of the driving pulse width, a driving pulse width value corresponding to these detected values, to thereby calculate the driving pulse width.

10. A capacitor charger in which a resonant type inverter section is switched by driving pulses at a fixed frequency to generate an ac voltage, the ac voltage is converted to a dc voltage by a rectifier, and a capacitor is charged using the dc voltage, comprising:

a control section that controls such that the voltage of the capacitor is increased by a boost voltage Δ

Vn (n is a natural number, Δ

V1, Δ

V2, . . . ) at each input to the resonant type inverter section of a first type of driving pulse with a predetermined, fixed driving pulse width W1, calculates an n^th first type of driving pulse with the fixed driving pulse width W1 when a relationship between a charging voltage V1 of the capacitor and a target voltage value V2 satisfies [V2−

V1<

Δ

Vn+ . . . Δ

Vn+k] (k is a natural number, k<

n), or [V2−

V1<

Δ

Vn], calculates the number of driving pulses of a second type of driving pulse with a fixed driving pulse width W2 (W1>

W2) that is supplied in order to increase the voltage of the capacitor by [V2−

V1] when the relationship [V2−

V1<

Δ

Vn+ . . . Δ

Vn+k] or [V2−

V1<

Δ

Vn] is satisfied, drives the resonant type inverter section by the first type of driving pulse until a relationship [V2>

V1>

V2−

V1<

Δ

Vn+ . . . Δ

Vn+k] or [V2−

V1<

Δ

Vn] is satisfied for the charging voltage V1, drives the resonant type inverter section by the second type of driving pulse when the relationship [V2>

V1>

V2−

V1<

Δ

Vn+ . . . Δ

Vn+k] or [V2−

V1<

Δ

Vn] is satisfied, and charges the capacitor to the target voltage value V2.

13. A capacitor charger according to claim 10, wherein the control section calculates the driving pulse width using a predetermined equation based on an input voltage value input to the capacitor charger, a voltage value of charging voltage V1, and a current value supplied to the capacitor.

16. A capacitor charger according to claim 10, wherein the control section reads out from a lookup table showing a relationship between detected values of input voltage input to the capacitor charger, voltage values of the charging voltage V1, and current values supplied to the capacitor, and values of the driving pulse width, a driving pulse width value corresponding to these detected values, to thereby calculate the driving pulse width.

19. A capacitor charger according to claim 10, wherein the control section reads out from a lookup table showing a relationship between detected values of input voltage input to the capacitor charger and the charging voltage V1, and values of the driving pulse width, a driving pulse width value corresponding to these detected values, to thereby calculate the driving pulse width.

11. A capacitor charger in which a resonant type inverter section is switched by driving pulses at a fixed frequency to generate an ac voltage, the ac voltage is converted to a dc voltage by a rectifier, and a capacitor is charged using the dc voltage, comprising:

a control section that controls such that the voltage of the capacitor is increased by a boost voltage Δ

Vn (n is a natural number, Δ

V1, Δ

V2, . . . ) at each input to the resonant type inverter section of a first type of driving pulse with a predetermined, fixed driving pulse width W1, calculates an n^th first type of driving pulse with the fixed driving pulse width W1 when a relationship between a charging voltage V1 of the capacitor and a midpoint preset voltage value V3, that is lower than a target voltage value V2, satisfies [V2−

V1<

Δ

Vn+ . . . Δ

Vn+k] (k is a natural number, and k<

n), drives the resonant type inverter section by a second type of driving pulse of a fixed driving pulse width W3 obtained by another calculation when the relationship [V2−

V1<

Δ

Vn+ . . . Δ

Vn+k] is satisfied, calculates a controlled pulse width or the number of controlled driving pulses of a third type of driving pulse when a relationship [V2−

V1<

Δ

Vp] (p is a natural number) is satisfied for the charging voltage V1 of the capacitor, drives the resonant type inverter section by the third type of driving pulse, and charges the capacitor to the target voltage value V2.

14. A capacitor charger according to claim 11, wherein the control section calculates the driving pulse width using a predetermined equation based on an input voltage value input to the capacitor charger, a voltage value of charging voltage V1, and a current value supplied to the capacitor.

17. A capacitor charger according to claim 11, wherein the control section reads out from a lookup table showing a relationship between detected values of input voltage input to the capacitor charger, voltage values of the charging voltage V1, and current values supplied to the capacitor, and values of the driving pulse width, a driving pulse width value corresponding to these detected values, to thereby calculate the driving pulse width.

20. A capacitor charger according to claim 11, wherein the control section reads out from a lookup table showing a relationship between detected values of input voltage input to the capacitor charger and the charging voltage V1, and values of the driving pulse width, a driving pulse width value corresponding to these detected values, to thereby calculate the driving pulse width.