S.R. CLC/TR 50462:2008
Current
The latest, up-to-date edition.
Hardcopy , PDF
English
01-01-2008
Introduction
1 Scope
2 Normative references
3 Definitions
4 Symbols
4.1 General symbols
4.2 Symbols for uncertainty
5 Power measurement, systematic deviation and uncertainty
6 Procedures for no-load loss
6.1 General
6.2 Model function for no-load losses at reference conditions
6.3 Uncertainty budget
7 Procedures for load loss
7.1 General
7.2 Model function for load loss at reference conditions
7.3 Uncertainty budget for measured power P[2] referred to
rated current
7.4 Uncertainty budget for reported load loss
8 Three-phase calculations
8.1 Power
8.2 Reference voltage (current)
9 Reporting
9.1 Uncertainty
9.2 Traceability
10 Estimation of corrections and uncertainty contributions
10.1 Ratio error of instrument transformers
10.2 Phase displacement of instrument transformers
10.3 Power meter
10.4 Voltage measurement in no-load loss
10.5 Ampere meter in load loss measurement
10.6 Correction to sinusoidal waveform
10.7 Winding temperature h at load loss test
10.8 Winding resistance
Annex A (informative) Example of load loss uncertainty evaluation
for a large power transformer
A.1 Introduction
A.2 Transformer rating
A.3 Measuring method and instrumentation used
A.4 Model of the measurand
A.5 Results of the measurements
A.6 Uncertainty of load loss
A.7 Estimates of the single contributions to the uncertainty
Annex B (informative) Example of load loss uncertainty evaluation
for a distribution transformer
B.1 Introduction
B.2 Transformer rating
B.3 Measuring instrumentation
B.4 Model of the measurand
B.5 Results of the measurements
B.6 Uncertainty of load loss
B.7 Estimate of the single contributions to the uncertainty
formation
Annex C (informative) General rules for the uncertainty estimate
C.1 The basic concepts
C.2 Measurements, estimates and uncertainties
C.3 Evaluation of the input quantity uncertainties
C.4 Evaluation and expression of the expanded uncertainty
Annex D (informative) Sensitivity coefficients for uncertainty
contributions due to phase displacement correction of
measurements at low power factor
D.1 Introduction
D.2 Sensitivity factors
Annex E (informative) Model function for load loss temperature
correction
E.1 General
E.2 Model function
E.3 Sensitivity coefficients
E.4 Estimation of temperature during load loss test
E.5 Simplified analysis
Annex F (informative) Measurement of winding resistance
F.1 Description of the measurement
F.2 Inductive voltage drop
Bibliography
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