IEC 61400-21-1:2019 includes: \u00b7 definition and specification of the quantities to be determined for characterizing the electrical characteristics of a grid-connected wind turbine; \u00b7 measurement procedures for quantifying the electrical characteristics; \u00b7 procedures for assessing compliance with electrical connection requirements, including estimation of the power quality expected from the wind turbine type when deployed at a specific site. The measurement procedures are valid for single wind turbines with a three-phase grid connection. The measurement procedures are valid for any size of wind turbine, though this part of IEC 61400 only requires wind turbine types intended for connection to an electricity supply network to be tested and characterized as specified in this part of IEC 61400. This first edition cancels and replaces the second edition of 61400-21 published in 2008. This edition includes the following new items with respect to 61400-21: a) frequency control measurement; b) updated reactive power control and capability measurement, including voltage and cos ? control; c) inertia control response measurement; d) overvoltage ride through test procedure; e) updated undervoltage ride through test procedure based on Wind Turbine capability; f) new methods for the harmonic assessment.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | National foreword <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Figures Figure 1 \u2013 Example of step response <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 4 Symbols and units <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 5 Abbreviated terms <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 6 Wind turbine specification 7 Test conditions and test systems 7.1 General 7.2 Overview of required test levels <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 7.3 Test validity Tables Table 1 \u2013 Overview of required test levels <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 7.4 Test conditions <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 7.5 Test equipment <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Figure 2 \u2013 Measurement system description including the most significant components Table 2 \u2013 Specification of requirements for measurement equipment <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 8 Measurement and test of electrical characteristics 8.1 General 8.2 Power quality aspects 8.2.1 General 8.2.2 Flicker during continuous operation <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Figure 3 \u2013 Fictitious grid for simulation of fictitious voltage <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 8.2.3 Flicker and voltage change during switching operations <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 8.2.4 Harmonics, interharmonics and higher frequency components <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 8.3 Steady-state operation 8.3.1 General 8.3.2 Observation of active power against wind speed <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Figure 4 \u2013 Active power as a function of the wind speed (example) Table 3 \u2013 Number of 10-min time-series per wind speed bin Table 4 \u2013 Number of measurements per power bin (10 min average) <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | 8.3.3 Maximum power Figure 5 \u2013 Number of measurements in power bins (example) Figure 6 \u2013 Number of measurements in wind speed bins (example) <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Table 5 \u2013 Measured maximum active power values <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | 8.3.4 Reactive power characteristic (Q = 0) 8.3.5 Reactive power capability <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | 8.3.6 Voltage dependency of PQ diagram Figure 7 \u2013 Example of PQ capability diagram for a given voltage at WT level <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 8.3.7 Unbalance factor <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 8.4 Control performance 8.4.1 General 8.4.2 Active power control <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | Figure 8 \u2013 Adjustment of active power reference value Figure 9 \u2013 Example of active power response step <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | Table 6 \u2013 Accuracy of the active power control values Table 7 \u2013 Results from the active power reference test <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | 8.4.3 Active power ramp rate limitation <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | Figure 10 \u2013 Example of available active power and activepower in ramp rate limitation modefigue Table 8 \u2013 Active power ramp rate calculation <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 8.4.4 Frequency control Figure 11 \u2013 Example of an active power control function P=f(f), with the different measurement points and related steps of frequency <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | Table 9 \u2013 Example of Settings for the frequency dependent active power function <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | 8.4.5 Synthetic inertia <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | 8.4.6 Reactive power control Figure 12 \u2013 Synthetic inertia \u2013 definitions <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | Figure 13 \u2013 Test for static error <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | Figure 14 \u2013 Test of dynamic response (example) <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | 8.5 Dynamic performance 8.5.1 General 8.5.2 Fault ride-through capability Table 10 \u2013 Test for static error Table 11 \u2013 Test for dynamic response <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | Figure 15 \u2013 Example UVRT test equipment <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | Figure 16 \u2013 Tolerances of the positive sequence voltage for the undervoltage eventwith disconnected WT under test <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | Figure 17 \u2013 Tolerance of positive sequence overvoltage event <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | Figure 18 \u2013 Example OVRT capacitor test unit <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | Figure 19 \u2013 Example of an undervoltage test chart Table 12 \u2013 Example of undervoltage events <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | Figure 20 \u2013 Example of an overvoltage capability curve <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | Table 13 \u2013 Example of overvoltage tests <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | 8.6 Disconnection from grid 8.6.1 General 8.6.2 Grid protection <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | Table 14 \u2013 Grid protection tests <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | Figure 21 \u2013 Example of step ramp for overvoltage or frequency testing <\/td>\n<\/tr>\n | ||||||
| 74<\/td>\n | Figure 22 \u2013 Example of pulse ramp for over voltage or frequency testing Figure 23 \u2013 Example of the test levels to determine the release time <\/td>\n<\/tr>\n | ||||||
| 75<\/td>\n | 8.6.3 Test of rate of change of frequency RoCoF (df\/dt) protection device <\/td>\n<\/tr>\n | ||||||
| 76<\/td>\n | 8.6.4 Reconnection test <\/td>\n<\/tr>\n | ||||||
| 77<\/td>\n | Annex\u00a0A (informative)Reporting A.1 Overview A.2 General Table A.1 \u2013 General report information <\/td>\n<\/tr>\n | ||||||
| 78<\/td>\n | Table A.2 \u2013 General data Table A.3 \u2013 Nominal data Table A.4 \u2013 Test conditions <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | A.3 Power quality aspects Figure A.1 \u2013 Voltage flicker Pst vs. active power Figure A.2 \u2013 Flicker coefficient c(30\u00b0) vs. active power Table A.5 \u2013 Flicker coefficient per power bin (95th percentile) <\/td>\n<\/tr>\n | ||||||
| 80<\/td>\n | Figure A.3 \u2013 Flicker coefficient c(50\u00b0) vs. active power Figure A.4 \u2013 Flicker coefficient c(70\u00b0) vs. active power Figure A.5 \u2013 Flicker coefficient c(85\u00b0) vs. active power Table A.6 \u2013 Start-up at cut in wind speed <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | Figure A.6 \u2013 Time series of 3-phase voltages as RMSof start-up at the wind speed of \u2026 m\/s Figure A.7 \u2013 Time series of 3-phase currents as RMSof start-up at the wind speed of \u2026 m\/s Figure A.8 \u2013 Time series of active and reactive powerof start-up at the wind speed of \u2026 m\/s Table A.7 \u2013 Start-up at nominal active power <\/td>\n<\/tr>\n | ||||||
| 82<\/td>\n | Figure A.9 \u2013 Time series of 3-phase voltages as RMSof start-up at nominal active power Figure A.10 \u2013 Time series of 3-phase currents as RMSof start-up at nominal active power Figure A.11 \u2013 Time series of active and reactive powerof start-up at nominal active power Table A.8 \u2013 Worst-case switching between generators <\/td>\n<\/tr>\n | ||||||
| 83<\/td>\n | Figure A.12 \u2013 Time series of 3-phase voltages as RMSof change from generator stage 1 to stage 2 Figure A.13 \u2013 Time series of 3-phase currents as RMSof change from generator stage 1 to stage 2 Figure A.14 \u2013 Time series of active and reactive powerof change from generator stage 1 to stage 2 Figure A.15 \u2013 Time series of 3-phase voltages as RMSof change from generator stage 2 to stage 1 Figure A.16 \u2013 Time series of 3-phase currents as RMSof change from generator stage 2 to stage 1 <\/td>\n<\/tr>\n | ||||||
| 84<\/td>\n | Figure A.17 \u2013 Time series of active and reactive powerof change from generator stage 2 to stage 1 Table A.9 \u2013 General test information Table A.10 \u2013 95th percentile of 10-min harmonic magnitudes per power bin <\/td>\n<\/tr>\n | ||||||
| 86<\/td>\n | Table A.11 \u2013 95th percentile of 10-min harmonic magnitudes per power bin <\/td>\n<\/tr>\n | ||||||
| 87<\/td>\n | Table A.12 \u2013 95th percentile of 10-min harmonic magnitudes per power bin <\/td>\n<\/tr>\n | ||||||
| 88<\/td>\n | A.4 Steady-state operation Figure A.18 \u2013 Max. of the 95th percentiles of integerharmonic currents vs. harmonic order Figure A.19 \u2013 Max. of the 95th percentiles ofinterharmonic currents vs. frequency Figure A.20 \u2013 Max. of the 95th percentiles of higherfrequency current components vs. frequency Table A.13 \u2013 Active power against wind speed (see 8.3.2) <\/td>\n<\/tr>\n | ||||||
| 89<\/td>\n | Figure A.21 \u2013 Active power as a function of the wind speed Table A.14 \u2013 Measurement data set Table A.15 \u2013 Maximum active power <\/td>\n<\/tr>\n | ||||||
| 90<\/td>\n | Figure A.22 \u2013 Reactive power vs. active power Table A.16 \u2013 Reactive power characteristic <\/td>\n<\/tr>\n | ||||||
| 91<\/td>\n | Figure A.23 \u2013 PQ-Diagram Table A.17 \u2013 PQ-diagram <\/td>\n<\/tr>\n | ||||||
| 92<\/td>\n | Figure A.24 \u2013 PQ-Diagram Table A.18 \u2013 PQ-diagram at maximum voltage <\/td>\n<\/tr>\n | ||||||
| 93<\/td>\n | Figure A.25 \u2013 PQ-Diagram Table A.19 \u2013 PQ-diagram at minimum voltage Table A.20 \u2013 P-IUFi diagram <\/td>\n<\/tr>\n | ||||||
| 94<\/td>\n | Figure A.26 \u2013 Mean 1-min current unbalance factor over active power Figure A.27 \u2013 Time-series of active power reference values, available power and measured active power output during active power control for the evaluation of the static error Figure A.28 \u2013 Time-series of measured wind speed during active power control during the test of the static error Table A.21 \u2013 General test information Table A.22 \u2013 Static error <\/td>\n<\/tr>\n | ||||||
| 95<\/td>\n | Figure A.29 \u2013 Time-series of active power reference values, available power and measured active power output during active power control for the evaluation of the settling time Figure A.30 \u2013 Time-series of available and measured activepower output during ramp rate limitation Table A.23 \u2013 Dynamic response Table A.24 \u2013 General test information Table A.25 \u2013 Active power ramp rate calculation at start-up <\/td>\n<\/tr>\n | ||||||
| 96<\/td>\n | Figure A.31 \u2013 Time-series of measured wind speed during ramp rate limitation Figure A.32 \u2013 Time-series of available and measured activepower output during ramp rate limitation Figure A.33 \u2013 Time-series of measured wind speed during ramp rate limitation Table A.26 \u2013 General test information Table A.27 \u2013 Active power ramp rate limitation at start-up <\/td>\n<\/tr>\n | ||||||
| 97<\/td>\n | Figure A.34 \u2013 Time-series of available and measured activepower output during ramp rate limitation Figure A.35 \u2013 Time-series of measured wind speed during ramp rate limitation Table A.28 \u2013 General test information Table A.29 \u2013 Active power ramp rate limitation at normal stop Table A.30 \u2013 General test information <\/td>\n<\/tr>\n | ||||||
| 98<\/td>\n | Figure A.36 \u2013 Time-series of available and measured activepower output during ramp rate limitation Figure A.37 \u2013 Time-series of measured wind speed during ramp rate limitation Table A.31 \u2013 Active power ramp rate limitation in normal operation Table A.32 \u2013 General test information <\/td>\n<\/tr>\n | ||||||
| 99<\/td>\n | Figure A.38 \u2013 Time-series of available power, measured active powerand reference value of the grid frequency change Figure A.39 \u2013 Time-series of measured wind speed Figure A.40 \u2013 Measured active power over frequency change Table A.33 \u2013 Test at 0,25 \u00d7 Pn < P < 0,5 \u00d7 Pn <\/td>\n<\/tr>\n | ||||||
| 100<\/td>\n | Figure A.41 \u2013 Time-series of available power, measured activepower and reference value of the grid frequency change Figure A.42 \u2013 Time-series of measured wind speed Figure A.43 \u2013 Measured active power over frequency change Table A.34 \u2013 Test at P > 0,8 x Pn <\/td>\n<\/tr>\n | ||||||
| 101<\/td>\n | Figure A.44 \u2013 Test 1, time-series of available power, measured active power and reference value of the grid frequency for 0,25 \u00d7 Pn < P < 0,5 \u00d7 Pn Figure A.45 \u2013 Test 1, time-series of wind speed for 0,25 \u00d7 Pn < P < 0,5 \u00d7 Pn Table A.35 \u2013 Synthetic inertia results <\/td>\n<\/tr>\n | ||||||
| 102<\/td>\n | Figure A.46 \u2013 Test 2, time-series of available power, measured active power and reference value of the grid frequency for 0,25 \u00d7 Pn < P < 0,5 \u00d7 Pn Figure A.47 \u2013 Test 2, time-series of wind speed for 0,25 \u00d7 Pn < P < 0,5 \u00d7 Pn Figure A.48 \u2013 Test 3, time-series of available power, measured active power and reference values of the grid frequency for P > 0,8 \u00d7 Pn Figure A.49 \u2013 Test 3, time-series of wind speed for P > 0,8 \u00d7 Pn Figure A.50 \u2013 Test 4, time-series of available power, measured active power and reference value of the grid frequency for P > 0,8 \u00d7 Pn <\/td>\n<\/tr>\n | ||||||
| 103<\/td>\n | Figure A.51 \u2013 Test 4, time-series of wind speed for P > 0,8 \u00d7 Pn Figure A.52 \u2013 Test 5, time-series of available power, measured active power and reference value of the grid frequency for v > vn Figure A.53 \u2013 Test 5, time-series of wind speed for v > vn Figure A.54 \u2013 Test 6, time-series of available power, measured active power and reference value of the grid frequency for v > vn Figure A.55 \u2013 Test 6, time-series of wind speed for v > vn <\/td>\n<\/tr>\n | ||||||
| 104<\/td>\n | Figure A.56 \u2013 Time-series of reactive power reference values and measured reactive power during the test of reactive power control Figure A.57 \u2013 Time-series of active power during the test of reactive power control Table A.36 \u2013 General test information Table A.37 \u2013 Static error <\/td>\n<\/tr>\n | ||||||
| 105<\/td>\n | Figure A.58 \u2013 Time-series of reactive power reference values and measured reactive power during the test of reactive power dynamic response Figure A.59 \u2013 Time-series of active power during the testof reactive power dynamic response Table A.38 \u2013 Dynamic response <\/td>\n<\/tr>\n | ||||||
| 106<\/td>\n | A.5 Dynamic performance (see 8.5) Figure A.60 \u2013 Wave shape of 3-phase voltages during entrance of voltage dip\/swell when the WT under test is not connected Table A.39 \u2013 Results for tests where the WT is not connected <\/td>\n<\/tr>\n | ||||||
| 107<\/td>\n | Figure A.61 \u2013 Wave shape of 3-phase voltages during clearance of voltage dip\/swell when the WT under test is not connected Figure A.62 \u2013 3-phase voltages as RMS (1 line period) duringthe test when the WT under test is not connected Figure A.63 \u2013 Positive sequence voltage during the test whenthe WT under test is not connected <\/td>\n<\/tr>\n | ||||||
| 108<\/td>\n | Table A.40 \u2013 Results for tests where the WT is connected <\/td>\n<\/tr>\n | ||||||
| 109<\/td>\n | Figure A.64 \u2013 Wave shape of 3-phase voltages during entranceof the voltage dip\/swell when the WT under test is connected Figure A.65 \u2013 Wave shape of 3-phase voltages during clearanceof the voltage dip\/swell when the WT under test is connected Figure A.66 \u2013 3-phase voltages as RMS (1 line period) duringthe test when the WT under test is connected Figure A.67 \u2013 Positive and negative sequence fundamental voltage duringthe test when the WT under test is connected Figure A.68 \u2013 3-phase currents as RMS (1 line period) duringthe test when the WT under test is connected <\/td>\n<\/tr>\n | ||||||
| 110<\/td>\n | Figure A.69 \u2013 Pos. and neg. sequence fundamental current duringthe test when the WT under test is connected Figure A.70 \u2013 Pos. sequence fundamental active power duringthe test when the WT under test is connected. Figure A.71 \u2013 Pos. sequence fundamental reactive power duringthe test when the WT under test is connected Figure A.72 \u2013 Pos. sequence fundamental active current duringthe test when the WT under test is connected Figure A.73 \u2013 Pos. sequence fundamental reactive current duringthe test when the WT under test is connected <\/td>\n<\/tr>\n | ||||||
| 111<\/td>\n | A.6 Disconnection from grid (see 8.6) Figure A.74 \u2013 Wind speed or available power during the test whenthe WT under test is connected Table A.41 \u2013 Voltage protection Table A.42 \u2013 Frequency protection Table A.43 \u2013 Complete trip circuit test <\/td>\n<\/tr>\n | ||||||
| 112<\/td>\n | Figure A.75 \u2013 Voltage during the reconnection test of 10\u00a0s Figure A.76 \u2013 Active power during the reconnection test of 10\u00a0s, including the recovery Table A.44 \u2013 RoCoF test results Table A.45 \u2013 RoCoF test information Table A.46 \u2013 Reconnection test results <\/td>\n<\/tr>\n | ||||||
| 113<\/td>\n | Figure A.77 \u2013 Time-series of measured wind speed during the reconnection test of 10\u00a0s Figure A.78 \u2013 Voltage during the reconnection test of 60\u00a0s Figure A.79 \u2013 Active power during the reconnection test of 60\u00a0s, including the recovery Figure A.80 \u2013 Time-series of measured wind speed during the reconnection test of 60\u00a0s Figure A.81 \u2013 Voltage during the reconnection test of 600\u00a0s <\/td>\n<\/tr>\n | ||||||
| 114<\/td>\n | Figure A.82 \u2013 Active power during the reconnection test of 600\u00a0s including the recovery Figure A.83 \u2013 Time-series of measured wind speed during the reconnection test of 600\u00a0s <\/td>\n<\/tr>\n | ||||||
| 115<\/td>\n | Annex\u00a0B (informative)Voltage fluctuations and flicker B.1 Continuous operation B.2 Switching operations Figure B.1 \u2013 Measurement procedure for flicker duringcontinuous operation of the wind turbine <\/td>\n<\/tr>\n | ||||||
| 116<\/td>\n | B.3 Verification test of the measurement procedure for flicker B.3.1 General Figure B.2 \u2013 Measurement procedure for voltage changes and flickerduring switching operations of the wind turbine Table B.1 \u2013 Nominal values of the wind turbine usedin the verification tests <\/td>\n<\/tr>\n | ||||||
| 117<\/td>\n | B.3.2 Fictitious grid performance testing Table B.2 \u2013 Input relative current fluctuation, \u0394I\/I, for flicker coefficientc((\u03c8k) = 2,00\u00a0(\u00a05 % when Sk,fic = 20\u00b7Sn Table B.3 \u2013 Input relative current fluctuation, \u0394I\/I, for flicker coefficientc((\u03c8k) = 2,00\u00a0(\u00a05 % when Sk,fic = 50\u00b7Sn <\/td>\n<\/tr>\n | ||||||
| 118<\/td>\n | B.3.3 Distorted um(t) voltage with multiple zero crossings B.3.4 Distorted um(t) voltage with inter-harmonic modulation Table B.4 \u2013 Test specification for distorted voltage with multiple zero crossings <\/td>\n<\/tr>\n | ||||||
| 119<\/td>\n | B.3.5 Slow frequency changes B.4 Deduction of definitions B.4.1 Flicker coefficient <\/td>\n<\/tr>\n | ||||||
| 120<\/td>\n | B.4.2 Flicker step factor <\/td>\n<\/tr>\n | ||||||
| 121<\/td>\n | B.4.3 Voltage change factor <\/td>\n<\/tr>\n | ||||||
| 122<\/td>\n | Annex\u00a0C (normative)Measurement of active power, reactive power and voltage C.1 General C.2 Generator convention of the signs Figure C.1 \u2013 Positive directions of active power, reactive power, instantaneous phase voltages and instantaneous phase currents with generator convention <\/td>\n<\/tr>\n | ||||||
| 123<\/td>\n | C.3 Calculation of positive, negative and zero sequence quantities C.3.1 Phasor calculations Figure C.2 \u2013 Examples of the power phasor diagrams of the generator convention in each quadrant with respective instantaneous phase voltage and current <\/td>\n<\/tr>\n | ||||||
| 126<\/td>\n | C.3.2 Calculation of the positive sequence quantities using phasor components <\/td>\n<\/tr>\n | ||||||
| 127<\/td>\n | C.3.3 Calculation of the negative sequence quantities using phasor components <\/td>\n<\/tr>\n | ||||||
| 128<\/td>\n | C.3.4 Calculation of the zero sequence quantities using phasor components <\/td>\n<\/tr>\n | ||||||
| 130<\/td>\n | Annex\u00a0D (informative)Harmonic evaluation D.1 General D.2 General analysis methods D.2.1 General D.2.2 Harmonic voltages D.2.3 Harmonic phase angles and magnitudes <\/td>\n<\/tr>\n | ||||||
| 131<\/td>\n | Figure D.1 \u2013 Definition of the phase angles of the spectral line in generator convention \u2013 (5th harmonic with \u03b1I5\u00a0= + 120\u00b0 and \u03b1U5\u00a0= + 170\u00b0shown as an example, thus 5th harmonic phase angle is \u03c65\u00a0= + 170\u00b0 \u2212 120\u00b0 = + 50\u00b0) <\/td>\n<\/tr>\n | ||||||
| 132<\/td>\n | Figure D.2 \u2013 Comparison of harmonic amplitude aggregation (dotted) no aggregated amplitude directly from DFT with 10-cycle window, (dashed) 10-second aggregation <\/td>\n<\/tr>\n | ||||||
| 133<\/td>\n | Figure D.3 \u2013 Comparison of the prevailing angle ratio (PAR) <\/td>\n<\/tr>\n | ||||||
| 134<\/td>\n | D.2.4 Statistical analysis D.2.5 Sample rate adjustment D.2.6 Determination of background harmonic voltage distortion D.2.7 Diurnal variations of the harmonic voltage and current <\/td>\n<\/tr>\n | ||||||
| 135<\/td>\n | D.2.8 Shutting down neighbouring WT or loads D.2.9 Harmonics of current and voltage over power <\/td>\n<\/tr>\n | ||||||
| 136<\/td>\n | D.2.10 Filters switching <\/td>\n<\/tr>\n | ||||||
| 137<\/td>\n | D.2.11 Measuring at a standard source D.2.12 Harmonics power flow + voltage measurement, phase angle <\/td>\n<\/tr>\n | ||||||
| 138<\/td>\n | D.2.13 Voltage harmonics with and without operation of the tested wind turbine Table D.1 \u2013 Example of measurements results presentation <\/td>\n<\/tr>\n | ||||||
| 139<\/td>\n | D.2.14 Measurements at different sites D.2.15 Harmonic model D.3 Determination of harmonic amplitude affected by space harmonics at DFAG systems <\/td>\n<\/tr>\n | ||||||
| 141<\/td>\n | Annex\u00a0E (informative)Assessment of power quality of wind turbines and wind power plants E.1 General E.2 Voltage fluctuations E.2.1 General <\/td>\n<\/tr>\n | ||||||
| 142<\/td>\n | E.2.2 Continuous operation E.2.3 Switching operations <\/td>\n<\/tr>\n | ||||||
| 143<\/td>\n | E.3 Current harmonics, interharmonics and higher frequency components <\/td>\n<\/tr>\n | ||||||
| 144<\/td>\n | Table E.1\u2013 Specification of exponents in accordance with IEC\u00a0TR 61000-3-6 <\/td>\n<\/tr>\n | ||||||
| 145<\/td>\n | Annex\u00a0F (informative)Guidelines for the transferability of test results to different turbine variants in the same product platform <\/td>\n<\/tr>\n | ||||||
| 146<\/td>\n | Figure F.1 \u2013 Block diagram for generic wind turbine (source IEC\u00a061400-27-1) <\/td>\n<\/tr>\n | ||||||
| 147<\/td>\n | Table F.1\u2013 Main components influencing the electrical characteristics of the WT <\/td>\n<\/tr>\n | ||||||
| 149<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Wind energy generation systems – Measurement and assessment of electrical characteristics. Wind turbines<\/b><\/p>\n |