Gustav Robert Kirchhoff

In 1845, as a student, Kirchhoff announced Kirchhoff’s laws, which allow calculation of the currents, voltages, and resistances of electrical networks. Extending the theory of Georg Simon Ohm, he generalized the equations describing current flow to the case of electrical conductors in three dimensions. In further studies he demonstrated that current flows through a conductor at the speed of light.

Gaia LV Network Design / application

Development of new infrastructure Specially developed five-conductor load flow technique. Contact safety definition

Optimal network design
Gaia LV Network Design offers indispensable support when planning the most economical low voltage distribution network. Based on pre-conditions like cables costs, preferred cable types, cost of losses and maximum allowed voltage drop, the program calculates the right cables for the most economical network. In other words, the total investment and operational costs are minimized. Further, Gaia LV Network Design evaluates short-circuit withstand, power quality and contact safety.
The construction of a new network is supported by a “wizard”, which defines source, cable lengths and loads. The cable types are suggested by the optimization routine, taking into account the time frame, transformer tap setting and requirements concerning voltage quality, short-circuit withstand and contact safety.

Easy-to-use
As Gaia LV Network Design is used by people who are not always very familiar with extensive network calculations, much attention has been paid to the user-friendliness. The program is menu-driven and uses a comprehensible graphical user interface, reducing the risk of input errors.

Unbalanced network
Most LV distribution systems are unbalanced networks. In particular, the neutral conductors and the detailed earthing system prohibit the use of a symmetrical components based approach.
Gaia LV Network Design utilizes a unique network model, in which all conductors and mutual couplings are represented. This has been made possible with a specially developed five-conductor load flow technique.

Contact safety
Gaia LV Network Design is specially designed to ensure contact safety in both TT and TN-earthed networks. The program evaluates all neutral and sheath currents and voltages in the event of a phase-to-earth fault in the network – taking the effects of all protection devices into account. The contact safety is the result of a low contact voltage and a short exposure duration.

Power quality
The most important factors that determine the power quality are the voltage level and frequently occurring voltage dips.
The voltage level is calculated using a stochastic load flow, evaluating expected mean values and expected extremes. The calculation is based on a full unbalanced network model.
The voltage dip analysis evaluates the sensitivity for switching large loads, both balanced and unbalanced.
The short-circuit analysis determines the adequacy of the network to withstand severe faults.