Voltage-type dc power supply and control method of voltage-type dc power supply

Patent metadata

Field	Value
Publication number	US-2016141971-A1
Application number	US-201314904336-A
Country	US
Kind code	A1
Filing date	Dec 26, 2013
Priority date	Sep 27, 2013
Publication date	May 19, 2016
Grant date	—

Abstract

In a voltage-type DC power supply provided with an inverter, current supply from the inverter to the load side is suppressed when arc is generated. DC output from the voltage-type DC power supply is suspended and resumed: upon suspending the DC output, the chopper is separated from the inverter, thereby suppressing excessive current to the load when arc is generated, allowing the arc to be extinguished at high speed, and holding the current passing through the chopper in the form of circulating current. Upon restarting the inverter, the circulating current being held is supplied to the load, thereby reducing a delay of supply of DC power to the load at the time of resuming the DC output from the voltage-type DC power supply.

First claim

What is claimed is:

1 . A voltage-type DC power supply comprising, a voltage step-down chopper constituting a DC source,
an inverter having a bridge circuit including four switching elements; a first switching element to a fourth switching element, being configured to convert DC output from the voltage step-down chopper in single-phase AC power by operating the switching elements, a rectifier configured to perform AC-DC conversion of an output from the inverter, and to supply a direct current thus obtained to a load, and a controller configured to control the voltage step-down chopper and the inverter, and the voltage-type DC power supply further comprising, a short-circuit section between the voltage step-down chopper and the inverter, configured to establish a short-circuit between a positive terminal and a negative terminal of the voltage step-down chopper, wherein, when the arc discharge occurs, the controller turns off the first to the fourth switching elements in the inverter, turns off the switching element (Q 1 ) in the voltage step-down chopper, turns on a short-circuit switching element (Q 2 ) in the short-circuit section, and forms a circulating circuit by the inductor (L F ) and diode (D 1 ) in the voltage step-down chopper and the short-circuit switching element (Q 2 ) in the short-circuit section, and when the arc is extinguished, or after a lapse of a preset-time from occurrence of the arc discharge, the controller turns on the first to the fourth switching elements in the inverter, turns on the switching element (Q 1 ) in the voltage step-down chopper, and turns off the short-circuit switching element (Q 2 ) in the short-circuit section, thereby supplying the circulating current passing through the circulating circuit, to the inverter.

2 . The voltage-type DC power supply according to claim 1 , further comprising a short circuit between the voltage step-down chopper and the inverter, the short circuit having a switching element configured to connect and disconnect between the positive terminal and the negative terminal of the voltage step-down chopper, wherein,
the short-circuit switching element of the short-circuit section serves as the switching element in the short circuit.

3 . The voltage-type DC power supply according to claim 2 , wherein,
the short circuit comprises the short-circuit switching element (Q 2 ) connecting between the positive terminal and the negative terminal of the voltage step-down chopper, a smoothing capacitor (C F ) connecting between input terminals of the inverter, and a diode (D 2 ) connecting between the positive terminals or between the negative terminals of the smoothing capacitor (C F ), thereby configuring a boosting circuit.

4 . A method of controlling a voltage-type DC power supply comprising,
a voltage step-down chopper constituting a DC source, an inverter having a bridge circuit comprising four switching elements; a first switching element to a fourth switching element, being configured to convert DC output from the voltage step-down chopper to single-phase AC power by operating the switching elements, a rectifier configured to perform AC-DC conversion of an output from the inverter, and to supply a direct current thus obtained to a load, a short-circuit section between the voltage step-down chopper and the inverter, configured to establish a short-circuit by a short-circuit switching element between a positive terminal and a negative terminal of the voltage step-down chopper, and a controller configured to control the voltage step-down chopper and the inverter, wherein, when the arc discharge occurs, the controller turns off the first to the fourth switching elements in the inverter, turns off the switching element (Q 1 ) in the voltage step-down chopper, turns on the short-circuit switching element (Q 2 ) in the short-circuit section, and forms a circulating circuit by the inductor (L F ) and diode (D 1 ) in the voltage step-down chopper and the short-circuit switching element (Q 2 ) in the short-circuit section, during a period until the arc is extinguished or until a preset time has elapsed from occurrence of the arc discharge, the controller holds circulating current passing through the circulating circuit, and when the arc is extinguished or after a lapse of the preset time from the occurrence of the arc discharge, the controller turns on the first to the fourth switching elements in the inverter, turns on the switching element (Q 1 ) in the voltage step-down chopper, and turns off the short-circuit switching element (Q 2 ) in the short-circuit section, thereby supplying the circulating current passing through the circulating circuit, to the inverter.

Assignees

• Kyosan Electric Mfg

Inventors

• Yuzurihara Itsuo
• Kodama Shinichi
• Adachi Toshiyuki

Classifications

• H02M5/458 Primary

  using semiconductor devices only · CPC title

• H02M3/1582 Primary

  Buck-boost converters (H02M3/1584 takes precedence) · CPC title

• H02M1/36

  Means for starting or stopping converters · CPC title

• H02M7/4807

  having a high frequency intermediate AC stage · CPC title

• H02M1/007

  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 title