Calculations > Switchability

The calculation analyzes the restoration of electricity supply during grid failures.

Preparation

The voltage and load rate limits must be defined in the Options, at Calculation | Limits.

The afternoon and evening load and generation rates should be defined in the Options, at Calculation | Presets.

The disturbance analysis options must be defined in the Options, under Calculation | Network analysis | Failure analysis.

All circuit breakers and fuses must be modeled in the network. It is not necessary to specify circuit breaker protections.

Enexis

For Enexis, the percentages and maximum number of switching operations are hard-wired in:

•The maximum number of switching operations is three.

•In the load situation, the load is 100% and the generation, PV and wind are 0%.

•In the generation situation, PV and wind are 100% and load is 25%.

These options are automatically applied when using the Enexis network key.

Calculation

Start the calculation with Calculate | Special | Switchability.

The calculation performs the failure analysis for all non-mesh medium-voltage cables in load situation (evening) and generation situation (afternoon).

Resultaten

The following results for each cable are available for each load/generation situation:

•Offshoot

•Possible switching points

•Switched points

•Good and fast solution

•Weakest branch load rating

•Number of overloaded branches

•Lowest-node voltage

•Highest-node voltage

The options for viewing the results are:

•in the scheme

•in Calculate | Results | Overview

•in Calculate | Results | Details

•in Calculate | Results | Export

Scheme

For cables, the number of switching operations.

The color of the cables has a meaning after performing the calculation. The colors are not adjustable.

Color indication

A cable that can be switched with few switching operations in both situations is drawn in the color green.

A cable that can be switched in both situations with many switching operations is drawn in the color orange.

A cable that cannot be switched in at least one of the situations is drawn in the color red.

For up to one, two or three switch actions, one switch action is little and two or three is much.

At a maximum of four, five or six switching acts, one, two or three switching acts is few and four, five or six is many.

Calculate | Results | Overview

This screen lists:

•Offshoot cables (where in fault cannot be switched)

•Non-offshoot cables in which in failure (complete) switching cannot be done

•Cables that cannot be rapidly switched.

Calculate | Results | Details

Of selected cables, the number of switching operations in the two situations is shown.

The Details button shows all results of the two situations in a table.

Calculate | Results | Export

Of all cables, all results are exported to an Excel file.