The document outlines the CERC regulations for the deviation settlement mechanism and the related tariff regime, detailing the transition from a two-part tariff to a three-part structure that includes fixed, variable, and unscheduled interchange charges. It describes the complexities of frequency management in the grid, including how penalties are applied for deviations from scheduled generation or consumption. The regulations aim to ensure grid security by minimizing deviations and optimizing generation and distribution of electricity.

1. CERC (Deviation Settlement
Mechanism and related matters)
Regulations,2014 dated 06.01.14
Effective from 17.02.2014
1/18/2016 1ERPC, KOLKATA
S.KEJRIWAL ( Executive Engineer, Commercial), ERPC , Kolkata
Mob: 09831919509
E-mail : sshyam1079@rediffmail.com

2. TARIFF REGIME-BRIEF OVERVIEW
• Two part Tariff since 1992 (K.P.Rao Committee
Report)
• Both Fixed Cost as well as Variable Cost were
charged to the beneficiaries in the proportion
of actual energy drawn by them during a
period
• Generating stations were paid incentive at a
certain rate for any excess generation over
and above the designated PLF
1/18/2016 ERPC, KOLKATA 2

3. TARIFF REGIME-BRIEF OVERVIEW
1/18/2016 ERPC, KOLKATA 3
• Low freq during peak time
• High freq during off-peak time
• Rapid and wide changes in freq ( apprx 1 Hz in
5-10 minutes)
• Frequent grid disturbance resulting in tripping
of generating stations, interruption of supply
to large blocks of consumers and
disintegration of regional grid

4. TARIFF REGIME-BRIEF OVERVIEW
1/18/2016 ERPC, KOLKATA 4
• Govt appoints M/s ECC,USA in 1994 to prepare and
submit a report
• Report concludes faulty tariff regime
• Perpetual conflict of commercial interest
• Suggested implementation of ABT
• Govt constitutes NTF/RTFs in 1995 to study the
report
• Govt pursued its efforts, held due consultations
and finally forwarded the ECC report alongwith
NTF minutes and a note on ABT to CERC in May
1999

5. TARIFF REGIME-BRIEF OVERVIEW
1/18/2016 ERPC, KOLKATA 5
• The matter was heard in CERC from 26-28th of
July,1999
• CERC issued ABT order dated 04.01.2000
• Order stayed various High courts of the
country due to objections/apprehensions
expressed by various SEBs/GENCOs
• Hon’ble Supreme court finally vacated the stay
• ABT implemented in WR wef 01.07.2002 and
than in all other regions

6. ABT TARIFF STRUCTURE:
THREE PART TARIFF:
1. FIXED CHARGE:
• Generators assigned target availability
• Total fixed cost payable to a generator over the year is
linked to the average annual availability. Hence the name
Availability Based Tariff
• Charged to beneficiaries in the proportion of their share in
the generating station
2. VARIABLE CHARGE:
• Charged to beneficiaries to the extent of their drawal
schedule

7. ABT TARIFF STRUCTURE:
THREE PART TARIFF:
3. UNSCHEDULED INTERCHANGE(UI) CHARGE:
• Actual Generation – Scheduled Generation (For
Generators)
• Total Actual Drawal – Total Scheduled Drawal
(For Beneficiaries)
• Worked out for each 15 min time block
• Based on average frequency of the relevant time
block

8. ABT TARIFF STRUCTURE:
THREE PART TARIFF:
3. UNSCHEDULED INTERCHANGE(UI) CHARGE:
• Overdrawal/Underinjection under low freq
(Penalty)
• Overinjection/Underdrawal under high freq (Nil
or low reward)
• Overdrawal/Underinjection under high freq (Nil
or low Penalty)
• Overinjection/Underdrawal under low freq
(Reward)

9. UI ACCOUNTING – PRELIMINARY PROCESS AND
ROLE OF RLDCs:
SCHEDULING:
• Each day of 24 hours starting from 00.00 hours be
divided into 96 time blocks of 15 minutes each
• Each generating station is to make advance declaration
of its capacity for generation in terms of MWh delivery
ex-bus for each time block of the next day
• Based on the above declaration, concerned RLDC shall
communicate to the various beneficiaries their
respective shares of the available capability
• After the beneficiaries give their requisition for power
based on the generation schedules, the RLDC shall
prepare the generation schedules and drawal
schedules for each time block after taking into account
technical limitations and transmission constraints

10. UI ACCOUNTING – PRELIMINARY PROCESS AND
ROLE OF RLDCs:
METERING AND METERDATA PROCESSING:
• All Regional entities including beneficiaries/generators are
responsible for downloading raw meterdata and sending it to
RLDC
• RLDC to further process the data and transmit the processed
data to RPC for accounting purpose
• RLDC to also send time block wise frequency for each day of the
week along with time block wise schedule for each regional
entity for each day of the week
• RLDC to also intimate any discrepancy with respect to
addition/outage of any line in the network of any entity, outage
of any generating unit, any erroneous metering, and any other
information having commercial implication

11. UI ACCOUNTING –ROLE OF RPCs:
• Design program as per the relevant CERC Regulation
incorporating various rate/volume capping and UI
rate vector for accounting
• Every week download the processed meterdata
along with schedule and frequency sent by RLDC
• Incorporate the changes/discrepancies in the
network and metering with respect to the previous
week
• Feed inputs(Actual, Schedule and frequency) to the
program

12. UI ACCOUNTING –ROLE OF RPCs:
• Calculate Total Actual drawal/injection, Schedule
drawal/injection and UI/Deviation charges including
additional UI/Deviation charges for each regional entity for
each day of the week
• Calculate Total Actual drawal/injection, Schedule
drawal/injection and UI/Deviation charges including
additional UI/Deviation charges for each regional entity for
entire week
• Apportion any pool surplus/deficit among the beneficiaries
• Issue the final weekly account and publish in the website
• Revise the account as and when required

13. UI MECHANISM: 2003-2013
• Initially freq band fixed at 50.5 – 49 Hz
• Gradually narrowed down to 50.2 – 49.7 Hz
• max UI rate linked to the cost of generation from
diesel or liquid fuel based generating stations
• Altered considering variation in prices of costly
fuel
• ISGS capping of 105% wrt to DC in a time block
and 101% wrt to DC over a day
• Additional UI Charge

14. Replacement of UI Regulations which was in effect
since 17.09.12
Objective:
• Discourage deviation from Schedule
• Operate within the freq band
• Ensure grid security
• Operation of network elements within acceptable limits
Important Changes vis-à-vis UI regulation:
• Buyer/Seller
• Rate vector:
1/18/2016 14ERPC, KOLKATA

15. SL No RATE FOR DEVIATION CHARGE
1 f>=50.05Hz, RDC=0
2 50.05>f>=50.00, RDC increases by 35.6 p/u for each 0.01Hz step
3 50.00>f>=49.7, RDC increases by 20.84 p/u for each 0.01Hz step
4 f<49.7,RDC=824.04p/u
0
100
200
300
400
500
600
700
800
900
50.2
50.16
50.12
50.08
50.04
50
49.96
49.92
49.88
49.84
49.8
49.76
49.72
49.68
49.64
49.6
49.56
49.52
Rate for Deviation Charge ( paise/unit )
Rate for Deviation
Charge ( paise/unit )
178 paise/unit at 50 Hz
803.2 paise/unit at 49.7 Hz
Maximum Deviation Rate
= 824.04 paise/unit
1/18/2016 15ERPC, KOLKATA

16. • BUYERs/SELLERs
1. Overinjection/Underdrawal:
• Charges for Deviation receivable for
overinjection/underdrawal in a time block within
the volume capping of 12% of Schedule or 150MW
whichever is less in normal Deviation Charge
depending on freq.
• For any overinjection/underdrawal beyond the
volume capping limit in a time block, the charges
receivable is zero.
• Additional Charges for Deviation for
overinjection/underdrawal in any time block when
f>=50.10Hz at 178 p/u
1/18/2016 16ERPC, KOLKATA

17. 2. Overdrawal/Underinjection:
A. Charges for Deviation payable for
overdrawal/underinjection in a time block in normal
Deviation Charge depending on freq.
B. Additional charges for Deviation levied for
overdrawal/underinjection beyond the volume capping
limit as follows:
• Freq ---- 49.7 Hz and above & Sch >= 150 MW
a. 12% of Sch in a time block < = 150 MW
Overdrawal/
Underinjection
12-15% 15-20% Above 20%
Additional Charges for
Deviation
20 % of Normal
Deviation Charge
depending on
average freq of that
block
40 % of Normal
Deviation Charge
depending on
average freq of that
block
100 % of Normal
Deviation Charge
depending on
average freq of that
block
1/18/2016 17ERPC, KOLKATA

18. b) 12% of Sch in a time block > 150 MW
• Freq ---- Below 49.7 Hz
Additional Charges levied = 824.04 p/u
Total Charges = 1648.08 p/u
Overdrawal/
Underinjection
150-200MW 200-250MW Above 250MW
Additional Charges
for Deviation
20 % of Normal
Deviation Charge
depending on
average freq of
that block
40 % of Normal
Deviation Charge
depending on
average freq of
that block
100 % of Normal
Deviation Charge
depending on
average freq of that
block
1/18/2016 18ERPC, KOLKATA

19. Corrigendum dated 17.02.14
1/18/2016 ERPC, KOLKATA 19
Freq ---- 49.7 Hz and above & Sch < 150 MW
Overdrawal/
Underinjection
12-15% of 150 MW 15-20% of 150 MW Above 20% of 150
MW
Additional Charges for
Deviation
20 % of Normal
Deviation Charge
depending on
average freq of that
block
40 % of Normal
Deviation Charge
depending on
average freq of that
block
100 % of Normal
Deviation Charge
depending on
average freq of that
block

20. 1/18/2016 ERPC, KOLKATA 20
DEVIATION
UNDERINJECTION /
OVERDRAWAL
OVERINJECTION /
UNDERDRAWAL
HIGH FREQ HIGH FREQLOW FREQ LOW FREQ
NIL OR LOW DC
PAYABLE,
NIL OR LOW ADC
PAYABLE
NIL OR LOW DC
RECEIVABLE,
NIL OR ADC
PAYABLE AT 178
P/U
HIGH DC PAYABLE,
HIGH ADC
PAYABLE
DC RECEIVABLE
TILL MIN OF 12
% OF SCH OR 150
MW,
NO ADC PAYABLE
DC = DEVIATION CHARGE
ADC = ADDITIONAL CHARGE
FOR DEVIATION

21. ILLUSTRATIONS:
(All Energy figures in MWH)
Sch Act Dev Freq(
in Hz)
Dev Rate
(
Rs/MWH
)
Dev Charge
Receivable
(+)/Payable(-)
(in Rs.)
Quantum of
Deviation
for Addl Dev
Charge
Additional Dev
Charge
Payable(in Rs.)
1 -204.34 -173.68 30.66 49.81 5739.6 24.52*5739.6 0 0
2 -204.37 -191.10 13.27 50.07 0 0 0 0
3 -167.45 -131.98 35.47 49.61 8240.40 20.05*8240.4 0 0
4 -224.45 -257.57 -33.12 50.07 0 0 0 0
5 -241.38 -238.82 2.56 50.11 0 0 2.56 -2.56*1780
6 -209.65 -278.11 -68.54 50.02 1068 -68.54*1068 43.38 -34239
7 -364.09 -434.52 -70.43 50.01 1424 -70.43*1424 32.93 -21972
8 -31.752 -56.137 -24.384 50.04 356 -24.384*356 19.88 -6356
9 -186.88 -220.23 -33.35 49
.64
8240.40 -33.35*8240.4 33.35 -33.35*8240.4
1/18/2016 21ERPC, KOLKATA

22. Schedule = -204.34MWH Actual = -173.68MWH
Deviation(Underdrawal) = -173.68-(-204.34) = 30.66MWH
Freq = 49.81 Hz, Dev Rate = 5739.60 Rs/MWH
Min ( 12% of Sch=24.52, 37.5) = 24.52MWH
Deviation Charges Receivable = Rs. 24.52* 5739.6
Additional Deviation Charges Payable = 0
1/18/2016 22ERPC, KOLKATA
UTILITY DATE TIME BLOCK
GRIDCO 01.05.14 00.00 HRS
UTILITY DATE TIME BLOCK
GRIDCO 24.05.14 18.00 HRS
Schedule = -241.38MWH Actual = -238.82MWH
Deviation(Underdrawal) = -238.82-(-241.38) = 2.56MWH
Freq = 50.11 Hz, Dev Rate = 0.00 Re/MWH
Deviation Charges Receivable = Rs. 0* 2.56= 0
Additional Deviation Charges Payable = Rs. 2.56 * 1780 = Rs 4558

23. Schedule = -209.65MWH Actual = -278.11MWH
Deviation = -278.11-(-209.65) = -68.54MWH
Freq = 50.02 Hz, Dev Rate = 1068 Rs/MWH
Min ( 12% of Sch=25.16, 37.5) = 25.16MWH
Overdrawal allowed without levy of Addl Charge for Deviation = 25.16MWH
Quantum of Overdrawal on which Addl Charges for Deviation to be levied =
68.54-25.16 = 43.38 MWH
1/18/2016 23ERPC, KOLKATA
12-15%
3% of Sch*20%
of Dev Rate of
that time block=
0.03*209.65*0.2
*1068=
Rs1343.43
15-20%
5% of Sch*40%
of Dev Rate of
that time block=
0.05*209.65*0.4
*1068=
Rs4478.12
Above20%
(43.38-8% of
Sch)*100% of
Dev Rate of that
time block=
26.608*1*1068=
Rs28417.34
UTILITY DATE TIME BLOCK
GRIDCO 01.05.14 08.15 HRS

24. Schedule = -364.09MWH Actual = -434.52MWH
Deviation = -434.52-(-364.09) = -70.43MWH
Freq = 50.01 Hz, Dev Rate = 1424 Rs/MWH
Min ( 12% of Sch=43.69, 37.5) = 37.5MWH
Overdrawal allowed without levy of Addl Charge for Deviation = 37.5MWH
Quantum of Overdrawal on which Addl Charges for Deviation to be levied =
70.43-37.50 = 32.93 MWH
150-200MW
(200-150)/4*20% of
Dev Rate of that
time block=
12.5*0.2*1424
=Rs 3560
200-250MW
(250-200)/4*40% of
Dev Rate of that
time block=
12.5*0.4*1424
=Rs 7120
Above250MW
(32.93-12.5-
12.5)*100% of
Dev Rate of that
time block=
7.93*1*1424
=Rs 11292.32
1/18/2016 24ERPC, KOLKATA
UTILITY DATE TIME BLOCK
WBSETCL 10.03.14 21.00 HRS

25. Schedule = -31.752MWH Actual = -56.137MWH
Deviation = -56.137-(-31.752) = -24.384MWH
Freq = 50.04 Hz, Dev Rate = 356 Rs/MWH
Overdrawal allowed without levy of Addl Charge for Deviation
= 12% of 37.5= 4.5MWH
Quantum of Overdrawal on which Addl Charges for Deviation to be levied =
24.38-4.5 = 19.88 MWH
1/18/2016 25ERPC, KOLKATA
12-15%
3% of 37.5*20%
of Dev Rate of
that time block=
1.125*0.2*356=
Rs80.10
15-20%
5% of 37.5*40%
of Dev Rate of
that time block=
1.875*0.4*356=
Rs267
Above20%
(19.88-8% of
37.5)*100% of
Dev Rate of that
time block=
16.88*1*356=Rs
6009.28
UTILITY DATE TIME BLOCK
GRIDCO 05.03.14 19.00 HRS

26. 0
50
100
150
200
250
300
350
50.2
50.16
50.12
50.08
50.04
50
49.96
49.92
49.88
49.84
49.8
49.76
49.72
49.68
49.64
49.6
49.56
Rate for Deviation Charge ( paise/unit )
Rate for Deviation
Charge ( paise/unit )
178 paise/unit at 50 Hz
Maximum Deviation Rate
= 303.04 paise/unit
• Thermal Stations regulated by CERC and using coal
under APM as fuel:
1/18/2016 26ERPC, KOLKATA

27. • Thermal Stations regulated by CERC and using coal
under APM as fuel:
1. 105% time block capping and 101% day capping w.r.t DC of
ISGS has been done away with
2. Overinjection:
• Charges for Deviation receivable for overinjection in a time
block within the volume capping of 12% of Schedule or
150MW whichever is less in normal Deviation Charge subject
to a capping of 303.04p/u depending on freq.
• For any overinjection beyond the volume capping limit in a
time block, the charges receivable is zero.
• Additional Charges for Deviation for overinjection in any
time block when f>=50.10Hz at 178 p/u
1/18/2016 27ERPC, KOLKATA

28. 3. Underinjection:
A. Charges for Deviation payable for underinjection
in a time block in normal Deviation Charge
subject to a capping of 303.04p/u depending on
freq.
B. Additional charges for Deviation levied for
underinjection beyond the volume capping limit
as follows:
• Freq ---- 49.7 Hz and above & Sch >= 150 MW
a. 12% of Sch in a time block < = 150 MW
Underinjection 12-15% 15-20% Above 20%
Additional Charges
for Deviation
20 % of
MIN(303.04p/u ,
Normal Deviation
Charge)
40 % of
MIN(303.04p/u ,
Normal Deviation
Charge)
100 % of
MIN(303.04p/u ,
Normal Deviation
Charge)
1/18/2016 28ERPC, KOLKATA

29. b) 12% of Sch in a time block > 150 MW
This is a new provision added to this regulation.
• Freq ---- Below 49.7 Hz
Additonal Charges levied = 303.04 p/u
Total Charges = 606.08 p/u
Underinjection 150-200MW 200-250MW Above 250MW
Additional Charges
for Deviation
20 % of
MIN(303.04p/u ,
Normal Deviation
Charge)
40 % of
MIN(303.04p/u ,
Normal Deviation
Charge)
100 % of
MIN(303.04p/u ,
Normal Deviation
Charge)
1/18/2016 29ERPC, KOLKATA

30. ILLUSTRATION:
1) Overinjection
Sch Act Dev Freq Dev Rate Dev
Rate
Applic
-able
Min (12% of
Col2,150)
Dev Charge
Receivable
Additio
nal Dev
Charge
Payable
1 1450 1480 30 49.9 407.24 303.04 150 30*303.04 0
2 1450 1680 230 50 178 178 150 150*178 0
3 1200 1380 180 49.96 261.36 261.36 144 144*261.36 0
4 1300 1350 50 50.12 0 178 0 50*178
1/18/2016 30ERPC, KOLKATA

31. Sch Act Dev Freq Dev Rate Dev
Rate
Applic-
able
Min
(12% of
Col2,15
0)
Dev Charge
Payable
Additional Dev Charge
Payable
1 1450 1420 -30 49.9 407.24 303.04 150 30*303.04 0
2 1450 1280 -170 50 178 178 150 170*178 20*.2*178
3 1450 1240 -210 49.96 261.36 261.36 150 210*261.36 50*0.2*261.36+10*0.4
*261.36
4 1450 1190 -260 49.8 594.8 303.04 150 260*303.04 50*0.2*303.04+50*0.4
*303.04+10*303.04
5 1180 1150 -30 49.75 678.16 303.04 141.6 30*303.04 0
6 1180 1000 -180 49.98 219.68 219.68 141.6 180*219.68 35.4*0.2*219.68+3*0.4
*219.68
7 1180 940 -240 49.88 428.08 303.04 141.6 240*303.04 35.4*0.2*303.04+59*0.
4*303.04+4*303.04
8 1180 1075 -105 49.70 803.2 303.04 141.6 105*303.04 0
9 1180 1075 -105 49.69 803.2 303.04 141.6 105*303.04 105*303.04
UNDERINJECTION
1/18/2016 31ERPC, KOLKATA

32. In a time block: Sch injection = 1450MW Act injection= 1190MW
Deviation =1190-1450 = -260MW
Freq = 49.8 Hz, Dev Rate = 594.80 paise/unit
Dev Rate applicable = MIN( Normal Dev Rate, 303.04)=303.04 paise/unit
Min ( 12% of Sch=174MW, 150MW) = 150MW
Total underinj allowed without levy of Addl Charge for Deviation = 150MW
Quantum of Underinjection on which Addl Charges for Deviation to be
levied = 260-150 = 110 MW
150-200MW
(200-150)*20% of
MIN(Normal Dev
Rate of that time
block,303.04)=
50*0.2*303.04pa
isa/unit
200-250MW
(250-200)*40% of
MIN(Normal Dev
Rate of that time
block,303.04)=
50*0.4*303.04pa
isa/unit
Above250MW
(110-50-
50)*100% of
MIN(Normal
Dev Rate of
that time
block,303.04)=
10*1*303.04p
aisa/unit
1/18/2016 32ERPC, KOLKATA

33. In a time block: Sch injection = 1180MW Act injection= 940MW
Deviation = 940-1180 = -240MW
Freq = 49.88 Hz, Dev Rate = 428.08 paisa/unit
Dev Rate applicable = MIN( Normal Dev Rate, 303.04)=303.04 paise/unit
Min ( 12% of Sch=141.6MW, 150MW) = 141.6MW
Total underinj allowed without levy of Addl Charge for Deviation = 141.6MW
Quantum of Underinjection on which Addl Charges for Deviation to be
levied = 240-141.6 = 98.4 MW
12-15%
3% of Sch*20%
MIN(Normal Dev
Rate of that time
block,303.04)=
35.4*0.2*303.04
paisa/unit
15-20%5% of Sch*40%
MIN(Normal Dev
Rate of that time
block,303.04)=
59*0.4*303.04
paisa/unit
Above20%
(98.4-8%of
Sch)*100%
MIN(Normal Dev
Rate of that time
block,303.04)=
4*1*303.04
paisa/unit
1/18/2016 33ERPC, KOLKATA

34. • Infirm power:
1. Injection:
• Period of 6 months allowed
• Domestic coal/lignite/hydro: 178p/u against 165 p/u
• Imported coal: 303p/u against 330p/u
• Exemption from volume limit
2. Drawal:
• Exemption from volume limit for f>=49.7Hz
• No levy of Additional charges for deviation at f<49.7Hz.
(As per present UI regulation Addl. UI Charges applicable)
1/18/2016 34ERPC, KOLKATA

35. Accounting of Charges for Deviation:
• RLDCs to furnish data by every Thursday
• RPCs to prepare and issue statement of
Deviation including Additional Charges for
Deviation by every Tuesday for 7 day period
ending on penultimate Sunday.
• All payments including interest , if any, to be
credited to “Regional Deviation Pool Account
Fund”
• Fund to be operated and maintained by RLDCs
1/18/2016 35ERPC, KOLKATA

36. Other Important Clauses:
• Any Additional Charge for Deviation collected from a
regional entity shall be retained in the “Regional
Deviation Pool Account Fund” of the concerned region
where the regional entity is located
• In the event of sustained deviation from schedule in
one direction (positive or negative) by any regional
entity, such regional entity (buyer or seller) shall have
to make sign of their deviation from schedule changed,
at least once, after every 12 time blocks. To illustrate, if
a regional entity has positive deviation from schedule
from 07.30 hrs to 10.30 hrs, sign of its deviation from
schedule shall be changed in the 13th time block i.e.
10.30 to 10.45 hrs from positive to negative or negative
to positive as the case may be.
1/18/2016 36ERPC, KOLKATA

37. Other Important Clauses: (contd…….)
• RLDCs shall, on monthly basis, prepare and publish on
its website the records of the Deviation Accounts,
specifying the quantum of over-drawl/ under-injection
and corresponding amount of Charges for Deviation
payable/receivable for each buyer and seller for all the
time-blocks when grid frequency was "49.90Hz and
above" and "below 49.90" Hz separately.”
• Any surplus amount in the Deviation Pool Account Fund
on the last day of the month shall be transferred to
PSDF in first week of the next month
• On commencement of these regulations:
a) CERC (UI & related matters) regulation shall stand
repealed
b) Regional UI Pool Account Fund shall continue to
operate till the UI Accounts settlement is completed
1/18/2016 37ERPC, KOLKATA

38. Schedule of Payments:
• Payment to be made within 10 days of issue of statement by RPC
• For delay of more than 2 days i.e beyond 12 days of issue of statement by
RPC, simple interest @ 0.04% to be levied for each day of delay
• Payments to receivable entities to be made within 2 working days of
receipt of payments in the fund
• In the event of delay of payment by Payable entities, the receivable entities
shall be paid from the balance in the fund. If sufficient fund not there,
payment to be made on pro rata basis
• Utilities defaulting at any time in previous FY shall open an LC equal to
110% of its average payable weekly liability in favour of the concerned
RLDC within a fortnight of date these regulations come into force
• Utilities defaulting at any time in current FY shall open an LC equal to 110%
of its weekly outstanding liability in favour of the concerned RLDC within a
fortnight from the due date of payment
• LC to be increased to 110% of the payable weekly liability for Deviation in
any week during the year, if it exceeds the previous LC amount by more
than 50%
• For payments not received within 12 days, RLDC entitled to encash the LC
to the extent of default which has be recouped within 3 days
1/18/2016 38ERPC, KOLKATA

39. Relevant Clauses from IEGC , 2nd Amendment
Regulations effective from 17.02.2014
• Clause 3(7)(g):”RLDCs shall devise standard instantaneous message formats
in order to give directions in case of contingencies and/or threat to the
system security to reduce deviation from schedule by the bulk consumer,
SLDC/StateUtility/ISGS/Regional Entity/Injecting Utility at different
overdrawal/underdrawal/over-injection/underinjection conditions
depending upon the severity. The concerned SLDC/other regional entity
shall ensure immediate compliance with these directions of RLDC and send
a compliance report to the concerned RLDC “
• Clause 4(1): “……..The regional entities shall regulate their generation
and/or consumers’ load so as to maintain their actual drawl from the
regional grid close to the above schedule. Maximum inadvertent deviation
allowed during a time block shall not exceed the limits specified in the
Deviation Settlement Mechanism Regulations. Such deviations should not
cause system parameters to deteriorate beyond permissible limits and
should not lead to unacceptable line loadings. Inadvertent deviations, if any,
from net drawl schedule shall be priced through the Deviation Settlement
mechanism as specified by the Central Commission from time to time. Every
regional entity shall ensure reversal of sign of deviation from schedule at
least once after every twelve time blocks”
1/18/2016 39ERPC, KOLKATA

40. Relevant Clauses from IEGC , 2nd Amendment
Regulations effective from 17.02.2014 (contd…)
• Clause 4(2)(7): ”The SLDC, SEB / distribution licensee shall always restrict the net
drawl of the state from the grid within the drawl schedule keeping the deviations
from the schedule within the limits specified in the Deviation Settlement
Mechanism Regulations. The concerned SEB/distribution licensee/User, SLDC shall
ensure that their automatic demand management scheme mentioned in clause
5.4.2 acts to ensure that there is no over-drawl. If the automatic demand
management scheme has not yet been commissioned, then action shall be taken as
per manual demand management scheme to restrict the net drawal from grid to
within schedules and all actions for early commissioning of Automatic Demand
Management Scheme (ADMS) shall be initiated “
• Clause 4(3)(10): The ISGS is normally expected to generate power according to the
daily schedules advised to them barring any inadvertent deviations. Maximum
deviation allowed during a time block shall not exceed the limits specified in the
Deviation Settlement Mechanism Regulations. Such deviations should not cause
system parameters to deteriorate beyond permissible limits and should not lead to
unacceptable line loadings. Inadvertent deviations, if any, from the ex-power plant
generation schedules shall be appropriately priced in accordance with Deviation
Settlement Mechanism Regulations. In addition, deviations from schedules causing
congestion, shall also be priced in accordance with the Central Electricity Regulatory
Commission (Measure to relieve congestion in real time operation) Regulations,
2009”
1/18/2016 40ERPC, KOLKATA

41. Relevant Clauses from IEGC , 2nd Amendment
Regulations effective from 17.02.2014 (contd…)
• Clause 4(5)(12): …….. the RLDC may direct the SLDCs/ISGS/
other regional entities to increase/decrease their
drawal/generation in case of contingencies e.g. overloading of
lines/transformers, abnormal voltages,threat to system
security. Such directions shall immediately be acted upon.
Incase the situation does not call for very urgent action, and
RLDC has some time for analysis, it shall be checked whether
the situation has arisen due to deviations from schedules…….
• Clause 4(7)(24): "Hydro generating stations are expected to
respond to grid frequency changes and inflow fluctuations.
Maximum deviation allowed during a time block shall be as per
the CERC Deviation Settlement Mechanism Regulations."
1/18/2016 41ERPC, KOLKATA

42. 1/18/2016 42ERPC, KOLKATA