POWER SUPPLY DEVICE FOR ELECTROMOTIVE RAILCAR

• US 20010012207A1
• Filed: 01/21/1999
• Published: 08/09/2001
• Est. Priority Date: 01/30/1998
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: NOMURA, YOSHIHITO
• Granted Patent: US 6,388,904 B2
• Time in Patent Office: Days
• US Class Current: 363/17
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 7/08 arranged for operation in parallel

Abstract

A power supply device for an electromotive railcar comprises a first capacitor connected to receive a DC voltage for outputting a first DC voltage, a DC/AC/DC converter, including an inverter bridge including power transistors connected to the first capacitor in parallel, an insulating transformer with high carrier frequency having a primary winding connected to an output of the inverter bridge and a rectifier circuit connected to a secondary winding of the insulating transformer to receive a second DC voltage, and a three-phase inverter including a bridge circuit of power transistors for generating a three-phase AC voltage on the basis of the second DC voltage.

Claims

1. A power supply device for an electromotive railcar adapted to receive an external DC voltage from an external electric line, comprising:

a first capacitor connectable to receive said external DC voltage and outputting a first DC voltage in response to the external DC voltage;

a DC/AC/DC converter including an inverter bridge having a plurality of power transistors connected to said first capacitor in parallel, an insulating transformer with a high carrier frequency and having a primary winding connected to an output of said inverter bridge, and a rectifier circuit connected to a secondary winding of said insulating transformer to receive a second DC voltage; and

a three-phase inverter including a bridge circuit having a plurality of power transistors for generating a three-phase AC voltage on the basis of said second DC voltage.

2. The power supply device for an electromotive railcar as recited in

claim 1

, wherein a carrier frequency band of said insulating transformer of said DC/AC/DC converter is in the range of 1 to 6 KHz.

3. The power supply device for an electromotive railcar as recited in

claim 1

, wherein said inverter bridge is a commutation system having a partial resonance which switches each of said power transistors at the time a zero-voltage or a zero-current is applied to each of said power transistors.

4. The power supply device for an electromotive railcar as recited in

claim 1

, further comprising a smoothing circuit including a DC reactor and a second capacitor for smoothing said second DC voltage from an output of said rectifier circuit of said DC/AC/DC converter.

5. The power supply device for an electromotive railcar as recited in

claim 4

, wherein a capacity of said second capacitor is large enough so as to remove a ripple wave with a predetermined frequency caused by load fluctuation.

6. The power supply device for an electromotive railcar as recited in

claim 1

, further comprising:

a discharge circuit including a series circuit of a power transistor and a discharge resistor connected to discharge said second DC voltage; and

a voltage surveillance circuit for detecting said second DC voltage and turning on said power transistor at a time said voltage surveillance circuit detects that said second DC voltage is over a predetermined voltage in order to discharge regeneration energy from load objects.

7. The power supply device for an electromotive railcar as recited in

claim 1

, further comprising:

an AC filter including a series circuit of an AC reactor and an AC capacitor connected to an output of each phase of said three-phase inverter; and

one terminal of said AC capacitor being connected to receive a neutral point of said second DC voltage.

8. The power supply device for an electromotive railcar as recited in

claim 1

, further comprising:

an AC filter including a series circuit of an AC reactor and an AC capacitor connected to an output of each phase of said three-phase inverter; and

one terminal of said AC capacitor being connected to a neutral point of said secondary winding of said insulating transformer.

11. The power supply device for an electromotive railcar as recited in

claim 1

or

9

, further comprising:

a discharge circuit including a series circuit of a power transistor and a discharge resistor connected to discharge said second DC voltage; and

a voltage surveillance circuit for detecting said second DC voltage and turning on said power transistor at a time said voltage surveillance circuit detects that said second DC voltage is over a predetermined voltage in order to discharge regeneration energy from load objects.

12. The power supply device for an electromotive railcar as recited in

claim 1

or

9

, further comprising:

an AC filter including a series circuit of an AC reactor and an AC capacitor connected to an output of each phase of said three-phase inverter; and

one terminal of said AC capacitor being connected to receive a neutral point of said second DC voltage.

13. The power supply device for an electromotive railcar as recited in

claim 1

or

9

, further comprising:

an AC filter including a series circuit of an AC reactor and an AC capacitor connected to an output of each phase of said three-phase inverter; and

one terminal of said AC capacitor being connected to a neutral point of said secondary winding of said insulating transformer.

9. A power supply device for an electromotive railcar adapted to receive an external DC voltage from an external electric line, comprising:

a series circuit of a plurality of first capacitors connected to receive said external DC voltage for outputting a first DC voltage;

a plurality of DC/AC/DC converters, each of said DC/AC/DC converters including an inverter bridge having a plurality of power transistors respectively connected to one of said plurality of first capacitors in parallel, an insulating transformer with a high carrier frequency and having a primary winding connected to an output of said inverter bridge, and a rectifier circuit connected to a secondary winding of said insulating transformer to receive an second DC voltage; and

a three-phase inverter including a bridge circuit having a plurality of power transistors for generating a three-phase AC voltage on the basis of said second DC voltage.

10. The power supply device for an electromotive railcar as recited in

claim 9

, wherein:

each of said insulating transformers has a common core; and

the number of turns of said primary windings are the same in said DC/AC/DC converters and the number of turns of said secondary windings are the same in said DC/AC/DC converters respectively.

14. A power supply device for an electromotive railcar adapted to receive an external DC voltage from an external electric line, comprising;

a first capacitor having a first terminal to receive said DC voltage and for providing a first DC voltage in response to the external DC voltage and having a second terminal;

a DC/AC/DC converter having a pair of inputs connected in parallel to the first and second terminals of the first capacitor and having a pair of outputs for providing a second DC voltage in response to the external DC voltage; and

a three-phase inverter having a pair of inputs connected in parallel to the pair of outputs of the DC/AC/DC converter and having three outputs for generating a three-phase AC voltage in response to said second DC voltage.

15. The power supply device for an electromotive railcar as recited in

claim 14

, wherein the DC/AC/DC converter comprises:

an inverter bridge having a plurality of power transistors and having a pair of inputs connected in parallel to the first capacitor and having a pair of outputs;

an insulating transformer having a primary winding connected in parallel to the outputs of the inverter bridge and having a secondary winding for providing the second DC voltage; and

a rectifier circuit connected to the secondary winding of the insulating transformer to receive the second DC voltage.