Grid, Load Despatch and IEGC

Prepared by:Harit Puri (32)

Kuldeep (40)Nitesh Gupta (53)

Mahesh shringi (44)

An electrical grid is an interconnected

network for delivering electricity from

suppliers to consumers.

GRID

What is an electric grid ?

Gov

ernm

ent

Regu

lato

rsTransmission

Generation

Distribution

Users

Traders

NLDC/RLDC

Advantages of Power GRID ?

DEMAND Management

Load Shedding Reduction

Merit Order Dispatch

Better Utilization of Generating

Assets

Frequency Improvement

GRID REGION MAXIMUM LOADSUPPLIED(15.2.2013)

Northern Region

31625 MW

Eastern Region

13980MW

Western Region

36161MW

Southern Region

28981MW

Northeastern Region

1593MW

Load Supplied

Western Grid: It Comprises of Gujarat, Maharashtra, Madhya Pradesh, Goa, Daman & Diu, Dadra & Nagar Haveli and

Chhattisgarh.

Eastern Grid: It Comprises of Bihar, Jharkhand, West Bengal,

Sikkim and Orissa.

Southern Grid: It Comprises of Andhra Pradesh, Tamil Nadu, Karnataka, Pondicherry and Kerala.

Northern Grid: It Comprises of Haryana, Uttar Pradesh, Delhi, Uttarakhand, Rajasthan, Himachal Pradesh, Punjab and Jammu & Kashmir.

North- Eastern Grid: It Comprises of Assam, Meghalaya, Arunachal Pradesh, Nagaland, Manipur, Mizoram and Tripura.

Indian National Grid

INSTALLED CAPACITY 210.9GW

0:00:000:03:000:06:000:09:000:12:000:15:000:18:000:21:000:24:000:27:000:30:000:33:000:36:000:39:000:42:000:45:000:48:000:51:000:54:000:57:001:00:001:03:001:06:001:09:001:12:001:15:001:18:001:21:001:24:001:27:001:30:001:33:001:36:001:39:001:42:001:45:001:48:001:51:001:54:001:57:002:00:002:03:002:06:002:09:002:12:002:15:002:18:002:21:002:24:002:27:002:30:002:33:002:36:002:39:002:42:002:45:002:48:002:51:002:54:002:57:003:00:003:03:003:05:593:09:003:12:003:15:003:18:003:21:003:24:003:27:003:30:003:33:003:36:003:39:003:42:003:45:003:48:003:51:003:54:003:57:004:00:004:03:004:06:004:09:004:12:004:15:004:18:004:21:004:24:004:27:004:30:004:33:004:35:594:39:004:42:004:45:004:48:004:51:004:54:004:57:005:00:005:03:005:06:005:09:005:12:005:15:005:18:005:21:005:24:005:26:595:29:595:33:005:36:005:39:005:42:005:45:005:48:005:51:005:54:005:57:006:00:006:03:006:06:006:09:006:12:006:15:006:18:006:21:006:24:006:27:006:30:006:33:006:36:006:39:006:42:006:45:006:48:006:51:006:54:006:57:006:59:597:03:007:06:007:09:007:12:007:15:007:18:007:21:007:24:007:27:007:30:007:33:007:36:007:39:007:42:007:45:007:48:007:51:007:54:007:57:008:00:008:03:008:06:008:09:008:12:008:15:008:18:008:21:008:24:008:27:008:30:008:33:008:36:008:39:008:42:008:45:008:48:008:51:008:54:008:57:009:00:009:03:009:06:009:09:009:12:009:15:009:18:009:21:009:24:009:27:009:30:009:33:009:36:009:39:009:42:009:45:009:48:009:51:009:54:009:57:0010:00:0010:03:0010:06:0010:09:0010:12:0010:15:0010:18:0010:21:0010:24:0010:27:0010:30:0010:33:0010:36:0010:39:0010:42:0010:45:0010:48:0010:51:0010:54:0010:57:0011:00:0011:03:0011:06:0011:09:0011:12:0011:15:0011:18:0011:21:0011:24:0011:27:0011:30:0011:33:0011:36:0011:39:0011:42:0011:45:0011:48:0011:51:0011:54:0011:57:0012:00:0012:03:0012:06:0012:09:0012:12:0012:15:0012:18:0012:21:0012:24:0012:27:0012:30:0012:33:0012:36:0012:39:0012:42:0012:45:0012:48:0012:51:0012:54:0012:57:0013:00:0013:03:0013:06:0013:09:0013:12:0013:15:0013:18:0013:21:0013:24:0013:27:0013:30:0013:33:0013:36:0013:39:0013:42:0013:45:0013:48:0013:51:0413:54:0013:57:0014:00:0014:03:0014:06:0014:09:0014:12:0014:15:0014:18:0014:21:0014:24:0014:27:0014:30:0014:33:0014:36:0014:39:0014:42:0014:45:0014:48:0014:51:0014:54:0014:57:0015:00:0015:03:0015:05:5915:09:0015:12:0015:15:0015:18:0015:21:0015:24:0015:27:0015:30:0015:33:0015:36:0015:39:0015:42:0015:45:0015:48:0015:51:0015:54:0015:57:0016:00:0016:03:0016:06:0016:09:0016:12:0016:15:0016:18:0016:21:0016:24:0016:27:0016:30:0016:33:0016:35:5916:39:0016:42:0016:45:0016:48:0016:51:0016:54:0016:57:0017:00:0017:03:0017:06:0017:09:0017:12:0017:15:0017:18:0017:21:0017:24:0017:26:5917:29:5917:33:0017:36:0017:39:0017:42:0017:45:0017:48:0017:51:0017:54:0017:57:0018:00:0018:03:0018:06:0018:09:0018:12:0018:15:0018:18:0018:21:0018:24:0018:27:0018:30:0018:33:0018:36:0018:39:0018:42:0018:45:0018:48:0018:51:0018:54:0018:57:0018:59:5919:03:0019:06:0019:09:0019:12:0019:15:0019:18:0019:21:0019:24:0019:27:0019:30:0019:33:0019:36:0019:39:0019:42:0019:45:0019:48:0019:51:0019:54:0019:57:0020:00:0020:03:0020:06:0020:09:0020:12:0020:15:0020:18:0020:21:0020:24:0020:27:0020:30:0020:33:0020:36:0020:39:0020:42:0020:45:0020:48:0020:51:0020:54:0020:57:0021:00:0021:03:0021:06:0021:09:0021:12:0021:15:0021:18:0021:21:0021:24:0021:27:0021:30:0021:33:0021:36:0021:39:0021:42:0021:45:0021:48:0021:51:0021:54:0021:57:0022:00:0022:03:0022:06:0022:09:0022:12:0022:15:0022:18:0022:21:0022:24:0022:27:0022:30:0022:33:0022:36:0022:39:0022:42:0022:45:0022:48:0022:51:0022:54:0022:57:0023:00:0023:03:0023:06:0023:09:0023:12:0023:15:0023:18:0023:21:0023:24:0023:27:0023:30:0023:33:0023:36:0023:39:0023:42:0023:45:0023:48:0023:51:0023:54:0023:57:0048.0

48.5

49.0

49.5

50.0

50.5

51.0

N.E.W. GRID Vs SR GRID FREQUENCY PLOT FOR 15-feb-2013

NEW GRID FREQ SR GRID FREQTime -->

Fre

uen

cy in

Hz

-->

Enable transfer of power from power surplus regions to deficit regions.

Enable optimal development and utilisation of coal and hydro resources, in the overall interest of the nation.

Improve economy, reliability and quality of power supply.

ADVANTAGES

In case of any major disturbance whole Grid may get collapsed resulting in total blackout in the country. Monitoring of Grid

discipline will become more

complex.

DISADVANTAGES

Present IR Capacity = 8,500 MWBy the year 2012 = 30,000 MW

500 MW

1200 MW

1000MW

2000MW

500 MW

500 MW

Inter Regional links

Introduction to IEGC

Introduction to IEGC

The Indian Electricity Grid Code (IEGC) lays down • Rules, guidelines and standards to be followed by the

various agencies and participants in the system to plan, develop, maintain and operate the power system, in the most efficient, reliable, economic and secure manner, while facilitating healthy competition in the generation and supply of electricity.

• Role of Statutory bodies- CEA, CTU, RPC, SLDC, RLDC

Evolution of IEGCFirst draft prepared by

POWERGRID as CTU in Mar-99

•Enforced w.e.f 01s

t

Feb 2000

Approved by CERC in Jan 2000 after public hearing

•Issued on 22n

d

Feb 02, enforced w.e.f 01s

t

April 2002

First revision by IEGC review panel

•Draft issued by CERC-June 2005, enforced from 1s

t

April 2006

Second revision (Regulation 2006)

•June2006, September 2008, March 2009, March 2012

Amendments

•In force from 2n

d

April,2012

Fourth revision (Regulation 2012)

Special Scheduling Provision for Renewable Energy (IEGC 2010)

• For new wind energy plants, the new code stipulates that all fluctuations within ± 30% of schedule will be borne by interstate grid.

• The new grid code allows the new wind energy generators to fine-tune their schedules (based on forecasting) to as close as three hours before actual generation.

Role of Regulators (CERC / SERCs)

Electricity Act 2003• Section 79 subsection (1) clause (h)

• “The Central Commission shall discharge the following functions…• (a)…• (h) To specify Grid Code having regard to Grid Standards…”

• Section 86 subsection (1) clause (h)• “The State Commission shall discharge the following• functions…• (a)…• (h) Specify State Grid Code consistent with the Grid Code specified

under clause (h) of subsection (1) of section 79”

ObjectiveDocumentation of the principles and procedures

which define the relationship between the various Users of the Inter-State Transmission System (ISTS),

as well as the Regional and State Load Despatch Centres.

Facilitation of the operation, maintenance, development and planning of economic and

reliable National / Regional Grid.

Facilitation for beneficial trading of electricity by defining a common basis of operation of the

ISTS, applicable to all the Users of the ISTS.

Scope

Applies to • All parties that connect with and / or utilize the ISTS

DVC • Treatment similar to SEB

BBMB / SSP• Treated as intra-state generating stations

Structure of IEGC (1)Role of various Organizations and their linkages

Planning Code for inter-state transmission

Connection conditions• Procedure for connection to the ISTS• Site responsibility schedule

Operating Code for Regional Grids• Operating Policy• System Security Aspects• Demand Estimation for operational purposes• Demand Management• Periodic Report• Recovery Procedures• Event Information

Structure of IEGC (2)

Scheduling and Despatch Code

• Procedure for scheduling of ISGS• Complementary Commercial Mechanisms• Modality of flow of information between the ISGS and the NLDC/RLDC/SLDCs and

other Regional Entities

Operating Code for Regional Grids

Operating Code (1)

System Security Aspects

• … no part of the grid shall be deliberately isolated …• … tripping of any important element to be intimated to the RLDC …• … generating units shall operate in Restricted Governors mode of operation …• … except under emergency … no constituent shall suddenly reduce his generating output … • … all generating units shall normally have their automatic voltage regulators (AVRs) in operation …• … protection and relay settings shall be coordinated …• All Regional constituents shall make all possible measures to ensure that the grid frequency always remains within the 49.5 – 50.2

Hz band …

Operating Code (2)

System Security Aspects (contd.)

• … shall provide automatic under frequency and df/dt load shedding…• … shall also facilitate identification, installation and commissioning of SPS …• Procedures shall be developed to recover from partial/total collapse …• … regional constituent shall provide adequate and reliable communication facility …• … regional constituent shall send information / data including disturbance recorder/sequential event recorder output, etc. to RLDC …• Voltage range (kV rms)

• Nominal-765 / Max-800 / Min-728• Nominal-400 / Max-420 / Min-360• Nominal-220 / Max-245 / Min-198• Nominal-132 / Max-145 / Min-122• Nominal-110 / Max-121 / Min-99

Fault Clearance time & Voltage limits as per CERC

Nominal System Voltage ( kV)

Fault Clearing Time(milli-second)

Vpf(kV)

Vf(kV)

400 100 360.00 60.0

220 160 200.00 33.0

132 160 120.00 19.8

110 160 96.25 16.5

66 300 60.00 9.9

Here Vf= 15% of nominal voltage, Vpf= 80% of nominal voltage

Source: CERC INDIA

Operating Code (3)

Demand Estimation for Operational Purposes

• Demand disconnection

Demand Management

• Weekly, Quarterly

Periodic Reports• Responsibility• Reportable events• Reporting Procedure

Operational Liaison

Outage Planning

Recovery Procedures

Event Information

Management of Indian Electricity Grid Code

•IEGC Review panel•Director (Operation), PGCIL as its Chairman & convenor

Earlier

•Review Panel disbanded•Responsibility now vests with CERC•Review request application to CERC •CERC can change on its own also

Present

Few examples of grid indiscipline

Non-compliance of RLDC instructions

Switching of ISTS elements without RLDC permission (except under emergency)

Manning of control centers by inadequately qualified & untrained trained personnel

Deliberately isolating part of the grid from the rest of the regional grid

suddenly reducing generating unit output by more than one hundred (100) MW (20 MW in case of North-Eastern region)

Sudden increase in its load by more than one hundred (100 MW) (20 MW in case of North-Eastern region)

Few examples of grid indisciplineNot ensuring providing of RTU and other

communication equipment for sending real-time data to SLDC/RLDC at least before date of

commercial operation of the generating stations or sub-station/line being connected to ISTS

Protection systems unable to isolate the faulty equipments within the specified fault clearance time

with reliability, selectivity and sensitivity

Not sending information/data including disturbance recorder/sequential event recorder output etc., to

RLDC for purpose of analysis of any grid disturbance/event.

How is IEGC enforced?

Non-compliance by RPC/RLDC

• Matter to be reported to CERC by any agency through petitions

Non-compliance by constituents other than RLDC/RPC

• RLDCs to report the matter to CERC• MS may also report to CERC if the matter can not be solved at RPC forum.

CERC may take appropriate action based on reports/petitions

CERC may initiate sou-motu actions also.

Role of Various Organizations

ROLE OF VARIOUS ORGANIZATIONS AND THEIR LINKAGES

In the light of the Electricity Act, 2003, it has become necessary to redefine the role of National Load Despatch Centers (NLDCs), Regional Load Despatch Centers (RLDCs), State Load Despatch Centers (SLDC)/Regional Electricity Boards (REBs), the Central Transmission Utility (CTU) etc. and their organizational linkage so as to facilitate development and smooth operation of Regional Grids and National Grid at large.

National Load Despatch Center

In accordance with section 26 of Electricity Act, 2003 the National

Load Despatch Centre was established by the Central

Government at the national level:•For optimum scheduling and despatch of electricity among the Regional load despatch centers.•As an Apex Body to ensure integrated operation of the National Power System and discharge its functions.

Functions of NLDC

Supervision over the RLDCs.

Scheduling and despatch of electricity over inter-regional links in accordance with Grid standards specified by the Authority and Grid Code specified by the Central Commission in coordination with RLDCs.

Coordination with RLDCs for achieving maximum economy and efficiency in operation .

Monitoring of operations and grid security of the National Grid.

Supervision and control over inter regional links as may be required for ensuring stability of the power system under its control.

Co-ordination with Regional Power Committees for regional outage schedule in the national perspective to ensure optimum utilization of power resources.

Coordination with RLDCs for the energy accounting of inter-regional exchange of power.

Coordination for restoration of synchronous operation of National Grid with RLDCs.

Co-ordination for trans-national exchange of Powers.

Providing operational feed-back for National Grid planning to the Authority and the Central Transmission Utility.

Levy and collection of such fee and charges from the Generating Companies or the licensees involved in the power system as may be specified by the Central Commission.

Role of RLDCs

According to sections 28 and 29 of Electricity Act, 2003, the functions of RLDCs are as follows:

•The Regional Load Despatch Centre shall be the apex body to ensure integrated operation of the power system in the concerned region.•The Regional Load Despatch Centre shall comply with such principles, guidelines and methodologies in respect of wheeling and optimum scheduling and despatch of electricity as may be specified in the Grid Code.

The Regional Load Despatch Centre shall-

Be responsible for optimum scheduling and despatch of electricity within the region, in accordance with the contracts entered into with the licensees or the generating companies operating in the region

Monitor grid operations & keep accounts of quantity of electricity transmitted through the regional grid

Exercise supervision and control over the Inter-State transmission system

Be responsible for carrying out real time operations for grid control and despatch of electricity within the region through secure and economic operation of the regional grid in accordance with the Grid Standards and the Grid Code.

Few Exclusive Functions Of RLDCSystem operation and control including inter-state /

interregional transfer of power, covering contingency analysis and operational planning on real time basis;

Scheduling / re-scheduling of generation;

System restoration following grid disturbances;

Meter data processing;

Compiling and furnishing data pertaining to system operation;

Operation of regional UI pool account and regional reactive energy account.

State Load Despatch Center (SLDC)

The State Load Despatch Centre shall be the apex body to ensure integrated operation of the power system in a State.

Be responsible for optimum scheduling and despatch of electricity within a State, in accordance with the contracts entered into with the licensees or the generating companies operating in that State.

Monitor grid operations

Keep accounts of the quantity of electricity transmitted through the State grid.

Exercise supervision and control over the intra-state transmission system

Be responsible for carrying out real time operations for grid control and despatch of electricity within the State through secure and economic operation of the State grid in accordance with the Grid Standards and the State Grid Code.

Under Section 33 of E-Act 2003

The State Load Despatch Centre in a State may give such directions and exercise such supervision and control as may be required for ensuring the integrated grid operations

Every licensee, generating company, generating station, substation and any other person connected with the operation of the power system shall Comply with the direction issued by the SLDC

SLDC shall comply with the directions of the RLDC.

Day-ahead resource scheduling process

Availability Declaration

SLDC

Requisition & Bilateral Agreements

Injection Schedule Drawal Schedule

Revision if any Revision in Requisition

FinalInjection Schedule

FinalDrawal Schedule

09:00

10:00

15:00

18:00

20:00

22:00

RLDC

ISGS

Time

Revisions duringCurrent day

Revisions duringCurrent day

0 to 24 hours

Entitlements

CONTROL ROOM

Control Room of Load Despatch Centre

In the control room Two experienced Assistant Executive Engineers, 1 or 2 FAX operators are working round the clock in 3 shifts.

The two shift in charge Engineers continuously monitor the system depending upon the online data and take the necessary action to maintain the system safe and secure.

One Executive Engineer in charge of Grid operation is also supervising the activities taking place in the control room for smooth running.

Functions of Load Despatch Manager &

Overview of Smart Grids

POSSIBLE SYSTEM PROBLEMS

UNIT FAILURE

INSUFFICIENTGENERATION

TRANSFORMER/LINE FAILURE

LOSS OFLOAD

REDUCEDNETWORKREDUNDANCY

LINE OVERLOADORUNSATISFACTORYBUS VOLTAGE

BUS ISOLATED

LOSS OFGENERATION

ISLANDING

SYSTEM COLLAPSE

Duties and Responsibilities of a Load despatch manager in SLDCs and RLDCs

Monitoring of system parameters and security

To ensure the integrated operation of the power system grid in the region

System studies planning and contingency analysis

Analysis of tripping / disturbances and facilitating immediate remedial measures

CONTINUED………

Daily scheduling and operational planning

Facilitating bilateral and inter regional exchanges

Computation of energy dispatch and drawl values using SEMs

Augmentation of telemetry , communication and computational facilities

POWERGRID is Responsible for Grid Management / System Operation of the five Regional Load Despatch Centers with load despatch manager (RLDCs) .

• Apex Body for Integrated Grid Operation of the Region • Scheduling and Despatch of Electricity on real time basis• Energy Accounting• Supervision and Control of Inter – State Transmission System• Ensure Grid Security and adherence to Indian Electricity Grid Code (IEGC)

RLDCs manager - Responsibilities

This Has Resulted Into

Load Dispatch manager as a controller

Overview of Smart Grid

What is Smart Grid?

A smart grid puts information and communication technology into electricity generation, delivery, and consumption, making systems cleaner, safer and more reliable and efficient.

Modernization of the electricity delivery system so that it monitors, protects and automatically optimizes the operation of its interconnected elements – from the central and distributed generator through the high-voltage network and distribution system, to industrial users and building automation systems, to energy storage installations and to end-use consumers and their thermostats, electric vehicles, appliances and other household devices.

The Smart Grid in large, sits at the intersection of Energy, IT and Telecommunication Technologies.

The Smart Grid is a combination of hardware, management and reporting software, built atop an intelligent communications infrastructure.

In the world of the Smart Grid, consumers and utility companies alike have tools to manage, monitor and respond to energy issues.

The flow of electricity from utility to consumer becomes a two-way conversation, saving consumers money, energy, delivering more transparency in terms of end-user use, and reducing carbon emissions.

Need of Smart Grid

Increasing demand:

High Aggregate Technical & Non Technical, Losses:18%-62%

Ageing assets…transformers, feeders etc.,

Grid to carry more power: Need for, Reliability and greater Security

Billing and collections: Profitability of distribution companies

Energy mix: Need for Renewable to reduce carbon footprint

Integrate isolated technologies : Smart Grid enables better energy management.

Proactive management of electrical network during emergency situations.

Better demand supply / demand response management.

Better power quality

Reduce carbon emissions.

Increasing demand for energy : requires more complex and critical solution with better energy management

Smart Grid Applications

Distributed Generation and Alternate Energy Sources

Self-Healing Wide-Area Protection and Islanding

Asset Management and On-Line Equipment Monitoring

Demand Response and Dynamic Pricing

Participation in Energy Markets

Shared Information – Continuously Optimizing – Intelligent Responses!

Real-time Simulation and Contingency Analysis

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Smart Grid Benefits

Economic Development

• New Jobs: The manufacture, installation, operation and maintenance of the smart grid and its components will create new jobs within the state.

• Innovation: Smart grid innovation will enable the growth of business while rewarding customers with valuable new products.

• Lower Costs: Costs rise over time and energy is no exception, but the smart grid should provide less costly energy than otherwise would be possible. As such, it will save customers money which can be invested or consumed as they choose.

Customer Satisfaction

• Higher Customer Satisfaction: The combination of lower costs, improved reliability and better customer control will raise satisfaction among all types of customers (residential, commercial, industrial, institutional).

• Improved Reliability: Smart grid will reduce and shorten outages and improve the quality of power.

• Customer Energy/Cost Savings: As pricing becomes more transparent and is aligned with the underlying economics of generation and distribution, customers’ decisions to save money will benefit society as well

• Highest Security: Security will be incorporated into the design of the smart grid and will require the implementation of practices and procedures by individual stakeholders. In this way, the physical and cyber security risks can be managed to the highest standards possible.

References

• www.cercindia.gov.in• www.cea.nic.in• www.nldc.in• www.srldc.org• www.nrldc.org• www.sldcguj.com• www.powergridindia.com

Querries???

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