S.No. Powergrid's Comments Alstom's replies

1 Noted and Incorporated.

2

3

4

5 The functionality check of redundant Ethernet port of PMU may be included. Shall be demonstrated.

6

7 As per TS, cyber security audit by Cert-in certified third party auditors is to be performed during FAT.

8 Continuous 100 hour availability test is to be performed during FAT.

As per cl.8.6.1.3 of TS (FAT methodology for PMUs and Substation equipment), all functional and routine tests have to beconducted as part of PMU FAT. Functionality check includes checking of hardware for correct functioning and ensuring that application specificsoftware settings have been applied.(refer ALSTOM manual for PMU). Routine tests as given in p.96 of TS have been considered for FAT.

Routine tests as given in p.96 of TS have been considered for FAT in line with Approved FAT procedure for PMU panels.

As per Cl.1.3 of POWERGRID- URTDSM-A/GEN-3-500 Rev.D dt. 13.11.2014, sub-station specific configuration files shall be preparedoffline for the PMUs based on Annexure-2 of approved BOQ for a specific sub-station and downloaded to the PMU for testing.However, as per MQP annexure submitted for approval by ALSTOM, the tests are proposed to be carried out on default settings.This needs to be reviewed.

The availability of a stable and accurate timing signal is critical for testing the PMUs as deficiencies in timing signal are liable tobe attributed to PMU. The PMUs synchronize to 1pps timing signal from GPS. Therefore, all its current and voltage inputs mustalso synchronize with the same signal. Hence, the GPS signal may be fed to both the PMU and test set generating voltages andcurrents using splitter circuit to ensure a source signal accuracy better than 0.2% TVE(total vector error).The test setup proposed may ensure this important requirement.

These tests form part of Functional type tests, which have been performed at VTU, USA and witnessed by Powergrid and consultants (Mr.Phadke and team).

The criteria for acceptance of PMU metered values vis-à-vis measured values in software may be given in the proposed FATdocument Rev.D dt. 13.11.2014.

PMU measured values shall match with those measured in Source Test kit's software.

While verifying the communication port operation of PMU, the acceptable accuracy level for measurement of voltages, currents,frequency and ROCOF read through data analyzer software vis-à-vis Omicron measured values may be specified in FATdocument Rev.D dt.13.11.2014.

Accuracy levels have been verified during the Functional type tests performed at VTU, USA. During FAT, PMU measured values shall match with those measured in Source Test kit's software.

It may be confirmed whether Phasor terminal software (available at www.alstom.com) is being used for capturing data stream transmissionfrom Ethernet port.

Open PDC shall be used as PMU data analyser software, as it is compatible with various makes of Phasor Measurement Units.

This shall be applicable for PDC software of WAMS (supplied by Alstom NMS team at Noida)

This shall be part of Availability test to be conducted at site during installation and commissioning.