Inrush current suppression apparatus

Patent metadata

Field	Value
Publication number	US-9425615-B2
Application number	US-201314029272-A
Country	US
Kind code	B2
Filing date	Sep 17, 2013
Priority date	Mar 17, 2011
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

According to one embodiment, there is provided an inrush current suppression apparatus that suppresses an inrush current generated when shunt capacitors are connected to a power system. The apparatus includes a power supply voltage measurement unit measuring a power supply voltage, a circuit breaker current measurement unit measuring a circuit breaker current, a residual voltage polarity determination unit determining the polarities of three phases of a residual voltage, a specific phase determination unit determining a specific phase, a closing phase detector detecting a closing phase, and a circuit breaker closing unit closing the circuit breaker in the closing phase.

First claim

What is claimed is:

1. An inrush current suppression apparatus that suppresses an inrush current generated when three phases of shunt capacitors including a directly grounded neutral point are simultaneously connected to a three-phase alternating-current electric power system on a power supply side by a three-phase collective operation circuit breaker which collectively operates three phases, the inrush current suppression apparatus comprising:
a power supply voltage measurement unit configured to measure a power supply voltage which is a voltage on the power supply side of the three-phase collective operation circuit breaker;
a three-phase collective operation circuit breaker current measurement unit configured to measure a circuit breaker current which is a current running through the three-phase collective operation circuit breaker;
a residual voltage polarity determination unit configured to determine the polarities of three phases of a residual voltage on the shunt capacitor side of the three-phase collective operation circuit breaker after the opening of the three-phase collective operation circuit breaker in accordance with the circuit breaker current measured by the three-phase collective operation circuit breaker current measurement unit;
a specific phase determination unit configured to determine a specific phase having a polarity different from those of the other two phases among the polarities of the three phases of the residual voltage determined by the residual voltage polarity determination unit;
a closing phase detector configured to detect a closing phase in which the power supply voltage measured by the power supply voltage measurement unit of the specific phase determined by the specific phase determination unit becomes a peak value of the same polarity as the polarity of the specific phase of the residual voltage determined by the residual voltage polarity determination unit; and
a circuit breaker closing unit configured to close the three-phase collective operation circuit breaker in the closing phase detected by the closing phase detector.

2. An inrush current suppression apparatus that suppresses an inrush current generated when three phases of shunt capacitors including a directly grounded neutral point are simultaneously connected to a three-phase alternating-current electric power system on a power supply side by a three-phase collective operation circuit breaker which collectively operates three phases, the inrush current suppression apparatus comprising:
a power supply voltage measurement unit configured to measure a power supply voltage which is a voltage on the power supply side of the three-phase collective operation circuit breaker;
a shunt capacitor side voltage measurement unit configured to measure a shunt capacitor side voltage which is a voltage on the shunt capacitor side of the three-phase collective operation circuit breaker;
a residual voltage polarity determination unit configured to determine the polarities of three phases of a residual voltage on the shunt capacitor side of the three-phase collective operation circuit breaker after the opening of the three-phase collective operation circuit breaker in accordance with the shunt capacitor side voltage measured by the shunt capacitor side voltage measurement unit;
a specific phase determination unit configured to determine a specific phase having a polarity different from those of the other two phases among the polarities of the three phases of the residual voltage determined by the residual voltage polarity determination unit;
a closing phase detector configured to detect a closing phase in which the power supply voltage measured by the power supply voltage measurement unit of the specific phase determined by the specific phase determination unit becomes a peak value of the same polarity as the polarity of the specific phase of the residual voltage determined by the residual voltage polarity determination unit; and
a circuit breaker closing unit configured to close the three-phase collective operation circuit breaker in the closing phase detected by the closing phase detector.

3. An inrush current suppression apparatus that suppresses an inrush current generated when three phases of shunt capacitors including a directly grounded neutral point are simultaneously connected to a three-phase alternating-current electric power system on a power supply side by a three-phase collective operation circuit breaker which collectively operates three phases, the inrush current suppression apparatus comprising:
a power supply voltage measurement unit configured to measure a power supply voltage which is a voltage on the power supply side of the three-phase collective operation circuit breaker;
a three-phase collective operation circuit breaker current measurement unit configured to measure a circuit breaker current which is a current running through the three-phase collective operation circuit breaker;
a residual voltage polarity determination unit configured to determine the polarities of three phases of a residual voltage on the shunt capacitor side of the three-phase collective operation circuit breaker after the opening of the three-phase collective operation circuit breaker in accordance with the circuit breaker current measured by the three-phase collective operation circuit breaker current measurement unit;
a specific phase determination unit configured to determine a specific phase having a polarity different from those of the other two phases among the polarities of the three phases of the residual voltage determined by the residual voltage polarity determination unit;
a closing phase detection unit configured to detect a closing phase to suppress the inrush current out of the phases in which a line-to-line voltage, of the power supply voltage measured by the power supply voltage measurement unit, of the other two phases different from the specific phase determined by the specific phase determination unit becomes a zero point; and
a circuit breaker closing unit configured to close the three-phase collective operation circuit breaker in the closing phase detected by the closing phase detector.

4. An inrush current suppression apparatus that suppresses an inrush current generated when three phases of shunt capacitors including a directly grounded neutral point are simultaneously connected to a three-phase alternating-current electric power system on a power supply side by a three-phase collective operation circuit breaker which collectively operates three phases, the inrush current suppression apparatus comprising:
a power supply voltage measurement unit configured to measure a power supply voltage which is a voltage on the power supply side of the three-phase collective operation circuit breaker;
a shunt capacitor side voltage measurement unit configured to measure a shunt capacitor side voltage which is a voltage on the shunt capacitor side of the three-phase collective operation circuit breaker;
a residual voltage polarity determination unit configured to determine the polarities of three phases of a residual voltage on the shunt capacitor side of the three-phase collective operation circuit breaker after the opening of the three-phase collective operation circuit breaker in accordance with the shunt capacitor side voltage measured by the shunt capacitor side voltage measurement unit;
a specific phase determination unit configured to determine a specific phase having a polarity different from those of the other two phases among the polarities of the three phases of the residual voltage determined by the residual voltage polarity determination unit;
a closing phase detector configured to detect a closing phase to suppress the inrush current out of the phases in which a line-to-line voltage, of the power supply voltage measured by the power su

Assignees

• Toshiba Kk

Inventors

• Koshizuka Tadashi
• Saito Minoru
• Maruyama Shiro
• Maehara Hiroyuki
• Sato Yoshimasa

Classifications

• H01H33/593

  for ensuring operation of the switch at a predetermined point of the AC cycle (for multipolar switches H01H9/563) · CPC title

• H01H9/563 Primary

  for multipolar switches, e.g. different timing for different phases, selecting phase with first zero-crossing · CPC title

• H02H9/001

  limiting speed of change of electric quantities, e.g. soft switching on or off (progressive control of electronic switches for eliminating interferences H03K17/16) · CPC title

• H02H9/045 Primary

  adapted to a particular application and not provided for elsewhere · CPC title