WebNIR

Calculation of the current capacity according to the CEI 11-60 Standard (Second edition, June 2002): Capacity at the thermal limit of external overhead electric lines with voltage greater than 100 kV

Calculation of flow rate in normal service

Nominal Voltage Select... 380 kV 220 kV 132 ÷ 150 kV

Region Seleziona... Valle d'Aosta Piedmont Liguria Lombardy Emilia Romagna Veneto Trentino-Alto Adige Friuli Venezia Giulia Tuscany Umbria Lazio Marche Abruzzo Molise Campania Puglia Basilicata Calabria Sicily Sardinia

Altitude above sea level m

Periodo Select... Hot Cold

Conductor diameter mm

Conductor type Select... Bimetallic aluminum-steel Bimetallic aluminum-steel alloy Aluminum-steel alloy Copper Copper alloy

Aluminum/steel ratio

Tension constant m

Imbalance of spans in the section

Extra-clearance m

Reference to the highest ground clearance only, for 380 kV powerlines

Calculate Reset

I_SN = ...

Calculation of catenary parameters

In the Catenary tab, it is possible to carry out 3 types of calculations, relating to the geometric parameters of a catenary, for the purpose of evaluating the stray field from a power line using a model that takes into account the exact geometry of the conductors.

The reference system is described by a Cartesian plane xOz, on which the curve lies. The supports therefore have an abscissa x₁ and x₂, respectively, and the length of the span is given by L=|x₂ - x₁|.

In the first case, if you want to obtain the coordinates of the minimum clearance of the curve and its length starting from the other known parameters, you need to insert the values ​​of:

• span length L;
• altitude above the ground of the initial z₁ and final z₂ suspension points;
• tensioning constant k;

and press the Calculate button.

In the second case, of interest to determine the tensioning constant when both the coordinates of the suspension points and the altitude above the ground of the minimum clearance are known, the following must be entered:

• span length L;
• altitude above the ground of the initial suspension points z₁, final z₂ and of the minimum clearance z₀;

and press the Calculate

Finally, the third case allows you to determine the tension constant and the coordinates of the minimum if all the other parameters are known. You must enter:

• span length L;
• altitude above the ground of the initial suspension points z₁, final z₂ and the minimum clearance z₀;
• cable length;

and press the Calculate

The results are provided in numerical form in the relevant box of interest.

Calculation of the flow rate according to the CEI 11-60 Standard

In the CEI 11-60 Flow Rate tab it is possible to calculate the current as required by the Prime Ministerial Decree (Setting of exposure limits, attention values ​​and quality objectives for the protection of the population from exposure to electric and magnetic fields at the network frequency (50 Hz) generated by power lines). In particular, in Art. 6:

To determine the buffer zones, reference must be made to the quality objective referred to in art. 4 and the current flow rate in normal service of the power line, as defined by the CEI 11-60 standard.

The interface allows you to enter all the parameters needed to perform the calculation; for their definition, please refer to the contents of the aforementioned standard.

By pressing the Calculate button, the result is shown at the bottom of the tab.