Load Settlement System. Procedures and Methods

Transcription

1 Procedures and Methods Effectve January 01

2 TABLE OF CONTENTS 1. NTRODUCTON STE TO SETTLEMENT ZONE MAPPNG.... LOAD PROFLNG... LOAD RESEARCH SAMPLES... SAMPLNG ACCURACY REQUREMENTS... HSTORC CLASS LOAD PROFLES... LOAD PROFLNG METHOD... MODELNG ACCURACY REQUREMENT... DEEMED LOAD PROFLES... PROFLNG CAP.... DSTRBUTON LOSSES AND UFE... HSTORC LOSS STUDES... SERVCE LEVEL... CALCULATON OF TOTAL SYSTEM LOSSES... ALLOCATON OF TOTAL SYSTEM LOSSES... UNACCOUNTED FOR ENERGY OTHER DSCRETONARY MATTERS... 1 ESTMATON OF CONSUMPTON AMOUNTS... 1 DEEMED TMES... 1 MPLEMENTATON ASSUMPTONS... 1 POST FNAL ADJUSTMENT MECHANSM (PFAM) PROCESSNG... 1 CUMULATVE METERNG VALDATON TEST PARAMETERS... 1 APPENDX A CALCULATON OF HOURLY ENERGY CONSUMPTON, LOSS AND UFE 1 CUMULATVE METERED AND UNMETERED STES... 1 NTERVAL METERED STES... 1 APPENDX B DEVELOPMENT OF THE SYSTEM LOSS EQUATON... 1 ATCO Electrc January 01

3 . NTRODUCTON ATCO Electrc s s degned to meet the requrements of Alberta Utltes Commson (AUC) Rule 01 Settlement System Code Rules (SSC). The SSC s a set of rules establshed by the AUC under the authorty of secton.1(1) of the Electrc Utltes Act. All Market Partcpants as defned n the Electrc Utltes Act are requred to comply wth the SSC. ATCO Electrc has been allowed dscreton n mplementng some aspects of the SSC. Under secton. of the SSC, ATCO Electrc, as Load Settlement Agent (LSA), s responble for makng publc on ts webte the procedures and methods used to conduct settlement. The dscretonary procedures and methods mplemented by ATCO Electrc that mpact load settlement calculatons are descrbed n ths document. Two appendces are also ncluded as part of ths document. n Appendx A, a method s provded for determnng hourly customer te energy consumpton, loss and unaccounted for energy (UFE) from the SSC transacton set. Appendx B provdes background nformaton wth respect to the calculaton of the system loss equaton parameters. Questons wth respect to ATCO Electrc load settlement may be emaled to settlement@atcoelectrc.com. ATCO Electrc 1 January 01

4 . STE TO SETTLEMENT ZONE MAPPNG 1 Secton. ) of the SSC requres ATCO Electrc as LSA to dsclose ndvdual te to settlement zone mappng rules. ATCO Electrc asgns every te for whch t s the LSA and all ts servce terrtory to a ngle settlement zone.. LOAD PROFLNG Secton.1 1) of the SSC defnes the acceptable methods for calculatng load profles. The ATCO Electrc load settlement system uses only load research-based profles or deemed profles. All customer tes whch are not nterval metered are asgned a specfc class load profle based on ther dstrbuton tarff rate class. Each te s asgned a profle class code. Specfc codes have been asgned to nterval metered tes to ndcate such. All other codes are asgned accordng to rate class. The table below lsts the rate classes wth ther assocated profle class codes. 1 Non-nterval Metered Profle Classes Rate Class Profle Class Code Redental RES Farm FRM Small General Servce COM rrgaton RR Street and Prvate Lghtng LTE Olfeld OL Large General Servce / ndustral ND 1 nterval Metered Profle Classes Customer Ste Sze Profle Class Code Stes MW NPD Stes 00 kw and < MW NTV Customer requested NTV ATCO Electrc January 01

5 1 Secton. 1) of the SSC requres ATCO Electrc, as LSA, to state publcly the exstng rate classes for whch separate load research-based profles are used n load settlement. The profles for the redental, farm, small general servce and large general servce/ndustral rate classes are load researchbased profles. Deemed profles are used for the olfeld, lghtng and rrgaton classes. The use of class specfc load profles for calculatng monthly pool payments ensures that the energy costs are allocated to each class as farly as posble. However, the cost of such an mplementaton needs to be balanced aganst the degree for farness acheved. The cost/beneft was maxmzed by combnng other load research needs wth that of load settlement so as to provde the same degree of farness to the customer as they prevously had. Load Research Samples Secton of the SSC defnes the standards for load profles based on load research samples. For detals on the requrements for estmaton accuracy, frame adequacy, and sample degn and mplementaton please refer to Secton of the SSC. The class load profles used by ATCO Electrc for load settlement are based on hstorc load surveys. ATCO Electrc uses the method of stratfed random samplng for the selecton of samples to represent each class. Ths method s commonly used to ensure the most accurate results for a gven sample ze. A load profle for each class s developed from metered data collected from the selected tes ung the combned rato estmaton technque. The value of the load profle for each hour s the energy (kw.h) used n that hour by the average customer te n the class. Samplng Accuracy Requrements Secton.. ) of the SSC requres the degn samplng varance V cs to meet the followng crteron: RSE cs V cm U c 0.00 Hstorc Class Load Profles 0 The hstorcal profles used n load settlement are posted on ATCO Electrc s web te and can be accessed at ATCO Electrc January 01

6 Load Proflng Method For load research-based profles, ATCO Electrc uses a proflng method known as proxy day for estmatng class load profles. The proxy day method compares the avalable characterstcs of the settlement day to the characterstcs of hstorc days. The hstorc day that best matches the settlement day s used as the proxy day. The hstorcal class profle for that day s then used as the class profle for the settlement day. Ths process s repeated every day to produce a class load profle for the settlement perod. The proxy day method requres a lbrary of class load profles for hstorc days as well as assocated characterstcs for selectng the proxy day. These profles are developed from the hstorc load studes descrbed above. The system load profle s a commonly used assocated characterstc. The system load profle (DSLS) s defned as the energy delvered to the settlement zone less the energy delvered to all transmson-connected tes. Other characterstcs that may be used nclude day type, season, temperature and tme of the system peak. The proxy day selecton process used by ATCO Electrc s provded by LODESTAR Corporaton. LODESTAR uses a two step process to fnd a proxy day. The frst step uses nformaton about settlement day to select a lst of matchng elgble days. The nformaton used to select the elgble days may nclude a combnaton of the followng characterstcs: Day type Holday Season System Peak Tme Ambent Temperature These parameters may be vared for each profle class to ensure the elgble days selected best represent the characterstcs of the class. Once a lst of matchng elgble days has been selected, the lst s ranked by comparng the system load profle for the settlement day to that of each elgble day. Rankng may be done ung a magntude comparson or a shape comparson. The two methods may also be combned by selectng a weghtng factor for each comparson and summng the weghted values. The elgble day wth the hghest rank s then selected as the proxy day. ATCO Electrc January 01

7 Once the proxy day selected, the date of the proxy day s used to select the load profle for the class from the lbrary of hstorc class load profles. Modelng Accuracy Requrement Secton.. ) of the SSC requres the modelng varance V cm to satsfy the followng crteron RSE cm V cm U c For detals regardng ths crteron see the secton of the SSC. To select the parameters that meet the above crteron for each profle class, ATCO Electrc has analyzed load profle data for the hstorcal perod ndcated n the table below. Ung the methods descrbed n secton of the SSC, ATCO Electrc has determned that the SSC requrements can be met ung the followng parameters. Redental Farm Small Olfeld ndustral General Servce Hstorcal Perod System Load Profle scaled DSLS scaled DSLS DSLS DSLS scaled DSLS Day Type Day of Week Day of Week None Week Day/ None Weekend Holday No No Yes Yes Yes Season Seasons Seasons Monthly Seasons Monthly Peak Separaton All Peaks All Peaks All peaks All Peaks All Peaks Magntude Weght Shape Weght Acheved RSE cm Deemed Load Profles Secton.1 ) of the SSC requres rrgaton, olfeld and unmetered loads to be profled ung a deemed shape. ATCO Electrc deems the olfeld load shape to be the one determned from load research samples. The rrgaton load profle s deemed to be flat n the months of Aprl through October. The value of the profle for each hour s the average hourly energy (kw.h) used by an rrgaton customer te n the perod Aprl through October. The value of the lghtng load profle for each hour s a number between 0 and 1 that represents the proporton of the hour that the lghts are on. The deemed load shape for all other unmetered loads s the load shape of the profle class to whch the customer te belongs. ATCO Electrc January 01

8 The deemed load profles used n load settlement are posted on ATCO Electrc s web te. Proflng Cap Secton. 1) of the SSC requres a proflng cap of MW or the WSP s current polcy, whchever s lower. ATCO Electrc s proflng cap s 00 kw constent wth currently approved rate schedules. nterval metered customer tes that are below the proflng cap and are not a part of a profle class load research sample wll be settled accordng to ther own nterval data. ATCO Electrc January 01

9 . DSTRBUTON LOSSES AND UFE 1 Secton.1 ) of the SSC requres ATCO Electrc, as a Wres Servce Provder (WSP), to provde 0 days notce pror to mplementng changes to load settlement loss calculatons. Ths document descrbes the procedures ATCO Electrc wll use to perform load settlement loss calculatons on and after the effectve date of ths document. Background nformaton as to how the parameters used n these procedures were derved s also provded. Hstorc Loss Studes Secton.1 1) of the SSC requres the WSPs that have been dong loss calculatons as part of cost-of-servce studes to contnue to use mlar methods to those they have been ung. The parameters used n the loss calculaton procedures descrbed below come from two sources: prevous load settlement calculatons and dstrbuton loss studes of randomly selected dstrbuton feeders. Annual dstrbuton losses were determned from total annual energy delvered to the settlement zone less the total annual te energy consumpton. The source of ths nformaton s 00 through 0 load settlement results adjusted for PFAMs applcable to the same perod. The average annual dstrbuton system losses (.% of total annual te energy consumpton) calculated from these results form the bas for determnng the requred loss calculaton parameters. The separaton of total dstrbuton losses nto prmary and secondary dstrbuton losses for each loss group s based on the results of studes ATCO Electrc conducted on randomly selected dstrbuton feeder systems. nformaton on feeder loadng, confguraton, phycal characterstcs and the customer mx served from the feeders are used to determne the dstrbuton system losses for each loss group. Servce Level 0 1 For the purpose of performng loss calculatons the ATCO Electrc dstrbuton system has been separated nto prmary and secondary dstrbuton systems. Prmary dstrbuton consts of all -phase kv lnes. There are no transformers n the prmary dstrbuton system. Secondary dstrbuton ncludes all elements of the dstrbuton system that are not part of the prmary dstrbuton system. ATCO Electrc January 01

10 A servce level attrbute s asgned to each te based on whether the te takes servce drectly from the transmson system, from the prmary dstrbuton system or from the secondary dstrbuton system. Stes connected to the secondary dstrbuton system have a secondary servce level. Stes connected to the prmary dstrbuton system have a prmary servce level. Stes that are connected to the transmson system have a transmson servce level. Calculaton of Total System Losses Secton. 1) of the SSC asgns to ATCO Electrc as LSA the responblty for calculatng dstrbuton losses for each settlement nterval. Secton.. ) of the SSC requres the zone losses to be the sum of the separately determned retaler losses or to be calculated frst and then allocated to the retalers. For each settlement nterval ATCO Electrc calculates the total dstrbuton losses for each servce level and allocates these losses to retalers. The losses are calculated by applyng a loss equaton to the hourly load for the dstrbuton system. The prmary dstrbuton energy loss for each hour s calculated as follows: PL A A D P0 P Where PL s the loss (kw.h) wthn the prmary dstrbuton system n hour D s the total energy delvered (kw.h) to the dstrbuton system n hour (does not nclude transmson-connected tes) A P0 and A P are loss equaton parameters of the prmary dstrbuton system As there are no transformers n the prmary dstrbuton system, the constant loss coeffcent A P0 s zero. The value of the A P coeffcent for the 01 settlement year s determned as follows (see Appendx B): A p ke (0.011)(0) (1.000)(01) p P where p p s the rato of the total annual prmary energy loss to the total annual energy delvered to the dstrbuton system from hstorcal studes s the number of hours n the year k s the constant determned from the dstrbuton system load shapes for 00 to 0 E s the forecast energy delvered to the dstrbuton system for 01 (kw.h) ATCO Electrc January 01

11 Thus for each hour the total energy loss for ATCO Electrc s prmary dstrbuton system s calculated by multplyng the A P coeffcent by the square of the hourly energy delvered to the dstrbuton system. The secondary dstrbuton energy loss for each hour s calculated as follows: SL A A D S 0 S Where SL s the loss (kw.h) wthn the secondary dstrbuton system n hour D s the total energy delvered (kw.h) to the dstrbuton system n hour (does not nclude transmson-connected tes) A S0 and A S are loss equaton parameters of the secondary dstrbuton system The values of the A S0 and A S coeffcents for the 01 settlement year are determned as follows (see Appendx B): A A c p E (0.0)(0.01)(01) 0 s s S 0 ps(1 c ke ) (0.01)(0)(1 0.0) (1.000)(01) s S where p s s the rato of the total annual secondary energy loss to the total annual energy delvered to the dstrbuton system from hstorcal studes s the number of hours n the year c s s the rato of the annual constant loss to the total annual loss n the secondary dstrbuton system k s the constant determned from the dstrbuton system load shape for 00 to 0 E s the forecast energy delvered to the dstrbuton system for 01 (kw.h) For each hour the total energy loss for ATCO Electrc s secondary dstrbuton system s calculated by multplyng A S by the square of the hourly energy delvered to the dstrbuton system and addng A S0. Allocaton of Total System Losses 0 Secton. 1) of the SSC asgns to ATCO Electrc as LSA the responblty for establshng the formulas for allocatng dstrbuton losses for each nterval to the customer tes. ATCO Electrc allocates dstrbuton system losses by loss group whch s comprsed of servce level and loss class. The secondary dstrbuton loss allocated to each te by hour s calculated ung the followng equatons: ATCO Electrc January 01

12 SL SF SA E s SF ss SL SA E s Where SL s the secondary loss (kw.h) allocated to te s n hour SF s the factor that ensures all secondary loss for hour s allocated SA s s the secondary loss allocaton factor (see table below) for the loss group to whch te s belongs E s the energy consumpton (kw.h) for te s n hour SL s the total secondary loss (kw.h) n hour S s the set of all energzed tes s n hour The prmary dstrbuton loss allocated to each te by hour s calculated ung the followng equatons: PL PF PA s ( E SL ) PF ss PL PAs ( E SL) Where PL s the prmary loss (kw.h) allocated to te s n hour PF s the factor that ensures all prmary loss for hour s allocated PA s s the prmary loss allocaton factor (see table below) for the loss group to whch te s belongs E s the energy consumpton (kw.h) allocated to te s n hour PL s the total prmay loss (kw.h) n hour S s the set of all energzed tes s n hour The loss allocaton factors used were developed from an analys of hstorc load profle data and dstrbuton loss studes. For the years 00 through 00 the dstrbuton system losses were modeled ung the load profle of the energy delvered to the dstrbuton system as well as load profles, annual energy consumpton, and annual energy losses for each loss group. The loss group load profles were developed from the hourly loads of sample tes. The annual energy consumpton was calculated from te meterng. The annual energy losses are calculated from hstorc loss studes. The followng procedure was used to develop the loss allocaton factors for the prmary and secondary dstrbuton systems separately. Total loss profles for each year were estmated ung a load/loss relatonshp of the form descrbed above. Next, ntal loss allocaton factors for each loss group were calculated by dvdng the annual energy losses by the annual energy consumpton for each loss group. An teratve process was then used to refne the loss allocaton factors. The frst step consted of scalng the load profle for each loss group to the group annual energy loss ung the estmated loss allocaton factors. n the second step the resultng group loss profle was adjusted for each hour so that the sum of losses for all the loss ATCO Electrc January 01

13 1 groups was equal to the total loss profle. Because ths hourly adjustment changed the shape of the group loss profles the loss allocaton factors were readjusted. Ths teratve process was repeated and the loss allocaton factors refned untl the dfference between the total loss profle energy and the annual energy loss for each loss group was less than 0.%. The loss allocaton factors for each loss group determned for each year were averaged to arrve at the loss allocaton factors reported below. Loss Group Loss Group Code Secondary Loss Allocaton Factor (SA s ) Prmary Loss Allocaton Factor (PA s ) Loss Class Servce Level Redental Secondary RESSECN Redental Prmary RESPRM Redental Transmson RESTRAN 0 0 REA and Co Farm Secondary FRMSECN REA and Co Farm Prmary FRMPRM REA and Co Farm Transmson FRMTRAN 0 0 Small General Servce Secondary COMSECN Small General Servce Prmary COMPRM Small General Servce Transmson COMTRAN 0 0 rrgaton Secondary RRSECN rrgaton Prmary RRPRM rrgaton Transmson RRTRAN 0 0 Street Lghtng Secondary STLSSECN Street Lghtng Prmary STLSPRM Street Lghtng Transmson STLSTRAN 0 0 Prvate Lghtng Secondary SENTSECN Prvate Lghtng Prmary SENTPRM Prvate Lghtng Transmson SENTTRAN 0 0 Olfeld Secondary OLSECN Olfeld Prmary OLPRM Olfeld Transmson OLTRAN 0 0 ndustral < MW Secondary NDSECN ndustral < MW Prmary NDPRM ndustral < MW Transmson NDTRAN 0 0 ndustral > MW Secondary NPDSECN ndustral > MW Prmary NPDPRM ndustral > MW Transmson NPDTRAN 0 0 The target annual energy loss expressed as a percentage of annual energy consumpton for the loss group to whch customer te s belongs can be calculated as follows: Ps 0 PAs SAs ( PAs SAs ) ATCO Electrc January 01

14 Where P s PA s SA s s the percentage annual energy loss for the loss group to whch te s belongs s the prmary loss allocaton factor for the loss group to whch te s belongs s the secondary loss allocaton factor for the loss group to whch te s belongs Unaccounted For Energy 1 Secton..1 of the SSC requres that the UFE calculated for each hour be allocated to the customer tes of all retalers n proporton to ther settled load and allocated losses. Transmson-connected customer tes blled ung the same nterval metered data as s used n the calculaton of POD load are exempt from ths calculaton. ATCO Electrc allocates UFE for each hour n proporton to the energy consumpton and assocated losses for that hour. The followng formula s used for ths purpose: 1 U UF W ( E PL SL ) UF ss W U ( E PL SL) Where U s the UFE (kw.h) allocated to te s n hour UF s the factor that ensures all UFE for hour s allocated E s the energy consumpton (kw.h) for te s n hour PL s the prmary loss (kw.h) allocated to te s n hour SL s the secondary loss (kw.h) allocated to te s n hour U s the total UFE (kw.h) n hour W s 0 for UFE exempt tes n hour and 1 for all other tes n hour S s the set of all energzed tes s n hour ATCO Electrc 1 January 01

15 . OTHER DSCRETONARY MATTERS Estmaton of Consumpton Amounts 1 Secton. ) of the SSC asgns to ATCO Electrc, as LSA, the responblty of estmatng cumulatve consumpton amounts where consumpton calculated from meter readngs s not yet avalable. For daly, monthly, nterm and fnal settlement these estmates are based on customer rate class profles and energy consumpton from the most recent perod for whch energy consumpton between actual reads s avalable as follows: E E DCM m P P c c Where E s the energy consumpton (kw.h) estmated for te s n hour P c s the average te energy (kw.h) for profle class c n hour E DCM s the energy consumpton (kw.h) for te s from the most recent DCM coverng readng perod m that ends pror to the profle freeze date. Deemed Tmes Secton.1 of the SSC allows ATCO Electrc, as WSP, to defne an assumed tme of day for the readng of cumulatve meters as well as for energze and de-energze events. For the purpose of performng load settlement, ATCO Electrc deems these events to have taken place at the end of the day durng whch they were actually performed. mplementaton Assumptons Secton. 1) of the SSC specfes assumptons under whch the calculaton formulas of secton. have been developed. These assumptons are that energzaton, de-energzaton and profle class changes for a customer te wll always be accompaned wth a meter read on the same day and that swtch of retaler wll not necessarly be accompaned by a meter read. ATCO Electrc has mplemented the settlement calculatons constent wth these assumptons. Post Fnal Adjustment Mechansm (PFAM) Procesng Secton.. (1) (c) of the SSC requres LSAs to dentfy ther PFAM processes and tme lnes. These are descrbed n the followng paragraphs. ATCO Electrc 1 January 01

16 Followng the fnal settlement run each month, an automated process dentfes changes to cumulatve consumpton te data nce the prevous fnal settlement run affectng perods already fnal settled and produces the requred RSA transactons. These transactons are revewed and submtted by the end of the th buness day of the followng month (see SSC Secton.. (1)). All other changes to data between the same two fnal settlement runs affectng perods already fnal settled are dentfed manually. The requred RSA and/or TAA transactons are manually prepared and submtted at the same tme as the RSA transactons produced by the automated process. The followng procedures are used n the producton of RSA transactons: The fnal settled hourly energy consumpton, loss and UFE for a te s determned ung the SSC transacton set as descrbed n Appendx A. Corrected hourly energy consumpton for tes settled ung cumulatve consumpton s determned as descrbed n SSC Secton.. (1). Corrected hourly loss and UFE are determned as follows: L' U ' E' E E' E L U Where L s the corrected energy loss (kw.h) for te s n hour L s the fnal settled energy loss (kw.h) for te s n hour U s the corrected UFE (kw.h) for te s n hour U s the fnal settled UFE (kw.h) for te s n hour E s the corrected energy consumpton (kw.h) for te s n hour E s the fnal settled energy consumpton (kw.h) for te s n hour Daly profles are used n producng the RSA transacton set only n the case where fnal profles are not avalable. The use of daly profles n such cases allows RSA transactons to be ssued one month earler wth very lttle mpact on the result. Secton.. (1) (c) of the SSC requres partes to wthhold submttng a PFAM Applcaton Form after dentfyng an error untl the LSA s able to process the RSA transacton set as per the LSA s processes and tmelnes. For ATCO Electrc ths wthholdng perod s calendar days. Ths allows for the maxmum number of days between fnal settlement runs and the maxmum number of days between the last fnal settlement run and date the RSA and/or TAA transactons must be submtted. ATCO Electrc 1 January 01

17 Cumulatve Meterng Valdaton Test Parameters 1 Secton...1 of the SSC requres MDMs to make avalable to the market the hgh and low lmts for usage and demand n ther cumulatve meterng valdaton tests. For ths nformaton please refer to the AUC Rule 00 Alberta Tarff Bllng Code Rules, secton A1.. ATCO Electrc 1 January 01

18 APPENDX A CALCULATON OF HOURLY ENERGY CONSUMPTON, LOSS AND UFE 1 1 n ths appendx, a method s provded for determnng hourly customer te energy consumpton, loss and UFE from the SSC transacton set. n the followng: The WC, WSD and SP transactons used must be from the same settlement run. Cumulatve meter reads, energzaton, de-energzaton, profle class changes and retaler swtches are all deemed to occur on daly boundares. Ste s s a member of profle class c as well as loss group g and s enrolled to retaler r on day d whch s n meter readng perod m. Hour s wthn day d. Cumulatve Metered and Unmetered Stes 1 1 Hourly energy consumpton, loss and UFE for cumulatve metered and unmetered tes can be calculated as follows: 1 E E sd d E E rcg rcg 1 1 L U L sd d U sd d L L U rcg rcg U rcg rcg Where E E sd E rcg L L sd L rcg U U sd s the energy consumpton (kw.h) for te s n hour s the energy consumpton (kw.h) for te s n day d (from the WSD transacton) s the energy consumpton (kw.h) for all tes wth retaler r, profle class c and loss group g n hour (from the WC transacton) s the energy loss (kw.h) for te s n hour s the energy loss (kw.h) for te s n day d (from the WSD transacton) s the energy loss (kw.h) for all tes wth retaler r, profle class c and loss group g n hour (from the WC transacton) s the UFE (kw.h) for te s n hour s the UFE (kw.h) for te s n day d (from the WSD transacton) ATCO Electrc 1 January 01

19 U rcg s the UFE (kw.h) for all tes wth retaler r, profle class c and loss group g n hour (from the WC transacton) nterval Metered Stes Hourly energy consumpton, loss and UFE for cumulatve metered and unmetered tes can be calculated as follows: L U L E U E rcg rcg rcg rcg E W EW Where E s the energy consumpton (kw.h) for te s n hour (from the DM transactons avalable at the tme of the settlement run) E rcg s the energy consumpton (kw.h) for all tes wth retaler r, profle class c and loss group g n hour (from the WC transacton) L s the energy loss (kw.h) for te s n hour L rcg s the energy loss (kw.h) for all tes wth retaler r, profle class c and loss group g n hour (from the WC transacton) U s the UFE (kw.h) for te s n hour U rcg s the UFE (kw.h) for all tes wth retaler r, profle class c and loss group g n hour (from the WC transacton) W s a weghtng factor that has the value 0 f te s s transmson-connected n hour n day d (from the WSD transactons) and a value of 1 f t s not Note that the last formula does not work for a transmson-connected te that s not deemed to be a drect connect te accordng to secton.. ) a) ) of the SSC. ATCO Electrc 1 January 01

20 APPENDX B DEVELOPMENT OF THE SYSTEM LOSS EQUATON n ths appendx the coeffcents of the followng system loss equaton are developed. l A A e 0 Where l s the system loss for hour e s the system load for hour A 0 s the constant coeffcent assocated wth transformer core losses A s the coeffcent assocated wth restve lne losses Assumptons Total dstrbuton system transformer capacty grows at approxmately the same rate as the load growth n the dstrbuton system. The load growth for the secondary and prmary dstrbuton systems s approxmately the same. Defnton of Varables e s the energy flow n nterval nto the dstrbuton system. c s the rato of the annual constant energy loss to the annual total energy loss. p s the rato of the annual total energy loss to the annual total energy flow nto the system l s the total energy loss n the dstrbuton system n nterval s the total number of ntervals n the year. L s the total energy loss for the year E s the total energy enterng the system durng the year. By Defnton E e 1 1 c Annual Constant Energy Loss L L p E L l 1 ATCO Electrc 1 January 01

21 From the system loss equaton l A A e 0 Annual Constant Energy Loss A 1 0 A 0 Combnng, and L 1 l 1 A 0 1 A e A A 0 1 e From equaton and Annual Constant Energy Loss cpe Combnng and 1 1 cpe A 0 Combnng equaton, and pe cpe A Solvng for A e 1 1 A pe(1 c) e Substtutng and nto the equaton for the total loss for nterval becomes 1 l cpe pe(1 c) e e 1 ATCO Electrc 1 January 01

22 The value of c and p can be determned from hstorc loss studes and E s normally forecasted. The value that s not readly avalable s the sum of the square of the nterval energy. Ths value can be determned from ts relatonshp to E, the annual energy delvered to the system. From hstorc load data, t has been found that over a calendar year, the average of the square of the nterval energy has a lnear relatonshp to the square of the average nterval energy. 1 e E k Smplfyng the equaton we have 1 e k E 1 Solvng for the constant k 1 k e 1 1 E By calculatng an average k for hstorc nterval energy, the sum of the square of the nterval energy may be estmated from the forecast annual energy. The resultng energy loss equaton for nterval becomes: l cpe p(1 c) 1 ke e 1 And the loss coeffcents are: 1 cpe A0 A p(1 c) 1 ke ATCO Electrc 0 January 01

23 1 1 f we defne the followng relatonshps, the loss equaton can be dsaggregated to the prmary and secondary dstrbuton systems. p p S p P cp cs ps cp pp Where c p s the rato of the annual constant energy loss n the secondary dstrbuton system to the total annual energy loss n the secondary dstrbuton system c s s the rato of the annual constant energy loss n the prmary dstrbuton system to the total annual energy loss n the prmary dstrbuton system p p s the rato of the total annual energy loss n the prmary dstrbuton system to the annual energy delvered to the dstrbuton system p s s the rato of the total annual energy loss n the secondary dstrbuton system to to the annual energy delvered to the dstrbuton system As there are no transformers n the prmary dstrbuton system, c p s equal to zero and the loss coeffcents for the prmary dstrbuton system becomes 1 A P0 0 A P pp ke 1 And the loss coeffcents for the secondary dstrbuton system are 1 A S 0 cs ps E A S pp(1 cs ) ke ATCO Electrc 1 January 01