Power distribution network monitoring system for detecting abnormalities

Patent metadata

Field	Value
Publication number	US-11156641-B2
Application number	US-201716481120-A
Country	US
Kind code	B2
Filing date	Nov 24, 2017
Priority date	Mar 15, 2017
Publication date	Oct 26, 2021
Grant date	Oct 26, 2021

Abstract

A power distribution network monitoring system includes a CT sensor and a power management device. The CT sensor includes a measurement component and a transmitter. The measurement component is installed at a plurality of predetermined positions along a power line constituting the power distribution network, and measures current of the power line at each predetermined position. The transmitter wirelessly transmits, as transmission data, the power spectrums of the fundamental wave, third harmonic, and fifth harmonic, as well as the effective current values used to detect abnormalities in the power distribution network, the data being at least part of the data measured by the measurement components. The power management device includes a receiver and a management database. The receiver receives the transmission data. The management database stores the received data.

First claim

The invention claimed is:

1. A power distribution network monitoring system, comprising:
a measuring instrument including:
measurement components configured to be installed at a plurality of predetermined positions along a power line constituting a power distribution network and perform electrical measurement of the power line at each of predetermined positions; and
a transmitter configured to transmit wirelessly, as transmission data, a detection data that is at least part of data measured by the measurement components and is used for a detection of abnormalities in the power distribution network and/or a detection result data about a result of using the detection data to perform abnormality detection;

a management device including:
a receiver configured to receive the transmission data, which includes the detection data and/or the detection result data; and
a storage component configured to store the detection data and/or the detection result data;

an abnormality detector provided in one of the measuring instrument and the management device and configured to use the detection data to detect abnormalities in the power distribution network to obtain the detection result data; and
a notification unit provided in one of the measuring instrument and the management device and configured to send a notification of the detection result data when the abnormality detector detects an abnormality.

2. The power distribution network monitoring system according to claim 1 ,
wherein the transmission data includes the detection data,
the management device includes the abnormality detector and the notification unit, and
the storage component of the management device is configured to store detection result data about results of abnormality detection.

3. The power distribution network monitoring system according to claim 2 ,
further comprising a relay configured to receive wirelessly the detection data from the plurality of measuring instruments, and transmits the detection data to the receiver of the management device,
wherein the receiver of the management device is configured to receive the detection data via the relay.

4. The power distribution network monitoring system according to claim 2 ,
wherein the abnormality detector is configured to detect at least one of following kinds of abnormality: an abnormality related to overload, an abnormality related to the balance of power in three power lines constituting three phases, an abnormality related to power loss, and an abnormality related to a harmonic wave.

5. The power distribution network monitoring system according to claim 4 ,
wherein the notification unit is configured to send a notification about a type of the abnormality when the abnormality detector detects any of the abnormalities.

6. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about an effective value of current of the power line, and
the abnormality detector is configured to detect abnormalities in the power distribution network based on the effective value of the current.

7. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about a fundamental wave of the current of the power line and about harmonic waves with respect to the fundamental wave, and
the abnormality detector is configured to detect abnormalities in the power distribution network on the basis of information about the fundamental wave and the harmonics of the current.

8. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about an effective value of current of the power line, and
the abnormality detector is configured to detect occurrence of an abnormality related to overload at the predetermined position when the effective value is above a preset threshold.

9. The power distribution network monitoring system according to claim 8 ,
wherein a plurality of the thresholds are set such that the value increases stepwise, and
the abnormality detector is configured to determine that degree of abnormality is greater in proportion to how much a large threshold is exceeded.

10. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about an effective value of current of the power line,
the measuring instruments are attached to each of three power lines arranged in parallel to form three phases, and
the abnormality detector is configured to detect occurrence of an abnormality related to balance of power in the three power lines based on the effective value of each of the power lines.

11. The power distribution network monitoring system according to claim 10 ,
wherein an average effective value is an average of the effective values obtained in a predetermined period for each of the three power lines,
an overall average value is an average of three average effective values of the three power lines,
a diverging average effective value is the most deviated average effective value with respect to the overall average value among the three average effective values, and
the abnormality detector is configured to detect that balance abnormality has occurred in the three power lines when a degree of deviation from the overall average value of the diverging average effective value is larger than a preset threshold.

12. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about an effective value of current of the power line,
the measuring instruments are provided at two places along a specific power line of the power distribution network and to all of branch lines branching off from between the two points of the specific power line, and
the abnormality detector is configured to detect that an abnormality related to power loss between the two locations of the specific power line has occurred based on the effective values at the two locations of the specific power line and of the effective values of all the branch lines.

13. The power distribution network monitoring system according to claim 12 ,
wherein an average effective value is an average of the effective values obtained in a predetermined period for each of the branch line and each of the two locations,
the abnormality detector is configured to detect that an abnormality related to power loss has occurred when a ratio of a loss amount to a usage amount is above a predetermined threshold,
the usage amount is a sum of the average effective values of all of the branch lines,
the loss amount is a remainder of subtracting the usage amount from a reduction amount, and
the reduction amount is a difference between the average effective value on an upstream side, and the average effective value on a downstream side, out of the two locations of the specific power line.

14. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about an effective value of current of the power line,
the measuring instruments are provided at two locations of a specific power line of the power distribution network, and
the abnormality detector is configured to detect that an abnormality related to power loss has occurred between the two locations of the specific power line based on the effective values at the two locations of the specific power line.

15. The power distribution network monitoring system according to claim 2 ,
wherein the detection data includes information about a fundam

Assignees

• Omron Tateisi Electronics Co

Inventors

• Takeya Hiroaki
• Adachi Tatsuya

Classifications

• H02J13/1331

  using wireless data transmission · CPC title

• H02J13/12

  Monitoring network conditions, e.g. electrical magnitudes or operational status · CPC title

• H02J13/1335

  involving a local wireless network, e.g. Wi-Fi®, ZigBee® or Bluetooth® · CPC title

• Y04S10/52

  Outage or fault management, e.g. fault detection or location · CPC title

• Y04S10/30

  State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge · CPC title