Three-phase power supply with three-phase three-level DC/DC converter

• US 8,411,473 B2
• Filed: 12/20/2010
• Issued: 04/02/2013
• Est. Priority Date: 12/20/2010
• Status: Expired due to Fees

• Current Assignee: Allis Electric Co., Ltd.
• Original Assignee: Allis Electric Co., Ltd.
• Inventors: Cheng, Chaur-Ping, Chen, Po-Yuan, Fang, Chih-Hsing, Chan, Wen-Wei
• Primary Examiner(s): Laxton, Gary L
• Application Number:
  US12/972,794
• Publication Number:
  US 20120155124A1
• Time in Patent Office: 834 Days
• Field of Search: 363/15, 363/16, 363/17, 363/34, 363/37, 363/67, 363/69, 363/86, 363/126, 363/44, 363/47
• US Class Current: 363/37
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters

Abstract

A three-phase power supply with a three-phase three-level DC/DC converter includes a full-bridge thyristor converter with three-set four in-series power switch elements, a three-phase isolated transformer, a full-bridge rectifier, a rectifying circuit, and a low-pass filtering circuit. The three-phase power supply is used to deliver power energy from the AC input voltage to the load. The power switch elements, which separated to each other at 120-degree phase differences, are controlled through a phase shift scheme. Therefore, the three-level circuit structure is provided to reduce withstanding voltage of the power switch elements, further the zero-voltage switching (ZVS) is achieved by the isolated transformer and the power switch elements to increase the efficiency of the DC/DC converter.

Claims

1. A three-phase power supply with a three-phase three-level DC/DC converter receiving a three-phase AC voltage, each phase of the three-phase power supply comprising:

a full-bridge thyristor converter having two thyristors electrically connected in series to each other to convert the AC voltage into a DC voltage;

a full-bridge rectifier having two power switch elements electrically connected in series to each other to receive and rectify the DC voltage outputted from the full-bridge thyristor converter;

a full-bridge switching circuit with four series switches including an upper arm and a lower arm, the upper arm having a first power switch element and a second power switch element and the lower arm having a third power switch element and a fourth power switch element to switch the DC voltage into a rectangular voltage, respectively;

wherein each of the power switch elements has an anti-parallel diode and a parasitic capacitance, respectively;

an isolated transformer having a primary-side winding and a secondary-side winding, and the primary-side winding electrically connected to the full-bridge switching circuit to receive the rectangular voltage and vary the magnitude of the rectangular voltage according to a turn ratio between the primary-side winding and the secondary-side winding;

a rectifying circuit electrically connected to the secondary-side winding of the isolated transformer to rectify an output voltage produced from the secondary-side winding; and

a low-pass filtering circuit electrically connected to the rectifying circuit to filter out high-frequency harmonic components of the rectified output voltage of the rectifying circuit and output a DC output voltage;

whereby the three-level power supply is provided to reduce withstanding voltage of the power switch elements, further zero-voltage switching (ZVS) is achieved by the isolated transformer and the power switch elements to increase the efficiency of the DC/DC converter.

2. The three-phase power supply in claim 1, wherein the rectifying circuit is a full-wave rectifying circuit.

3. The three-phase power supply in claim 1, wherein the rectifying circuit is a half-wave rectifying circuit.

4. The three-phase power supply in claim 1, wherein the low-pass filtering circuit is composed of a filtering inductor and a filtering capacitor.