Rajasthan Electricity Grid Code, 2008
Resolution By
RERC
Notification No. and date
RERC / Secy / Reg - 74 Dated: 24-05-2008
Objectives
1. To provide certainity to STU, SLDC and other Users by enabling them to understand their obligations in operating the State Transmission System.
2. To improve the grid stability and performance, and to set up minimum standards of system parameters.
3. To define requirements for new entrants i.e. future new generating companies, licensee(s) and consumers.
4. To direct the generating companies as to what performance characteristics their plant shall provide.
5. To have better coordination by providing a clear and consistent disclosure mechanism for all information.
6. To facilitate operation, maintenance, development and planning of economic and reliable State Transmission System.
7. To indicate how generation is to be scheduled and despatched
[Clause 2.1]
2. To improve the grid stability and performance, and to set up minimum standards of system parameters.
3. To define requirements for new entrants i.e. future new generating companies, licensee(s) and consumers.
4. To direct the generating companies as to what performance characteristics their plant shall provide.
5. To have better coordination by providing a clear and consistent disclosure mechanism for all information.
6. To facilitate operation, maintenance, development and planning of economic and reliable State Transmission System.
7. To indicate how generation is to be scheduled and despatched
[Clause 2.1]
Regulations called as
Rajasthan Electricity Regulatory Commission (Rajasthan Electricity Grid Code) Regulations 2008. In short REGC.
Planning Code for Intra-state Transmission- Introduction
1. System planning identifies the method for data submissions by Users to STU and the procedure to be applied by STU in the planning and development of the STS
2. The requirement for reinforcement or STS extension may arise due to development on a User's system already connected to the STS, introduction of a new Connection point between the User's system and the STS, increase in the system capacity etc.
3. The Transmission System development shall be planned in advance with sufficient lead time, for detailed engineering, design and construction work and the time required for obtaining statutory approvals from various agencies for implementation of the scheme(s).
[Clause 5.1]
2. The requirement for reinforcement or STS extension may arise due to development on a User's system already connected to the STS, introduction of a new Connection point between the User's system and the STS, increase in the system capacity etc.
3. The Transmission System development shall be planned in advance with sufficient lead time, for detailed engineering, design and construction work and the time required for obtaining statutory approvals from various agencies for implementation of the scheme(s).
[Clause 5.1]
Planning Code for Intra-state Transmission- Planning Philosophy
1. SLDC shall be responsible for assessing the availability and its requirement in kW, kWH & kVAr for one year on monthly basis and STU for next five and ten years on an annual basis.
2. The assessment shall be based on the historical data, load requirement projected by the DISCOMs, maintenance schedule of GENCO, maintenance schedules of TRANSCO, transmission constraints, generation and transmission capacity additions.
3. Methodoogy is provided by STUs for planning in the grid code
4. All the Users shall furnish the desired, planning data to STU by 31st March every year to enable STU to formulate and finalise the plan by 30th September each year for the next 5 years. STU may extrapolate the demand forecast of Discoms for the purpose of long term projections.
[Clause 5.2]
2. The assessment shall be based on the historical data, load requirement projected by the DISCOMs, maintenance schedule of GENCO, maintenance schedules of TRANSCO, transmission constraints, generation and transmission capacity additions.
3. Methodoogy is provided by STUs for planning in the grid code
4. All the Users shall furnish the desired, planning data to STU by 31st March every year to enable STU to formulate and finalise the plan by 30th September each year for the next 5 years. STU may extrapolate the demand forecast of Discoms for the purpose of long term projections.
[Clause 5.2]
Planning Code for Intra-state Transmission- Criterion
1. The Planning Criterion is based on the security philosophy as per Transmission Planning Criteria and CEA guidelines on which ISTS and STS have been planned.
2. The ISTS/STS shall be secured against contingency outages without necessitating loads shedding or rescheduling of generation during Steady State Operations.
3. STS shall be capable of withstanding the loss of most severe single system infeed i.e outage of a generating station or interregional interconnection or all line connections between two stations without loss of stability.
4. ) The contingencies shall not cause Loss of supply, prolonged operation of the system frequency below and above specified limits, Unacceptable high or low voltage, System instability and Unacceptable overloading of ISTS/STS elements
[Clause 5.3]
2. The ISTS/STS shall be secured against contingency outages without necessitating loads shedding or rescheduling of generation during Steady State Operations.
3. STS shall be capable of withstanding the loss of most severe single system infeed i.e outage of a generating station or interregional interconnection or all line connections between two stations without loss of stability.
4. ) The contingencies shall not cause Loss of supply, prolonged operation of the system frequency below and above specified limits, Unacceptable high or low voltage, System instability and Unacceptable overloading of ISTS/STS elements
[Clause 5.3]
Planning Code for Intra-state Transmission- Planning Data
1. To enable STU / SLDC to conduct System Studies and prepare perspective plans for electricity demand, generation and transmission, the Users and / or Rajasthan Renewable Energy Corporation (RREC)shall furnish timely data, to STU.
2. The data pertaining to the Generating Station including CPPs and Generating Units owned by Distribution Licensee shall be updated on addition of Generating Units/modification of the Distribution Systems.
3. The User /STU shall exchange data as provided in IEGC relating to generation and energy transmission from ISTS.
4. One time data shall be submitted within 6 months from the date REGC comes into effect, by all concerned to the STU. The data other than the one time data shall be made available to STU on 1st of April and 1st of October every year.
5.Data already furnished’ as per earlier Grid Code shall be considered to have been submitted under REGC.
[clause 5.5]
2. The data pertaining to the Generating Station including CPPs and Generating Units owned by Distribution Licensee shall be updated on addition of Generating Units/modification of the Distribution Systems.
3. The User /STU shall exchange data as provided in IEGC relating to generation and energy transmission from ISTS.
4. One time data shall be submitted within 6 months from the date REGC comes into effect, by all concerned to the STU. The data other than the one time data shall be made available to STU on 1st of April and 1st of October every year.
5.Data already furnished’ as per earlier Grid Code shall be considered to have been submitted under REGC.
[clause 5.5]
Planning Code for Intra-state Transmission- Implementation of Transmission Plan
1. The DISCOM shall submit its power requirement to SLDC for the ensuing year by 31st October on monthly basis as per their entitlement and share in generating stations.
2. DISCOM shall project the demand for the next 5 and 10 years on annual basis to SLDC & STU. In case information is not received timely, the SLDC & STU shall assess the requirement and convey to the DISCOM.
3. The demand forecasts shall be updated annually or whenever major changes are made in the existing planning.
4. SGS shall provide its generation capacity to STU / SLDC for power evacuation from its power stations for each of the succeeding 5 years along with transmission system augmentation proposals to STU, annually by 31st March.
5.The planning for strengthening the State Transmission System for power evacuation from outside the state stations shall be initiated by STU.
6. The State Transmission System proposals identified on the basis of planning studies shall be discussed, reviewed and finalized and approved by the Technical Committee and apprised the SPC.
[clause 5.4]
2. DISCOM shall project the demand for the next 5 and 10 years on annual basis to SLDC & STU. In case information is not received timely, the SLDC & STU shall assess the requirement and convey to the DISCOM.
3. The demand forecasts shall be updated annually or whenever major changes are made in the existing planning.
4. SGS shall provide its generation capacity to STU / SLDC for power evacuation from its power stations for each of the succeeding 5 years along with transmission system augmentation proposals to STU, annually by 31st March.
5.The planning for strengthening the State Transmission System for power evacuation from outside the state stations shall be initiated by STU.
6. The State Transmission System proposals identified on the basis of planning studies shall be discussed, reviewed and finalized and approved by the Technical Committee and apprised the SPC.
[clause 5.4]
Connection Code/ Grid connectivity- Introduction
1. Connection Conditions specify the technical, design and operational criteria to be complied with by the User connected to the STS in ensuring the following:
1.1. All Users or prospective Users are treated equitably.
1.2. New Connections shall not cause any adverse effect on the existing Users, nor shall a new Connection shall suffer because of existing Users.
1.3. The ownership and responsibility of the equipments for the sites where ever a Connection is made.
[clause 6.1]
1.1. All Users or prospective Users are treated equitably.
1.2. New Connections shall not cause any adverse effect on the existing Users, nor shall a new Connection shall suffer because of existing Users.
1.3. The ownership and responsibility of the equipments for the sites where ever a Connection is made.
[clause 6.1]
Connection Code/ Grid connectivity- Objective
1. To take care of modifications in equipment rating, if any, for the system and grid connection point equipments on account connectivity modifications.
2. To satisfy protection standards and relay coordination aspects at the connection point as per grid norms.
3. To provide telemetering, SCADA and the relevant data at the interconnection points.
4. To take care of the system in the event of grid initiated disturbances and not to rely on grid defense mechanisms alone.
5. To participate islanding and other grid scheme(s) by contributing generation/load wherever available, as decided by STU / SLDC and to follow load restoration guidelines during islanded operation.
6. To provide protection-tripping data for grid disturbances to SLDC and to Protection Coordination Committee for analysis in ensuring safe and reliable grid operation.
7. TO assist in start up power and restoration by RLDC/SLDC for which the tariff shall be as decided by RERC.
8. To perform testing/calibration of equipments and meters at inter connection points in the presence of interested parties and the utilities and to make available the test reports to the parties and to concerned utilities/organizations including SPC.
9. To plan maintenance schedule of lines/ICTs or bay at connection point in consultation with the STU / SPC.
10. To train sub-station/line staff at the interconnection of requester and existing utility of tie points with regard to safety and operation procedures to be conducted annually and mutually.
[clause 6.2]
2. To satisfy protection standards and relay coordination aspects at the connection point as per grid norms.
3. To provide telemetering, SCADA and the relevant data at the interconnection points.
4. To take care of the system in the event of grid initiated disturbances and not to rely on grid defense mechanisms alone.
5. To participate islanding and other grid scheme(s) by contributing generation/load wherever available, as decided by STU / SLDC and to follow load restoration guidelines during islanded operation.
6. To provide protection-tripping data for grid disturbances to SLDC and to Protection Coordination Committee for analysis in ensuring safe and reliable grid operation.
7. TO assist in start up power and restoration by RLDC/SLDC for which the tariff shall be as decided by RERC.
8. To perform testing/calibration of equipments and meters at inter connection points in the presence of interested parties and the utilities and to make available the test reports to the parties and to concerned utilities/organizations including SPC.
9. To plan maintenance schedule of lines/ICTs or bay at connection point in consultation with the STU / SPC.
10. To train sub-station/line staff at the interconnection of requester and existing utility of tie points with regard to safety and operation procedures to be conducted annually and mutually.
[clause 6.2]
Connection Code/ Grid connectivity- Procedure for connection
1. A User seeking to establish new or modified arrangement(s) for Grid connection and/or use of transmission system of Transmission Licensee shall submit the application in the form as may be specified by STU.
2. The STU shall specify the Connection Point, technical requirements and the voltage to be used, along with the protection requirements.
3. The SGS (except CPPs) shall make available the up-to-date capability curves for all Generating Units, indicating restrictions to SLDC, to allow accurate system studies and effective operation of the State Transmission System.
4. CPPs shall furnish the net reactive capability that shall be available for Export to / Import from STS.
[clause 6.6]
2. The STU shall specify the Connection Point, technical requirements and the voltage to be used, along with the protection requirements.
3. The SGS (except CPPs) shall make available the up-to-date capability curves for all Generating Units, indicating restrictions to SLDC, to allow accurate system studies and effective operation of the State Transmission System.
4. CPPs shall furnish the net reactive capability that shall be available for Export to / Import from STS.
[clause 6.6]
Connection Code/ Grid connectivity- Connection Agreement
1. A condition requiring both the parties to comply with the REGC.
2. Connection details and/or use of system charges.
3.Details of capital works related payments of reinforcement and systemextension.
4. Electrical system with connectivity diagram.
5. General philosophy and protection guidelines.
6. A Site Responsibility Schedule
[clause 6.9]
2. Connection details and/or use of system charges.
3.Details of capital works related payments of reinforcement and systemextension.
4. Electrical system with connectivity diagram.
5. General philosophy and protection guidelines.
6. A Site Responsibility Schedule
[clause 6.9]
Connection Code/ Grid connectivity- Important technical requirements for connectivity to the grid
1. The SLDC in coordination with RLDC and the Users shall make all possible efforts to maintain grid frequency within the 49.0 – 50.5 Hz band in accordance with IEGC 5.2 (l).
2. The SLDC, and the Users shall ensure that the grid voltage remains within theoperating limits as specified in IEGC 5.2 (r).
3. Voltage harmonics: Total harmonic distortion for nominal volatage 400 kV , 220kV, 132 kV are 2.0%, 2.5% and 3% respectively and Individual harmonic of any particular frequency for nominal volatage 400 kV , 220kV, 132 kV are 1.5%, 2% and 2% respectively .
3. The total harmonic current drawn from the transmission system at any point shall not exceed 8% of the fundamental frequency current.
4. Maximum limit of voltage imbalance for below 220 kV and 220 kV & above are 3% and 2% respectively.
5. Discoms shall ensure that their loads do not affect STS in terms of causing any imbalance in voltage at the interconnection point beyond the permissible limits and the harmonics in system voltage at the interconnection pointbeyond the prescribed limits.
6. In the event of Grid disturbances / Grid contingencies in the Northern Regional grid, the Transmission Licensee shall not be liable to maintain the system parameters within the normal range of voltage and the frequency.
[clause 6.6.4-6.6.6]
2. The SLDC, and the Users shall ensure that the grid voltage remains within theoperating limits as specified in IEGC 5.2 (r).
3. Voltage harmonics: Total harmonic distortion for nominal volatage 400 kV , 220kV, 132 kV are 2.0%, 2.5% and 3% respectively and Individual harmonic of any particular frequency for nominal volatage 400 kV , 220kV, 132 kV are 1.5%, 2% and 2% respectively .
3. The total harmonic current drawn from the transmission system at any point shall not exceed 8% of the fundamental frequency current.
4. Maximum limit of voltage imbalance for below 220 kV and 220 kV & above are 3% and 2% respectively.
5. Discoms shall ensure that their loads do not affect STS in terms of causing any imbalance in voltage at the interconnection point beyond the permissible limits and the harmonics in system voltage at the interconnection pointbeyond the prescribed limits.
6. In the event of Grid disturbances / Grid contingencies in the Northern Regional grid, the Transmission Licensee shall not be liable to maintain the system parameters within the normal range of voltage and the frequency.
[clause 6.6.4-6.6.6]
Corrigendum/ Amendment, if any
Yes
Rajasthan Electricity Grid Code, 2008 (1st Amendment)
Resolution By
RERC
Notification No. and date
RERC/Secy/Reg. 88 Dated: 10.06.2011
Planning Code for Intra-state Transmission- Criterion
1. Addition of new planning criterion i.e. Outage of one 765 kV S/C line
[clause 5.3 (i) of principal regulation]
[clause 5.3 (i) of principal regulation]
Connection Code/ Grid connectivity- Important technical requirements for connectivity to the grid
1.Amendment in the frequency i.e. “49.0-50.5 Hz” shall be substituted by the figures and word “49.5 – 50.2”.
2. Ammendment in the maximum voltage limit in the grid
3. Ammendment in the voltage harmonics i.e. The total harmonic distortion for voltage at the connection point shall not exceed 5% with no individual harmonic higher than 3%.
4. Ammendment in Voltage Unbalance limit i.e. 33 kV and above shall not exceed 3.0%.
[clause 6.6.4. of principal regulation]
2. Ammendment in the maximum voltage limit in the grid
3. Ammendment in the voltage harmonics i.e. The total harmonic distortion for voltage at the connection point shall not exceed 5% with no individual harmonic higher than 3%.
4. Ammendment in Voltage Unbalance limit i.e. 33 kV and above shall not exceed 3.0%.
[clause 6.6.4. of principal regulation]