Islanding Scheme Covering Bengaluru Metropolitan Area
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Southern Regional Power Committee Bengaluru Minutes of the Meeting to deliberate on Islanding Scheme for Bangalore, held on 16.02.2021 through WebEx. A meeting to discuss formation of Islanding Scheme for Bangalore was held on 16.02.2021 under the chairmanship of Member Secretary (MS), SRPC in on-line mode though WebEx. The list of participants is attached at Annexure-I. 2. MS, SRPC welcomed all the participants to the meeting. He informed the forum that in the meeting held on 28.12.2020, to review Islanding Schemes in the country, Hon’ble Minister of State (IC) for Power and New & Renewable Energy, Government of India directed that Islanding Schemes should be designed for all major cities of the country, including Bangalore. Accordingly, SRPC was directed to take steps for devising an Islanding scheme covering Bangalore area. Member Secretary pointed out that absence of embedded generation has been a major drawback to have islanding scheme in Bangalore. However, considering the economy-driving aspects of Bangalore, like IT sector, Medical companies, Laboratories, Defence installations, and metro rail, etc., it is sensible to design and put in place an apt Islanding scheme for Bangalore area so that all its major loads can be guaranteed to remain immune to external grid failures. 3. Then, Superintending Engineer (P&SS), SRPC presented the philosophy adopted in identifying the Islanding Schemes that are under operation in Southern Region (SR), and detailed the guidelines being followed to form Islanding. The salient aspects, as given under, were explained: Approved Islanding Schemes in southern region are non-adaptive in nature. That is Islands are formed with anticipated load-generation balance and with tripping of predetermined feeders/ ICTs/ generators. Islanded system should preferably have 20% excess generation than load. Islanding scheme should preferably have a good mix of Thermal–Hydro–Gas based generation. Under Frequency Relays (UFRs), meant for giving load relief, should not be present on the Islanding feeders. Island should be formed by tripping minimum number of lines. Generators in the Islanded system should be kept on FGMO/RGMO. Load flow studies are to be carried out for verifying the operation of the Islanded system. Wind/ solar generating feeders shall not form part of Islanding Scheme; hence incoming wind/ solar feeders to the substation are to be tripped at Islanding Frequency. All generation shall go to House-Load in the unavoidable eventuality of unsuccessful formation of Island. If the frequency rises above 52 Hz even after FGMO/RGMO operation (due to non- availability of anticipated loads at the time of separation), high-frequency time-graded tripping of generators is to be carried out. Minutes of the Meeting to deliberate Islanding Scheme for Bangalore held on 16.02.2021 1/3 4. SE (P&SS) stated that keeping above in view, a preliminary analysis was made w.r.t. the proposed Islanding Scheme for three scenarios. First case considering Bangalore exclusively, second case considering Bangalore and Mysore together and third case covering entire Karnataka state. The quantum of loads considered for these three scenarios based on latest PSSE ATC Basecase data were presented as below: Area Avg. Peak df/dt Load AUFR Load Load Anticipated Load in MW Relief in MW Relief in MW Diversity Load in MW (a) (b) (c) Factor [=dx(a-b-c)] (d) Bengaluru 3434 976 672 1 1786 Extended 4038 1180 928 1 1930 Bengaluru (Bengaluru & Mysore) Karnataka State 9657 1476.88 3221.18 1 4959 For each of the above cases, the details of the generators (with their actual PLF’s as furnished by concerned SR-Utilities) to be considered in suitable combinations so as to maintain requisite LGBR in the proposed Island were explained as below: Bangalore Island Option 1: Suitable Generation including Talcher Option 2: Suitable Generation excluding Talcher Extended Bengaluru (Bengaluru & Mysore) Island Option 1: Suitable Generation including Talcher Option 2: Suitable Generation excluding Talcher Karnataka State Island The LGBR in the proposed Island for above five cases is as follows: Case Area Participating Generators Anticipated Anticipated No. Generation Load, MW (MW) 1 Bengaluru T,K,S 2180 1786 2 Bengaluru R,B,K,S 1985 1786 3 Extended T,U,S 2180 1930 Bengaluru (Bengaluru & Mysore) 4 Extended K,B,R,U,S 2345 1930 Bengaluru (Bengaluru & Mysore) 5 Karnataka K,T,B,R,U,S,Y,N,V,Ka, OH 5660 4959 State Desired Island formation by tripping requisite lines/ ICT’s for all above cases was demonstrated. Minutes of the Meeting held on 16.02.2021 to deliberate Islanding Scheme for Bangalore 2/3 In this regard, SLDC, KPTCL suggested that Varahi hydel station would be a good generation source to be included in the island(s) considering the Pelton wheel turbines available there, which would facilitate flexibility within island. Constituents also expressed that generation from Talcher (Stage-II) through Talcher- Kolar HVDC link is a dependable one, and should be included in the proposed Island. Further, it was also noted that the no. of elements to be tripped would be limited, if Talcher generation is taken into account. The details of the presentation made by SRPC are given at Annexure-II. 5. CGM, SRLDC stated that formation of Bangalore island was under consideration for a long time and still it remains to be a big challenge. The options of considering small area islands and big area island covering whole Bangalore were indeed challenging. Small islands integration would also pose a problem. 6. Subsequently, SRLDC presented three cases of islanding within Bangalore, viz., Kolar-HVDC Island (1800 MW load- have to restrict load to 1200 MW), Yelahanka Island (310 MW load) and Nelamangala Island (1100 MW load). SRLDC pointed out that the schemes ought to be adaptive. SRLDC stated that regarding Kolar-HVDC island, viability of operation in frequency control mode may be confirmed from the officers concerned at PGCIL, Kolar HVDC. Also the dynamic nature of the HVDC need to be considered, in addition to the load generation balance. Another concern would be the short circuit level in the Kolar, Somanahalli and Hoody substations proposed to be covered under the Kolar-HVDC island. Load would be decided based on no. of units available at Talcher. It was mentioned by SRLDC that under Nelamangala island Peenya, Devanahalli area and, if required, Mysore area could also be considered. The loads would be fed through 400kV BTPS-Jindal-BPS – Chikanayakahalli - Nelamangala D/C, 400kV Talaguppa - Chikanayakahalli- Nelamangala D/C and 400kV Nelamangala - Bidadi D/C. Generation to be decided at BPS based on unit availability. Would sense number of units available at RTPS, BTPS, Jindal and depending on units available, 400kV lines to be tripped at BPS end. Yelahanka island would be considered along with the upcoming Yelahanka gas generating plant (1X370 MW). To this, SLDC, KPTCL pointed out that the upcoming Yelahanka CCGP would be unlikely on bar continually (i.e., it may operate at low PLF). SE(MRT), KPTCL also opined that the sub-islands, within Bangalore, as proposed could be considered, including generation at Varahi HEP and UPCL (Thermal). The details of the presentation made by SRLDC are given at Annexure-III. 7. BESCOM was requested to identify important and critical loads and feeders in Bangalore, which would be an essential input. 8. During the discussion, MS, SRPC stated that as it would be difficult to predict success of any island and also Bangalore islanding being a special case, a scheme for Bangalore islanding has to be devised and implemented without having any preconceived notion about island formation. He suggested for forming a larger island at frequency before 47.9 Hz, and then forming smaller islands at usual islanding frequency i.e. 47.9 Hz. Minutes of the Meeting held on 16.02.2021 to deliberate Islanding Scheme for Bangalore 3/3 9. The meeting concluded with the decision to constitute a Task Force, comprising members from SRPC, SRLDC, KPTCL, SLDC-KPTCL and BESCOM to study in detail the options presented, viz., Bengaluru Island, Karnataka State Island and the sub-Bangalore islands. SRLDC suggested that HVDC, Kolar Officials may also be invited to the meeting of the Task Force. ***** Minutes of the Meeting held on 16.02.2021 to deliberate Islanding Scheme for Bangalore 4/3 ANNEXURE-I SRPC Meeting to deliberate Islanding Scheme for Bangalore held on 16.02.2021 List of Participants Sl. No. Name Designaton Organisation Phone Email 1 S.P.Kumar CGM SRLDC, POSOCO 9449599163 [email protected] 2 Goodelli Madhukar Chief Manager SRLDC, POSOCO 9449599194 [email protected] 3 M. Pradeep Reddy Manager SRLDC, POSOCO 4 L Sharath Chand Manager SRLDC, POSOCO 5 Uday Trivedi Vice President UPCL-Adani Power Limited 9099055054 [email protected] 6 M Shanthi CEE RT&R&D KPTCL 9448365163 [email protected] 7 BV Girish SEE RT Zone KPTCL 8277893665 [email protected] 8 Nagaraj MC i/c SEE, RT Circle KPTCL Bengaluru 9448365077 [email protected] 9 Pushpa S EEE RT KPTCL 9480812570 [email protected] 10 Rajeshwari bhat AEE RT KPTCL 9448365116 [email protected] 11 Sumana Bhat AEE RT KPTCL 9448365110 [email protected] 12 Vidya M J AE RT KPTCL 9480813622 [email protected] 13 K.S.Shenoy SEE KPCL 9449599083 [email protected] 14 Channabasavarju EEE KPCL 9481547035 [email protected] 15 Rajgopal S EEE KPCL 9449755384 [email protected] 16 Pradeep M AE KPCL 9141607644 [email protected] 17 Krishnegowda L K AE KPCL 9141607619 [email protected] 18 A. BALAN Member Secretary SRPC [email protected] 19 N R L K PRASAD Superintendenting Engineer SRPC [email protected] 20 LEN. J.B Executive Engineer SRPC 9449682204 [email protected] 21 BETSY SEBASTIAN Assistant Executive Engineer SRPC [email protected] Annexure-II Islanding Scheme covering Bengaluru Metropolitan area A.