Apparatus and method for power conversion having diode in charging and discharging circuit

• US 20070115704A1
• Filed: 01/17/2007
• Published: 05/24/2007
• Est. Priority Date: 11/02/2004
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Ito, Youichi
• Granted Patent: US 7,443,705 B2
• Time in Patent Office: Days
• US Class Current: 363/125
• CPC Class Codes: H02M 1/4241 using a resonant converter
• 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

Abstract

A power converting apparatus includes a rectifying circuit having a pair of AC power input terminals and a pair of rectified voltage output terminals; a reactor; and a charging and discharging circuit connected between the rectified voltage output terminals. The charging and discharging circuit includes a first condenser connected with one of the rectified voltage output terminals and one of the AC power input terminals; and a second condenser connected with the other of the rectified voltage output terminals and the one AC power input terminal. The reactor generates a resonance current together with the first condenser and the second condenser, and the second condenser discharges to zero voltage while the first condenser is charged.

Claims

1. A power converting apparatus comprising:

a rectifying circuit having a pair of AC power input terminals and a pair of rectified voltage output terminals;

an inductor; and

a charging and discharging circuit connected between said rectified voltage output terminals,

wherein said charging and discharging circuit comprises;

a first charging and discharging circuit connected with one of said rectified voltage output terminals and one of said AC power input terminals; and

a second charging and discharging circuit connected with the other of said rectified voltage output terminals and said one AC power input terminal,

said first charging and discharging circuit comprises a first diode and a first capacitor connected with said first diode in series,

said second charging and discharging circuit comprises a second diode and a second capacitor connected with said second diode in series, and

said charging and discharging circuit further comprises;

a switch section connected in parallel with a series connection of said first and second diodes,

said inductor generates a resonance current together with said first capacitor and said second capacitor, and

said second capacitor discharges to zero voltage while said first capacitor is charged.

2. The power converting apparatus according to claim 1, wherein said switch section comprises two switches which are connected in parallel with said first and second diodes, respectively.

3. The power converting apparatus according to claim 1, wherein said switch comprises a switching element.

4. The power converting apparatus according to claim 2, wherein each of said switches comprises a switching element.

5. A power converting method comprising the steps of:

connecting a rectifying circuit with an AC power supply;

charging a first charging and discharging section which is connected between a first output terminal as one of two first output terminals of said rectifying circuit and one of two AC power input terminals of said rectifying circuit;

discharging from a second charging and discharging section which is connected between a second output terminal as the other of the two first output terminals of said rectifying circuit and said one AC power input terminal in synchronization with said charging;

charging said second charging and discharging section after a half period of said first charging and discharging period;

discharging said first charging and discharging section in synchronization with said charging said second charging and discharging section;

continuing to connect a terminal of said first charging and discharging section on a side of said AC electric power input terminals and a terminal of said second charging and discharging section on a side of said AC electric power input terminals during a rated operation; and

intermittently opening the terminal of said first charging and discharging section on the side of said AC electric power input terminals and the terminal of said second charging and discharging section on the side of said AC electric power input terminals during a low load operation.

6. The power converting method according to claim 5, wherein said first charging and discharging section and said second charging and discharging section have capacitors, respectively,

an inductor is provided between said AC electrode input terminal and said rectifying circuit or between said rectifying circuit and said first charging and discharging section, and

a maximum value of a current flowing from one of said first capacitor and said second capacitor to said one AC input terminal at a rated operation is substantially same as a maximum value of a rated input current.

7. The power converting method according to claim 5, wherein capacitances of said first capacitor and said second capacitor and an inductance of said inductor are determined such that a resonance frequency is in a range of 3 times to 5 times of a frequency of AC power supplied to said AC power input terminals.

8. The power converting method according to claim 5, said first charging and discharging section and said second charging and discharging section have capacitors, respectively,

an inductor is provided between said AC electrode input terminal and said rectifying circuit or between said rectifying circuit and said first charging and discharging section,

a charging period of one of said first and second capacitors and a discharging period of the other capacitor are synchronized with each other, and

said one capacitor discharges to zero voltage after being charged.

9. The power converting method according to claim 8, wherein capacitances of said first capacitor and said second capacitor and an inductance of said inductor are determined such that a resonance frequency is in a range of 3 times to 5 times of a frequency of AC power supplied to said AC power input terminals.

10. A power converting circuit comprising:

a rectifying circuit having a pair of AC power supply input terminals and a pair of rectification voltage output terminals;

a charging and discharging circuit connected between the rectification voltage output terminals; and

an inductor connected with one of the AC power supply input terminals,

wherein said charging and discharging circuit comprises a first capacitor, a first diode, a second diode and a second capacitor, which are connected in series between the rectification voltage output terminals.

11. The power converting circuit according to claim 10,

wherein one of the AC power input terminals is connected with a common node between said first capacitor and said second capacitor,

said first capacitor is connected between one of the rectification voltage output terminals and a first node,

said first diode is connected between said first node and said common node,

said second diode is connected between said common node and a second node, and

said second capacitor is connected between the other of the rectification voltage output terminals and said second node.

12. The power converting circuit according to claim 11, wherein one of the AC power input terminals is connected with said common node.

13. The power converting circuit according to claim 11, wherein said charging and discharging circuit further comprises:

a switching element connected with said first diode and said second diode in parallel between said first node and said second node.