CNO - CR-GCC-TR8-09667-A066-1 - Fault-ride-through de 2025

HUAWEI SUN2000-330KTL-H1/-H2

Certification Report Fault Ride Through Huawei Technologies Co., Ltd.

Report No.: CR-GCC-TR8-09667-A066-1

Date: 2023-07-26DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page i DNV Renewables Certification is the trading name of DNV’s certification business in the renewable energy industry.

The certification body is DNV Renewables Certification GmbH, Brooktorkai 18, 20457 Hamburg with organisational control to other entities within the DNV Group.

Project name: HUAWEI SUN2000-330KTL-H1/-H2 DNV Energy Systems

Renewables Certification DNV Renewables Certification GmbH Brooktorkai 18 20457 Hamburg Germany

Tel.: +49 40 36149-0

Report title: Certification Report

Fault Ride Through

Customer: Huawei Technologies Co., Ltd.,

Administration Building, Headquarters of Huawei Technologies Co., Ltd., Bantian, Longgang District, Shenzhen, 518129, PRC Customer contact: sunyashen@huawei.com Date of issue: 2023-07-26

Project No.: 10384250

Report No.: CR-GCC-TR8-09667-A066-1

Applicable contract(s) governing the provision of this Report: (L2C: 236553) Objective: Verification of the FRT-capability of the PV-Inverters HUAWEI SUN2000-330KTL-H1/-H2

Prepared by: Verified and approved by:

Torge Wehrend Senior Engineer Sofien Ben Saad Senior Engineer

Copyright © DNV 2023. All rights reserved. Unless otherwise agreed in writing: (i) This publication or parts thereof may not be copied, reproduced or

Prepared by: Verified and approved by:

Torge Wehrend Senior Engineer Sofien Ben Saad Senior Engineer

Copyright © DNV 2023. All rights reserved. Unless otherwise agreed in writing: (i) This publication or parts thereof may not be copied, reproduced or transmitted in any form, or by any means, whether digitally or otherwise; (ii) The content of this publication shall be kept confidential by the customer; (iii) No third party may rely on its contents; and (iv) DNV undertakes no duty of care toward any third party. Reference to part of this publication which may lead to misinterpretation is prohibited.

The information in this document is classified as: ☐ Open ☐ DNV Restricted ☒ DNV Confidential ☐ DNV Secret Additional authorised personnel for distribution within DNV:

Renewables Certification

Can the document be distributed internally within DNV after a specific date? ☒ NO ☐ YES

Keywords GCC, Certification, Low Voltage Ride Through, LVRT, Fault Ride Through, FRT,

GCC, VDE-AR-N 4110, VDE-AR-N 4120, FGW TG8, inverter

Rev. no. Date Reason for issue Prepared by Verified and approved by 0 2023-05-15 First issue Torge Wehrend Sofien Ben Saad 1 2023-07-26 Updating the chapter 5.3 Torge Wehrend Sofien Ben Saad

Digitally signed by Wehrend, Torge Date: 2023.07.26 13:59:33 +02'00'

Ben Saad, Sofien 2023.07.26 14:01:46 +02'00'DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page ii

DNV Renewables Certification is the trading name of DNV’s certification business in the renewable energy industry. The certification body is DNV Renewables Certification GmbH, Brooktorkai 18, 20457 Hamburg with organisational control to other entities within the DNV Group.

Table of contents 1 EXECUTIVE SUMMARY................................................................................................................................... 2 2 ASSESSMENT CRITERIA ................................................................................................................................ 2 3 SCOPE OF ASSESSMENT .............................................................................................................................. 3 3.1 General 3 4 GENERAL INFORMATION ............................................................................................................................... 4 4.1 Schematic description of the generating unit 4 4.2 Technical data of main components 4 4.3 Performed tests, test setup 5 5 ASSESSMENT ACCORDING TO FGW TG8, REV. 9 (A.1.2.7.3.1 AND A.2.2.7.3.1) ....................................... 6 5.1 Remaining on the grid 8 5.2 Reactive current control 8 5.3 Feed-in of fault current 9 5.4 Limited dynamic grid support 11 5.5 Multiple faults 12 5.6 Contribution to short-circuit current (A.1.2.7.4.1 and A.2.2.7.4.1) 13 6 CONDITIONS .................................................................................................................................................. 15 7 CONCLUSION ................................................................................................................................................ 16 8 REFERENCES ................................................................................................................................................ 17 9 ANNEX ............................................................................................................................................................ 18DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 2

1 EXECUTIVE SUMMARY The purpose of this certification report is to document the assessment of the low voltage ride-through (LVRT) as well as the high voltage ride-through (HVRT) capability of the inverters of the type HUAWEI SUN2000-330KTL-H1/-H2. In addition to LVRT and HVRT, this report also uses the general term fault ride-through (FRT).

the high voltage ride-through (HVRT) capability of the inverters of the type HUAWEI SUN2000-330KTL-H1/-H2. In addition to LVRT and HVRT, this report also uses the general term fault ride-through (FRT). Grid code requirements other than the FRT capability are not part of this report. The control behaviour and other grid code requirements are assessed within the scope of the certification report CR-GCC-TR8-09667-A067. The documented results of the type tests and the corresponding manufacturer’s documentation were assessed according to the assessment criteria of the guidelines in section 2. The result of the assessment is stated at the end of this certification report, which gives a recommendation as part of the final certification decision. 2 ASSESSMENT CRITERIA /A/ VDE-AR-N 4110: Technische Regeln für den Anschluss von Kundenanlagen an das Mittelspannungsnetz und deren Betrieb (TAR Mittelspannung), VDE Verband der Elektrotechnik Elektronik Informationstechnik e.V., vom November 2018 (VDE-AR-N 4110 Technical requirements for the connection and operation of customer installations to the medium voltage network (TCR medium voltage)) /B/ VDE-AR-N 4120: Technische Regeln für den Anschluss von Kundenanlagen an das Hochspannungsnetz und deren Betrieb (TAR Hochspannung), VDE Verband der Elektrotechnik Elektronik Informationstechnik e.V., vom November 2018 (VDE-AR-N 4120 Technical requirements for the connection and operation of customer installations to the high voltage network (TCR high voltage)) /C/ FGW TG3: Technische Richtlinie für Erzeugungseinheiten und -anlagen, Teil 3: Bestimmung der elektrischen Eigenschaften von Erzeugungseinheiten und -anlagen, Speicher sowie für deren Komponenten am Mittel-,

/C/ FGW TG3: Technische Richtlinie für Erzeugungseinheiten und -anlagen, Teil 3: Bestimmung der elektrischen Eigenschaften von Erzeugungseinheiten und -anlagen, Speicher sowie für deren Komponenten am Mittel-, Hochund Höchstspannungsnetz, Fördergesellschaft Windenergie und andere Dezentrale Energien (FGW), Revision 25, vom 01.09.2018 (FGW Technical Guidelines, Part 3: Determination of the Electrical Characteristics of Power Generating Units and Systems, Storage Systems as well as their Components in Medium, High and Extra-High Voltage Grids) /D/ FGW TG8: Technische Richtlinie für Erzeugungseinheiten und -anlagen, Teil 8: Zertifizierung der elektrischen Eigenschaften von Erzeugungseinheiten und -anlagen, Speicher sowie für deren Komponenten am Stromnetz, Fördergesellschaft Windenergie und andere Dezentrale Energien (FGW), Revision 9, vom 01.02.2019 (FGW Technical Guidelines, Part 8: Certification of the Electrical Characteristics of Power Generating Units and Systems, Storage Systems as well as their Components on the Grid)DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 3

3 SCOPE OF ASSESSMENT 3.1 General The assessment of the fault ride-through capability of the inverter HUAWEI SUN2000-330KTL-H1/-H2 contains an assessment of the following: • The completeness of documents and measurements • The plausibility of the documents received • The compliance of the test conditions of the documents with those listed in section 2 • Assessment of the measurement results against the requirements and guidelines listed in section 2DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 4

4 GENERAL INFORMATION

• Assessment of the measurement results against the requirements and guidelines listed in section 2DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 4

4 GENERAL INFORMATION 4.1 Schematic description of the generating unit The Huawei solar inverter family SUN2000-330KTL-H1/H2, consisting of: SUN2000-330KTL-H1, SUN2000-330KTL-H2 convert electrical energy generated by photovoltaic modules (DC) to three-phase alternating current (AC). The rated output voltage is 800 V. The inverter type SUN2000-330KTL-H1 was tested for the default rated active power of 300 kW, but the maximum active power limit can be increased up to the apparent power limit of 330 kVA when the ambient temperature is below 30 degrees Celsius. The electrical data of the generating unit is summarized in the following section. 4.2 Technical data of main components Technical data of the main components of the HUAWEI SUN2000-330KTL-H1/-H2 is given below, as provided in the Manufacturer’s Information /3/. Table 4-1 General Specifications Generating Unit SUN2000-330KTL-H1 SUN2000-330KTL-H2 No. of phases 3 3 Max. apparent power 330 kVA 330 kVA Rated active power 300 kW 275 kW Rated AC-voltage (phase to phase) 800 V 800 V Rated frequency 50 Hz 50 Hz Rated current 216.6 A 198.5 A Contribution to short circuit current 238.2 A 238.2 A

Table 4-2 DC Input Generating Unit SUN2000-330KTL-H1 SUN2000-330KTL-H2 Min. DC input voltage 500 Vdc 500 Vdc Max. DC input voltage 1500 Vdc 1500 Vdc Max. DC input current 656 A 656 A

Generating Unit SUN2000-330KTL-H1 SUN2000-330KTL-H2 Min. DC input voltage 500 Vdc 500 Vdc Max. DC input voltage 1500 Vdc 1500 Vdc Max. DC input current 656 A 656 A

Table 4-3 Inverter-Power section Generating Unit SUN2000-330KTL-H1 SUN2000-330KTL-H2 Manufacturer HUAWEI HUAWEI Type name SUN2000-330KTL-H1 SUN2000-330KTL-H2 Generic type Transformerless Transformerless Pulse rate of inverter 14.1 kHz 14.1 kHz Software Version V500R023C00 V500R023C00

Table 4-4 Software version Firmware version V500R023 Software version V500R023C00DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 5

Table 4-5 Disconnection device Generating Unit HUAWEI SUN2000-330KTL-H1/-H2 Manufacturer HongFa Type HF192F12-H3F The transformer is not part of the generating unit and consequently has not been part of the assessment. The grid protection is integrated into the control of the generating unit. All parameters are documented in the “Parameter list SUN2000-330KTL-H1/-H2”/4/. 4.3 Performed tests, test setup The Fault Ride-Through (FRT) tests were performed on a HUAWEI SUN2000-330KTL-H1/-H2 inverter by DNV China Company Limited at the Huawei lab in Shanghai according to the requirements of the FGW TG3 /C/. The undervoltages and overvoltages were generated by a grid emulator (controlled voltage source) directly connected to the 800 V terminals of the inverter.

Company Limited at the Huawei lab in Shanghai according to the requirements of the FGW TG3 /C/. The undervoltages and overvoltages were generated by a grid emulator (controlled voltage source) directly connected to the 800 V terminals of the inverter. The 2-phase faults described in this report were realised on the LV side by the customer’s grid emulator in such a way as if the fault had occurred on the MV side of a delta-star (Dy) transformer. A two-phase fault on the MV side (type C) therefore translates to a fault of type D on the LV side. (Refer to Figure D-3 out of the FGW TG3 /C/ given in the Figure 4-1).

Figure 4-1: Transformation of a phase-to-phase fault clear of earth through a Dy transformer The FRT tests were performed in accordance with the requirements of the FGW TG3 /C/. All tests required by FGW TG3 /C/ have been performed.DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 6

5 ASSESSMENT ACCORDING TO FGW TG8, REV. 9 (A.1.2.7.3.1 AND A.2.2.7.3.1) The following tables summarise the general assessment criteria and the results of the assessment. The tables were extracted from the FGW TG8 /D/. For this reason, the numbering given is not consecutive. The other tables on remaining on the grid, feed-in of fault current, limited dynamic grid support, multiple faults, and contribution to shortcircuit current can be found in the corresponding chapters of this report. For the following tables the assessments for each of VDE-AR-N 4110 /A/ and VDE-AR-N 4120 /B/ have been combined, as they are basically identical. Table 5-1 General criteria No Evaluation criteria Acceptance criteria Assessment result 1 Self-protection allows operation between the lower and upper FRT boundary curves.

as they are basically identical. Table 5-1 General criteria No Evaluation criteria Acceptance criteria Assessment result 1 Self-protection allows operation between the lower and upper FRT boundary curves. The tests required by the VDE regulations /A/ and /B/ have been successfully completed Compliant. See measurement report /2/. 2 FRT tests were successfully carried out with pre-fault reactive power inside the range of ±10% PrE. True Compliant. See measurement report /2/. 3 An FRT test was successfully carried out with the maximum underexcited and one with the maximum overexcited reactive power according to the manufacturer's specification (or with cos φ ≤0.95 overexcited or underexcited, as long as the capacity of the PGU is higher). True Compliant. See measurement report /2/. 4 The behaviour of the PGU or the component in the event of abrupt voltage changes was verified by a voltage swell of at least 10 % Un to a value > 110 % Un for symmetrical voltage increases and to ≥ 110 % Un as the greatest phase-to-phase voltage for asymmetrical voltage increases with a duration of ≥ 5 s. Minimum duration ≥ 5s Compliant. See measurement report /2/. Please refer A) below for further explanations. 4.1 Starting from 2021-01-01, should the PGU be commissioned as part of a PGS, ride-through of a symmetrical voltage swell by at least 15 % Un to a value > 115 % Un for ≥ 5 s or ≥ 115 % Un for ≥ 60 s has to be proved additionally in the form of a manufacturer's declaration. True Compliant. 4.2 It is shown under which assumptions a ride-through of a symmetrical voltage swell of at least 15 % Un up to a value > 115 % Un for ≥ 5 s or ≥ 115 % Un for ≥ 60 s is possible or not possible.

True Compliant. 4.2 It is shown under which assumptions a ride-through of a symmetrical voltage swell of at least 15 % Un up to a value > 115 % Un for ≥ 5 s or ≥ 115 % Un for ≥ 60 s is possible or not possible. True No assumptions. Is always possible. 5 The correct behaviour in the transition from dynamic to quasistationary operation of the generating units must be demonstrated for a symmetrical voltage dip with a minimum duration of ≥ 60 s by reducing the grid voltage to a value between 85 % and 90 % Un. True Compliant. See measurement report /2/. 6 The correct behaviour in the transition from dynamic to quasistationary operation of the generating units must be demonstrated for a symmetrical voltage swell by increasing the grid voltage to a value ≥ 110 % Un for ≥ 60 s. True Compliant. See measurement report /2/. 7 During the fault, the PGU feeds a reactive current as required (see the following table for type 2). True Compliant. 8 The PGU can ride through multiple faults in accordance with the requirements. True Compliant. See measurement report /2/. A) After an abrupt voltage change, the voltage reference value (1min average voltage), which is used for calculating the additional reactive current, is frozen for one second /5/. In the event off another abrupt voltage change (over 5%) within this 1 second, the reactive current feed-in takes place based on the frozen reference voltage value /5/.DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 7

Table 5-2: Additional Requirements for Type 2 No Additional evidence Acceptance criteria Assessment result A The tests according to FGW TG3 /C/ were carried out without disconnecting the PGU from the grid. With that, the FRT capability of the auxiliary drives used in the measurement is proven.

Table 5-2: Additional Requirements for Type 2 No Additional evidence Acceptance criteria Assessment result A The tests according to FGW TG3 /C/ were carried out without disconnecting the PGU from the grid. With that, the FRT capability of the auxiliary drives used in the measurement is proven. True All tests required according to FGW TG3 /C/ were performed without disconnection from the grid. See measurement report /2/ and. B A voltage-time characteristic (capacity of the PGU) is available. The manufacturer's specification should at least correspond to the required capacity defined in the VDE regulations /A/ and /B/. Manufacturer’s information available. (if necessary under conditions at PGS level) Specification has been made and corresponds to the required capacity. See Figure 5-1 below as well as manufacturer’s declaration /1/. The voltage time characteristics for HVRT (OVRT) and LVRT (UVRT), given in the manufacturer’s declaration /1/, is at the Figure 5-1.

Figure 5-1: HVRT and LVRT voltage over time characteristicsDNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 8

5.1 Remaining on the grid For type 2 PGUs the following applies: Table 5-3: Remaining on the grid No Evaluation criteria Acceptance criteria Assessment result Remaining on the grid 1.1 The PGU does not become unstable and does not disconnect from the mains as long as all line-to-line voltages are within the limit curve required by the VDE regulations /A/ and /B/. The tests required by the VDE regulation /A/ and /B/ have been successfully completed. All required FRT tests were successfully completed. See measurement reports /2/. 1.2 All UVRT (LVRT) and OVRT (HVRT) tests have been fully

The tests required by the VDE regulation /A/ and /B/ have been successfully completed. All required FRT tests were successfully completed. See measurement reports /2/. 1.2 All UVRT (LVRT) and OVRT (HVRT) tests have been fully completed. True All UVRT and OVRT tests were carried out completely. See measurement reports /2/. Please refer A) below for further explanations. 1.3 The PGU did not disconnect from the grid during all UVRT tests. True In all UVRT tests there was no disconnection from the grid. See measurement reports /2/. 1.4 The PGU did not disconnect from the grid during all OVRT tests. True In all OVRT tests there was no disconnection from the grid. See measurement reports /2/. None of the documented FRT tests (two-phase or three-phase), including tests with a pre-fault reactive current, led to a shut-down of the inverter. All tests according to FGW TG3 /C/ were carried out twice. The inverter injected reactive current as required by VDE-AR-N 4110 /A/ and VDE-AR-N 4120 /B/ as a result of a continuous voltage regulation (see section 5.2) and did not consume any more inductive reactive power than before the fault. A) The OVRT (HVRT) tests #115.1, #115.2, #110.1, #110.2 according from FGW TG3 /C/ are not listed in the measurement report /2/. However, those tests were performed by Huawei and the raw data was submitted to DNV. There is no disconnection from the grid and a corresponding reactive current injection is performed. Accordingly, all the under and over voltage ride through tests are completed. 5.2 Reactive current control During two-phase and three-phase faults, the inverter injects reactive current in both the positive and negative

DNV. There is no disconnection from the grid and a corresponding reactive current injection is performed. Accordingly, all the under and over voltage ride through tests are completed. 5.2 Reactive current control During two-phase and three-phase faults, the inverter injects reactive current in both the positive and negative sequence, in accordance with the characteristics given by VDE-AR-N 4110 /A/ and VDE-AR-N 4120 /B/. The positive and negative sequence reactive current fed into the fault is proportional to the change in positive and negative sequence voltage, in both the overvoltage and undervoltage cases. The proportionality constant (k-factor), which determines the magnitude of the injected reactive current, was set to 2 for most of the tests. The adjustability of the k-factor was verified, in accordance with FGW TG3 /C/, with further tests at partial power as well as with the k-factor set to 4. The k-factor applies to the reactive current control in both the positive and the negative sequence, but there are different k-factors for the LVRT and HVRT cases. The pre-fault reactive current was correctly taken into consideration for the calculation of the additional reactive current during the faults. Tests were also carried out with limited dynamic grid support activated. For asymmetrical faults, the sum of the absolute values of reactive current in the positive and the negative sequence is limited to 1.0 p.u. in order to prevent any of the phase currents reaching values above 1 p.u. of the nominal current. Faults are detected by using two voltage thresholds for detecting over voltage and under voltage, as well as a threshold for detecting abrupt voltage changes. In all cases, the phase voltages are assessed. The LVRT threshold is set to 0.9Un, while the HVRT threshold is set to 1.1Un. Noticed that there is a hysteresis implemented with a default threshold

of 0.02Un. This threshold is adjustable in the range from 0.02Un to 0.1Un (Un is the rated voltage of the inverter /4/) /3/. The abrupt voltage change threshold is set to 5%.DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 9

5.3 Feed-in of fault current Table 5-4: Feed-in of fault current No Evaluation criteria Acceptance criteria Assessment result Feed-in of fault current Note: It is also permissible to have continuous dynamic grid support in the sense of the following requirements, which is per manently active and active in parallel with steady-state voltage maintenance, independent of fulfilment of the criteria for the fault start and end. 7.1 The rise time of max 30 ms of the additional reactive current in the positive and negative phase sequence system after the start of the fault is provided for each measurement in the measurement report according to TG3 and meets the requirements. True ) All rise times are ≤ 30 ms for the tests described in the measurement reports /2/. Please refer A) below for further explanations. () 7.2 The settling time of max 60 ms of the additional reactive current in the positive and negative phase sequence system after the start of the fault is provided for each measurement in the measurement report according to TG3 and meets the requirements. True ) All settling times are ≤ 60 ms for the tests described in the measurement reports /2/. Please refer A) below for further explanations. () 7.3 For all measurements according to TG3 where the required k-factor may not be possible to be reached due to a current limitation, a reactive current having the value of the rated current must be injected on each (affected) phase. (VDE 4110 /A/ section 10.2.3.3.2, 7th bullet point as well as VDE

k-factor may not be possible to be reached due to a current limitation, a reactive current having the value of the rated current must be injected on each (affected) phase. (VDE 4110 /A/ section 10.2.3.3.2, 7th bullet point as well as VDE 4120 /B/ section 10.2.3.3, 7th bullet point) True Please refer A) below for further explanations. 7.4 (MV) From section A.1.2.7.3.1 of TG8 /D/ (medium voltage): The additional positive and negative reactive current fed into the grid must comply with the limits specified in Annex C.1 of VDE 4110 /A/ (To be proven for voltage excursions with fault voltages ≥ 15% Un bis 120% Un). The limits according to Appendix C.1 of the VDE 4110 /A/ were observed for all measurements. Tolerance bands are not exceeded in any of the tests. See measurement report /2/. 7.4 (HV) From section A.2.2.7.3.1 of TG8 /D/ (high voltage): The rise time of a maximum of 30 ms of the additional positive and negative reactive current after onset of fault is to be reported according to TG3 /C/ for each test. (this criteria is identical to 7.1 above) Rise times of sliding rms values shall be ≤ 50 ms for each test. All rise times are ≤ 30 ms for the tests described in the measurement report /2/. Please refer A) below for further explanations. () 7.5 – 7.10 Not relevant for solar converters. - - 7.11 The rise time of the active current after the end of the fault may be a maximum of 1 s. (VDE 4110 /A/ section 11.2.5.7

7.5 – 7.10 Not relevant for solar converters. - - 7.11 The rise time of the active current after the end of the fault may be a maximum of 1 s. (VDE 4110 /A/ section 11.2.5.7 and VDE 4120 section 11.2.5.6) True The rise time of the active current after fault clearance is significantly less than 1 s for all tests. See measurement report /2/. 7.12 Continuous dynamic grid support is used. Details provided below Please refer B) below for further explanations. () according to VDE regulation /A/ voltage dips down to a remaining voltage of 0 % are not assessed for reactive current. A) The injected reactive current of the inverter was assessed for two-phase and three-phase faults with a view to rise time and settling time according to FGW TG3 /C/ and FGW TG8 /D/. The voltage dips performed with a remaining voltage magnitude of less than 15 % were not considered for assessment of the reactive current injection. For all two-phase and three-phase faults, the determined rise times and settling times were below 50 ms (except the Case #72, which will be followingly explained) and 80 ms respectively. This assessment is based on the times stated in the measurement report /2/, which have been measured in the fundamental frequency positive sequence system which includes an additional 20 ms for calculation of the sliding RMS value. This means that the rise and settling times to be assessed are determined by subtracting 20 ms of the rise and settling times reported in the measurement report /2/. For the case #48, the settling time is also less than 60ms which shown in Figure 5-3, According to the VDE regulations /A/ and /B/ therefore, the required rise and settling times are therefore considered to have been met. At the test cases #1, #3, #72, #85, and #8, #10,

than 60ms which shown in Figure 5-3, According to the VDE regulations /A/ and /B/ therefore, the required rise and settling times are therefore considered to have been met. At the test cases #1, #3, #72, #85, and #8, #10, #12, #14, the calculated k-factors were smaller than two due to the limit of reactive current injection which the algorithms of FRT control strategy is illustrated in Figure 5-2.DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 10

B) The FRT control strategy implemented in the tested solar inverter is given in Figure 5-2 and is compliant to the VDE 4110 /A/ and VDE 4120 /B/.

Figure 5-2: Control strategy for FRT /3/ In Figure 5-2, for asymmetric faults the positive reactive current 𝐼𝑞+ and negative reactive current 𝐼𝑞- are limited to IN separately in the first equation. The tests documented in the measurement report /2/ demonstrate that the control strategy depicted in the figure above was followed. In some asymmetrical cases, 𝐼𝑞+ and 𝐼𝑞- does not decrease steadily (keep the same ratio) if one or both of the 𝐼𝑞+ and 𝐼𝑞- components exceed the rated current IN. This can be accepted as it is not a strict requirement, and the differences are not very significant. The tests documented in the measurement report /2/ demonstrate that the control strategy depicted in the figure above was followed.

Figure 5-3: Positive sequence reactive current and voltage of case #48 /2/DNV – Report No. CR-GCC-TR8-09667-A066-1 – www.dnv.com Page 11

Table 5-5: Additional Requirements about k-factor No Additional evidence Acceptance criteria Assessment result

Table 5-5: Additional Requirements about k-factor No Additional evidence Acceptance criteria Assessment result C The proportionality factor k is adjustable between 2 and 6 in steps of 0.5 or smaller. True The k-factor can be adjusted between 0 and 10 in steps of 0.1 for LVRT and between 0 and 6 for HVRT. In both cases the step size is 0.1. See parameter list /4/. D The adjustability of the k-factor must be proven through tests with different k-factors (k=2 and k=4). They have to be carried out in accordance with TG3. (Manufacturer’s declaration) The adjustability has been proven by the corresponding tests. See measurement report /2/. The proportionality factor, designated as k, which determines the level of the reactive current fed into the grid, was set to a value of k = 2 in the majority of the tests. The k factor can be set between 0 and 10. To prove the adjustability, the tests required according to FGW TG3 /C/ were carried out with test case number 75.5 (Case #36) and 75.8 (Case #42) and 110.4 (Case #87) and 115.1 (Case #76) with k = 4. The pre-fault reactive current was correctly considered by the FRT controller for the calculation of the additional reactive current during FRT events. This has also been proven by the test case numbers 75.3 (Case #32) and 75.4 (Case #34) as required by the FGW TG3 /C/. The reactive power before the emulated fault was ±0.67 p.u.. The active power output during these tests was 0.2 p.u. which corresponds to a power factor