Kabushiki Kaisha Toshiba

Keisuke Udagawa

Tadashi Koshizuka

Shiro Maruyama

Noriyuki Nagayama

Minoru Saitoh

Minoru Saito

Hiroyuki Maehara

Yoshimasa Sato

A residual magnetic flux estimation deviceincludes a DC power-source control devicewhich controls a DC power sourceto apply a DC voltage across two terminals of a &#x394; connection that is a secondary winding or a tertiary winding, a voltage measuring devicewhich measures a terminal voltage at the primary side of a three-phase transformera computing devicethat determines a phase having a high voltage between the two phases other than the phase to which the voltage is applied, and a residual magnetic flux measuring devicethat measures a phase-to-phase residual magnetic flux between the two phases other than the high-voltage phase, and estimates a measured value of the phase-to-phase residual magnetic flux as a maximum residual magnetic flux in the measurement-target three-phase transformer.

Method of estimating the residual magnetic flux of transformer and residual magnetic flux estimation device

According to one embodiment, there is provided a magnetizing inrush current suppression apparatus including an interrupting phase detection unit that detects a phase when the transformer that converts a three-phase alternating-current voltage to a single-phase alternating-current voltage is disconnected, a single-phase alternating-current voltage measurement unit that measures the single-phase alternating-current voltage on the power system side of the circuit breaker, and a closing unit that closes the circuit breaker in the detected phase, based on the measured single-phase alternating-current voltage.

Magnetizing inrush current suppression apparatus

Inrush current suppression apparatus for suppressing a transformer inrush current including a transformer side voltage measurement unit which measures a voltage at a side of a transformer, a residual magnetic flux calculation unit which calculates three line-to-line residual magnetic fluxes, a power supply side voltage measurement unit which measures a voltage at a side of a power supply, a stable-state magnetic flux calculation unit which calculates three line-to-line stable-state magnetic fluxes, based on the voltage at the side of the power supply, a phase determination unit which determines a phase in which phases of the three line-to-line stable-state magnetic fluxes are respectively the same in polarity as phases of the three line-to-line residual magnetic fluxes, and a closing unit which closes the circuit breaker in the phase determined by the phase determination unit.

Transformer inrush current suppression apparatus

Growing community of inventors

Urayasu, Japan

Keisuke Udagawa