IEC 60076-19-1:2023 defines the procedures that are applied to evaluate the uncertainty affecting the measurements of no-load and load losses during the routine tests on power transformers. This document centres on measuring systems utilizing digital instruments, although the procedures can be adapted to evaluation of systems with analogue instruments where further uncertainty sources have to be taken into account. This document specifies how to determine measurement uncertainty and how to apply corrections for known errors in the measurement chain. Information vis-\u00e0-vis judgement and traceability are given in IEC 60076-8:1997, 10.1 and 10.2.<\/p>\n
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| 74<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 77<\/td>\n | Annex ZA (normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 82<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 84<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 86<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 88<\/td>\n | 4 Symbols 4.1 General symbols <\/td>\n<\/tr>\n | ||||||
| 89<\/td>\n | 4.2 Symbols for uncertainty 4.2.1 General designations 4.2.2 Specific designations 5 Power measurement, systematic deviation and uncertainty 5.1 General <\/td>\n<\/tr>\n | ||||||
| 90<\/td>\n | 5.2 Traceability 5.3 Model function 5.4 Measuring systems 6 Procedures for no-load loss measurement 6.1 General <\/td>\n<\/tr>\n | ||||||
| 91<\/td>\n | 6.2 Model function for no-load losses at reference conditions <\/td>\n<\/tr>\n | ||||||
| 92<\/td>\n | 6.3 Uncertainty budget for no-load loss <\/td>\n<\/tr>\n | ||||||
| 93<\/td>\n | 7 Procedures for load loss measurement 7.1 General 7.2 Model function for load loss measurement at rated current Tables Table 1 \u2013 Measured no-load loss uncertainties <\/td>\n<\/tr>\n | ||||||
| 94<\/td>\n | 7.3 Model function for load loss at rated current and reference temperature <\/td>\n<\/tr>\n | ||||||
| 95<\/td>\n | 7.4 Uncertainty budget for the measured power P2 recalculated to rated current 7.4.1 General 7.4.2 Uncertainties of measured load loss power P2 at ambient temperature \u03b82 7.5 Uncertainty budget for reported load loss at reference temperature Table 2 \u2013 Measured load loss uncertainties at ambient temperature <\/td>\n<\/tr>\n | ||||||
| 96<\/td>\n | 8 Three-phase power calculations Table 3 \u2013 Absolute uncertainty of load losses PLLreported at reference temperature \u03b8r <\/td>\n<\/tr>\n | ||||||
| 97<\/td>\n | 9 Reporting 10 Estimate of corrections and uncertainty contributions 10.1 Instrument transformers 10.1.1 General <\/td>\n<\/tr>\n | ||||||
| 98<\/td>\n | 10.1.2 Ratio error of instrument transformers <\/td>\n<\/tr>\n | ||||||
| 99<\/td>\n | 10.1.3 Phase displacement of instrument transformers <\/td>\n<\/tr>\n | ||||||
| 101<\/td>\n | 10.2 Voltage and current measurements <\/td>\n<\/tr>\n | ||||||
| 102<\/td>\n | 10.3 Power meter 10.4 Advanced system with specified system uncertainty Table 4 \u2013 Measured no-load loss uncertainties, advanced system <\/td>\n<\/tr>\n | ||||||
| 103<\/td>\n | 10.5 Correction to sinusoidal waveform 10.6 Winding resistance measurement Table 5 \u2013 Measured load loss uncertainties at ambient temperature, advanced system <\/td>\n<\/tr>\n | ||||||
| 104<\/td>\n | 10.7 Winding temperature at load loss measurement 10.7.1 General 10.7.2 R2 and \u03b82 determined from temperature measurement <\/td>\n<\/tr>\n | ||||||
| 105<\/td>\n | 10.7.3 R2 and \u03b82 determined by resistance measurement <\/td>\n<\/tr>\n | ||||||
| 107<\/td>\n | Annex A (informative)Example of no-load loss uncertainty evaluation \u2013Advanced measuring system A.1 General (intent of example) A.2 Transformer specification A.3 Measuring system Table A.1 \u2013 Three-phase transformer oil immersed transformer Table A.2 \u2013 Uncertainty specification of the power measuring system <\/td>\n<\/tr>\n | ||||||
| 108<\/td>\n | A.4 Measurements A.5 Correction of measured values A.6 Calculation of uncertainty Table A.3 \u2013 Measured data Table A.4 \u2013 Corrected values <\/td>\n<\/tr>\n | ||||||
| 109<\/td>\n | A.7 Reported loss and uncertainty estimate Table A.5 \u2013 Uncertainty of no-load loss (according to Table 1) <\/td>\n<\/tr>\n | ||||||
| 110<\/td>\n | Annex B (informative)Example of no-load loss uncertainty evaluation \u2013Calibration based procedure B.1 General B.2 Transformer specification B.3 Measuring system Table B.1 \u2013 Three-phase transformer oil immersed transformer <\/td>\n<\/tr>\n | ||||||
| 111<\/td>\n | B.4 Measurements Table B.2 \u2013 Uncertainties of measuring system current and voltage transducers Table B.3 \u2013 Uncertainties of power meter Table B.4 \u2013 Measured data <\/td>\n<\/tr>\n | ||||||
| 112<\/td>\n | B.5 Correction of measured values B.6 Uncertainty calculation Table B.5 \u2013 Corrected values Table B.6 \u2013 Uncertainty of no-load loss (according to Table 1) <\/td>\n<\/tr>\n | ||||||
| 113<\/td>\n | B.7 Reported loss and uncertainty estimate <\/td>\n<\/tr>\n | ||||||
| 114<\/td>\n | Annex C (informative)Example of load loss uncertainty evaluationclass index procedure C.1 General C.2 Transformer specification C.3 Measuring system Table C.1 \u2013 Three-phase transformer dry type transformer <\/td>\n<\/tr>\n | ||||||
| 115<\/td>\n | C.4 Measurements Table C.2 \u2013 Uncertainties of measuring system current and voltage transducers Table C.3 \u2013 Measured data <\/td>\n<\/tr>\n | ||||||
| 116<\/td>\n | C.5 Calculation in accordance with IEC 60076-1 C.6 Uncertainty calculation Table C.4 \u2013 Results based on measured data Table C.5 \u2013 Derivation of standard uncertainty contributions <\/td>\n<\/tr>\n | ||||||
| 117<\/td>\n | Table C.6 \u2013 Uncertainty budget for measured load lossat ambient temperature (Table 2) Table C.7 \u2013 Uncertainty budget for absolute uncertaintyof load loss reported at reference temperature (Table 3) <\/td>\n<\/tr>\n | ||||||
| 118<\/td>\n | C.7 Reported loss and uncertainty estimate <\/td>\n<\/tr>\n | ||||||
| 119<\/td>\n | Annex D (informative)Determination of exponent n in expression for no-load loss Table D.1 \u2013 Example of measured no-load loss versus applied voltage <\/td>\n<\/tr>\n | ||||||
| 120<\/td>\n | Figure D.1 \u2013 Evaluation of exponent n from data in Table D.1 <\/td>\n<\/tr>\n | ||||||
| 121<\/td>\n | Annex E (informative)Measurement uncertainty and test results E.1 General E.2 Test results, guarantees, tolerances, uncertainty limits E.3 Traceability as tool for quality assurance <\/td>\n<\/tr>\n | ||||||
| 122<\/td>\n | E.4 Means and methods to prove uncertainty claims and traceability E.4.1 Calibration <\/td>\n<\/tr>\n | ||||||
| 123<\/td>\n | E.4.2 Calibration certificate <\/td>\n<\/tr>\n | ||||||
| 124<\/td>\n | E.4.3 Guidance on scope of a calibration <\/td>\n<\/tr>\n | ||||||
| 125<\/td>\n | Annex F (normative)Calculation of uncertainty of losses with differentreference temperatures and\/or winding material <\/td>\n<\/tr>\n | ||||||
| 126<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Tracked Changes. Power transformers – Rules for the determination of uncertainties in the measurement of the losses on power transformers<\/b><\/p>\n |