BS IEC 62891:2020
$167.15
Maximum power point tracking efficiency of grid connected photovoltaic inverters
| Published By | Publication Date | Number of Pages |
| BSI | 2020 | 38 |
IEC 62891:2020 provides a procedure for the measurement of the efficiency of the maximum power point tracking (MPPT) of inverters used in grid-connected photovoltaic (PV) systems. Both the static and dynamic MPPT efficiency are considered. Based on the static MPPT efficiency calculated in this document and steady state conversion efficiency determined in IEC 61683 the overall efficiency can be calculated. The dynamic MPPT efficiency is indicated separately.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 4 | CONTENTS |
| 6 | FOREWORD |
| 8 | 1 Scope 2 Normative references 3 Terms and definitions 3.1 Inverter input (PV generator) |
| 9 | 3.2 Inverter output (grid) 3.3 Measured quantities |
| 10 | 3.4 Calculated quantities |
| 11 | 4 MPPT efficiencies 4.1 General description |
| 12 | 4.2 Test set-up |
| 13 | 4.3 Static MPPT efficiency 4.3.1 Test conditions Figures Figure 1 – Example test set-up for MPPT efficiency measurements |
| 14 | 4.3.2 Measurement procedure Tables Table 1 – Test specifications for static MPPT efficiency |
| 15 | 4.3.3 Evaluation – Calculation of static MPPT efficiency 4.4 Test conditions for dynamic MPPT efficiency 4.4.1 Dynamic MPPT efficiency |
| 16 | 4.4.2 Measurement procedure 4.4.3 Evaluation – Calculation of the dynamic MPPT efficiency |
| 17 | 5 Calculation of the overall efficiency |
| 18 | Annex A (normative)Requirements on the measuring apparatus A.1 PV generator simulator A.1.1 General A.1.2 Requirements on the static characteristic Table A.1 – General requirements on the simulated I/Vcharacteristic of the PV generator |
| 19 | A.1.3 Requirement on the transient stability A.1.4 Requirements on the dynamic characteristic A.1.5 Requirements on electrical characteristic A.1.6 Calibration – Uncertainty A.2 AC power supply |
| 20 | Annex B (normative)Test conditions for dynamic MPPT efficiency B.1 Test profiles Figure B.1 – Test sequence for fluctuations betweensmall and medium irradiation intensities |
| 21 | Figure B.2 – Test sequence for fluctuations betweenmedium and high irradiation intensities |
| 22 | B.2 Test sequence with ramps 10 % – 50 % GSTC (See Table B.1) Table B.1 – Dynamic MPPT-Test 10 % -> 50 % GSTC(valid for the evaluation of ηMPPTdyn) |
| 23 | B.3 Test sequence with ramps 30 % – 100 % GSTC (See Table B.2) B.4 Start-up and shut-down test with slow ramps (See Table B.3 and Figure B.3) Table B.2 – Dynamic MPPT-Test 30 % -> 100 % GSTC(valid for the evaluation of ηMPPTdyn) Table B.3 – Dynamic MPPT- Slow Ramp 1 % -> 10 % GSTC(valid for the evaluation of ηMPPTdyn) |
| 24 | B.5 Total test duration Figure B.3 – Test sequence for the start-up and shut-down testof grid connected inverters |
| 25 | Annex C (normative)Models of current/voltage characteristic of PV generator C.1 PV generator model for MPPT performance tests |
| 26 | Table C.1 – Technology-dependent parameters |
| 27 | Figure C.1 – Irradiation-dependent V-I- and V-P characteristic of a c-Si PV generator Table C.2 – MPP-values obtained with the cSi PV model |
| 28 | Figure C.2 – Irradiation-dependent V-I- and V-P characteristicof a thin-film PV generator |
| 29 | C.2 Alternative PV generator model for MPPT performance tests Table C.3 – MPP-values obtained with the TF-PV mode |
| 31 | Annex D (normative)Efficiency weighting factors D.1 European efficiency D.2 CEC efficiency Table D.1 – Weighting factors and partial MPP power levelsfor the calculation of the European efficiency Table D.2 – Weighting factors and partial MPP power levels forthe calculation of the CEC efficiency (California Energy Commission) |
| 32 | Annex E (normative)Specification of the static MPPT and conversion efficiencyin terms of normalised rated AC power E.1 General E.2 Re-normalisation of output power PAC to the rated output power PAC,r E.3 Representation of the conversion efficiency in terms of normalised rated output power Table E.1 – Measured quantities at the conversion efficiency test |
| 33 | E.4 Interpolation on normative nodes Table E.2 – Conversion efficiency in term of rated AC power Table E.3 – Allowed limits for the nodes of the normalised AC power |
| 34 | Table E.4 – Sought values by means of interpolation |
| 35 | E.5 Result Table E.5 – Interpolated conversion efficiencies |
| 36 | Bibliography |
