System stability monitoring device and system stability monitoring system

Patent metadata

Field	Value
Publication number	US-10628896-B2
Application number	US-201515507397-A
Country	US
Kind code	B2
Filing date	May 28, 2015
Priority date	Sep 3, 2014
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A system stability monitoring device monitors the stability of a power system and is equipped with: a storage unit for storing spot information indicating the positional relationship between a plurality of measurement spots in the power system; a receiving unit for receiving time-series measurement information measured by a measuring device provided at each of the measurement spots; and a calculation unit for detecting the frequency components of the power fluctuation from the measurement information, selecting, based on the frequency components, measurement spot group candidates that are measurement spots among the plurality of measurement spots, obtaining the electrical distances between the measurement spot group candidates on the basis of the spot information, and categorizing the measurement spot group candidates into at least one measurement spot group on the basis of the electrical distances.

First claim

The invention claimed is:

1. A system stability monitoring device that monitors stability of a power system, comprising:
a memory that stores spot information indicating a positional relationship between a plurality of measurement spots in the power system; and
a processor communicatively coupled to the memory;
wherein the processor is configured to:
receive time-series measurement information from a plurality of sensors that are provided at each of the plurality of measurement spots; and
detect frequency components of power fluctuation from the measurement information,
select measurement spot group candidates which are measurement spots among the plurality of measurement spots based on the frequency components detected,
determines electrical distances between the measurement spot group candidates based on the spot information, and
categorize the measurement spot group candidates into at least one measurement spot group based on the electrical distances determined.

2. The system stability monitoring device according to claim 1 , wherein the processor is further configured to:
calculate fluctuation information of the frequency components, wherein the fluctuation information includes at least one of a fluctuation frequency, an attenuation coefficient, and an amplitude of the frequency components.

3. The system stability monitoring device according to claim 2 , wherein the processor is further configured to:
calculate a degree of effect on fluctuation based on the fluctuation information, wherein degree of effect of fluctuation indicates an extent of effect of the frequency components on stability of the power system.

4. The system stability monitoring device according to claim 3 , wherein the the processor is further configured to:
determine whether or not the measurement spot group is unstable, based on the degree of effect on fluctuation calculated.

5. The system stability monitoring device according to claim 4 , wherein the spot information indicates at least one of a latitude and a longitude of each of the plurality of measurement spots, a topology between the plurality of measurement spots, impedance between the plurality of measurement spots, and characteristics of a power apparatus which is linked to vicinity of each of the plurality of measurement spots.

6. The system stability monitoring device according to claim 5 , wherein the processor is further configured to:
set measurement spots in which differences between the fluctuation frequencies detected are within a predetermined range, among the plurality of measurement spots, as the measurement spot group candidates.

7. The system stability monitoring device according to claim 3 , wherein the the processor is further configured to:
predict a time change of the degree of effect on fluctuation, and
determine whether or not a specified spot in the power system will be destabilized in future based on the time change of the degree of effect on fluctuation.

8. The system stability monitoring device according to claim 7 , wherein the processor is further configured to:
calculate a propagation situation of the degree of effect on fluctuation based on the time change of the degree of effect on fluctuation, and
calculate a destabilization time when the specified spot is destabilized based on the propagation situation.

9. The system stability monitoring device according to claim 3 ,
wherein the memory further stores past fluctuation information, and
wherein the processor is further configured to:
select the past fluctuation information corresponding to a situation of the measurement spot group, and
calculate the degree of effect on fluctuation based on frequency components in the selected past fluctuation information.

10. The system stability monitoring device according to claim 1 , wherein the electrical distances between two measurement spots of the plurality of measurement spots are proportional to impedance between two respective measurement spots.

11. The system stability monitoring device according to claim 1 , wherein the processor is configured to control a display to display at least one of a system diagram of the power system and a map, and a screen indicating the measurement spot group, based on the spot information.

12. A system stability monitoring system that monitors stability of a power system, comprising:
a plurality of sensors that are respectively provided at a plurality of measurement spots in the power system; and
a memory that stores spot information indicating a positional relationship between the plurality of measurement spots;
a processor that is communicatively coupled to the plurality of sensors and the memory,
wherein the processor is configured to:
receive time-series measurement information which is measured by each of the plurality of measuring devices, and
detect frequency components of power fluctuation from the measurement information,
select measurement spot group candidates which are measurement spots among the plurality of measurement spots based on the frequency components detected,
determines electrical distances between the measurement spot group candidates based on the spot information, and
categorize the measurement spot group candidates into at least one measurement spot group based on the electrical distances determined.

Assignees

• Hitachi Ltd

Inventors

• Yamazaki Jun
• Yatsu Masahiro
• Tobe Sumito
• Sato Yasuo
• Tomobe Osamu
• Kuroda Eisuke

Classifications

• H02J13/00

  Circuit arrangements for providing remote monitoring or remote control of equipment in a power distribution network · CPC title

• G06Q50/06 Primary

  Energy or water supply · CPC title

• H02J3/24

  Electricity · mapped topic

• H02J13/0079

  Electricity · mapped topic

• Y04S10/60

  Cross-Sectional Technologies · mapped topic