BS EN 61378-1:2011:2012 Edition
$215.11
Convertor transformers – Transformers for industrial applications
| Published By | Publication Date | Number of Pages |
| BSI | 2012 | 96 |
This Part of IEC 61378 deals with the specification, design and testing of power transformers and reactors which are intended for integration within semiconductor converter plants; it is not applicable to transformers designed for industrial or public distribution of a.c. power in general.
The scope of this International Standard is limited to application of power converters of any power rating. Typical applications are: thyristor rectifiers for electrolysis; diode rectifiers for electrolysis; thyristor rectifiers for large drives; thyristor rectifiers for scrap melting furnaces, and diode rectifiers feeding inverters for variable speed drives. The standard also covers the regulating unit utilized in such application as step down regulating transformers or autotransformers. The valve winding highest voltage for equipment is limited to 36 kV.
This standard is not applicable to transformers for HVDC power transmission. These are highvoltage transformers, and they are subjected to d.c. voltage tests.
The standards for the complete converter plant (IEC 60146 series, or other publications dedicated to particular fields of application) may contain requirements of guarantees and tests (such as insulation and power loss) for the whole plant, including the converter transformer and possibly auxiliary transformers and reactor equipment. This does not relieve the application of the requirements of this standard concerning the guarantees and tests applicable to the converter transformer itself as a separate component before being assembled with the remainder of the converter plant.
The guarantees, service and type tests defined in this standard apply equally to transformers supplied as part of an overall converter package, or to those transformers ordered separately but for use with converter equipment. Any supplementary guarantee or special verification has to be specifically agreed in the transformer contract.
The converter transformers covered by this standard may be of the oil-immersed or dry-type design. Unless specific exceptions are stated in this standard, the transformers comply with IEC 60076 series for oil-immersed transformers, and with IEC 60076-11 for dry-type transformers.
NOTE For some converter applications, it is possible to use common distribution transformers of standard design. The use of such standard transformers in the special converter applications may require a certain derating. This matter is not specifically covered in this standard, which deals with the requirements to be placed on specially designed units. It is possible to estimate this derating from the formulae given in 5.1, and also from Clause 9 of IEC 60076-8:1997.
This standard deals with transformers with one or more active parts installed in the same tank like regulating (auto)transformer and one or two rectifier transformers. It also covers transformers with transductors and/or one or more interphase transformers.
For any combination not listed above an agreement between the purchaser and manufacturer is necessary regarding the determination and the measurement of the total losses.
This standard deals with transformers star Y and delta D and any other phase shifting connections (like zig-zag, extended delta, polygon etc.). Phase shifting windings can be placed on either the regulating or rectifier transformer.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | CONTENTS |
| 10 | FOREWORD |
| 12 | 1 Scope |
| 13 | 2 Normative references 3 Terms, definitions and acronyms 3.1 Terms and definitions |
| 14 | 3.2 Acronyms Figures Figure 1 – B6U or DB 6 pulse double bridge connection |
| 15 | 4 Classification 4.1 General 4.2 Normal service conditions Figure 2 – DSS 6 pulse connection |
| 16 | 4.3 Provision for unusual service conditions 5 Ratings 5.1 General 5.2 Rated power at rated frequency and load capability |
| 17 | 5.3 Rated and service voltages 5.4 Rated current 5.5 Phase displacement and terminal identification for three-phase transformer |
| 18 | 5.6 Rating plate 5.7 Units with tertiary windings loaded with filter and compensation |
| 19 | 5.8 On load tap-changers 6 Load loss and voltage drop in transformers and reactors 6.1 General 6.2 Determination of transformer load loss under distorted current loading |
| 23 | 6.3 Current sharing, losses and hot spot in high current windings |
| 24 | 6.4 Effect of geometrical winding arrangement and magnetic coupling between windings on their eddy current losses due to harmonics in transformers with three or more windings wound on the same core limb |
| 26 | Figure 3 – Leakage fields for a three-winding transformerwith closely coupled valve windings |
| 27 | Figure 4 – Leakage fields for a three-winding transformer with decoupled valve windings |
| 28 | Figure 5 – Leakage fields for a three winding transformer with loosely coupled double concentric valve windings |
| 29 | Figure 6 – Leakage fields for a three winding transformer with loosely coupled double-tier valve windings |
| 30 | 6.5 Losses in interphase transformers, current-balancing reactors, series-smoothing reactors and transductors |
| 31 | 6.6 Voltage drops in transformers and reactors |
| 32 | Figure 7 – Typical transductor regulating curve (with max voltage drop at zero control current) and tolerance band |
| 33 | 7 Tests for converter transformers 7.1 General |
| 34 | 7.2 Measurement of commutating reactance and determination of the inductive voltage drop |
| 35 | 7.3 Measurement of voltage ratio and phase displacement 7.4 Dielectric tests |
| 36 | 7.5 Load loss test 7.6 Temperature rise tests |
| 39 | 8 On load noise level with transductors and/or IPT |
| 40 | Tables Table 1 – Connections and calculation factors |
| 42 | Annex A (informative) Determination of transformer service load loss at rated non-sinusoidal converter current from measurements with rated transformer current of fundamental frequency |
| 44 | Figure A.1 – Cross-section of a winding strand |
| 45 | Table A.1 – Specified harmonic currents and phase displacement in the valve windings |
| 46 | Table A.2 – Resistance measurements at 20 °C winding temperature |
| 47 | Figure A.2 – Terminal identification for winding connection Y y0y6 |
| 49 | Table A.3 – Specified harmonic currents and phase displacementin the line and valve windings |
| 50 | Figure A.3 – Terminal identification for winding connection D d0y1 Table A.4 – Measurements from test report |
| 51 | Figure A.4 – Valve current DB connection rectangular shape positive shape |
| 52 | Figure A.5 – Valve current DB connection rectangular shape positive and negative shape Table A.5 – Resulting current harmonics |
| 53 | Table A.6 – Resulting current harmonics |
| 54 | Table A.7 – Resulting current harmonics |
| 55 | Table A.8 – Detailed transformer load losses at rated tap position, with tertiary unloaded |
| 56 | Figure A.6 – Valve current DSS connection rectangular shape Table A.9 – Resulting current harmonics |
| 57 | Table A.10 – Specified harmonic currents and phase displacementin the line and valve windings |
| 58 | Table A.11 – Resulting current harmonics |
| 59 | Table A.12 – Detailed transformer load lossesat rated tap position, with tertiary unloaded |
| 60 | Annex B (informative) Short-circuit test currents and load losses in transformersfor single-way converters (total loss injection) |
| 61 | Annex C (informative) Current sharing measurement in high current valve windings |
| 62 | Figure C.1 – Example of valve high current windingand measurement equipment disposition |
| 63 | Figure C.2 – Transformer windings arrangement |
| 64 | Figure C.3 – Measurement circuit for the in-phase measurement |
| 65 | Figure C.4 – Measurement circuit for the in-opposition measurement |
| 66 | Table C.1 – Measurements and comparison with the simulations madeby finite element method software for the in-phase current distribution |
| 67 | Figure C.5 – Measurements and comparison with the simulations madeby finite element method software for the in-phase current distribution |
| 68 | Table C.2 – Measurements and comparison with the simulations made by finite element method software for the in-opposition current distribution |
| 69 | Figure C.6 – Measurements and comparison with the simulations madeby finite element method software for the in-opposition current distribution |
| 70 | Annex D (informative) Examples of duty cycles Table D.1 – Examples of duty cycles for different applications |
| 71 | Annex E (informative) Guidelines for design review |
| 74 | Annex F (informative) Determination of loss in transformer tank due to magnetic field. 3D simulation and guidelines for tank losses evaluation and tank hotspot calculation |
| 75 | Annex G (informative) Short-circuit measurements of rectifier transformers equippedwith built in transductors |
| 77 | Annex H (informative) Determination of the transformer voltage ratio and phase displacementby the turn ratio measurements Table H.1 – Single phase ratio measurements |
| 78 | Figure H.1 – Yd1 connection Figure H.2 – Yd11 connection |
| 79 | Figure H.3 – Pd0+7,5 connection |
| 80 | Figure H.4 – Oscilloscope connection Figure H.5 – Oscilloscope with phase B + 7,5° lag referring to phase A |
| 81 | Figure H.6 – Oscilloscope with phase B – 7,5° lead referring to phase A |
| 82 | Annex I (informative) Phase displacement connections and terminal indicationsof converter transformers Figure I.1 – Counterclockwise phase displacement Figure I.2 – Yd11 connection Figure I.3 – Yd1 connection |
| 83 | Figure I.4 – Example I.1 phase displacement Figure I.5 – Example I.2 phase displacement |
| 87 | Annex J (normative) Correlation between IEC 61378-1 and IEC 60146-1-1 ratings Figure J.1 – DB connection ideal rectangular current blocks |
| 88 | Figure J.2 – DSS Connection rectangular current blocks Table J.1 – Harmonics content up to 25th in DB 6 pulse connection(ideal rectangular current waveshape) |
| 89 | Table J.2 – Harmonics content up to 25th in DSS 6 pulse connection(ideal rectangular current waveshape) |
| 90 | Table J.3 – Calculation factor comparison example |
| 91 | Table J.4 – Calculation factor comparison general factors |
| 94 | Bibliography |
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BS EN 61378-1:2011:2012 Edition
Convertor transformers – Transformers for industrial applications Published By Publication Date Number of Pages BSI…
