Bridge type power converter

• US 5,835,371 A
• Filed: 07/03/1997
• Issued: 11/10/1998
• Est. Priority Date: 06/23/1995
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Yamakawa Denki
• Original Assignee: Kabushiki Kaisha Yaskawa Denki
• Inventors: Sonoda, Sumitoshi, Kume, Tsuneo, Yamada, Kenji, Sawa, Toshihiro
• Primary Examiner(s): Riley, Shawn
• Application Number:
  US08/793,346
• Time in Patent Office: 495 Days
• Field of Search: 363/17, 363/132, 363/136, 363/98, 363/56, 363/74, 363/40
• US Class Current: 363/132
• CPC Class Codes: H02M 1/34 Snubber circuits
• CPC Class Codes: H02M 1/346 Passive non-dissipative snubbers
• CPC Class Codes: H02M 7/5233 the commutation elements being in a push-pull arrangement
• CPC Class Codes: H02M 7/538 in a push-pull configuration H02M7/5375 takes precedence ; with oscillating arrangements H02M7/53832, H02M7/53846
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H03K 17/08148 in composite switches
• 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 bridge-type power converter has, in each phase, a inductor (L₁) connected between a connection point of said two switching elements (Q₁, Q₂) and an output terminal; capacitors (C₁, C₂) connected between the output terminal and a positive or negative side of a d.c. bus for changing an output voltage along a curve determined by a phenomenon of resonance with the reactor (L₁) when the semiconductors switching elements (Q₁, Q₂) operate, causing abrupt changes of a voltage at the connection point; diodes (D₃, D₄) for changing a current path at a time when the resonance goes approximately one quarter of period to thereby stop the resonance; and constant voltage diodes (ZD₁, ZD₂) for absorbing the energy stored in the inductor (L₁) during the resonance.

Claims

1. A bridge-type power converter comprising, in each phase,;

a series connection of two semiconductor switching elements each having a backward parallel diode, one end of which is connected to a positive side of a d.c. bus and the other to a negative side of the d.c. bus,

an inductor connected between a connection point of said two switching elements and an output terminal;

capacitors connected between said output terminal and a positive or negative side of said d.c. bus for changing an output voltage along a curve determined by a phenomenon of resonance with said inductor when said semiconductors switching elements operate, causing abrupt changes of a voltage at said connection point;

diodes for changing a current path at a time when said resonance goes approximately one quarter of period to thereby stop said resonance; and

constant voltage diodes for absorbing energy stored in said inductor during said resonance.

2. A bridge-type power converter according to claim 1, wherein said constant voltage diodes connected to said positive and negative sides of said d.c. bus in each phase of a multiple phase bridge-type power converter are replaced by diodes forming a high-voltage or low-voltage priority circuit and diodes forming a backward current path, respectively.

3. A bridge-type power converter according to claim 1, wherein said constant voltage diodes are replaced by a constant voltage circuit which comprises transistors so as to provide a reverse conduction characteristic.

4. A bridge-type power converter according to claim 2, wherein said constant voltage diodes are formed by transistors.

5. A bridge-type power converter according to claim 2, which further comprises a chopper circuit for controlling voltages across capacitors which replace said constant voltage diodes and returning absorbed power to said d.c. bus.

6. A bridge-type power converter according to anyone of claims 1 to 5, which further comprises a.c. terminals connected to an a.c. power source for performing an a.c.-to-d.c. power conversion.

7. A bridge-type power converter according to claim 1, which further comprises a unit formed by additions to said switching elements and connected between said power converter and an electric motor or a power source.