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Settlement System under ABT Regime
WHAT IS SETTLEMENT ?
• “ Settlement means Closing the payment/receipt/adjustment process of
bill for the period under consideration”• To be FAIR and EQUITABLE• To RECOVER DUES at the EARLIEST
(Billing Cycle)• TRANSPERANCY• Dispute Resolution• Reconciliation
Capacity charge:
Capacity charge is based on Annual Fixed Charge and will be related to availability of generating station. Availability means the readiness of the generating station to deliver ex-bus output expressed as a percentage of its rated ex-bus output capability.
Energy charge:
Energy charge is related to the scheduled ex-bus energy to be sent out from the generating station and will be worked out on the basis of paise per KWh.
AVAILABILITY TARIFF(ABT)(a) CAPACITY CHARGE(b) ENERGY CHARGE(c) ADJUSTMENT FOR DEVIATIONS
(UI CHARGE)
(a) = a function of Ex-bus MW availability of power plant for the day declared before the day starts x SEB’s % share
.(b) = MWh for the day as per ex=bus drawl schedule for the SEB
finalized before the day starts x Energy charge rate
(c) =Σ(Actual energy interchange in a 15 min time block – scheduled energy interchange for the time block) x UI rate for the time block.
TOTAL PAYMENT FOR THE DAY =(a) + (b)± ( c)
SETTLEMENT SYSTEMFor the day: 0000 hrs. to 2400 hrs.
Central Generating Stations 1 2 3
Ex-Bus Capability x1 x2 x3(Forecast) ____ ___ ___
SEB-A’s share a1 a2 a3SEB-B’s share b1 b2 b3SEB-C’s share c1 c2 c3
For a particular 15 minute time block
SEB-A’s requisition a’1 a’2 a’3SEB-B’s requisition b’1 b’2 b’3SEB-C’s requisition c’1 c’2 c’3
___ ___ ___CGS’s schedule x1’ x2’ x3’
MW
SRLDC/Comml/IEGC/37
SETTLEMENT SYSTEM
Total capacity charge payable to CGS-1 for the day= x1 * capacity charge rate of CGS-1
Total Energy charge payable to CGS-1 for the day
= x1’ * Energy charge rate of CGS-1 4
Total capacity charge payable by SEB-A for the day
= a1 * capacity charge rate of CGS-1
+ a2 * -do- CGS-2
+ a3 * -do- CGS-3Total Energy charge payable by SEB-A for the day
= (a1’) * Energy charge rate of CGS-1 ( 4 )
+ (a2’) * -do- CGS-2 ( 4 )
+ (a3’) * -do- CGS-3 ( 4 )
All capacity charge and Energy charge payments to be made by SEBs directly to CGS.
SRLDC/Comml/IEGC/38
SETTLEMENT SYSTEM
Actual (metered) injection of CGS-1 in the time block = X1 MWh.
Excess injection = (X1 – x1’ ) MWh.
4
Amount payable to CGS-1 for this =(X1-x1’) * pool price for the block.
4
SEB-A’s scheduled drawl for time block = a1’+a2’+a3’ = a’ MW (ex-CGS Bus)
SEB-A’s NET drawal schedule = (a’ – Notional Transm. Loss) MW
= (a’ – Notional Transm. Loss) = A’ MWH
4
Actual (metered) net drawal of SEB-A during time block = A MWH
Excess drawal by SEB-A = (A-A’) MWh.
Amount payable by SEB-A for this = (A-A’) * pool price for the block.
All above payments for deviations from schedules to be routed through a pool A/C operated by RLDC
SRLDC/Comml/IEGC/39
AVAILABILITY
• Availability in relation to a generating station for any period means the average of the DCs for all the days during that period expressed as a percentage of the installed capacity of generating station minus normative auxiliary consumption in MW and shall be computed as per the following formula:
Present Definition Capacity charges
% Availability = i=1
N
DCi/ {NxICx(100-Auxn) }%10000
Where DCi = Average Declared Capacity for i th day of the period in MW N = Total no. of days during the period Auxn = Normative Auxiliary Consumption as % of gross Gen.
IC= installed capacity in MW
% Availability forms the basis for calculations
i=1
N
SGi/ {NxICx(100-Auxn) }%10000PLF =
Recovery of Annual fixed charges 100% recovery if % Availability >=Target Availability
- Pro-rata reduction if %Avb<T.Avb.
- Target Availability For Fixed charges recovery - Target PLF for incentive
-Both to be Notified by CERC-Financial Year forms the basis for calculations
ISGS Target Availabilty Target PLF
RSTPS 80% 80%
NLC 75% 75%
Monthly Capacity charges receivable by an ISGS:1 st Month = (1xACC1)122 nd Month = (2xACC2-1ACC1)12….….12 th month = (12xACC12-11ACC11)12where ACC1,ACC2…….ACC12 = Annual capacity charges corresponding to the cum. Availability up to the corresponding month.
Monthly Capacity charges payable by a beneficiary :1 st Month = (1xACC1xWB1)122 nd Month = (2xACC2xWB2-1ACC1xWB1)12….….12 th month = (12xACC12xWB12-11xACC11xWB11)12where WB1,WB2…..WB12 = Weighted average % share up to the corresponding month.
Name Of ISGS
Aux.
Consumption
Variable
Charges (Ps)
RSTPS 7.93% 98
NLC II/1 10.00% 75
NLC II/2 10.00% 100
NLC TPS 1 (EXP)
9.50% 131
TALCHER-
STAGE II
7.5% 74
Energy charges
The Energy Charges Payable by beneficiary to the ISGS =
Variable Charge of ISGS X
Requisition of beneficiary from The ISGS
The Energy Charges Receivable by ISGS from beneficiaries =
Variable Charge of ISGS X
Despatch schedule of ISGS
• Flat rate of 25ps/u
• For ex-bus Schedule Energy in Excess of ex-bus energy corresponding to Target PLF
Incentive as per existing norms
Settlement Systems* On weekly basis : For seven day period ending on penultimate Sunday
•RLDC to furnish Scheduling & Metering data to REB• Sectt. by Thursday noon
•REB Sectt. to issue Weekly UI a/c by Tuesday
•Pool a/c operated by RLDC•Settlement for UI on weekly basis•All accounts open for 20 days
SRLDC/Comml/IEGC/34
Settlement System contd..
• On monthly basis :• REB to issue REA specifying % Avb, %
Net Entitlement, % Energy charges, Wt. Avg. Ent. for Tr. Ch. etc.
• Capacity and Energy Charges, Incentive etc.
• –billed directly by ISGS based on REA issued by REB
WEEKLY ENERGY ACCOUNTING:
WEEKLY CYCLE : 00 HRS OF EACH MONDAY TO 24 HRS; OF THE THE FOLLOWING SUNDAY
ACTIVITIES MONDAY MORNING : SEM DATA DOWNLOADED TO DCD
: DCD DATA LOADED TO A LOCAL PC: DATA SENT TO RLDC via E-MAIL
(LATEST TUESDAY MORNING )THURSDAY NOON : RLDC CONVEYS PROCESSED DATA TO
REBTues day : WEEKLY UI a/c & Reactive charges
issued BY REBBILLING
Cap. Charge : BILLED MONTHLY based on DAILY DC BY ISGS
ENERGY CHARGE : BILLED MONTHLY based on DAILY DRAWL SCHEDULES ISSUED BY RLDC
UI a/c Paid/Disbursed as per UI a/c issued by REB
REACTIVE a/c
Variations in actual generation/drawal and scheduled generation /drawal are accounted through UI. This is a frequency linked charge which is worked out for each 15 minute time block.
Charges for all UI transaction, based on average frequency have following rate of paise per KWh from 01.01.03 up to 31.03.04.
UI rate (Paise per KWh)
Average Frequency of time block50.5 Hz. and above 0.0Below 50.5 Hz. and upto 50.48 Hz. 5.6Below 49.04 Hz. and upto 49.02 Hz. 414.4Below 49.02 Hz. 420.0Between 50.5 Hz. and 49.02 Hz. Linear in 0.02 Hz. step
Unscheduled Interchanges (UI)
UI rate w.e.f 01.04.04 to 30.09.04 UI rate (Paise per KWh)
Average Frequency of time block50.5 Hz. and above 0.0Below 50.5 Hz. and upto 50.48 Hz. 8.0Below 49.04 Hz. and upto 49.02 Hz. 592.0Below 49.02 Hz. 600.0Between 50.5 Hz. and 49.02 Hz. Linear in 0.02 Hz. step
• UI rate w.e.f 01.10.04 UI rate (Paise per KWh)
Average Frequency of time block (Hz,)Below Not below ----- 50.50 0.050.50 50.48 6.050.48 50.46 12.0----- ----- ----- ----- ----- ----- 49.84 49.82 204.049.82 49.80 210.049.80 49.78 219.049.78 49.76 228.0----- ----- ----- ----- ----- ----- 49.04 49.02 561.049.02 ----- 570.0(Each 0.02 Hz. Step is equivalent to 6.0 paise/kWh in the 50.5-49.8 Hz. Frequency range and to 9.0 paise/kWh in the 49.8-49.0 Hz. Frequency range).
Energy transactions of UI from/to Pool
Over Gen. By ISGS-1
Under drawl by SEB-A
UI import from IR-1
Under gen. By ISGS-2
No one to one correspondence
System frequency UI
RateRegional Pool
Over drawl by SEB-BUI Export to IR-2
Operation of Pool
Separate Pool a/cs operated by RLDCs on behalf of REBs for UI, IRE and Reactive charges
Regional Pool
Payable by ISGS-2
Payable by SEB-BPayable by IR-2at its UI rate
Receivable by ISGS-1 (up to DC) Receivable by SEB-A Receivable by IR-1
at its UI rateNo one to one correspondence
No cross adjustments allowed between the constituents
Where do SEMs come into picture?
• Only measuring Deviations from Schedulei.e. UI
• To measure 15 min block-wise Energy and Frequency
Issues concerned :-Specifications-Location criterion-Main/Check/Standby philosophy
ISTS
ISGS -II
SEB-B drawalMain = (T+U+X)
Standby = (V+W+Y)
SEB-A drawalMain = (G+H+N+O+Y)Standby = (L+M+Q+R+X)
Metering Philosophy under ABT regime
Other than NTPC Station
ISGS-I injectionMain = (F+G+H+J+K)Check=(F'+L+M+J'+K')Standby = (A+B+C+D+E)
NTPC Station
SEB-B
ISGS-II injectionMain = (M1+M2)Check=(C1+C2)Standby = (S1+S2)
ISGS -I
Aux. Aux.
ISTS
ISTS
SEB-A
SEB-A
A B D EC
FF'
G HJJ'
KK'
L M
SEB-A
ST U
VW
X
Y
SEB-B
N O P
Q R
C1 C2
M1 M2
S1 S2
Aux.
Main Meter
Standby Meter
Check Meter
Points for Energy AccountingInjection by NTPC Generating Stations :
Main &check meters on Outgoing feeders Standby meters on HV side of GT/TT
Injection by other Generating Stations :
Main &check meters on HV side of GT/TT Standby meters on Outgoing feeders
Drawl by SEBs
Main -HV side of ICTs at GS and CTU S/S, Receiving end of Lines directly connected to ISGS
Respective ends of Lines connected to other SEBs Standby – LV/ Tertiary side of ICTs
Other end of lines connected to other SEBs
Special Energy Meter FeaturesSpecial Energy Meter Features
• STATIC TYPE
• COMPOSITE METER
• HIGHEST ACCURACY IN POWER INDUSTRY
• 3 PHASE-4 WIRE CONNECTIONS / MEASUREMENT
• DIRECT MEASUREMENT AS PER CT/PT SECONDARY QUANTITIES
- 110V PH TO PH/63.51 V PH-N
- 1 AMP OR 5 AMP
- VA BURDEN NOT >10 ON ANY OF THE PHASES
• WORKS ON REAL TIME CLOCK
• NO CALIBRATION REQUIRED
• TIME ADJUSTMENT FACILITY
• HIGH SECURITY OF DATA STORAGE
Raw dataWEEK FROM 0000 HRS OF 06-01-01 TO 0837 HRS OF 15-01-01NP-0185-A 91858.5 99968.5 39195.5 06-01-01 00 51 +21.57 48 +21.68 50 +21.71 49 +21.33 …. 04 19 +20.61 23 +20.80 19 +21.05 00 +21.35 … 08 00 +24.95 00 +24.95 00 +25.09 00 +24.38 … 12 71 +24.38 52 +23.98 30 +23.81 13 +24.03 …16 00 +23.37 00 +23.52 00 +22.87 00 +21.66 … 20 00 +25.75 00 +25.32 00 +25.40 00 +25.37 … NP-0185-A 94117.2 99968.5 40313.5 07-01-01 00 59 +20.94 54 +21.01 59 +20.79 58 +21.05 … 04 33 +20.05 38 +20.17 37 +20.49 28 +20.90 …08 00 +22.99 06 +23.10 00 +22.81 00 +22.94 … 12 85 +20.93 51 +20.65 21 +20.79 00 +19.89 … 16 07 +20.14 01 +20.53 00 +20.72 00 +20.66 …20 05 +23.62 08 +23.23 16 +23.25 27 +23.40 … NP-0185-A 96172.2 99968.5 41236.9 08-01-01
Special Energy Meter Various ChecksSpecial Energy Meter Various Checks
CHECKS for DATA VALIDATION :
• NOMINAL VOLTAGE CHECK• FREQUENCY• TIME CORRECTION• WATTHOUR CHECK• PREVIOUS WEEK DATA• ALGEBRAIC SUM
• RAW DATA IN WHr
• MWhr = RAW DATA x CT RATIO x PT RATIO
• PAIR CHECK DONE FOR MAIN/ CHECK/ STANDBY/ FICTMETERS ( ex. : for both sides of ICTs, Lines, GT side & Line side at ISGS.
Special Energy Meter Data ComputingSpecial Energy Meter Data Computing
Reactive Energy Accounting
Reactive Energy is measured
when system voltage is
> 103% of Nominal Voltage< 97% of Nominal Voltage
Loss computations
15 min block-wise % loss =
(Sum of all Injections from ISGS + net IR imports)
X 100
(Sum of all Injections from ISGS + net IR imports) -
(Sum of Drawals by all beneficiaries from Central Grid)
Use of Notional Loss in scheduling
• % Average loss (15 min. blockwise) aggregated over the last week will be used in Scheduling Process for the next week.
(for arriving at the ex-periphery Drawal Schedules of Beneficiaries)
0.5% REDUCTION MEANS MORE THAN 100 CR ANNUAL SAVINGS0.5% REDUCTION MEANS MORE THAN 100 CR ANNUAL SAVINGS
Loss for the week Loss % Week applied for
From To From To
16-Sep-02 22-Sep-02 4.83 30-Sep-02 6-Oct-02
6-Jan-03 12-Jan-03 3.9 20-Jan-03 26-Jan-03
20-Oct-03 26-Oct-03 3.38 3-Nov-03 9-Nov-03
19-Jan-04 25-Jan-04 3.92 2-Feb-04 8-Feb-04
24-May-04 30-May-04 2.55 7-Jun-04 13-Jun-04
9-Aug-04 15-Aug-04 2.54 23-Aug-04 29-Aug-04
17-Jan-05 23-Jan-05 3.25 31-Jan-05 6-Feb-05
7-Feb-05 13-Feb-05 3.04 21-Feb-05 27-Feb-05
30-May-05 5-Jun-05 2.95 13-Jun-05 19-Jun-05
27-Jun-05 3-Jul-05 3.49 11-Jul-05 17-Jul-05
11-Jul-05 17-Jul-05 3.73 25-Jul-05 31-Jul-05
25-Jul-05 31-Jul-05 3.53 8-Aug-05 14-Aug-05
1-Aug-05 7-Aug-05 3.3 15-Aug-05 21-Aug-05
8-Aug-05 14-Aug-05 2.92 22-Aug-05 28-Aug-05
TYPICAL %AVERAGE LOSS FIGURES FOR CENTRAL GRID IN SR
%Average losses In other Regions :
NR 3.5 to 4.5
ER 3.0 to 3.5
WR 5.0 to 6.0
OTHER REGIONS
%loss for different weeks from 2003- 2005
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
Week No.
%lo
ss
2003-042004-05
2005-06
REACTIVE ENERGY CHARGE :
PAYABLE FOR :
1. VAR DRAWALS AT VOLTAGES BELOW 97%2. VAR INJECTION AT VOLTAGES ABOVE 103%
RECEIVABLE FOR:
1. VAR INJECTION AT VOLTAGES BELOW 97%2. VAR DRAWAL AT VOLTAGES ABOVE 103%
APPLIED FOR VAR EXCHANGES BETWEEN :
A) BENEFICIARY SYSTEM AND ISTS- THROUGH A POOL ACCOUNT
B) TWO BENEFICIARY SYSTEMS ON INTER-STATE TIES- BY THEMSELVES
RATE: @ Rs. 51.05/MVArh (for 205-06)Basic Rate : 4 paise/kvArh ( for the year 2000-01 )
5% ESCALATION PER YEAR
Issues in Reactive Energy charges
• Deficit in pool (SR & ER)-due to continuous High voltages in SR
Surplus in Pool (NR &WR)
Utilization of Accruals
Disputes in payments between Beneficiaries for Reactive charges in Inter-state Lines
SOUTHERN REGIONAL ELECTRICITY BOARDABT based U.I. AccountFOR A TYPICAL WEEK
NNOTE:
1. MAPS & KGS not covered under ABT; hence UI reduced to zero, under all conditions. IR Exchanges: - Metering points – For WR it is Chandrapur South Bus.
- For ER it is Gazuwaka East Bus & Talcher stage I&II interconnecting bus. ii) UI for IR exchanges with ER has been calculated at ER frequency.iii) UI charges with WR and ER has been taken as first charge, as per decision taken in Special Committee meeting held on 17.12.2002.
A. ABSTRACT OF UNSCHEDULED INTERCHANGES ( UI figures in Rs. Lakhs)
Utilities UI
PayableUtilities UI Receivable
KPTCL 720.47741 TNEB 641.48459
KSEB 457.19673 APTRANSCO 269.73260
PONDY 124.38710 ER 188.40533
NLC_II_2 14.72798 RSTPS 84.30154
NLC_II_1 13.81846 GOA 10.67606
TALCHER_II 2.36108 NLC_I_EXP 2.25996
WR 1.32476
TOTAL1332.9687
6TOTAL 1198.18484
A. ABSTRACT OF UNSCHEDULED INTERCHANGES (restricting to the lesser of the two as per the 126th SRE Board decision). (UI figures in Rs. Lakhs)Utilities UI Payable Utilities UI Receivable
KPTCL 647.62591 TNEB 641.48459
KSEB 410.96701 APTRANSCO 269.73260
PONDY 111.80962 ER 188.40533
NLC_II_2 13.23876 RSTPS 84.30154
NLC_II_1 12.42120 GOA 10.67606
TALCHER_II 2.12234 NLC_I_EXP 2.25996
WR 1.32476
TOTAL 1198.18484 TOTAL 1198.18484
payable to Pool
receivable from
APTRANSCO 516417KPTCL 1998690KSEB 231733TNEB 3185840
B.NET REACTIVE ENERGY CHARGES BETWEEN BENEFICIERIES:
280
0
APTRANSCOKPTCLKSEBAPTRANSCOKPTCL
11,410
0235,924
KPTCLTNEB
00
TNEBGOA
04,853
APTRANSCOKSEB
0APTRANSCO0
TNEBPONDY
0
A.REACTIVE ENERGY CHARGES WITH THE POOL :
( Amount in Rupees)
BY BENEFICIERY
FROM BENEFICIERY
KPTCL
AMOUNT RECEIVABLE
in Rupees
Beneficiaries Beneficiaries
GOA
KPTCL
KSEB
TNEB
PONDY
0
(as per decision in the 132nd meeting of SRE Board)
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