Bsi bs en 50160 2010 + a1 2015

BS EN 50160:2010+A1:2015 Incorporating corrigendum December 2010 BSI Standards Publication Voltage characteristics of electricity supplied by public electricity networks BS EN 50160:2010+A1:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 50160:2010+A1:2015, incorporating corrigendum December 2010 It supersedes BS EN 50160:2010 which is withdrawn The UK participation in its preparation was entrusted to Technical Committee GEL/8, Systems Aspects for Electrical Energy Supply A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2015 Published by BSI Standards Limited 2015 ISBN 978 580 89537 ICS 29.020; 29.240.01 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2010 Amendments/corrigenda issued since publication Date Text affected 31 March 2011 Modification of CENELEC Foreword 31 July 2015 Implementation of CENELEC amendment A1:2015: Annex ZA added EUROPEAN STANDARD EN 50160:2010+A1 NORME EUROPÉENNE EUROPÄISCHE NORM January 2015 Incorporating corrigendum December 2010 ICS 29.020 English version Voltage characteristics of electricity supplied by public electricity networks Caractéristiques de la tension fournie par les réseaux publics de distribution Merkmale der Spannung in öffentlichen Elektrizitätsversorgungsnetzen This European Standard was approved by CENELEC on 2010-03-01 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels © 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 50160:2010 E BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) –2– Foreword This European Standard was prepared by Working Group 1, Physical characteristics of electrical energy, of the Technical Committee CENELEC TC 8X, System aspects of electrical energy supply It was submitted to the formal vote and was approved by CENELEC as EN 50160 on 2010-03-01 This document is the result of an intensive cooperation between CENELEC and CEER, with involvement of CEER experts in TC 8X WG1 as well as in related Task Forces This document supersedes EN 50160:2007 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN and CENELEC shall not be held responsible for identifying any or all such patent rights The following dates were fixed: – – latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2011-03-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2013-03-01 The main differences from EN 50160:2007 are: – new organization of the document by grouping clauses related to events and continuous phenomena; – modification of some definitions and completion by some new definitions; – new Clause relevant to voltage characteristics in high voltage networks This work has been deemed so important, that before submission for vote, a CENELEC enquiry has been made, where NCs had the opportunity to respond to the most essential questions resulting from the WG discussions This enquiry resulted in an extensive number of valuable comments, which have been carefully examined for possible consideration either for the voting draft in particular or for further work within WG1 on some main issues Following that, the draft has been revised in depth, considering in particular the comments received on: – the subclauses relevant to supply voltage changes, where a new formulation (capable of encompassing the needs expressed by the vast majority of the NCs) has been introduced, – the new Clause 6, relevant to voltage characteristics in high voltage networks, where limits for harmonics and unbalance have been changed into indicative values, as new measurement surveys are taking place in several European countries, and it has been recognized as appropriate to wait for the relevant results before considering the setting of limits Foreword to amendment A1 This document (EN 50160:2010/A1:2015) has been prepared by CLC/TC 8X "System aspects of electrical energy supply" The following dates are fixed: • • latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with this document have to be withdrawn (dop) 2015-09-30 (dow) 2017-09-30 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights –3– BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) Annex ZA (informative) A-deviations A-deviation: National deviation due to regulations, the alteration of which is for the time being outside the competence of the CEN-CENELEC national member This European Standard does not fall under any Directive of the EU In the relevant CEN-CENELEC countries, these A-deviations are valid instead of the provisions of the European Standard until they have been removed Clause Deviation Norway The Norwegian Regulation No 1557 of 30 November 2004 on quality of supply in the Norwegian power system shall contribute to ensure a satisfactory quality of supply in the Norwegian power system and a social rational operation, expansion and development of the power system This includes taking into account public and private interests affected All deviations below are given according to this regulation and the requirements are stricter than the current edition of the EN 50160 The various parties’ responsibility for rectifying the situation when problems occur may differ from case to case This regulation applies to those who wholly or partially own, operate or use electrical installations or electrical equipment that are connected within the Norwegian power system, and who pursuant to the Energy Act is designated transmission system operator This regulation does not apply in Norwegian territorial waters, to direct-current voltage installations or to railway installations in Norway with a frequency of 16 2/3 Hz 3.17 The following definition applies for rapid voltage changes: Rapid voltage changes: A change of the voltage rms value within ± 10 % of the agreed voltage level and which occur more rapid than 0,5 % of the agreed voltage level per second Rapid voltage changes are expressed as the steady state and the maximum voltage change given respectively by: %U steadystate = %U max = ∆U steadystate U agreed ⋅ 100% ∆U max ⋅100% , U agreed where ΔUsteadystate is the steady state voltage change due to a voltage change characteristic, ΔUmax is the maximum voltage difference during a voltage change characteristic, and Uagreed is the agreed voltage level (i.e the nominal or the declared) A voltage change characteristic is the time function of the rms voltage change evaluated as a single value for each successive half period between zero-crossings of the source voltage between time intervals in which the voltage is in a steady state condition for at least second The voltage is in a steady state condition when the rms value is in between ± 0,5 % of the agreed voltage rms level BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) –4– 4.2.1, 5.2.1, 6.2.1 The frequency for systems with synchronous connection to an interconnected system shall normally be within 50 Hz ± 0,1 Hz for 100 % of the time For systems with no synchronous connection to an interconnected system, the frequency shall normally be within 50 Hz ± % for 100 % of the time 4.2.2.1 The supply voltage variations shall be within ± 10 % of the nominal voltage at all supply terminals in the low voltage network 4.2.2.2 All mean values of the supply voltage shall be within ± 10 % of the nominal voltage 100 % of the time at all supply terminals in the low voltage network 4.2.3.1, 5.2.3.1, 6.2.3.1 Rapid voltage changes shall be within the following limits at all supply terminals 100 % of the time: RVCs ΔUsteadystate ≥ 3% Maximum frequency per 24 hours period 0,23≤ UN ≤35 35 < UN 24 12 24 ΔUmax ≥ % 12 Rapid voltage changes due to earth faults or short circuits in the network, inrush current from transformers, back feeding after faults and necessary operation couplings to uphold a satisfactory quality of supply as a whole, are not embraced by the limits given in the table 4.2.3.2, 5.2.3.2, 6.2.3.2 The flicker severity shall be within the following limits at all supply terminals 100 % of the time: 0,23≤ UN ≤35 Short-term flicker, Pst [pu] Long-term flicker, Plt [pu] 35 < UN 1,2 1,0 1,0 0,8 Time interval 95% of the week 100% of the time 4.2.4, 5.2.4, 6.2.4 The negative phase sequence component of the supply rms voltage shall not exceed % of the positive phase sequence component as 10 mean values for 100 % of the time at all supply terminals 4.2.5, 5.2.5 The Total Harmonic Distortion (THD) shall not exceed % and % as a mean value over 10 and one week respectively for 100 % of the time at all supply terminals Limits for individual harmonics included in Table and Table in this standard shall apply for 100 % of the time at all supply terminals In addition; “odd harmonics, not multiple of 3”, above the harmonic order of 25 shall not exceed % as 10 mean values; “odd harmonics, multiple of 3”, above the harmonic order of 21, shall not exceed 0,5 % as 10 mean values “Even harmonics” above the harmonic order of 24 shall not exceed 0,5 % 6.2.5 The Total Harmonic Distortion (THD) shall not exceed % as 10 mean values for 100 % of the time at all supply terminals The individual harmonics shall not exceed the limits given in the following table as 10 mean values 100 % of the time at all supply terminals Odd harmonics Not multiples of Even harmonics Multiples of Harmonic order h Uh [%] Harmonic order h Uh [%] Harmonic order h Uh [%] 7, 11 13, 17 19, 23 25 >25 3.0 2.5 2.0 1.5 1.0 0.5 15, 21 > 21 3.0 1.5 0.5 0.3 >6 1.5 1.0 0.5 0.3 –5– BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) Contents 1 Scope and object 6 1.1 Scope 6 1.2 Object 6 2 Normative references 7 3 Terms and definitions 7 4 Low-voltage supply characteristics 12 4.1 General 12 4.2 Continuous phenomena 13 4.3 Voltage events 16 5 Medium-voltage supply characteristics 18 5.1 General 18 5.2 Continuous phenomena 19 5.3 Voltage events 22 6 High-voltage supply characteristics 24 6.1 General 24 6.2 Continuous phenomena 25 6.3 Voltage events 27 Annex A (informative) Special nature of electricity 30 Annex B (informative) Indicative values for voltage events and single rapid voltage changes 32 B.1 Long interruptions of the supply voltage 32 B.2 Short interruptions of the supply voltage 32 B.3 Voltage dips and swells 32 B.4 Swells (temporary power frequency overvoltages) between live conductors and earth 34 B.5 Magnitude of rapid voltage changes 34 Bibliography 35 Figures Figure ― Voltage levels of signal frequencies in percent of Un used in public LV networks 15 Figure ― Voltage levels of signal frequencies in percent of Uc used in public MV networks 22 Tables Table ― Values of individual harmonic voltages at the supply terminals for orders up to 25 given in percent of the fundamental voltage U1 15 Table ― Classification of dips according to residual voltage and duration 17 Table ― Classification of swells according to maximum voltage and duration 18 Table ― Values of individual harmonic voltages at the supply terminals for orders up to 25 given in percent of the fundamental voltage U1 21 Table ― Classification of dips according to residual voltage and duration 23 Table ― Classification of swells according to maximum voltage and duration 24 Table ― Indicative values of individual harmonic voltages at the supply terminals for orders up to 25 given in percent of the fundamental voltage U1 26 Table ― Classification of dips according to residual voltage and duration 28 Table ― Classification of swells according to maximum voltage and duration 28 BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) –6– Scope and object 1.1 Scope This European Standard defines, describes and specifies the main characteristics of the voltage at a network user's supply terminals in public low voltage, medium and high voltage AC electricity networks under normal operating conditions This standard describes the limits or values within which the voltage characteristics can be expected to remain at any supply terminal in public European electricity networks and does not describe the average situation usually experienced by an individual network user NOTE For the definitions of low, medium and high voltage see (Definitions) This European Standard does not apply under abnormal operating conditions, including the following: a) a temporary supply arrangement to keep network users supplied during conditions arising as a result of a fault, maintenance and construction work, or to minimize the extent and duration of a loss of supply; b) in the case of non-compliance of a network user's installation or equipment with the relevant standards or with the technical requirements for connection, established either by the public authorities or the network operator, including the limits for the emission of conducted disturbances; NOTE A network user’s installation may include load and generation c) in exceptional situations, in particular, 1) exceptional weather conditions and other natural disasters; 2) third party interference; 3) acts by public authorities; 4) industrial actions (subject to legal requirements); 5) force majeure; 6) power shortages resulting from external events The voltage characteristics given in this standard are not intended to be used as electromagnetic compatibility (EMC) levels or user emission limits for conducted disturbances in public electricity networks The voltage characteristics given in this standard are not intended to be used to specify requirements in equipment product standards and in installation standards NOTE The performance of equipment might be impaired if it is subjected to supply conditions which are not specified in the equipment product standard This standard may be superseded in total or in part by the terms of a contract between the individual network user and the network operator NOTE The sharing of complaint management and problem mitigation costs between the involved parties is outside the scope of EN 50160 Measurement methods to be applied in this standard are described in EN 61000-4-30 1.2 Object The object of this European Standard is to define, describe and specify the characteristics of the supply voltage concerning: a) frequency; b) magnitude; c) waveform; d) symmetry of the line voltages –7– BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) These characteristics are subject to variations during the normal operation of a supply system due to changes of load, disturbances generated by certain equipment and the occurrence of faults which are mainly caused by external events The characteristics vary in a manner which is random in time, with reference to any specific supply terminal, and random in location, with reference to any given instant of time Because of these variations, the values given in this standard for the characteristics can be expected to be exceeded on a small number of occasions Some of the phenomena affecting the voltage are particularly unpredictable, which make it very difficult to give useful definite values for the corresponding characteristics The values given in this standard for the voltage characteristics associated with such phenomena, e.g voltage dips and voltage interruptions, shall be interpreted accordingly Normative references The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies EN 60664-1 2007 Insulation coordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests (IEC 60664-1:2007) EN 61000-3-3 2008 Electromagnetic compatibility (EMC) – Part 3-3: Limits - Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current ≤ 16 A per phase and not subject to conditional connection (IEC 61000-3-3:2008) EN 61000-4-30 2009 Electromagnetic compatibility (EMC) – Part 4-30: Testing and measurement techniques – Power quality measurement methods (IEC 61000-4-30:2008) IEC 60364-5-53 + A1 2001 2002 Electrical installations of buildings – Part 5-53: Selection and erection of electrical equipment – Isolation, switching and control IEC/TR 61000-2-8 2002 Electromagnetic compatibility (EMC) – Part 2-8: Environment – Voltage dips and short interruptions on public electric power supply systems with statistical measurement results IEC/TR 61000-3-7 2008 Electromagnetic compatibility (EMC) – Part 3-7: Assessment of emission limits for fluctuating loads in MV and HV power systems Terms and definitions For the purposes of this document, the following terms and definitions apply 3.1 conducted disturbance electromagnetic phenomenon propagated along the line conductors of a supply network NOTE In some cases an electromagnetic phenomenon is propagated across transformer windings and hence between networks of different voltage levels These disturbances may degrade the performance of a device, equipment or system or they may cause damage 3.2 declared supply voltage Uc supply voltage Uc agreed by the network operator and the network user NOTE Generally declared supply voltage Uc is the nominal voltage Un but it may be different according to the agreement between the network operator and the network user BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) –8– 3.3 flicker impression of unsteadiness of visual sensation induced by a light stimulus whose luminance or spectral distribution fluctuates with time [IEV 161-08-13] NOTE Voltage fluctuation cause changes of the luminance of lamps which can create the visual phenomenon called flicker Above a certain threshold flicker becomes annoying The annoyance grows very rapidly with the amplitude of the fluctuation At certain repetition rates even very small amplitudes can be annoying 3.4 flicker severity intensity of flicker annoyance evaluated by the following quantities: – short term severity (Pst) measured over a period of ten minutes; – long term severity (Plt) calculated from a sequence of twelve Pst-values over a two hour interval, according to the following expression: Plt = 12 ∑ i =1 Psti 12 3.5 frequency of the supply voltage repetition rate of the fundamental wave of the supply voltage measured over a given interval of time 3.6 harmonic voltage sinusoidal voltage with a frequency equal to an integer multiple of the fundamental frequency of the supply voltage NOTE – Application: Harmonic voltages can be evaluated: individually by their relative amplitude (uh) which is the harmonic voltage related to the fundamental voltage u1, where h is the order of the harmonic; – globally, for example by the total harmonic distortion factor THD, calculated using the following expression: THD = 40 ∑ (u ) h=2 h NOTE Harmonics of the supply voltage are caused mainly by network users' non-linear loads connected to all voltage levels of the supply network Harmonic currents flowing through the network impedance give rise to harmonic voltages Harmonic currents and network impedances and thus the harmonic voltages at the supply terminals vary in time 3.7 high voltage HV voltage whose nominal r.m.s value is 36 kV < Un ≤ 150 kV NOTE Because of existing network structures, in some countries the boundary between MV and HV can be different 3.8 interharmonic voltage sinusoidal voltage with a frequency not equal to an integer multiple of the fundamental NOTE Interharmonic voltages at closely adjacent frequencies can appear at the same time forming a wide band spectrum BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) − – 24 – time aggregation applies; time aggregation consists in defining an equivalent event in the case of multiple successive events; the method used for aggregation of multiple events can be set according to the final use of data; some reference rules are given in IEC/TR 61000-2-8 5.3.2.6 Voltage swells classification If statistics are collected, voltage swells shall be classified according to the following table The figures to 10) be put in the cells refer to the number of equivalent events (see 5.3.2.5) NOTE For existing measurement equipment and/or monitoring systems, Table is to be taken as a recommendation Table ― Classification of swells according to maximum voltage and duration Swell voltage u % u ≥ 120 120 > u > 110 Duration t ms 500 < t ≤ 000 CELL S2 CELL T2 10 ≤ t ≤ 500 CELL S1 CELL T1 000 < t ≤ 60 000 CELL S3 CELL T3 NOTE Faults in the public distribution network, or in a network user's installation, give rise to temporary power frequency overvoltages between live conductors and earth; such overvoltages disappear when the fault is cleared Some indicative values are given in Annex B 5.3.3 Transient overvoltages Transient overvoltages in MV supply systems are caused by switching or, directly or by induction, by lightning Switching overvoltages generally are lower in amplitude than lightning overvoltages, but they can have a shorter rise time and/or longer duration NOTE The network users' insulation coordination scheme should be compatible with that adopted by the network operator High-voltage supply characteristics 6.1 General Network users with demands exceeding the capacity of the medium voltage network are generally supplied at nominal voltages above 36 kV This clause applies to such electricity supplies at nominal voltages up to and including 150 kV NOTE Network users may also be supplied at this voltage level to satisfy special requirements or to mitigate conducted disturbances emitted by their equipment This clause describes the voltage characteristics of electricity supplied by public high voltage networks In the following, a distinction is made between: – continuous phenomena, i.e deviations from the nominal value that occur continuously over time Such phenomena occur mainly due to load pattern, changes of load or nonlinear loads; – voltage events, i.e sudden and significant deviations from normal or desired wave shape Voltage events are typically due to unpredictable events (e.g faults) or to external causes (e.g weather conditions, third party actions) For some continuous phenomena limits are specified given at present (see Annex B) 11) ; for voltage events, only indicative values can be The magnitude of voltage is given by the declared voltage Uc 10) This table reflects the polyphase network performance Further information is needed to consider events affecting an individual single phase voltage in three-phase systems To calculate the latter, a different evaluation method has to be applied 11) For some specific parameters, in individual countries stricter limits can be found BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) – 25 – 6.2 Continuous phenomena 6.2.1 Power frequency The nominal frequency of the supply voltage shall be 50 Hz Under normal operating conditions the mean value of the fundamental frequency measured over 10 s shall be within a range of: – for systems with synchronous connection to an interconnected system: 50 Hz ± % (i.e 49,5 Hz 50,5 Hz) 50 Hz + % / - % (i.e 47 Hz 52 Hz) during 99,5 % of a year; during 100 % of the time, – for systems with no synchronous connection to an interconnected system (e.g supply systems on certain islands): 50 Hz ± % 50 Hz ± 15 % 6.2.2 (i.e 49 Hz 51 Hz) (i.e 42,5 Hz 57,5 Hz) during 95 % of a week; during 100 % of the time Supply voltage variations As the number of network users supplied directly from HV networks is limited and normally subject to individual contracts, no limits for supply voltage variations are given in this standard Existing product standards for HV equipment should be considered 6.2.3 Rapid voltage changes 6.2.3.1 Single rapid voltage change Rapid voltage changes of the supply voltage are mainly caused either by load changes in the network users' installations, by switching in the system or by faults If the voltage during a change crosses the voltage dip and/or the voltage swell threshold, the event is classified as a voltage dip and/or swell rather than a rapid voltage change 6.2.3.2 Flicker severity Under normal operating conditions, during each period of one week the long term flicker severity Plt caused by voltage fluctuation should be less or equal to for 95 % of the time NOTE This value was chosen on the assumption that the transfer coefficient between HV and LV system is In practice the transfer coefficients between HV levels and LV levels can be less than In the case of complaints, the HV limit and appropriate HV, MV and LV mitigation measures shall be chosen in such a way that at LV the Plt values not exceed NOTE Guidance can be found in IEC/TR 61000-3-7 NOTE In the case of related needs, an appropriate transition time has to be agreed upon with the relevant national authorities 6.2.4 Supply voltage unbalance Under normal operating conditions, during each period of one week, 95 % of the 10 mean r.m.s values of the negative phase sequence component of the supply voltage should be within the range % to % of the positive phase sequence component NOTE In some areas, unbalances up to about % at three-phase supply terminals occur NOTE In this European Standard only values for the negative sequence component are given because this component is the relevant one for the possible interference of appliances connected to the system BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) – 26 – NOTE The values given for supply voltage unbalance are only indicative; limits will be set on the basis of data made available by measurement campaigns 6.2.5 Harmonic voltage Under normal operating conditions, during each period of one week, 95 % of 10 mean r.m.s values of each individual harmonic voltage should be less than or equal to the indicative values given in Table Resonances may cause higher voltages for an individual harmonic NOTE Limits for each individual harmonic voltage are under consideration NOTE The limit for the THD of the supply voltage (including all harmonics up to the order 40) is under consideration NOTE The limitation to order 40 is conventional For measurement accuracy an appropriate type of voltage transformer should be used, particularly for the measurement of higher order harmonics; further information is given in EN 61000-4-30:2009, A.2 Table ― Indicative values of individual harmonic voltages at the supply terminals for orders up to 25 given in percent of the fundamental voltage u1 Odd harmonics Not multiples of Multiples of Order Relative Order Relative h amplitude h amplitude uh uh a 5% 3% 4% 1,3 % 11 3% 15 0,5 % 13 2,5 % 21 0,5 % 17 u.c 19 u.c 23 u.c 25 u.c Even harmonics Order h 24 Relative amplitude uh 1,9 % 1% 0,5 % NOTE No values are considered for harmonics of order higher than 25, as they are usually small, but largely unpredictable due to resonance effects NOTE Harmonics not multiple of of order higher than 13 are under consideration NOTE In some countries, limits for harmonics are already in place a Depending on the network design, the value for the third harmonic order can be substantially lower In the case of complaints, limits for harmonics in HV networks should be chosen on the base of MV network limits, suitably modified by a quantity (D) as resulting from the following formula: HV-LIMIT = MV-LIMIT - D D should be agreed between the HV network operator and the connected network user, if necessary in order to maintain harmonic levels of the connected network below the relevant limits NOTE D can be chosen differently, depending on the use (harmonic transmission from HV public networks to HV public networks, from HV public networks to MV public networks or from HV public networks to network users) 6.2.6 Interharmonic voltage Due to the low resonance frequency of the HV network, no values are given for interharmonic voltage NOTE Due to the very low resonant frequency in HV grids (200 Hz … 500 Hz), caused by high capacitances and inductances, interharmonics are of minor relevance in HV networks 6.2.7 Mains signalling voltage Due to the low resonance frequency of the HV network, no values are given for mains signalling voltages – 27 – BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) 6.3 Voltage events 6.3.1 Interruptions of the supply voltage Interruptions are, by their nature, very unpredictable and variable from place to place and from time to time For the time being, it is not possible to give fully representative statistical results of measurements of interruption frequency covering the whole of European networks A reference for actual values recorded in the European networks concerning interruptions is given in Annex B 6.3.2 Supply voltage dips/swells 6.3.2.1 General Voltage dips are typically originated by faults occurring in the public network or in the network users’ installations Voltage swells are typically caused by switching operations and load disconnections Both phenomena are unpredictable and largely random The annual frequency varies greatly depending on the type of supply system and on the point of observation Moreover, the distribution over the year can be very irregular 6.3.2.2 Voltage dip/swell measurement and detection If statistics are collected, voltage dips/swells shall be measured and detected according to EN 61000-430, using as reference the declared supply voltage The voltage dips/swells characteristics of interest for 12) this standard are residual voltage (maximum r.m.s voltage for swells) and duration Typically, on HV networks, the line to line voltages shall be considered Conventionally, the dip threshold is equal to 90 % of the reference voltage; the threshold for swells is equal to the 110 % of the reference voltage The hysteresis is typically %; reference rules for hysteresis are given in EN 61000-4-30:2009, 5.4.2.1 NOTE For polyphase measurements, it is recommended that the number of phases affected by each event is detected and stored 6.3.2.3 Voltage dips evaluation Evaluation of voltage dips shall be in accordance with EN 61000-4-30 The method of analyzing the voltage dips (post treatment) depends on the purpose of the evaluation Typically, on HV networks: − polyphase aggregation is applied; polyphase aggregation consists of defining an equivalent event characterized by a single duration and a single residual voltage; − time aggregation applies; time aggregation consists of defining an equivalent event in the case of multiple successive events; the method used for aggregation of multiple events can be set according to the final use of data; some reference rules are given in IEC/TR 61000-2-8 6.3.2.4 Voltage dips classification If statistics are collected, voltage dips shall be classified according to the following table The figures to be 13) put in the cells refer to the number of equivalent events (see 6.3.2.3) 12) In this standard, values for HV are expressed in percentage terms of the reference voltage This table reflects the polyphase network performance Further information is needed to consider events affecting an individual single-phase voltage in three-phase systems To calculate the latter, a different evaluation method has to be applied 13) BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) – 28 – NOTE For existing measurement equipment and/or monitoring systems, Table should be taken as a recommendation Table ― Classification of dips according to residual voltage and duration Residual voltage u % 90 > u ≥ 80 80 > u ≥ 70 70 > u ≥ 40 40 > u ≥ 5>u Duration t ms 10 ≤ t ≤ 200 CELL A1 CELL B1 CELL C1 CELL D1 CELL X1 200 < t ≤ 500 500 < t ≤ 000 000 < t ≤ 000 000 < t ≤ 60 000 CELL A2 CELL A3 CELL A4 CELL A5 CELL B2 CELL B3 CELL B4 CELL B5 CELL C2 CELL C3 CELL C4 CELL C5 CELL D2 CELL D3 CELL D4 CELL D5 CELL X2 CELL X3 CELL X4 CELL X5 Voltage dips are, by their nature, very unpredictable and variable from place to place and from time to time For the time being, it is not possible to give fully representative statistical results of measurements of voltage dip frequency covering the whole of European networks It should be noted that, due to the measurement method adopted, measurement uncertainty affecting the results has to be taken into account; this is particularly relevant for shorter events Measurement uncertainty is addressed in EN 61000-4-30 Generally, the duration of a voltage dip depends on the protection strategy adopted on the network, which may differ from network to network, depending on network structure and on neutral earthing As a consequence, typical durations not necessarily match the boundaries of the columns in Table 6.3.2.5 Voltage swells evaluation Evaluation of voltage swells shall be in accordance with EN 61000-4-30 Post treatment aimed at swells evaluation depends on the intended purpose Typically, on HV networks: − polyphase aggregation shall be applied; polyphase aggregation consists of defining an equivalent event characterized by a single duration and a single maximum r.m.s voltage; − time aggregation applies; time aggregation consists of defining an equivalent event in the case of multiple successive events The method used for the aggregation of multiple events can be set according to the final use of data; some reference rules are given in IEC/TR 61000-2-8 6.3.2.6 Voltage swells classification If statistics are collected, voltage swells shall be classified according to the following table The figures to 14) be put in the cells refer to the number of equivalent events (see 6.3.2.5) NOTE For existing measurement equipment and/or monitoring systems, Table is to be taken as a recommendation Table ― Classification of swells according to maximum voltage and duration Swell voltage u % u ≥ 120 120 > u > 110 14) 10 ≤ t ≤ 500 CELL S1 CELL T1 Duration t ms 500 < t ≤ 000 CELL S2 CELL T2 000 < t ≤ 60 000 CELL S3 CELL T3 This table reflects the polyphase network performance Further information is needed to consider events affecting an individual single phase voltage in three-phase systems To calculate the latter, a different evaluation method has to be applied – 29 – BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) A voltage swell generally occurs because of switching operations and load disconnections Faults in the public electricity network or in a network user's installation give rise to temporary power frequency overvoltages between live conductors and earth; such overvoltages disappear when the fault is cleared Generally, temporary power frequency overvoltages in HV not cause any concern to network users as normally any load is connected via transformers with different types of neutral earthing 6.3.3 Transient overvoltages Transient overvoltages in HV supply systems are caused by switching or, directly or by induction, by lightning Switching overvoltages generally are lower in amplitude than lightning overvoltages, but they may have a shorter rise time and/or longer duration NOTE The network users' insulation coordination scheme must be compatible with that adopted by the network operator BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) – 30 – Annex A (informative) Special nature of electricity Electricity is a form of energy which is particularly versatile and adaptable It is utilized by being converted into several other forms of energy: heat, light, mechanical energy and the many electromagnetic, electronic, acoustic and visual forms which are the bases of modern telecommunications, information technology and entertainment Electricity as delivered to the network users has several characteristics which are variable and which affect its usefulness to the network user This standard describes characteristics of electricity in terms of the alternating voltage With respect to the use of electricity it is desirable that the supply voltage would alternate at a constant frequency, with a perfect sine wave and a constant magnitude In practice, there are many factors which cause deviations from this In contrast to normal products, the application of electricity is one of the main factors which influence the variation of "characteristics" The flow of energy to network users’ appliances gives rise to electric currents which are more or less proportional to the magnitudes of the network users' demands As these currents flow through the conductors of the supply system, they give rise to voltage drops The magnitude of the supply voltage for an individual network user at any instant is a function of the cumulative voltage drops on all the components of the system through which that network user is supplied, and is determined both by the individual demand and by the simultaneous demands of other network users Since each network user's demand is constantly varying, and there is a further variation in the degree of coincidence between the demands of several network users, the supply voltage is also variable For this reason, this standard deals with the voltage characteristics in statistical or probabilistic terms It is in the economic interests of the network user that the standard of supply should relate to normally expected conditions rather than to rare contingencies, such as an unusual degree of coincidence between the demands of several appliances or several network users Electricity reaches the network user through a system of generation, transmission and distribution equipment Each component of the system is subject to damage or failure due to the electrical, mechanical and chemical stresses which arise from several causes, including extremes of weather conditions, the ordinary processes of wear and deterioration with age, and interference by human activities, birds, animals etc Such damage can affect or even interrupt the supply to one or to many network users To keep the frequency constant requires the amount of running generation capacity to be matched to the simultaneous combined demand instant by instant Because both the generation capacity and the demand are liable to change in discrete amounts, especially in the event of faults on the generation, transmission or distribution networks, there is always a risk of a mismatch, resulting in an increase or decrease of the frequency This risk is reduced, however, by connecting many systems into one large interconnected system, the generation capacity of which is very great relative to the changes which are likely to occur There are several other characteristics that may have a disturbing or damaging effect on network users' equipment, or even on the network users Some of these disturbing characteristics arise from unavoidable transient events in the supply system itself, resulting from faults or switching, or caused by atmospheric phenomena (lightning) Others, however, are the result of various uses of electricity which directly alter the waveform of the voltage, impose a particular pattern on its magnitude, or superimpose signalling voltages Coincidentally with the modern proliferation of equipment which has these effects, there is also an increase in the equipment which is susceptible to the disturbances This European Standard defines where possible the variations of the characteristics normally to be expected In other cases, the standard provides the best possible indication of what, in quantitative terms, is to be expected Since there is a considerable diversity in the structures of the electricity networks in different areas, arising from differences in load density, population dispersion, local topography etc many network users will experience considerably smaller variations of the voltage characteristics than the values given in this standard – 31 – BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) It is a particular feature of electricity that, with respect to some of its characteristics, its quality is affected by the user rather than by the producer or network operator In these cases the network user is an essential partner of the network operator, in the effort to maintain the quality of electricity It should be noted that this question is directly addressed by other standards, already published or in preparation Emission standards govern the levels of electromagnetic disturbances which network users' equipment may be allowed to generate Immunity standards set disturbance levels which the equipment should be capable of tolerating without undue damage or loss of function A third set of standards, for electromagnetic compatibility levels, has the function of enabling coordination and coherence of the emission and immunity standards, with the overall objective of achieving electromagnetic compatibility Although this standard has obvious links with compatibility levels, it is important to note that it relates to voltage characteristics of electricity It does not specify compatibility levels It should be especially noted that the performance of equipment might be impaired, if the equipment is subjected to supply conditions more severe than specified in their product standard BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) – 32 – Annex B (informative) Indicative values for voltage events and single rapid voltage changes B.1 General This annex is aimed at providing the reader with some information about indicative values currently available at a European level for some of the events defined and described in the standard Some information is also given about the way of using values given in the standard, and about the way of collecting further measurement data, in order to allow for comparisons between different systems and to have homogeneous data at a European level As many monitoring systems are in place in some countries, further information is available at a national level At a national level, more precise figures can be found; furthermore, some regulations may exist B.2 Long interruptions of the supply voltage Under normal operating conditions, the annual frequency of voltage interruptions longer than three minutes varies substantially between areas This is due to, among other things, differences in system layout (e.g cable systems versus overhead line systems), environmental and climatic conditions To obtain information about what can be expected, the local network operator should be consulted In different countries, national interruption statistics exist giving indicative values The CEER Benchmarking Reports on Quality of Supply give some statistics for a certain number of European countries and a review of applicable regulatory standards for long interruptions Principles for aggregating events should be considered when comparing statistical values for long interruptions B.3 Short interruptions of the supply voltage The duration of most of the short interruptions may be less than some seconds Indicative values, intended to provide readers with information on the range of magnitude which can be expected, can be found in IEC/TR 61000-2-8 (UNIPEDE statistics) When comparing statistical values for short interruptions, the following issues should be considered: − principles for aggregating events; − the possible exclusion of Very Short Interruptions (VSI) or transitory interruptions In some documents, short interruptions are considered to have durations not exceeding Sometimes control schemes are applied which need operating times of up to in order to avoid long voltage interruptions B.4 Voltage dips and swells NOTE The swells treated in this clause are between live conductors B.4.1 Use of Tables 2, and As detailed in product standards, voltage dips and swells, according to their severity, can impair the operation of equipment Classes and are defined in EN 61000-4-11 and in EN 61000-4-34 – 33 – BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) Although the cells of the Tables 2, and are not exactly coincident with the test levels table, it can be expected that equipment tested according to the relevant product standard should cope with voltage dips as indicated in the cells: − A1, B1, A2, B2 for class 2; − A1, B1, C1, A2, B2, A3, A4 for class Compatibility levels for industrial power networks are defined in EN 61000-2-4 Tables 2, and data can help the user to identify the expected performance of the network; in order to assess the probable behaviour of the equipment connected, its immunity has to be considered in accordance with such data The specification of immunity requirements (including tests specifications and performance criteria) is the responsibility of the product committees Generic EMC standards (EN 61000-6-1 and EN 61000-6-2) apply to products operating in a particular environment for which no dedicated product family /product EMC standards exist Nevertheless, and for information only, the performance criteria are reported below B.4.2 Performance criteria Performance criterion A: The apparatus shall continue to operate as intended during and after the test No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended The performance level may be replaced by a permissible loss of performance If the minimum performance level or the permissible performance loss is not specified by the manufacturer, either of these may be derived from the product description and documentation and what the user may reasonably expect from the apparatus if used as intended Performance criterion B: The apparatus shall continue to operate as intended after the test No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended The performance level may be replaced by a permissible loss of performance During the test, degradation of performance is however allowed No change of actual operating state or stored data is allowed If the minimum performance level or the permissible performance loss is not specified by the manufacturer, either of these may be derived from the product description and documentation and what the user may reasonably expect from the apparatus if used as intended Performance criterion C: Temporary loss of function is allowed, provided the function is self-recoverable or can be restored by the operation of the controls B.4.3 Currently available indicative values The vast majority of voltage dips has a duration less than s and a residual voltage above 40 % However, voltage dips with a smaller residual voltage and longer duration can occur infrequently In some areas, voltage dips with a residual voltage between 90 % and 85 % of Uc can occur very frequently as a result of the switching of loads in network users' installations Indicative values, which are intended to provide readers with information on the range of magnitude which can be expected, can be found in IEC/TR 61000-2-8 (UNIPEDE statistics) B.4.4 Methods for reporting measurement data The data relevant to voltage dips/swells should be presented according to the following guidelines The data collected should be homogeneous in terms of voltage levels Within the same voltage level, distinction should be made between networks with prevailing underground cables or aerial lines To cover all seasonal effects, the observation time should be at least one year The data should be collected in tables like and 6; the following data shall be reported: − average dips/swells incidence per bus per year; BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) – 34 – − 90 % or 95 % dips/swells incidence per bus per year; − maximum dips/swells incidence per bus per year B.5 Swells (temporary power frequency overvoltages) between live conductors and earth For low voltage systems, under certain circumstances, a fault occurring upstream of a transformer may produce temporary overvoltages on the LV side for the time during which the fault current flows Such overvoltages will generally not exceed 1,5 kV r.m.s For medium voltage systems, the expected value of such an overvoltage depends on the type of earthing of the system In systems with a solidly or impedance earthed neutral the overvoltage shall generally not exceed 1,7 Uc In isolated or resonant earthed systems the overvoltage shall generally not exceed 2,0 Uc The type of earthing will be indicated by the network operator Indicative values about overvoltages on distribution networks can be found in IEC/TR 61000-2-14 More information for LV systems can be found in IEC/TR 62066 B.6 Magnitude of rapid voltage changes For low voltage, under normal operating conditions, rapid voltage changes generally not exceed % Un, but changes of up to 10 % Un with a short duration of the sustained level might occur some times per day under some circumstances For medium voltage, under normal operating conditions, rapid voltage changes generally not exceed % Uc, but changes of up to % Uc with a short duration of the sustained level might occur some times per day under some circumstances These indicative values apply to the phenomenon of rapid voltage changes as defined in 3.14 At a national level, additional values may be available, but in some cases they are referred to another definition of rapid voltage change (∆Umax, see EN 61000-3-3:2008, 3.3 and Figure 2) In general, the frequency and magnitude of rapid voltage changes are related to the load variation by the users and to the short-circuit power level of the network – 35 – BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) Bibliography EN 50065-1 2001 Signalling on low-voltage electrical installations in the frequency range kHz to 148,5 kHz Part 1: General requirements, frequency bands and electromagnetic disturbances CLC/TR 50422 2003 Guide for the application of the European Standard EN 50160 EN 61000-2-2 2002 Electromagnetic compatibility Part 2-2: Environment - Compatibility levels for low-frequency conducted disturbances and signalling in public low-voltage power supply systems (IEC 61000-2-2:2002) EN 61000-2-4 2002 Electromagnetic compatibility Part 2-4: Environment - Compatibility levels in industrial plants for low-frequency conducted disturbances (IEC 61000-2-4:2002) EN 61000-4-11 2004 Electromagnetic compatibility (EMC) Part 4-11: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests (IEC 61000-4-11:2004) EN 61000-4-15 + A1 1998 2003 Electromagnetic compatibility (EMC) Part 4-15 Testing and measurement techniques - Flickermeter Functional and design specifications (IEC 61000-4-15:1997 + A1:2003) EN 61000-4-34 2005 Electromagnetic compatibility (EMC) Part 4-34: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests for equipment with input current more than 16 A per phase (IEC 61000-4-34:2005) EN 61000-6-1 2007 Electromagnetic compatibility (EMC) Part 6-1: Generic standards - Immunity for residential, commercial and light-industrial environments (IEC 61000-6-1:2005) EN 61000-6-2 2005 Electromagnetic compatibility (EMC) Part 6-2: Generic standards - Immunity for industrial environments (IEC 61000-6-2:2005) IEC 60038 + A1 + A2 1983 1994 1997 IEC standard voltages IEC 60050-161 1990 International Electrotechnical Vocabulary Chapter 161: Electromagnetic compatibility 2001 2003 Electrical installations of buildings Part 4-44: Protection for safety - Protection against voltage disturbances and electromagnetic disturbances IEC/TR 61000-2-14 2006 Electromagnetic compatibility (EMC) Part 2-14: Environment - Overvoltages on public electricity distribution networks IEC/TR 62066 2002 Surge overvoltages and surge protection in low voltage a.c power systems - General basic information IEC 60364-4-44 + A1 15) 15) Superseded by IEC 60364-4-44:2007, Low-voltage electrical installations − Part 4-44: Protection for safety − Protection against voltage disturbances and electromagnetic disturbances BS EN 50160:2010+A1:2015 EN 50160:2010+A1:2015 (E) UNIPEDE 91 en 50.02 CEER – 36 – Voltage dips and short interruptions in public medium voltage electricity supply systems 2001 2003 2005 Benchmarking Report on 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