Smart Grid implementation in

Transmission System…

Contents

Need of Smart grid

Building blocks

Key Technologies

Smart Grid for Transmission System

Conclusion

Large gap between generation and load

Uncontrolled power transfer

Overloading of system components

Higher losses in the system

Lack of reactive power support and regulation services

Poorly planned distribution network

Low metering efficiency and bill collection

Power theft

Need of Smart Grid

The term “Smart Grid” was coined by Andres E. Carvallo on April 24, 2007 at an IDC energy conference in Chicago.

Smart grid is integration of an electric grid, communication network , software and hardware to monitor, control and manage the creation, distribution, storage and consumption of energy.

The smart grid is not a thing but a vision to achieve.

The vision can be expressed in terms of it’s values, characteristics and milestones to achieve.

Definition

Reliability

Security

Economies

Efficiency

Environment friendly

Safety

Smart Grid values

Accommodate all generation and storage options

Enable new products, services and markets

Power quality

Optimize assets

Self healing (Automation)

Resist attack

Active participation by consumers

Smart Grid characteristics

Key Technologies

Sensing and Measurement

Advanced Control

Improved interface and Decision

Advanced Components

Integrated communication

Integrated communication

High speed fully integrated two way communication technology

It will be utilized for real time information and power exchange to optimize system reliability, asset utilization and security.

Areas of improvements include substation automation, distribution automation, SCADA and Energy management system.

Sensing and monitoring

Aimed at evaluation of congestion and grid stability, monitoring equipment health, energy theft and control strategies support.

Includes use of smart meters, wide area measurement system and digital protective relays.

Key Technologies

Advanced components

Innovation in materials, power electronics and diagnostic components.

Includes FACTs devices, HVDC, superconducting wires, distributed energy generation, storage devices, composite conductors and intelligent devices.

Advanced controls

Automation will enable rapid diagnosis and timely response event.

Includes analysis tools and operational applications such as SCADA, WAMS and substation automation.

It will support market pricing and enhance asset management.

Key Technologies

Improved interface and decision support

Smart grid require real time use of applications and tools

that enables grid operators and managers to take decision

quickly.

Includes visualization techniques that reduces large data

into easily understood visual formats, software system

providing multiple options and simulators.

Key Technologies

Smart Grid for Transmission

Major Challenges

1)Grid Management

2)Dispatch with the renewables

3)Limited observability

4)Dynamic state of system

5)Monitoring real time Voltage and Power flows

6)Congestion Management

7)Efficient system models

8)Fault Analysis

9)System control

10)Bottlenecks in communication facilities

Technologies

Flexible AC Transmission System (FACTS)

Dynamic Line Rating (DLR)

Wide Area Measurement System (WAMS)

Renewable Management System (RMS)

High Temperature Low Sag (HTLS) conductor

City Monitoring System (CMS)

Automated Fault Analysis System (AFAS)

Flexible A.C Transmission System (FACTS)

Increase in electricity demand requires increase in both generation and transmission.

Compare to generation, expansion of transmission is much difficult in terms of investment and right of way.

Higher transmission voltages is one of the solution. Power electronics technology can be best utilized for

system enhancement. Flexible AC Transmission System (FACTS) is developed

to improve the performance of long distance a.c transmission.

HVDC can also be used for long distance transmission with various added advantages over conventional a.c system.

Why FACTS

What is FACTS

FACTS Controllers

Series Shunt Series-Series Series-Shunt

TCSC

SSSC

SVC

STATCOM

IPFC UPFC

Thyristor based converter Voltage source converter

Definition : AC transmission systems incorporating the power electronic-based and other static controllers to enhance controllability and increase power transfer capability.

Increase in power transfer capability Steady state and transient stability

enhancement Dynamic reactive power compensation Reduced transmission losses Voltage regulation Damping of oscillations Increasing existing grid utilization Improvement of power quality Limiting short circuit current

Benefits of FACTS

Series controllers It can be variable impedance type such as capacitor,

reactor etc or power electronics based variable source. It injects voltage in series with line. If injected voltage is in phase quadrature with line

current it only supplies or absorbs reactive power.

Shunt controllers It can be variable impedance, variable source or

combination of both. It injects current in to system at point of connection. If injected current is in phase quadrature with line

voltage it supplies or absorbs reactive power.

FACTS Controllers

Thyristor based controller

x

VV 21

: reactance Line •

: Voltages•

- : difference Phase•

variables Control

21

)δcos(δx

VV

x

V

)δsin(δx

VV

21211

2121

* Q

flow power Reactive

*P

flow power Active

2

12

12

Thyristor Control Series Capacitor (TCSC)A capacitive reactance compensator which

consists of a series capacitor bank shunted by a thyristor-controlled reactor in order to provide a smoothly variable series capacitive reactance.

TCSC

Transient stability enhancement Voltage stability enhancement

TCSC applications

*

P *

P

capacitor series ith Wcapacitor series Without

1212 )δsin(δx-x

VV )δsin(δ

x

VV21

c

2121

21

SVC Configurations

Voltage source converter

t

scs

t

cs

X

Vsθco(VV

sinθX

V*VP

) Q

power Reactive

power Active

cV

θ

: Voltages•

: difference Phase•

variables Control

Voltage source converter

Static synchronous Compensator (STATCOM)STATCOM is the voltage-source converter, which

converts a DC input voltage into AC output voltage in order to compensate the active and reactive power needed by the system.

STATCOM

Cost for FACTS devices

HVDC

The High Voltage Direct Current (HVDC) technology is used to transmit electricity over long distances by overhead transmission lines or submarine cables.

Benefits of HVDC

Total investment cost is lower for long transmission lines.

Power flow can be controlled easily Lower losses compared with a.c system Asynchronous interconnection possible Absence of Skin and Ferranti effect Less corona and radio interference Ground can be used as return conductor Limits short circuit current HVDC cable for long distance water crossing

Wide Area Measurement System

Why WAMS

Facilitates:

• Synchronized wide area system visualization

• Dynamic measurement and representation of events

• Improving computational efficiency based on data

• Detection of power system oscillations

• Effective postmortem analysis

Page #29Copyright © 2015 PRDC, Bangalore

What is WAMS

A wide area measurement system (WAMS) consists of advanced measurement technology, information tools, and operational infrastructure that facilitate the understanding and management of the increasingly complex behavior exhibited by large power systems.

Advance measurement, Better visualization, Effective control

Page #30Copyright © 2015 PRDC, Bangalore

WAMS - Components

- PMU

- PDCMeasurement, Communication and Analysis

– PMU to PDC

– PDC to PDC

– Visualization

– Applications

Page #31Copyright © 2015 PRDC, Bangalore

WAMS Applications

High Temperature Low Sag (HTLS) Conductors

Why HTLS

Upgrade Method Benefits Challenges

Parallel single circuit line

Possibility of operation during new line construction

Right-of-way availability

Parallel line on existing towers

Lower transmission losses due to decrease in equivalent line

resistance

Expense for long duration of line outage.

Towers geometry may not support double circuit.

Voltage level increase

Lower transmission losses due to high voltage, low current

operation

Line outage duration expenses Right-of-way availability Transformer cost

Tower geometry may need modifications

Re-conductoring with HTLS

No upgrades in towers or insulation

Cannot increase security rating

Different Transmission Upgrade Options

HTLS conductors

• Re-stringing existing networks of 33 kV and higher voltages presents one of the greatest opportunities for energy efficiency gains worldwide, and one of the least disruptive with respect to environmental and social considerations.

• HTLS conductors can be an economically viable solution for increasing transmission capacity without acquiring new right-of-way for new lines, and may be the only practical solution for urbanized areas and other areas where right-of-way constraints exist.

• For new lines, HTLS conductors should be considered where right-of-way constraints exist (e.g., near airports); in general, HTLS conductors deliver built-in efficiency gains which should be considered as part of transmission expansion plans.

Different HTLS conductors

• Aluminium Conductor Steel Supported (ACSS)

• (Super)Thermal-Resistant Aluminium Alloys (TACSR)

• Composite Cores (ACCC and ACCR)

• Invar Core (STACIR)• Gap-Type Conductors (GAP)

Comparison of Conductors based on various parameters with respect to ACSR

Conductor Type

Current Carrying Capacity

CostCost/

CapacityLosses

ACSR 1 1 1 1

TACSR 2.43 1.3 0.54 1.09

ACCR 2.57 3.75 1.46 0.96

GAP 2.6 1.5 0.58 0.82

ACSS 2.66 1.7 0.64 1.04

ACCC 2.8 2.5 0.9 0.74

STACIR 2.86 4.25 1.5 0.97

Automated Fault Analysis System(AFAS)

Why AFAS

Facilitates:

• Automatic retrieval of disturbance files at a common location

• Automatic fault diagnosis, report generation and intimation to concerned personnel

• Substation and system level analysis for a fault

• Better fault location computation and hence facilitates faster fault clearing

What is AFAS

Automated Fault Analysis System (AFAS) may be defined as the ability of a specialized computer program to correlate and analyse available data about power system faults and disturbances.

Information extracted from AFAS can be utilized byOperating personnelProtection engineersMaintenance crew

AFAS - Components

- Relays- Analog Data - Digital Data

– Relay to SDC

– SDC to Main DC

– File Diagnosis

– Reporting

AFAS - Process

Processed File Storage

AFAS

Report Manager

Data Collector

AFAS - Architecture

Acquisition and Format

Converter

Acquisition and Format

Converter

AFAS EngineAFAS

Engine

Event records

DatabaseDatabase

Results FilterResults Filter

User interface

Remote Access System

Relays

Database Server

Client System

AFAS Server

AFAS – Applications

AFAS – Types of Analysis

Conclusion Existing grid conditions need to be analyzed in detail Smart grid project need to be executed in stages Goals need to be prioritized based on the requirements Adapting new technologies and keeping scope for future

compatibility Strengthening existing grid with advanced technologies in

spite of going for new construction wherever possible. Increase in customer participation and awareness is required New investment options in power industry need to be

provided Development in renewable energy sector Optimization of existing resources is the need