Record notes of discussions on the SPS for Adani Power Tiroda held on 22nd August 2014 at WRPC Mumbai.

A meeting was held at WRPC, Mumbai on 22nd Aug 2014 to discuss the issues involved in the proposed SPS at APL Tiroda. List of participants is enclosed at Annexure-I. Member Secretary, WRPC welcomed the participants and suggested that APL and MSETCL may brief on the conditions envisaged in the proposed SPS and the already implemented SPS for APL Tiroda. He further stated that 5th unit of APL Tiroda is expected to be synchronized shortly and therefore the likely scenario of the flows and commissioning of the remaining transmission system associated with APML needs to be updated by APL/MSSLDC. As far as system contingencies are concerned there are two corridors for evacuation of power from APL Tiroda namely 400kV Tiroda-Warora 400kV D/C and 765kV Tiroda Akola S/C and therefore while finalizing SPS loss of 765kV Tiroda-Akola2 or loss of 400kV Tiroda-Warora circuits would be required to be considered. APML stated that the 5th unit of 660 MW is likely to be synchronized within next 20 days. He informed that the 765/400 kV Ektuni substation is yet to be commissioned, therefore 765 kV Akola-Taptithanda line is presently charged at 400 kV and the 2nd circuit of 765 kV Tiroda-Akola2 is likely to be commissioned by end of September 2014. Thus evacuation of 5x660 MW units at APML Tiroda, presently, would be through the 400 kV Tiroda-Warora D/C (Quad) and 765 kV Tiroda-Akola2 S/C. MSSLDC representative informed that at present 4 units of 660MW APL Tiroda (3 units on bus connected to 400kV Warora & 1 Unit on bus connected to 765kV Akola2) are in operation. The 765 Tiroda bus is connected to 400kV Tiroda Bus with 1500MVA 765/400kV ICT. The power flow pattern with 4 units on bar and exbus generation of @2400MW at APL Tiroda is as follows 400kV Tiroda- Warora D/C =>> 1400MW 765kV Tiroda Akola2 S/C =>>1000MW The synchronization/commissioning of 5th Unit would result in increase in flow on 765kV Tiroda Akola2 S/C by around 400MW and around 150 MW on 400kV Tiroda- Warora D/C under normal system conditions. In view of the loading of lines emanating from 400 kV Akol-1 after commissioning of the 5th unit at APML Tiroda, a Special Protection Scheme has been envisaged and approved by MSETCL. He explained that as per the scheme manual / automatic backing down would be carried out at Tiroda / India bulls depending upon the loading of lines emanating from Akola1. He further informed that PPA for 2645 MW (exbus) has been signed by MSEDCL with APL Tiroda. General Manager WRLDC stated that with present generation level of 2400 MW at Tiroda and loading on 765 kV Tiroda-Akola2 of the order of 1000 MW & loading on 400 kV Tiroda-Warora D/C of the order of 1400 MW, there is a risk of losing entire Tiroda power station in the event of

loss of 765 kV Tiroda-Akola2 S/C as it occurred on 20th May 2014. He expressed concern on the n-1-1 insecure operation of Tiroda power station with injection of 2645 MW and only three outlets from Tiroda. He also stated that the angular separation between 765 kV Tiroda and Akola2 leads to difficulty in quick restoration of the 765 kV line after tripping. APML stated that an SPS for overloading of 400 kV Tirora-Warora lines is already implemented. As per the scheme there are three stages as below:

• Stage-I Alarm is generated when loading is more than 926 MW per ckt • Stage-II Automatic backing down of 300MW when loading is more than 1020

MW per ckt with a time delay of 3 seconds • Stage-III One unit would trip if loading is more than 1480 MW per ckt. with time

delay of 600 ms Member Secretary WRPC stated that till the 765kV Tiroda-Akola 2nd circuit is commissioned, the contingency of loss of 765kV Tiroda-Akola2 and loss of 400kV Tiroda-Warora lines needs to be considered with a generation dispatch of 2645MW (Power Purchase agreement quantum) for arriving at the backing down quantum required at APL Tiroda. SE (Protection), WRPC observed that there is a possibility of Tiroda units losing synchronism with the grid under transient conditions in the event of contingency of loss of 765 kV Tiroda-Akola2 S/C due to sudden transfer of loads from 765kV Tiroda-Akola2 to 400kV Tiroda-Warora D/Cs. However this needs to be validated by carrying out studies. APL agreed to examine the suggestion. MSETCL and WRLDC representatives felt that the in case of contingency of loss of 765kV Tiroda-Akola2, the generation should be brought down to a level so as to ensure system security. APML representative stated that there was a risk of tripping of units during fast ramping down from 2645 MW to 1800 MW. After deliberations, APML agreed to reduce generation to 2100 MW through automatic action in case of tripping of 765 kV Tiroda-Akola2 S/C. They also agreed to back down further if required through manual control in coordination with SLDC-Kalwa. After deliberations it was concluded that; Contingencies required to be considered and the actions suggested for the SPS:

1) Loss of 765kV Tiroda-Akola2 S/C : In this case, APL would backdown the generation to 2200MW exbus, through mill trip and control valve closing. Further manual generation backing down as per instructions of MSSLDC, if felt necessary. The logic for detection of loss of 765kV Tiroda-Akola2 S/C should be appropriately implemented by APL, to accommodate tripping of 765/400kV ICT at Akola2 also and the time delay for initiation of backing down after detection of loss of 765kV Tiroda-Akola2 S/C shall be kept below 1 sec.

2) Loss of 765kV Tiroda-Akola2 S/C and subsequent loss of 400kV Tiroda-Warora S/C: APL would bring down the ex bus generation to a level of 1100MW. The time delay for initiation backing down after detection of the above contingency shall be kept 600 msec.

(Note : The time delays in both contingencies, were introduced only to ensure that false tripping/backing down of units are avoided under transient conditions).

After deliberations APML agreed to reduce the time delays envisaged for the above contingencies.

3) The already approved SPS schemes for APL Tiroda (agreed SPS scheme between MSETCL & APL as intimated vide letter MSLDC/Tech-SO/1198 dated 01st July 2014, NLDC SPS) beyond Wardha and Akola shall remain unchanged.

SE(Protection) WRPC summarized the following information regarding various SPS’s at APL Tiroda;

A) SPS-1 : Envisaged for controlling impact of overloading at Akola & Aurangabad areas : As agreed between MSETCL & APL as intimated vide letter MSLDC/Tech-SO/1198 dated 01st July 2014 (enclosed at Annex-II).

B) SPS-2 : Envisaged for controlling impact of loss of evacuation of lines at APL Tiroda: As agreed at point-1&2 of this MoM above.

C) SPS-3: Envisaged by NLDC for SR-WR emergency conditions : As per NLDC letter NLDC/SR_synch_SPS dated 11.04.2014 (Tabulated at Annex-III)

It was agreed that the envisaged SPS and the necessary revision as above would be implemented by APML Tiroda in coordination with MSETCL before synchronization of the 5th unit at Tiroda. Meeting ended with thanks to the chair.

Annexure-I

LIST OF PARTICIPANTS OF MEETING ON SPS AT TIRODA HELD ON 22.08.2014

Sl.No. Organisation, Name & Designation E-mail Mobile

WRPC 1 Shri S.D. Taksande, M.S. sureshtaksande@gmial.com 9820878384 2 Shri Satyanarayan S., S.E. satyaguru@yahoo.com 9223399938 3 Shri P.D. Lone, E.E. pramod.lone@gmial.com 9867622823

MSLDC 4 Shri N.R. Sonkavday, S.E. n.sonkavday@gmail.com 9987783924 5 Shri D.K. Rokade, S.E. dkrokade@gmial.com 9167831551 6 Shri V.D. Pande, E.E. vasant.pande@mahasldc.in 9820741941

WRLDC/POSOCO 7 Shri P. Mukhopadhyay, G.M. prithwish.pmukh@posoco.in 9869438073 8 Shri Vivek Pandey, C.M. vivek.pandey@posoco.in 9869404673 9 Ms. Pushpa S., C.M. pushpa_seshadri@hotmail.com 9869404482

APL 10 Shri J. Nanda, C.O.O. jayadeb.nanda@adani.com 9099005292 11 Shri A. Mathur, G.M. akshayv.mathur@adani.com 9870663062 12 Shri Uday Trivedi, G.M. uday.trivedi@adani.com 9099055054

AND

AND

AND

India Bulls Line > 500MW

Akola-II to Akola-I Line Loading>800MW

Backdown 150MW at Indiabulls

Backdown 100 MW at Tiroda

Tripping of One Unit at Tiroda

Akola-II to Akola-I Line Loading>1000MW

ANDNOT

OR

Akola-I to Bhusawal Line > 570 MWAkola-I to Aurangabad Line 1 > 570 MWAkola-I to Aurangabad Line 2 > 570 MW

OR

Akola-I to Bhusawal Line > 640 MWAkola-I to Aurangabad Line 1 > 640 MWAkola-I to Aurangabad Line 2 > 640 MW

OR

Akola-I to Bhusawal Line > 700 MWAkola-I to Aurangabad Line 1 > 700 MWAkola-I to Aurangabad Line 2 > 700 MW

Stage-1 Alarm

OR

OR

Akola-I to Bhusawal Line > 640 MWAkola-I to Aurangabad Line 1 > 640 MWAkola-I to Aurangabad Line 2 > 640 MW

OR

Akola-I to Bhusawal Line > 700 MWAkola-I to Aurangabad Line 1 > 700 MWAkola-I to Aurangabad Line 2 > 700 MW