Monitoring an electrical power supply network
AssigneeSiemens Aktiengesellschaft
InventorsAndreas Litzinger, Stefan Piel
Life of this patent
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Abstract
A method and a device are provided for monitoring an electrical power supply network. A temporal frequency change value is determined for at least two sections or for at least two points of the power supply network. The frequency change value indicates the respective temporal frequency change of the network frequency. A conclusion is drawn regarding a possible islanding within the power supply network, and a warning signal which indicates the possible islanding within the power supply network is generated when the difference between the frequency change values, exceeds a predetermined frequency change threshold value.
Claims11
A method of monitoring an electrical power supply network, the method comprising:
- determining by a measuring instrument a temporal frequency change value for at least two sections of the power supply network or for at least two points of the power supply network, the change value indicating a respective temporal frequency change in a network frequency;
- and
- if a difference between the frequency change values exceeds a predetermined frequency change threshold value, drawing by a central device a conclusion regarding possible islanding within the power supply network and generating and outputting a warning signal indicating the possible islanding within the power supply network;
- if a difference between the frequency values exceeds a predetermined frequency threshold value, drawing by the central device a conclusion regarding the existence of islanding within the power supply network and generating an islanding signal indicating islanding within the power supply network;
- and
- after forming the islanding signal by the central device, resetting or switching off the islanding signal only if:
- the difference between the frequency values falls below a predetermined first resetting threshold value;
- and
- the difference between the temporal frequency change values falls below a predetermined second resetting threshold value.
An arrangement for monitoring an electrical power supply network, the arrangement comprising:
- at least one measuring instrument respectively disposed in each of at least two sections or at each of at least two points of the power supply network, said measuring instruments being configured for determining a frequency value indicating a respective network frequency and/or a temporal frequency change value indicating a respective temporal frequency change in a network frequency;
- and
- a central device configured:
- to draw a conclusion regarding possible islanding within the power supply network and to generate a warning signal indicating the possible islanding within the power supply network if a difference between the frequency change values exceeds a predetermined frequency change threshold value;
- and
- to draw a conclusion regarding the existence of islanding within the power supply network and generating an islanding signal indicating islanding within the power supply network if the difference between the frequency values exceeds a predetermined frequency threshold value;
- and
- after forming the islanding signal, to reset or switch off the islanding signal only if:
- the difference between the frequency values falls below a predetermined first resetting threshold value;
- and
- the difference between the temporal frequency change values falls below a predetermined second resetting threshold value.
In an electrical power supply network having measuring instruments disposed to measure in different sections or points of the power supply network frequency values indicating a network frequency and/or a temporal frequency change value indicating a temporal frequency change in the network frequency, a central device, comprising:
- a computing device configured for receiving from the measuring instruments, signals representing the network frequency and/or temporal frequency change values for the different sections or points in the power supply network and for generating a warning signal indicating possible islanding within the power supply network if a difference between the frequency change values exceeds a predetermined frequency change threshold value, and for generating an islanding signal indicating islanding within the power supply network if the difference between the frequency values exceeds a predetermined frequency threshold value, and, after forming the islanding signal, resetting or switching off the islanding signal only if:
- the difference between the frequency values falls below a predetermined first resetting threshold value;
- and
- the difference between the temporal frequency change values falls below a predetermined second resetting threshold value.
Dependencies are inferred from the claim text.