IEC TS 63106-2:2022

Simulators used for testing of photovoltaic power conversion equipment - Recommendations - Part 2: DC power simulators

IEC TS 63106-2:2022 provides recommendations for Low Voltage (LV) DC power simulators used for testing photovoltaic (PV) power conversion equipment (PCE) to utility interconnection or PV performance standards. This document primarily addresses DC power simulators used for testing of grid-interactive PCE, also referred to as grid-connected power converters (GCPCs). It also addresses some uses of DC power simulators for testing stand-alone and multi-mode PCEs.

General Information

• Status: Published
• Publication Date: 28-Mar-2022
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 82 - Solar photovoltaic energy systems
• Drafting Committee: WG 6 - TC 82/WG 6
• Current Stage: PPUB - Publication issued
• Start Date: 28-Apr-2022
• Completion Date: 29-Mar-2022

Standards Content (Sample)

IEC TS 63106-2 ®
Edition 1.0 2022-03
TECHNICAL
SPECIFICATION
colour
inside
Simulators used for testing of photovoltaic power conversion equipment –
Recommendations –
Part 2: DC power simulators
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IEC TS 63106-2 ®
Edition 1.0 2022-03
TECHNICAL
SPECIFICATION
colour
inside
Simulators used for testing of photovoltaic power conversion equipment –

Recommendations –
Part 2: DC power simulators
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-1093-5

– 2 – IEC TS 63106-2:2022 © IEC 2022
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 PCE types with respect to DC voltage levels . 10
4.1 General . 10
4.2 Module level PCE . 11
4.3 String level PCE . 11
4.4 Central PCE . 11
5 Test setup for utility interactive inverters . 11
5.1 General . 11
5.2 Test setup examples . 11
5.3 System configuration options . 12
5.3.1 General . 12
5.3.2 PV array . 12
5.3.3 PV array simulator. 13
5.3.4 DC power supply . 13
6 General recommendations for DC power simulator . 13
6.1 General . 13
6.2 DC output voltage accuracy and ripple . 14
6.3 I-V curve stability for EUT testing . 14
6.3.1 General . 14
6.3.2 DC irradiance change rate . 15
6.4 DC power simulator performance and characteristics for utility interaction tests . 16
6.5 Additional tests conducted with DC power simulators . 34
6.5.1 General . 34
6.5.2 PCE operational stability with sudden irradiance changes (due to
movement of sun between clouds) . 35
6.5.3 Automatic start and stop operation with gradual irradiance changes
(representing morning and evening conditions) . 36
6.5.4 PCE DC to AC power conversion efficiency measurement . 36
6.5.5 PCE maximum power point tracking efficiency measurement . 36
6.5.6 PCE total power conversion efficiency measurement . 37
6.6 Avoidance measures of transient impact to EUTs . 37
Annex A (informative) DC I-V curve dynamic accuracy against MPPT control . 38
A.1 General . 38
A.2 Example of DC I-V curve stability for MPPT properties . 38
A.2.1 MPPT control . 38
A.2.2 Recommended stability of operation on the I-V curve . 39
A.2.3 Recommended I-V curve resolution . 39
A.2.4 Use of DC power supply as an input of EUT . 39
Annex B (informative) DC power simulator stability against utility- frequency ripple
voltage/current . 41
B.1 General . 41
B.2 Example of twice the utility- frequency ripple voltage/current . 41
B.2.1 Twice the utility frequency ripple voltage/current . 41

IEC TS 63106-2:202 © IEC 2022 – 3 –
B.2.2 Stability of I-V curve for the DC ripple . 42
Annex C (informative) PV array simulator I-V curve stability against quick power change
in UVRT test . 44
C.1 General . 44
C.2 DC voltage/current shift by withdrawing power change in UVRT test . 44
Annex D (informative) DC I-V curve stability against low irradiance at sunrise and sunset . 47
D.1 General . 47
D.2 Example of a DC I-V curve stability against slow irradiance change rate in the
morning and evening – I-V curve with low irradiance periods and EUT input
voltage/current transition . 47
Annex E (informative) DC I-V curve behaviour in rapidly varying irradiance conditions . 49
E.1 General . 49
E.2 I-V curve response to varying irradiance . 49
E.2.1 Irradiance sudden change on I-V characteristics of the PV array (an
example) . 49
E.2.2 Recommendation of irradiance quick change rate for test of the EUT by PV
array simulator . 49
Bibliography . 52

Figure 1 – Examples of ports . 9
Figure 2 – Examples of fundamental setup of EUT test system . 12
Figure A.1 – Voltage and current swing by MPPT control on I-V curve around MPP. 38
Figure A.2 – Current and voltage swing by MPPT control on I-V curve below MPP . 39
Figure A.3 – Current and voltage swing by MPPT control on I-V characteristic curve of
DC power supply . 40
Figure B.1 – DC current and voltage ripple on single-phase GCPC . 41
Figure B.2 – DC current and voltage ripple on three-phase GCPC with UVRT test . 42
Figure B.3 – DC ripple I-V swing on I-V curve of PV array . 43
Figure C.1 – DC input voltage/current transition on zero-voltage ride through test – AC
voltage sudden reduction . 45
Figure C.2 – DC input voltage/current transition on zero-voltage ride through test – AC

voltage sudden recovery . 46
Figure C.3 – DC input voltage/current transition on UVRT test – AC voltage sudden
decrease . 46
Figure D.1 – DC input voltage/current transition area in the morning and evening . 47
Figure D.2 – DC input voltage transition pattern example in the morning . 48
Figure E.1 – DC input voltage/current quick transition and MPPT . 50
Figure E.2 – Irradiance quick change example . 50
Figure E.3 – Irradiation change rate for PV array and wind orientation . 51

Table 1 – Grid qualification/Requalification – In-range AC voltage before
connection/reconnection . 17
Table 2 – Grid qualification/Requalification – In-range AC frequency before

connection/reconnection . 18
Table 3 – Power capability: Nameplate P, Q, S under normal and near-normal grid
conditions . 19
Table 4 – Power capability: Limitation of P/Q/S/PF by setpoint . 20
Table 5 – Power capability: Ramp rate or soft start time-developing magnitude by set rate . 21

– 4 – IEC TS 63106-2:2022 © IEC 2022
Table 6 – Grid protection tests – AC over-voltage (OV) and under-voltage (UV) trip tests . 22
Table 7 – Grid protection tests: OF/UF trips . 22
Table 8 – Grid protection tests: Anti-islanding . 23
Table 9 – Grid protection tests: Rate of Change of Frequency (ROCOF) trips . 24
Table 10 – Grid protection tests: Open phase . 24
Table 11 – Power quality tests: Current harmonics, inter-harmonics, THDi . 25
Table 12 – Power quality tests: Flicker (continuous) . 26
Table 13 – Power quality tests: Current inrush (at connection switch close) . 27
Table 14 – Power quality tests: AC output current imbalance . 27
Table 15 – Power quality tests: Transi
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