Reference Requirement specification for. IT enabling Implementation of. Intra State Availability Based Tariff (ABT) in SLDC

Transcription

1 Reference Requirement specification for IT enabling Implementation of Intra State Availability Based Tariff (ABT) in SLDC A White Paper By C. Laakshmana Sabari Kalki Communication Technologies Limited #147, 5th Main, HSR Layout, Sector 7 Bangalore , INDIA info@kalkitech.com Phone: Web:

2 Table of Contents 1 Introduction Key Words Availability Based Tariff regulation Business Functions Application Packages Module 1: Energy Scheduling Module 2: STOA approval Module 3: State Energy Accounting Module 4: UI and Reactive energy charges balancing and settlement Module 5: Open Access charges and Open Access UI Module 6: Transmission Loss calculation for the state Module 7: Transmission Service Charges calculation and Invoicing Module 8: Meter Data Acquisition Module 9: Data storage, retrieval & archiving Module 10: Monitoring - Visualization Module 11: Presentation GUI & Reporting Module 12: Interactions General Requirements: Regulation Change Management: Deliverables: Software Hardware Documentation Training Annual Maintenance Contract Conclusion Reference Copyright Kalki Communication Technologies Ltd. All Rights Reserved 2

3 1 Introduction The objectives of Indian Electricity Act 2003 are Availability, Affordability, and Grid Discipline. One of the prime mechanisms devised by CERC to ensure that the objectives are met is the Availability Based Tariff (ABT) mechanism. The state electricity regulatory commissions have devised their own Intra State ABT regulations taking cue from CERC regulations and adding the state's individual constraints and criteria into account. Especially, the scheduling and energy accounting process is more complex than in regional level, the complexity being attributed to injection at various voltages (renewable energy, CPPs & IPPs, mini & micro hydels), drawal at various voltages (HT, LT), inter and intra state open access generators and consumers, multiple PPAs etc., The regulatory commissions and state grid codes have entrusted respective state load dispatch centre with the function of ensuring availability, affordability and grid discipline by implementing Intra State ABT.This whitepaper, based on extensive research and working closely with state load dispatch centre of various states in India, arrives at a set of specification for IT enabling of Implementation of Intra State ABT regulations and also enabling the state load dispatch centre to conduct their business effectively to fulfill their set objectives in the ABT regime. 2 Key Words ABT Availability Based Tariff BEE Bureau of Energy Efficiency CERC Central Electricity Regulatory Commission CGS Central Generating Stations CIM Common Information Model DISCOM Distribution Company ELD Economic Load Dispatch ERC Electricity Regulatory Commission FDS Functional Design Specification MYT Multi Year Tariff Order NREC Notified Rate of Energy OAC Open Access Customer PLF Plant Load Factor RLDC Regional Load Dispatch Centre SGS State Generating Stations SLDC State Load Dispatch Centre UI Unscheduled Interchange Copyright Kalki Communication Technologies Ltd. All Rights Reserved 3

4 3 Availability Based Tariff regulation Availability Based Tariff comprises of three components: (i) capacity charge, towards reimbursement of the fixed cost of the plant, linked to the plant's declared capacity to supply MWs, (ii) energy charge, to reimburse the fuel cost for scheduled generation, and (iii) unscheduled interchange, a payment for deviations from schedule, at a rate dependent on system conditions. The last component would be negative (indicating a payment by the generator for the deviation) in case the power plant is delivering less power than scheduled and positive in case the power plant is delivering more power than scheduled when the frequency is low. In addition to this, penalty (in geometric progression) will be levied for misdeclaration and incentive will be given for achieving PLF greater than the target at a rate notified by the regulatory commission. In short; Penalty for misdeclaration in geometric progression of two days fixed charges. Realization of capacity charges in prorata basis with respect to achieved availability being lesser than the notified availability. Incentives at notified rate for achieving more than the target PLF. Negative UI charges at notified UI rate corresponding to frequency, when dispatch is less than the schedule or drawal is more than the schedule. Positive UI charges at notified UI rate corresponding to frequency, when dispatch is more than the schedule or drawal is less than the schedule. Gaming constraints at 105% in a block and 101% in a day and UI rate capping. Levy of charges for reactive energy injection/ drawal or high/low when voltage is beyond the range of 3% deviation allowed from nominal voltage. Penalty for consuming more than the auxiliary consumption limit. In case of force majeure, actuals are taken as schedules and hence UI regime suspension in that period will be notified by SLDC. 4 Business Functions The business functions of state load dispatch centre in the light of ABT regime is: Scheduling day ahead and day of operation STOA approval State Energy Accounting UI and RE Bill invoicing Open access UI, open access charges calculation and bill invoicing Transmission loss for the state calculation Transmission service charges calculation and invoicing Meter Data Acquisition (i) Meter Data Acquisition 1) Off-line 2) On-line (ii) Meter Data Processing for grouping to measure logical entities Data storage, retrieval and archiving (CERC specifies to store data for 18 months minimum) Monitoring of the Grid - Visualization Reporting Copyright Kalki Communication Technologies Ltd. All Rights Reserved 4

5 Interaction with the following: o Regional load dispatch centre: to get entitlement and send requisition, to get implemented schedule, billing frequency, UI charge invoice. o State sector generating stations: to get declared capacity and send dispatch schedule. o Distribution companies: to send entitlement, get requisition and send drawal schedule. o Open access customer: to get application, send approval, and send schedule. o Load Dispatch Centre website 5 Application Packages Application packages required essentially for state load dispatch centre to carry out the business functions effectively are: 5.1 Module 1: Energy Scheduling The guidelines given by regulatory commission should be strictly adhered to: a) Scheduling process: State sector generating stations shall send their declared capacity in predefined template notified by SLDC, preferably by . Entitlement for the state in central sector generating stations declared capacity shall be downloaded from the RLDC website or from the sent by RLDC. Interstate open access schedule shall be downloaded from the RLDC website or from the sent by RLDC. Intra state open access schedule shall be obtained from the open access approved details available with SLDC. Power exchange/energy exchange schedules shall be downloaded from the RLDC website or from sent by the respective exchanges Based on allocation notified by government/erc and available power, quantum, the power available from transmission system for individual distribution companies shall be calculated as entitlement. The entitlement of distribution companies shall be intimated to the entities in pre-defined template notified by SLDC, preferably by . Based on its entitlement and load forecasting, distribution companies shall send their requisition of power in pre-defined template notified by SLDC, preferably by (calculation of power required for distribution is in the scope of respective distribution companies). There are few scenarios that can be expected. o Scenario 1: Intra State ABT regulation specifically says that the requisition from distribution companies shall be limited to its entitlement and bilateral exchange of entitled power is prohibited between distribution companies, and the additional power capacity available is notified to other distribution companies enabling them to request for it. Copyright Kalki Communication Technologies Ltd. All Rights Reserved 5

6 In this scenario, corresponding process has to be carried out again in getting the requirement of distribution companies. o Scenario 2: Intra State ABT regulation specifically says that the requisition from distribution companies shall be limited to its entitlement and bilateral exchange of entitled power is not prohibited between distribution companies. In this scenario, information on the bilateral exchange between distribution companies needs to be furnished by them. This leads to additional processing at SLDC to arrive at the final requirement of distribution companies. Also, this kind of a clause may result in gaming by distribution companies wherein load shedding may be done at areas of under privileged society and exchange that quantum with other distribution companies at a higher price. This kind of gaming is not captured at present in the ABT regulations. o Scenario 3: The distribution companies can request for their full power requirement calculated from their load forecasting system without considering the entitlement limitation. In this scenario, the scheduling mechanism will be simple, avoiding additional processes and gaming (if any possible). This will enable the SLDC to have day to day data collection for their future planning requirements and avoid tedious labour to collect that information in future. The quality of the information will also be better than that collected at future date. The entitlement shall be guideline to the distribution companies; whereas it will be the limiting quantum to SLDC scheduling process. Here when a distribution company requests for less quantum than its entitlement, the additional power capacity shall be allocated to other wanting distribution companies in the notified allocation percentage. SLDC shall calculate the dispatch schedule, requisition to RLDC and drawal schedule. In addition to the information obtained as specified in above clauses, the calculation shall be based on merit order dispatch (a set of logics involving merit order cost, technical minimum, ramp rate, etc.,) While considering technical minimum, the capacity declared by generating station shall be given more weightage than the technical minimum of that particular generating station. The calculated schedules shall be sent to corresponding utilities, in predefined templates, preferably by . Schedule Revision Management shall be provided. The Revision number of the schedules shall be distinct from the declared capacity/ CGS entitlement/ DISCOM requirement/ RLDC schedule. Copyright Kalki Communication Technologies Ltd. All Rights Reserved 6

7 5.2 Module 2: STOA approval The STOA approval shall calculate and publish TTC and ATC data to SLDC website. Both Inter State STOA and Intra State STOA applications shall be processed as per regulations. One critical feature required in the automation of work flow is the cross checking functionality. The issuance of STOA shall be subject to the receipt of previous OA charges payable if any by the STOA customer. In this case Interstate STOA, the system shall prepare approval status in the format notified by RLDC and send it to them. 5.3 Module 3: State Energy Accounting The State energy accounting shall be done for active energy, reactive energy, availability, plant load factor, state transmission loss, etc., The accounting shall be based on the readings taken in ABT meters installed at interface points and readings made available from PGCIL meters installed at interface points. The calculation shall be based on balancing and settlement mechanism notified by ERC or other responsible authorities taking into account all injection, drawal, and agreements for apportionment. 5.4 Module 4: UI and Reactive energy charges balancing and settlement Unscheduled interchange energy and reactive energy for all the utilities will be calculated based on Intra State ABT regulations and balancing and settlement of UI will be based on balancing and settlement code notified by regulatory commission of the state. Invoice for the same shall be prepared and sent to the utilities. 5.5 Module 5: Open Access charges and Open Access UI OA charges and OA UI shall be calculated based on the Open access regulations notified by the regulatory commission. The injection/drawal of OA customer shall be obtained from Energy Accounting. Invoice shall be prepared and sent to open access customers. 5.6 Module 6: Transmission Loss calculation for the state Loss calculation for the state boundary using Energy Balance technique shall be carried out on a weekly basis and notified to all stake holders. Transmission loss has to be collected from utilities in kind or cash as per the regulation. If the regulation opts for collection of transmission loss in kind, then the transmission loss calculated for the previous week shall be used for determining dispatch and drawal schedules. If the regulatory commission has not specified otherwise, say transmission loss percent notified by ERC for the year as a single value, this floating value of transmission loss percentage shall be used for the purpose. The system shall then provide options for entering the output of loss analysis which might have been carried out manually. This shall be given by provision for operator to enter reason for maximum and minimum loss enabling consolidation at a later stage. Snap shot of system conditions (Hz, I, V) during maximum and minimum loss shall be stored in the database for future reference. Copyright Kalki Communication Technologies Ltd. All Rights Reserved 7

8 5.7 Module 7: Transmission Service Charges calculation and Invoicing Transmission service charges shall be calculated based on the prevailing regulation notified by regulatory commission. Invoice of the same shall be prepared and sent to utilities in predefined templates. 5.8 Module 8: Meter Data Acquisition i. Meter Data Acquisition (MDA): a) Off-line MDA module: Provision for reading meter data from xml file or ASCII file shall be available. Sending of meter data in mrd files or ASCII files preferably by will be in the scope of respective substations. The mrd to xml file converter of the meter manufacturer shall be made available at the Intra State ABT implementation server by SLDC. b) On-line MDA module: For the purpose of on-line MDA, meters can be classified based on: (i) Nature of parameters and accuracy class measured: ABT compliant energy meters and Non ABT compliant energy meters. (ii) Communication protocol supported: Modbus support Proprietary protocol support multiple make and models DLMS COSEM compliant (in near future, CERC may notify metering regulations which specifies DLMS compliance) IEC support Meter Data can be classified into the following types: Load survey data 15 minute interval data Midnight data TOD data Exception data event logs Instantaneous data ABT data and instantaneous data from ABT Meter can be acquired directly from the ABT meter. The parameters and the periodicity of acquisition shall be finalized at the time of detailed discussions, the criteria being: 1. Meter type (PGCIL/CERC/ SERC specification ABT meter) 2. Parameters configured for measurement at the time of configuration 3. Communication time limitation for instantaneous parameters, normally there will be lag of more than one minute. In the absence of ABT meter infrastructure or authorization for the utility to make use of the said infrastructure, the on-line MDA software shall be able to acquire instantaneous data from SCADA/ RTU for monitoring purpose. A major limitation of SCADA/ RTU is the non availability of 15 minute interval data. The limitations of such a facility shall be Copyright Kalki Communication Technologies Ltd. All Rights Reserved 8

9 acceptable by utility provided; the limitations from the vendor are technological/ beyond their scope in nature. The administrative limitations if any shall be due addressed by the utility. Architecture and solution for Meter Data acquisition through SCADA/ RTU shall be given by the vendor in their functional design specification after study of the existing scenario in the utility. The on-line MDA software shall be able to fetch data from all types of meters classified above, including DLMS. For meters with proprietary protocols, SLDC shall facilitate the availability of the proprietary protocol details from the meter manufacturer. The communication media (GSM/ GPRS/ PSTN/ VSAT/ LAN) shall be suitably decided at the time of detailed engineering. However the on-line MDA software shall be independent of the communication media i.e., it shall be able to use any of the communication media suggested above. Meter data validation, estimation and editing functionality shall be provided. The VEE shall be based on internationally accepted industry standards and the validated data shall only be used in billing calculations. ii. Meter Data processing for grouping to measure logical entities The software shall process the meter data for grouping into logical entities like generating station, transmission & distribution hierarchy and operations & commercial hierarchy. The grouping shall be configurable by the user. 5.9 Module 9: Data storage, retrieval & archiving Database shall be provided to store, retrieve and archive data. Standard practices recommended by the Database company in its literature to administer its database effectively shall be followed. CERC specifies to store data for minimum 18 months. External storage media like an optical storage device or an external hard disc of minimum capacity 1TB shall be provided. To ensure high availability of Data, database redundancy shall be provided Module 10: Monitoring - Visualization On availability of real time data from interface points, the software shall display the critical parameters like frequency, active energy, reactive energy, power, voltage, current, etc., in both tabular and graphical formats enabling users to monitor the grid effectively. The software shall generate notifications when the parameters cross the operator defined limits like frequency limits of 49.2 Hz and 50.5 Hz. Visualization is the single point window through which operators and decision makers view the domain problems addressed. Hence this has to be rich in graphic and should be able to pictorially depict the domain for an easy and clear understanding of the information represented. Any problem in domain purview will carry out two levels of functions one is implementation of domain logic for solving problem area under consideration, and other is optimization of required objective function. A wide scope of display items includes the input process values from the problem domain presented pictorially, the work flow demanded by the problem area, the interactive control and input mechanism by the operator or user, personalized dash boards, statuesque information of the domain logic under execution, the results and outputs, statuesque information of the optimization logic and its results. Visualization features can be classified under two categories (i) web portal for delivering visual interface, (ii) graphical editor for configuring the web portal. Copyright Kalki Communication Technologies Ltd. All Rights Reserved 9

10 (i) Web Portal Rich web2.0 graphics. Display of process diagrams for domain areas like power plant, electric network topology. Display of network diagrams/symbols over geographical maps, parcel layouts. Navigation and search on the maps to point out the location with respect to network/operational hierarchy. Support for real-time trends, different types of charts including 2D and 3D representation. Enhanced reporting tools with flexibility for user configurable reports. Reports should be web based and output should be made available in pdf and Microsoft office formats. Navigation between screens and updating of real-time data should be within a couple of seconds. There should be zoom, pan and easy navigation facility for the network topology like display. There should be alarm display bars which can show critical alarms or messages for the operators and engineers. There shall be tickers which display coherent set of information which changes continuously and should be known to operators (example UI charges in previous 15 minute interval and the current demand for an ABT package running at LDC s). The reports, trends and charts should present statistical analysis on a historical data. There shall be proper authentication and access/control levels implemented. A system administrator can configure and enable/disable access to the system, and also he can monitor and define various access permission for each specific user. The login screen should be able to customize for an implementation with option to display an image supplied by the customer. Also there shall be provisions for display of customer logo in each screen. There should be dash-board displays customizable for a user and these personalized displays should be accessible based on the log-in. Support popular browsers like Mozilla, Internet Explorer. Dynamic displays/updates should happen without requirement for reloading of the page Module 11: Presentation GUI & Reporting The software shall be presented in web based GUI and the flow shall be user friendly with a standard look & feel. The dash board shall reflect standard information on the Grid specific to ABT. Raw and processed information shall be presented in both tabular and graphical formats. The reporting shall be comprehensive including Executive/ Operator information, Management Information, Customer information, Regulatory compliance information (like ERC and RTI) etc., The design of reports shall be optimal to reduce carbon foot print of SLDC; layout and number of pages to be consumed to report a specific information shall be optimized. The format of reports shall be provided by SLDC. However, the implementation agency shall Copyright Kalki Communication Technologies Ltd. All Rights Reserved 10

11 submit predefined templates in FDS. Reporting tool shall be provided for the users to prepare report templates Module 12: Interactions Suitable solution shall be proposed to enable SLDC to interact with entities like RLDC, Generation companies, Distribution companies, Open Access Customers, IEX, and PEX for information exchange. The solution shall remove/ reduce manual labour as much as possible. Manual intervention shall be required only for verification and authentication purpose. At present SLDC employs Excel based information exchange. The solution shall provide information to post in SLDC website in xml or CIM standards. 6 General Requirements Web based solution Modular architecture Application redundancy Database redundancy Role based security and user authentication at multiple levels Reliability Antivirus and firewall protection software shall be provided for one year. SLDC shall subscribe for the recommended Antivirus from next year onwards. Firewall shall be supplied and configured for the network conceived during detailed engineering. Configurable to the most possible extent (eg. UI rate shall be configurable) Easy adaptability to future change requirements in regulations Adherence to international standards preferably IEC 61970, IEC / CIM, DLMS User friendly design Extensive training to executives Complete documentation of user manuals, safety manuals, etc., 7 Regulation Change Management The system shall be designed in such a fashion that mostly when there is a regulation change it requires only a change in configuration. However, when there is a considerable shift in the regulations after freezing of functional design specification, and that cannot be handled by configuration changes, the issue shall be discussed on case by case basis between SLDC and implementing agency, and a viable solution man days required additional cost involved additional inputs required, etc., are arrived at. A change request form shall be designed and used for the purpose. The number and nature of changes shall be properly indented. Copyright Kalki Communication Technologies Ltd. All Rights Reserved 11

12 8 Deliverables 8.1 Software i. Software for implementation of Intra State ABT with following basic modules: ABT scheduling module State Energy Accounting module UI and RE charges billing module Open Access UI and open access charges calculation and billing module Transmission Loss of the state calculation module Transmission service charges calculation module On-line meter data acquisition module (scope of supply items shall be decided at the time of detailed engineering. Off-line meter data acquisition module Meter data VEE and processing module Monitoring - visualization i. Reporting Tool ii. Database iii. Application redundancy iv. Database redundancy v. Anti-virus vi. MS office 8.2 Hardware i. Server Two numbers- Minimum 4GB RAM and other latest configuration ii. Client PC Three numbers Minimum 1 GB RAM and other latest configuration iii. Networking including commissioning (switching, cabling, etc) iv. Firewall v. Printer One number vi. UPS and batteries 2 KVA for Server 1 No. vii. UPS 500 VA for client PC 3 No. viii. On-line meter data acquisition set of communication hardware like Data concentrator, modems, etc., depending on the communication media selected. (shall be decided on detailed engineering) 8.3 Documentation i. Functional Design Specification ii. User Manual iii. Training manual/ Instruction manual iv. Test case v. Test report (Site Acceptance Test performed at SLDC and signed positive by SLDC officials) Copyright Kalki Communication Technologies Ltd. All Rights Reserved 12

13 8.4 Training Training to SLDC officials shall be given in two levels (i) operator training and (ii) administrator training. The training shall be given to minimum five SLDC nominated officials. Training material shall be made available to trainees in prior advance to the training date. 8.5 Annual Maintenance Contract The implementation agency shall provide maintenance of the software and hardware supplied for two years under AMC agreement. An Engineer shall be stationed at site for the purpose. During the AMC period, if there is change in regulations that are not configurable, SLDC on discussion with implementation agency shall arrive at the man days required, additional inputs, additional cost involved. Based on the work-out, SLDC shall release addendum order to the implementation agency to implement the change in the system. 9 Conclusion The business function that needs to be carried out by SLDC to meet its set objectives in Intra State ABT regime has been enumerated. The IT framework including the basic application software required, the hardware infrastructure and communication architecture has been illustrated. With the dealt outline specification, SLDC can formulate system requirement specification in detail and call implementation agencies to provide IT infrastructure and software to implement Intra State ABT successfully. Reference Indian Electricity Act 2003 Central Electricity Regulatory Commission (Terms and Conditions of Tariff) Regulations, Central Electricity Regulatory Commission (Open Access in Inter-state Transmission) Regulations, Indian Energy Conservation Act 2003 IEC CIM model Intra State ABT regulations and Open Access regulations of various states in India. Copyright Kalki Communication Technologies Ltd. All Rights Reserved 13