Power system stabilization device and method

Patent metadata

Field	Value
Publication number	US-2017353033-A1
Application number	US-201515537986-A
Country	US
Kind code	A1
Filing date	Nov 25, 2015
Priority date	Dec 26, 2014
Publication date	Dec 7, 2017
Grant date	—

Abstract

A power system stabilization device for the stabilization control of a power system, includes an indicator calculation unit for calculating an acceleration index, which is an index representing the acceleration of a generator for supplying electric power to the power system, by using the generator output, which is the output of the generator, and the generator phase difference that indicates the temporal change of the phase angle of the generator output; a threshold value determining unit for determining whether or not the acceleration index exceeds a preset threshold value; and a control command unit for generating a control command for control details that constitute a correction to the stabilization control, set in advance for the threshold value, when the acceleration index exceeds the threshold value.

First claim

1 . A power system stabilization device performing stabilization control of a power system,
the power system stabilization device comprising: an indicator calculation unit configured to calculate, by using a generator output that is an output of a generator configured to supply electric power to the power system and a generator phase difference that indicates a change of a phase angle of the generator output with respect to time, an acceleration index that is an index representing an acceleration of the generator; a threshold value determining unit configured to determine whether the acceleration index exceeds a threshold set in advance; and a control command unit configured to issue, when the acceleration index exceeds the threshold, a control command for control details for correcting the stabilization control, which are set for the threshold in advance.

2 . The power system stabilization device according to claim 1 , wherein the generator phase difference is a time deviation of a voltage phase of a bus for the generator or a bus for an electric power plant including the generator.

3 . The power system stabilization device according to claim 1 , wherein the generator phase difference is a difference between a voltage phase of a bus for the generator or a bus for an electric power plant including the generator and a voltage phase of a bus at a predetermined distance from the generator.

4 . The power system stabilization device according to claim 1 , wherein the generator phase difference is a deviation between average values of phase angles of output of the generator in a predetermined period, which are calculated every predetermined period, in a period excluding times immediately before and immediately after occurrence of a failure.

5 . The power system stabilization device according to claim 1 , further comprising:
a generator phase database configured to hold the generator phase difference information; and a generator output database configured to hold the generator output.

6 . The power system stabilization device according to claim 1 , wherein the acceleration index is an energy value calculated with use of the generator output and the generator phase difference.

7 . The power system stabilization device according to claim 6 , wherein the acceleration index is an energy value determined by integrating the generator output with respect to the generator phase difference.

8 . The power system stabilization device according to claim 1 , wherein the threshold is determined in a manner that, when a power flow of the power system is changed from a stable state such that stability is deteriorated for each failure that possibly occurs in the power system, a stability limit, at which the power system becomes unstable in a case where the power flow of the power system is further changed, is determined, and a value of the acceleration index at the stability limit is determined as the threshold.

9 . The power system stabilization device according to claim 1 , wherein the threshold is one or more thresholds that are set for an elapsed time from occurrence of a failure in order to determine once or a plurality of times whether the acceleration index exceeds the threshold.

10 . The power system stabilization device according to claim 1 , wherein the threshold excess determining unit is configured to determine whether the acceleration index exceeds the threshold immediately after occurrence of a failure, and transmit a result of the determination to a central stabilizer that is configured to manage one or more electric power plants including an electric power plant to be subjected to control by the power system stabilization device.

11 . A power system stabilization method for executing stabilization control of a power system, the power system stabilization method comprising:
calculating, by index calculation means, an acceleration index representing an acceleration of a generator by using an output of the generator and a generator phase difference representing a change of a phase angle of the output of the generator with respect to time; determining, by threshold determination means, whether the acceleration index exceeds a threshold set in advance; and issuing, by control command means, when the acceleration index exceeds the threshold, a control command of control details for correcting the stabilization control, which are set for the threshold in advance.

Assignees

• Hitachi Ltd
• Chubu Electric Power

Inventors

• Kuroda Eisuke
• Sato Yasuo
• Kawahara Taichirou
• Hara Kouichi
• Yokoi Kouichi
• Katsuragi Keisuke
• Zashibo Toshihito
• Matsubara Takumi
• Kuwabara Makoto

Classifications

• G05B2219/2639

  Energy management, use maximum of cheap power, keep peak load low · CPC title

• G05B19/042

  using digital processors (G05B19/05 takes precedence) · CPC title

• H02J3/24 Primary

  Electricity · mapped topic

• H02J2003/001

  Electricity · mapped topic

• H02P9/105 Primary

  for increasing the stability · CPC title