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Vision Power Range
Vision Network Analysis
Vision Grid Navigator
Vision LV Network Design
Vision Cable Analysis
Vision Power Quality
Vision Fault Finder
• Application
• Overview

Charles-Augustin de Coulomb

French physicist best known for the formulation of Coulomb’s law, which states that the force between two electrical charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. Coulombic force is one of the principal forces involved in atomic reactions.

Vision Fault Finder / application

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1. Measured currents and voltages during a fault

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2. FFT transformation and determined calculation moment

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3. Simulated short circuit impedances in a cable section

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4. Schematic visualisation in
Vision Network Analysis

Step 1. Communication
Following an interruption in an MV cable network, all recorded voltage and current measurements are uploaded to the control centre from the substation. This recording also includes pre- and post-fault data.
The Vision Fault Finder application, installed at the control centre, is triggered and starts processing the received data.

Step 2. Signal processing and Analysis
A Fourier transform (FFT) and symmetrical components transform are carried out to determine the absolute voltages and currents as functions of time. The signals are analysed and it is decided whether this is a real fault or other event. In case of a real fault the calculation moment for the impedance is chosen such that most of the transients have disappeared.
The expert system applies fuzzy logic rules to identify the type of fault involved and the fault impedance.
The results are automatically passed to the Vision Network Analysis application.

Step 3. Simulation
Vision Network Analysis selects the correct network model and performs a number of short circuit analyses corresponding to the found fault type. The pre-fault values for the load and switches are used to adjust the network model.
For all short circuit calculations the simulated reactances, as “seen” from the substation into the direction of the feeder, are calculated.
After this it should be possible to match the measured reactance with the simulated reactances.

Step 4. Visualisation
Once the location has been calculated, the results will be presented to the operator graphically. The location will be visible in both the schematic and geographic network view. Also a report with all the details of the fault is sent to the printer.
With all this information the short circuits will be located efficiently. Finally the supply can be restored by rerouting the distribution feeders.