Cahier technique no 213 - studiecd.dk

1 Collection TechniqueCahier technique no. 213 Calculations forLV and HV networksB. de METZ-NOBLATB uilding a New electric World"Cahiers Techniques" is a collection of documents intended for engineersand technicians, people in the industry who are looking for more in-depthinformation in order to complement that given in product , these "Cahiers Techniques" are often considered as helpful"tools" for training provide knowledge on new technical and technological developmentsin the electrotechnical field and electronics.

2 They also provide betterunderstanding of various phenomena observed in electrical installations,systems and " Cahier technique " provides an in-depth study of a precise subject inthe fields of electrical networks, protection devices, monitoring and controland industrial automation latest publications can be downloaded from the schneider electric internetweb : :PressPlease contact your schneider electric representative if you want either a" Cahier technique " or the list of available "Cahiers Techniques" collection is part of the schneider electric s"Collection technique ".

3 ForewordThe author disclaims all responsibility subsequent to incorrect use ofinformation or diagrams reproduced in this document, and cannot be heldresponsible for any errors or oversights, or for the consequences of usinginformation and diagrams contained in this of all or part of a " Cahier technique " is authorised with thecompulsory mention:"Extracted from schneider electric " Cahier technique " no.." (pleasespecify).no. 213 Calculations forLV and HV networksECT 213 first issue, December 2004 Beno t de METZ-NOBLATESE engineer, worked for Saint-Gobain, then started at Merlin Gerinin is a member of the Electrical Network competence group thatstudies electrical phenomena concerning the operation of networksand their interaction with devices and technique schneider electric no.

4 213 / technique schneider electric no. 213 / forLV and HV networksThis Cahier technique publication is intended to provide a generaloverview of the main electrotechnical calculations carried out inengineering studies on electrical systems at all voltage is complementary to other Cahier technique publications that deal morewith the operation of devices and installations in electrical systems. Thisdocument will help owners, designers and operators understand theimportance of these calculations in ensuring correct use of the electricalnetwork and their impact on the total cost of Introductionp.

5 42 Life of an electrical Life cycle of an electrical networkp. phenomena in networksp. Types of networks and their operationp. Necessary calculationsp. Summary tablep. 73 Study Methodp. Role of the expertp. 104 Electrical-network Dependabilityp. Steady-state conditionsp. Short-circuitp. Protectionp. Stabilityp. Harmonicsp. Overvoltagesp. Electromagnetic compatibilityp. Measurements for auditsp. 285 Summary - Main risks for users - Answers provided by studiesp. 316 Conclusionp.

6 33 Appendix 1. Historyp. 34 Appendix 2. Softwarep. 35 Appendix 3. Necessary datap. 36 Bibliographyp. 37 Cahier technique schneider electric no. 213 / IntroductionElectrical networks have long been studied toensure effective supply of electricity to main aspects studied are design, operation that, in this document, the term "process"refers to all applications of electricity users(commercial, infrastructure, industry, distribution-system manager).Given the recent worldwide context, the importanceof electrical network studies is growing Over the past few years, the electrical world andits organisational modes have undergone With deregulation of the electric market, theeconomic rules have changed.

7 Consumers can takeadvantage of the competition between suppliers andutilities can extend their Users are refocusing on their core business anddivesting secondary activities such as thoserequired to run electrical networks. Examples aresubcontracting of maintenance or operation ofinstallations to specialised service Technological progress has also had a number of all, digital electronics and computer networkshave opened new horizons, but also imposed newconstraints. They have improved electric systeminstrumentation and control, including remotecontrol, but at the same time have made processesmore sensitive to energy , the trend toward multiple energy sources(combined heat and power - CHP, renewableenergy)

8 And the widespread use of non-linear loadscan, over time, have major impact on networkarchitecture and operating modes, due to voltagedisturbances, protection needs and Electricity is now considered a product like anyother, which implies a need for want access to electrical energysuited to their needs. Given the extremelydiverse requirements of processes in terms ofsafety and quality, the electricity supplied mustmeet the stipulated every level in the electrical supply chain(production, transmission, distribution), energysuppliers must satisfy customers and users inline with personalised contractual Environmental protection criteria have becomeobligatory in terms of the selection andconsumption of materials (minimumenvironmental impact) and energy (maximumefficiency).

9 C More than ever, economic aspects are acrucial must optimise the total cost of ownership(TCO) of the electrical network. The TCOincludes all expenditures required to useelectrical energy, investments, operation,maintenance and the purchase of demonstrate the importance of calculations inengineering studies, this Cahier Techniquepublication will successively discuss:v aspects pertaining to the life of an electricalnetwork;v calculation methods;v the main calculations required according to thetype of network and the applications that the calculations presented hererepresent only one element in the overallelectrical-engineering technique schneider electric no.

10 213 / Life of an electrical networkA number of aspects concerning the life of anelectrical network are discussed in this section,so that the readers can gain a better grasp ontheir own installations and take action at thecorrect level in terms of the subject presentedhere:c life cycle, the successive phases in the lifeof an electrical network from its design onthrough to upgrades (seeFig. 1);c electrical phenomena encountered in systemoperation;c types of networks and their operation, whichdirectly determine the impact of events onelectrical components;c finally, the calculations required to developeconomically and technically viable solutions,and which constitute one of the final selectioncriteria of the Life cycle of an electrical networkFig.