EN50588-1-2017设备最高电压不超过36kV的50Hz中等功率变压器.第1部分通用要求.p

EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 50588-1 September 2017 ICS 29.180 Supersedes EN 50588-1:2015 English Version Medium power transformers 50 Hz, with highest voltage for equipment not exceeding 36 kV - Part 1: General requirements Transformateurs 50 Hz de moyenne puissance, de tension la plus leve pour le matriel ne dpassant pas 36 kV - Partie 1: Exigences gnrales Mittelleistungstransformatoren 50 Hz, mit einer hchsten Spannung fr Betriebsmittel nicht ber 36 kV - Teil 1: Allgemeine Anforderungen This European Standard was approved by CENELEC on 2017-07-03. 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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization  Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 50588-1:2017 E EN 50588-1:2017 (E) 2 Contents Page European foreword . 3 1 Scope 4 2 Normative references . 5 3 Terms and definitions 6 4 Environmental classes . 8 5 Electrical characteristics . 8 5.1 Highest voltages for equipment for winding with Um 1,1 kV 8 5.2 Rated voltage for winding with Um 1,1 kV 8 5.3 Tapping 9 5.4 Connection designations for three phase transformers . 9 6 Load loss, no load loss, PEI, sound power level, short-circuit impedance . 9 6.1 General 9 6.2 Transformers with rated power Sr 3 150 kVA 10 6.3 Transformers with rated power 3 150 kVA 1,1 kV Insulation levels and dielectric test shall be in accordance with the requirements of EN 60076-3 and for dry type transformers in accordance with EN 60076-11. The values of the highest voltage Um for equipment are: 3,6 kV 7,2 kV 12 kV 17,5 kV 24 kV 36 kV NOTE National practices may require the use of highest voltages for equipment up to (but not including) 52 kV, when the rated voltage is less than 36 kV (such as Um = 38,5 kV or Um = 40,5 kV). 5.2 Rated voltage for winding with Um 1,1 kV For Um 1,1 kV, the preferred rated voltage value shall be chosen in the hereunder list: 400 V 410 V 415 V 420 V 433 V 690 V This document may be applied either as a whole or in part, to transformers with rated low voltages below 400 V and above 690 V. The values for short duration power frequency withstand and/or for the lightning impulse withstand test between windings and earth need to be stated by the purchaser. Typical values are respectively 10 kV and 30 kV. EN 50588-1:2017 (E) 9 5.3 Tapping Taps can be provided with DETC or OLTC devices: DETC: De-energized tap changer; OLTC: On load tap changer. For DETC, the preferred tapping ranges are 2,5 % with 3 tap positions and 2 x 2,5 % with 5 tap positions. On special request 4 x 2,5 % with 9 tap positions can be provided. Tapping ranges greater than 10 % or with more than 9 tap positions are unusual and subject to specific agreement. For transformer equipped with OLTC, the tapping range shall be smaller than 15 % with a maximum of 17 tap positions. Tapping ranges greater than 15 % or with more than 17 tap positions are unusual and subject to specific agreement. Tapping ranges outside the above definitions have to be specified by agreement between manufacturer and purchaser. 5.4 Connection designations for three phase transformers Preferred connection designations, following IEV 421-10-09, shall be in accordance with the provisions of Table 1. Table 1 Connections Sr 100 kVA 100 kVA 3 150 kVA and Sr 1,1 kV The maximum levels of losses indicated in Table 2, Table 3 and Table 4 can be increased by 20 % for no load loss and by 15 % for load loss and short circuit impedance unless otherwise specified should be increased by adding a value of 0,5 %. 6.2.4 Load loss and no load loss in case of dual voltage The level of losses given in 6.2.2 shall be weighted by the correction factors given in Table 6 below, in order to take care of variations related to dual voltage windings. Table 6 Correction of load loss and no load loss in case of dual voltage Ref Dual voltage Correction of load loss and no load loss A One winding In case of transformers with one high-voltage winding and two voltages available from tapped low-voltage winding, losses shall be calculated based on the higher low-voltage and shall comply with the levels indicated in Table 2, Table 3 and Table 4. The maximum available power on the lower low-voltage on such transformers shall be no more than 0,85 times its rated power. In case of transformers with one high-voltage winding with two voltages available from a tap, the maximum available power on the lower high-voltage on such transformer shall be limited to 0,85 of its nominal rated power. In the case where the full rated power is available regardless of the combination of voltages, the levels of losses indicated in Table 2, Table 3 and Table 4 can be increased by 15 % for no load loss and by 10 % for load loss. Such levels of losses shall refer to the highest voltage. B Both windings The maximum allowable losses indicated in Table 2, Table 3 and Table 4 can be increased by 20 % for no load losses and by 20 % for load losses for transformers with dual voltage on both windings if the rated power is the same regardless of the combination of voltages. The level of losses shall refer to the highest voltages of both windings. This remains valid even if further voltage combinations are available. EN 50588-1:2017 (E) 14 For transformers having dual voltage on both windings for which both voltages on one winding are fully rated in combination with one of the voltages on the other winding, the levels of losses shall be based on the highest power and the values indicated in Table 2, Table 3 and Table 4 can be increased by 15 % for no load losses and by 10 % for load losses. The level of losses shall refer to the highest voltages of both windings. This remains valid even if further voltage combinations are available. For transformer having insulation level according to Table 5 and having dual voltage according to Table 6 the loss level shall take into account both corrections. 6.2.5 Three winding transformers for PV applications Dual voltage correction factors given in Table 6, Ref A, apply also to transformers for photovoltaic applications, which have two low voltage windings that each have half the rated power of the high voltage winding. 6.3 Transformers with rated power 3 150 kVA 3 150 kVA. Table 7 Minimum Peak Efficiency Index (PEI) for Liquid immersed transformers RATED POWER (kVA) PEI (%) A AA 3 150 3 150 kVA. kPEI, the load factor at which PEI occurs for transformers with Sr 3 150 kVA. For dual voltage transformers, the maximum rated power at the lower voltage. EN 50588-1:2017 (E) 20 Conductor mass and the nature of the conductor. Core mass and the nature of the core material. For medium power pole mounted transformers, a visible display “For pole-mounted operation only”. In case correction factors apply on losses because of other insulation level or dual voltage as specified in subclauses 6.2.3 and 6.2.4, the loss class names to be written on the rating plate and in the technical documentation (e.g. A0, AA0, AAA0, Ak, Bk, Ck, ) shall remain the same, without mentioning the correction factors. In case of dual voltage transformers for which the full rated power is available regardless of the combination of voltages, the no load and load loss to be written on the rating plate and in the technical documentation shall refer to the highest voltage of the tapped winding. 9 Tests 9.1 Routine tests EN 60076-1 and EN 60076-11 apply unless otherwise stated in this standard. The test report of the transformers shall report the PEI value and the corresponding kPEI for transformers with Sr 3 150 kVA. For transformers with Sr 3 150 kVA the test report shall include the measured value of no load loss and load loss. 9.2 Type tests EN 60076-1 and EN 60076-11 apply unless otherwise stated in this standard. 9.3 Special tests EN 60076-1 and EN 60076-11 apply unless otherwise stated in this standard. 9.4 Special test for corrugated tank 9.4.1 General information For liquid immersed transformers with corrugated tank a special test to check the reliability of the tank along the life is described here after. 9.4.2 Temperature variation For the simulation of the seasonal and daily temperature variations, the average liquid temperature is assumed to vary between -25 C (minimum ambient temperature with disconnected transformer) and +88 C (the sum of maximum ambient temperature +40 C and maximum allowed average oil temperature rise: 0,8 x 60 K = 48 K). By agreement between manufacturer and purchaser the maximum temperature used for the endurance test shall be 40 C plus 0,8 times the liquid temperature rise determined by the temperature rise test as prescribed by EN 50464-4. 9.4.3 Sealing temperature When sealing the tank, the average liquid temperature shall be chosen between 15 C and 35 C and recorded. A manometer connected to the tank cover shall register the value zero. 9.4.4 Calculation of the volume variation From the temperature variations above, the liquid volume change from the relaxed stage at the sealing temperature shall be calculated using a volume expansion coefficient given by suppliers and generally equal to 7,5 10-4 (+/- 10 %) K-1 for mineral oil. EN 50588-1:2017 (E) 21 The following value may be taken for other liquids if no information is given by suppliers: Silicone 10 10-4 K-1 Natural ester 7,4 10-4 K-1 Synthetic ester 7,5 10-4 K-1 9.4.5 Test procedure 9.4.5.1 General These tests are considered as special tests. These tests shall be carried out on a tank which is considered as representative of a range of tanks by agreement between purchaser and supplier. 9.4.5.2 Measurement of pressure range The increase or decrease of the liquid volume as calculated in paragraph above shall be added to or extracted from the relaxed tank, and the corresponding overpressure (P+) and underpressure (P-) shall be registered by a manometer connected to the tank cover. The liquid temperature during the measurement shall be the same value as used for sealing 3 C as described in the paragraph above 9.4.5.3 Endurance test To simulate the volume expansion, the tank shall be subjected to 2 000 cycles with overpressure and underpressure. Each cycle comprises one overpressure and one underpressure. To achieve the overpressure and underpressure, the volume of liquid calculated in paragraph above shall be added to and extracted from the tank in the quantity calculated in paragraph above. The pressure P+ and P- shall be recorded during the test at intervals. The reading of the manometer with the tank relaxed shall be recorded before (P0) and after the test (P1) and the tank shall be topped up with liquid to reach the initial relaxing pressure P0. If requested for the test evaluation, the added volume shall be recorded. NOTE To avoid mechanical impulses, the test duration may not be too short. A minimum cycle duration of 120 s may be sufficient. A pause in the test procedure does not affect the test result. 9.4.5.4 Leakage test After the endurance test, the same tank shall be subjected to a 24 h static leakage test with an overpressure 1,2 times the maximum value recorded during the endurance test. 9.4.5.5 Evaluation of the tests After leakage test, the following events shall be observed: the tank shall not show leakages as observed by appropriate detecting means; no cracks shall occur in the tank; heavy and unexplained discrepancies on the pressure readings taken before, during and after the tests under measurement of pressure range and endurance test, have to be considered as possible indexes of abnormal events; by agreement between manufacturer and purchaser, a limit for the volume of liquid to be added at the end of the test may be specified for checking the permanent deformations of the tank. EN 50588-1:2017 (E) 22 9.5 Other technologies with level of no load loss AAA0 AAA0 classes (see Table 2 and Table 4) should be manufactured with material known or under development. To ensure reliability of these transformers, before to install on the network, manufacturers shall be able to prove their reliability at a long term by a short circuit withstand test and provide certificates of this test for similar transformers (see EN 60076-5 rules). The rules in EN 60076-5 regarding similarity between transformers and related to absorbed power, axial forces and winding stresses at short circuit shall be applied to determine the validity of the test. The procedure of test shall be as prescribed by EN 60076-1, EN 60076-3 and EN 60076-5, in particular, the following requirements: All the routine tests, including dielectric tests at 100 % of the prescribed test value (see EN 60076-3), shall be repeated. A lightning impulse test shall be performed at this stage. In order to consider the transformer as having passed the short-circuit test, the conditions indicated in EN 60076-1 and EN 60076-11 shall be fulfilled. In addition to EN 60076-5 criteria the value of measured no load loss before and after the short circuit test shall not deviate by more than 12 %. This measurement shall be done in the same laboratory. 10 Design requirements 10.1 Liquid immersed transformers 10.1.1 Type of liquid preservation system and degree of sealing The type of liquid preservation system and the degree of sealing shall be indicated in the enquiry and order. 10.1.2 Terminal markings Terminal markings shall be in accordance with IEC/TR 60616 unless otherwise specified. 10.1.3 Terminations The terminations to be used can be of the following types: a) open type bushings; b) plug-in type bushings; c) LV busbars; d) cable boxes. The requirements of the different types of terminations are described in the following standards: EN 50180, EN 50181, EN 50386 and EN 50387. 10.1.4 Distance between bushings 10.1.4.1 Distances between high-voltage liquid to air bushings The bushings clearance shall meet the requirements of EN 60076-3. 10.1.4.2 Preferred distance between centres of low-voltage bushings For currents up to 250 A 70 mm For currents above 250 A and up to 2 000 A 150 mm For currents above 2 000 A 165 mm EN 50588-1:2017 (E) 23 10.1.5 Rollers When rollers are fitted, they shall comply with EN 50216-4 for transformers with rated power Sr 3 150 kVA. For larger rated power this should be specified at the enquiry stage. 10.2 Dry-type transformers 10.2.1 Terminals HV and LV terminals could be located on the upper side or middle part or lower side. For easy understanding HV connecting leads side are fixed and used as reference side. LV terminals could be on the same or on the opposite side referred to the HV leads. Tapping could be on the same side or on the opposite side referred to the HV leads; preferred side is on the same HV side. At the enquiry stage the exact positions of HV leads/terminals, LV leads/terminals and tapping shall be stated. If in respect of leads with special dimensions and/or precise-exact dimensions and locations are needed, this needed information has to be given at the enquiry stage and agreed between manufacturer and purchaser. 10.2.2 Enclosure Refers to EN 60076-11. 11 Accessories 11.1 Liquid immersed transformers Accessories shall be in accordance with the appropriate parts of EN 50216 series when applicable. The type of liquid preservation system and the degree of sealing shall be indicated in the enquiry and order. If not otherwise specified, transformers shall be fitted with the accessories marked with an “X” as listed in Table 13. Accessories not crossed in this table are optional. Special care should be taken to avoid conflicts between accessories which may be non-compatible. EN 50588-1:2017 (E) 24 Table 13 List of accessories (non exhaustive) Type Hermetically sealed Breathing type with conservator or air cushion Tap changer type DETC OLTC DETC OLTC Rating plate X X X X Lifting device X X X X Filling hole and plug X X X X Rollers or skid chassis (Not applicable for pole mounted) X X X X Oil level indicator(s)   X X Conservator draining plug(s)   X X Dehydrating breather(s)   X X Gas and oil actuated relay(s)   X X Butterfly valve     Thermometer pocket     Pad-locking tap changer handle     Protective device     Conservator drain valve     Removable radiators instead of fixed radiator     Removable radiators insulating Butterfly valve     Jacking pads     Pulling eyes     11.2 Dry-type transformers Accessories shall be in accordance with the appropriate parts of EN 50216 series when applicable. If no otherwise specified, transformers shall be fitted with the accessories listed in Table 14. Table 14 List of accessories HV Terminal LV Terminal Earthing terminals Warning plate Terminal markings a Lif