HV industrial network design

Design of high voltage

Faced with increasingly fierce competition, industrialists must employ highly rigorous management and their production facilities must have a high level of availability. Electrical networks supply the energy required to run the production facilities. The provision of a continuous power supply to loads is strived for from the start of the network design, in particular during preliminary choices in the singleline diagram.

Reductions in electrical installation and operating costs, together with reliable failure-free operation, are vital conditions for profitability. This technical and economic optimization calls for detailed and global preliminary analyses, which include:

• specific needs and constraints related to the type of industry,
• integration of the limits and constraints of the public distribution network,
• standards and local practices,
• particularities of the operating personnel, facilities manager and maintenance personnel.

The scope of this study is limited to the analyses involved in the design of High Voltage (“HTA” and “HTB”) high power industrial installations which have the following main characteristics:

• installed capacity in the 10 MVA range,
• autonomous electrical energy production (when applicable),
• power supplied by a national transmission or distribution network (≥ 20 kV),
• private Medium Voltage distribution.

Main rules of industrial network design

The aim of this chapter is to explain how the industrial network design process takes into consideration all the obligations (needs and constraints) described in the previous chapter. Since plants are designed to operate non-stop, any break in the electrical power supply should be assessed during the analysis phase and the consequences examined in order to determine the measures to be taken. The method put forth in this chapter comprises two phases:

1. endeavouring to achieve an appropriate technical balance between needs and constraints (see chapter 1),
2. technical and economic optimization through the correct use of certain calculations and the concepts presented below.

Appendix 2, without being exhaustive, lists the main calculation software programs that are used by specialized network analysis engineers.

AUTHOR: Schneider Electric expert | Georges THOMASSET