Characteristics and target values of the voltage …

1 AAVice-pr sidence DistributionDirection Plans et Strat gies d affairesOrientations du r seauCharacteristics and target valuesof the voltage supplied by the Hydro-Qu bec medium andlow voltage systemsTranslated June 5, 2001 French original : February 2001 This document is translated from the French document intitled 'Caract ristiques et cibles de qualit de la tensionfournie par les r seaux moyenne et basse tension d Hydro-Qu bec ' (Report nr: 30012-01-02).In case of any difference between the English and French version, the French version shall prevail.(Blank page)SummaryThe purpose of this document is to familiarize customers with the different phenomenaaffecting voltage quality, to describe these phenomena; and to encourage customers to usethis information to adequately protect their equipment and minimise the possible impact ofvarious Characteristics and target values of the voltage presented in this document aregeneral in nature and intended for information purposes only.

2 These figures providethe best possible indication of what to expect; they in no way, however, guaranteethat a given customer in a specific zone may not experience larger variations of thevoltage Characteristics and a greater number of events. In no way does thisdocument constitute an obligation or guarantee of any kind whatsoever on the partof document describes, at the connection point to the medium and low- voltage system, theprincipal Characteristics and quality of voltage provided by the Hydro-Quebec distributionsystem under usual operating conditions. Unless otherwise noted, the characteristicsdescribed in this document apply to medium- voltage as well as low- voltage do not apply in cases of force majeure or in other specific situations outlined in theScope present document is partly based on practices recommended by national andinternational electricity supply standards and adapted to the Hydro-Quebec specifically, this document covers steady state voltage , harmonics, voltage imbalance,flicker, short interruptions, voltage dips, temporary overvoltages, frequency and voltagevariations.

3 And transient overvoltages. For certain Characteristics , target values are definedwith reference to standards and in terms of probability, , they are applicable for apercentage of time in a specific time period. For other Characteristics , however, factors suchas current knowledge or standardisation, the random or external nature of disturbances,enable us to provide only a general range of values representing current knowledge on , in order to ensure compatibility between customer equipment and theelectricity supplied, this equipment must have adequate immunity levels.

4 Also, disturbancesoriginating from customer equipment or installations must be below authorised emissionlevels, so that their cumulative effect on the system will not create an unacceptable risk ofexceeding compatibility last aspect, in relation to the control of disturbances produced by the installations ofcustomers connected to the distribution system, falls under Hydro-Qu bec emission limitsrequirements. Customers must therefore comply so that the target values presented hereinmay be reached.(Blank page)TABLE OF CONTENTS1. CLASSIFICATION OF THE DISTURBANCES AFFECTING THE ELECTRICAL SUPPLY STEADY STATE voltage - LOW STEADY STATE voltage MEDIUM NEUTRAL voltage (GROUND-NEUTRALVOLTAGE).

5 INTERRUPTIONS (DURATION 1 MINUTE).. HARMONIC voltage SHORT INTERRUPTIONS (DURATION < 1 MIN).. voltage TEMPORARY FREQUENCY RAPID voltage TRANSIENT OVERVOLTAGES - LOW TRANSIENT OVERVOLTAGES - MEDIUM A :STATISTICS ON voltage DIPS AND SHORTINTERRUPTIONS ON THE LOW AND MEDIUM voltage SYSTEMSAPPENDIX B :STATISTICS ON FREQUENCY VARIATIONSAPPENDIX C :EXTRACTS FROM BYLAW NUMBER 634 RESPECTING THE CONDITIONS GOVERNING THE SUPPLY OF ELECTRICITY Act respecting Hydro-Qu bec, ( , , )A Electrical Characteristics for MV and LVJune 2001ii1. PreambleThe purpose of this document is : to familiarize customers with the guidelines generally accepted by the internationalcommunity or defined by Hydro-Qu bec for the different phenomena affecting voltagequality; to remind customers that supplied electricity is subject to interruption or disturbance; to encourage customers to use the information provided to adequately protect theirequipment and to organize their use of electricity to minimise the possible impact of thevarious phenomena as necessary.

6 To encourage equipment suppliers to offer the necessary options to ensure thecompatibility of their equipment with the normal supply of electricity. The voltage Characteristics defined in this document are general in nature; they shouldnot, therefore, be regarded as complete or sufficient to ensure the correct operation of aninstallation or a given device. The customer must therefore consider these phenomena and Characteristics in theirentirety to ensure the adequate integration of an installation or device in its uniqueenvironment, all in accordance with applicable standards and codes.

7 It is also important to note that the Characteristics and target values presented in thisdocument provide the best possible indication of what to expect; they in no way, however,guarantee that a given customer in a specific zone may not experience values and anumber of events falling outside the bounds described in this document. In this respect, Hydro-Qu bec guarantees neither the maintenance of voltage andfrequency at a stable level nor the continuity of the supply and delivery ofelectricity. In no case shall it be held contractually or extra-contractually liable fordamage caused to property resulting from the supply or delivery of electricity orfailure to supply or deliver electricity, or resulting from accidental grounding,mechanical failure on its system, any interruption of service, frequency variationsor supply voltage variations.

8 (Bylaw 634, ) Moreover, even when the system is exploited within the limits defined in this document, itis still essential that equipment or processes be designed or immunised in such a waythat they are neither disturbed nor damaged by their electrical environment. This is why the customer must ensure the protection of property and the safety ofpersons wherever electricity is supplied or delivered and he is responsible forprotecting himself from the consequences of any interruption in the supply ordelivery of electricity and for protecting his electrical installation and apparatusfrom voltage variations and losses, frequency variations and accidentalgroundings.

9 (Bylaw 634, )A Electrical Characteristics for MV and LVJune 2001iii The measuring methods referred to in these pages are relatively new. As a consequence,the pertinent measuring devices may not be widely available for a few years yet. In themeantime, available measuring devices may be used, with results treated and interpretedrespecting the new methods as much as possible. Context This document is partly based on practices recommended by national and internationalstandards and adapted to the Hydro-Qu bec system. Among the standards currentlyused or being developed on power quality and compatibility between load and powersupply, priority was given to standards issued by the International ElectrotechnicalCommission (IEC) as well as to standard EN50160 [ 1 ] of the European Committee forElectrotechnical Standardisation (CENELEC), both among the most advanced standardsin the industry.

10 Furthermore, voltage quality measurements will be taken in the next few years to continueto quantify the various voltage quality indices as applied to the Hydro-Qu bec distributionsystem. With these measurements then at hand, the voltage quality disturbance levelsgiven here as a indicative guidelines may be more precisely defined. Under usual operating conditions, supply voltages are subject to variations for a number ofreasons : changes of the load connected to the supply system, disturbances generatedby various devices, and faults arising chiefly from external events. Characteristics mayvary randomly : over time at a specific supply point, or by location at a given point in time.