Software

LVPLAN: Low Voltage Electrification of a Village

For low voltage electrifcation studies it is recommended to use the new LAP software. Le contenu de cette page décrivant LVPLAN reste disponible pour information.

LVPLAN is a software assisting in the design of new Low Voltage aerial distribution networks in electrification projects. The software determines the optimal network design with respect to investment costs and losses, taking into account mechanical and electrical characteristics of the equipments and considering maximum admitted voltage drops. In most projects, resulting benefits in investment costs and losses are a multiple of the software acquisition cost.

What it does

First, one has to build - once - a library with types of lines, types of transformers, types of loads, poles, etc. This library is unique and will be used in all planning projects.

For each project, the user shall specify:

• A simplified graphical background showing the area to be electrified
• Localisation and types of loads in this area
• Proposed right-of-ways for the LV distribution lines.

Using this information, the program determines:

• The localisation of the poles
• The connections of the loads to the nearest pole
• The most economic line type for each section, considering investment costs, transit constraints, losses and voltage drops.
• The localisation of earth points
• Types of poles to be used according to their mechanical constraints
• Electrical results: currents, voltages, losses, ...

A detailed list of required equipment with cost estimate to build the network.

LVPLAN characteristics

Geographic network representation

The network components are located on the screen according to a metrical co-ordinates system. At any time, the position of the mouse pointer is shown in the status bar below the screen, in meters, from the lower-left corner of the diagram.

Background diagram

The background diagram is composed of static lines and text. It can be split in 9 different layers, according to the level of detail. This allows for adequate representation of geographical details depending on the zoom factor. The background diagram is created and updated either with the mouse or with a digitising table.

Static Data

BaseTypes of equipment used in the network - such as poles and lines - with their mechanical and electrical characteristics, are maintained in a static Data Base. The same Data Base is used in all studies.

Loads

Each load point is characterised by its peak value and its load type. The type of load determines the load factor, the daily load curve, the yearly growth, its icon in the diagram, and a sum-reduction table. This table will 'reduce' the sum of several loads of this type, taking into account that their peaks do not occur simultaneously.

LVPLAN results

Location of poles and connection of loads

The location of the poles, and the connection of the loads to the nearest pole are shown in the screen. The calculation of these locations takes into account the types of cables used, their traction forces on the poles, and the mechanical characteristics of these poles.

Electrical calculations

Electrical loads are characterised by their peak value for each year and a daily load profile. Considering these data, and the electrical characteristics of the cables, the program calculates currents, losses and voltage drops in the network. These results are obtained for the 24 hours of the daily load profile, at each year. These results can be shown on request on the screen.

Electric calculations

Electric calculation use a one-line representation of the network and assume equilibrated loads. The optimisation of the types of cables takes into account investment costs, losses, transit constraints and maximum voltage drops. Pole types are selected considering mechanical constraints resulting from the cable loads and the effect of winds on those cables.

Study period

The network is build to feed the loads at the final year of the study period. However, electric results (currents, losses, voltages) are calculated for each year of the study period. These results can be shown in the diagram at users request.This feature allows for quick identification of problem areas in the network.

Indication of overloads and voltage drops

In the diagram, the colour of the nodes is a measure of their voltage drop, according to a user-defined scale. In a similar way, for the line sections, their colour indicates their percentage of loading with respect to their transit capacity.

Reports

In addition to the various results displayed on the network diagram, LVPLAN generates various reports with mechanical and electrical results. A preview of each report can be shown on the screen for verification before it is printed.

List of required material

This report, which perhaps is the most useful report of LVPLAN, shows a detailed list of all required material to build the network, together with individual equipment costs.

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