Power switching control device

Patent metadata

Field	Value
Publication number	US-10490366-B2
Application number	US-201515778957-A
Country	US
Kind code	B2
Filing date	Dec 9, 2015
Priority date	Dec 9, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A power switching control device includes a unit to measure a power-supply-side voltage of a circuit breaker, a unit to calculate a current that flows through a resistor after a switch is turned on and before a circuit breaking unit is turned on, and to calculate an interelectrode voltage of the circuit breaking unit after the switch is turned on and before the circuit breaking unit is turned on, a unit to determine a target closing time point for the circuit breaking unit so that a target turn-on phase for the circuit breaking unit becomes a phase that is set in accordance with the capacitor, and to output a control signal such that the circuit breaking unit is closed at the target closing time point.

First claim

The invention claimed is:

1. A power switching control device to control opening and closing of a circuit breaker including a circuit breaking unit, a resistor connected in parallel to the circuit breaking unit, and a switch connected in parallel to the circuit breaking unit and connected in series to the resistor to be turned on prior to the circuit breaking unit, one end of the circuit breaking unit being connected to an AC power supply and the other end of the circuit breaking unit being connected to a phase modifier, the power switching control device comprising:
a processor to execute a program, and
a memory to store the program which, when executed by the processor, performs processes of,
measuring a power-supply-side voltage of the circuit breaker;
calculating a current that flows through the resistor after the switch is turned on and before the circuit breaking unit is turned on by using a measurement value of the power-supply-side voltage, a resistance value of the resistor, and an impedance of the phase modifier, and calculating an interelectrode voltage of the circuit breaking unit after the switch is turned on and before the circuit breaking unit is turned on by using the current and the resistance value;
determining a target closing time point for the circuit breaking unit so that a target turn-on phase for the circuit breaking unit becomes a phase that is set in accordance with the phase modifier, by using an interelectrode rate of decrease of dielectric strength and the interelectrode voltage of the circuit breaking unit; and
outputting a control signal to the circuit breaker such that the circuit breaking unit is closed at the target closing time point.

2. The power switching control device according to claim 1 , wherein
the phase modifier is a capacitor, and
the target turn-on phase is a phase at which an absolute value of the interelectrode voltage at a time when the circuit breaking unit is turned on is minimized.

3. The power switching control device according to claim 1 , wherein
the phase modifier is a reactor, and
the target turn-on phase is a phase at which an absolute value of the interelectrode voltage at a time when the circuit breaking unit is turned on is maximized.

Assignees

• Mitsubishi Electric Corp

Inventors

• Mori Tomohito
• Yamamoto Aya
• Yoshida Daisuke

Classifications

• H01H9/563 Primary

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

• H01H33/59

  Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the AC cycle · CPC title

• H01H33/16

  Impedances connected with contacts · CPC title

• H01H33/593

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

• H01H9/56 Primary

  for ensuring operation of the switch at a predetermined point in the AC cycle · CPC title