Role of Power Electronics for Safety and Conservation of

Electrical Energy

Ramjee Lal Meena

Department of Electrical Engineering

Delhi Technological University, Delhi-42

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ORGANISATION OF THE PRESENTATION

• Introduction to Power Electronics• Power Semiconductor Device (PDS)• Power Converter • Power Processor• Advantage of Power Electronics• Applications of Power Electronics for Electrical

Energy

Contd.

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Contd.• Emphasis of applications of Power

Electronics in  the area of Safety, Conservation, Power Quality and Renewable Sources

• Practical possible use of PE at  home• Trends of Power Electronics • NaMPET : GOI Mission

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Power Electronics • Power Electronics is the electronics

applied to conversion and control of electrical power.

• Range of Power ScaleMilliwatts(mW) Megawatts(MW) Gigawatts(GW)

• The primary task of Power Electronics is to process and control flow of electrical energy by supplying voltages and currents in a form that is optimally suited for user loads

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Power Semiconductor Devices

• Power Diode–Uni-polar, –uncontrolled, – switching device –used in applications such as rectification

and – circuit directional current control.

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SCR: Silicon Controlled Rectifier

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• This semi-controlled device turns on when a gate pulse is present and the anode is positive compared to the cathode.

• When a gate pulse is present, the device operates like a standard diode.

• When the anode is negative compared to the cathode, the device turns off and blocks positive or negative voltages present.

• The gate voltage does not allow the device to turn off

SCR: Silicon Controlled Rectifier

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Gate Turn Off Thyristor

• The GTO, unlike an SCR, can be turned on and off with a gate pulse.

• One issue with the device is that turn off gate voltages are usually larger and require more current than turn on levels.

• These devices, because of developments in IGCT technology are not very popular in the power electronics realm.

• They are considered controlled, uni-polar and bi-polar voltage blocking

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TRIAC• The TRIAC is a device that is

essentially an integrated pair of SCR connected in inverse-parallel on the same chip.[

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Power Transistors

• Power BJT

• Power MOSFET

• IGBT( Insulated Gate Bipolar Transistor )

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Power Converter

Power Processor

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Advantages of PE

• High Efficiency•High Reliability•Low Maintenance •Fast dynamic response ( ms, µs)•Small size •Low Cost (Mass Production)

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THE ITIC CURVE

0.0001 0.001 0.01 0.1 1 10 100 1000-100

-50

0

50

100

150

200

250

TIME IN SECONDS

PER

CEN

T C

HAN

GE

IN B

US

VOLT

AGE

8.33

ms

OVERVOLTAGE CONDITIONS

UNDERVOLTAGE CONDITIONS

0.5

CY

CLE

RATED

VOLTAGEACCEPTABLE

POWER

10%+--

FRIENDS• The word FRIENDS stands for Flexible

Reliable and Intelligent Electrical eNergy Delivery Systems

• Problem of Safety, Conservation and poor power quality can be solved by power electronics based FRIENDS devices

• Main FRIENDS devices • Static Current Limiter (SCL)• Static Circuit Breaker (SCB)• Static Transfer Switch (STS) 26

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General concept of FRIENDS

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FRIENDS Network

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Quality Control Center

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GTO-based SCL topology

ZnO Arrester

Back-to-back GTO Switch

Let-Through ReactorInductor

Iz

Ii

Isw If

Supply Side Load Side

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GTO and VCB based SCB topology

ZnO Arrester

Back-to-back GTO Switch

Iz

Ib

Isw If

Supply Side Load Side

High-Speed VCB

PreferredSource

CriticalLoad

FAULT

ZnO ZnO

Sw1 Sw2

ipp

ipniap

ian

ZfZf

AlternativeSource

Iz1Iz2

Is1Is2

Ia

Tpp

Thyristor based STS topology

Tpn

Tan

Tap

PreferredSource

CriticalLoad

FAULT

ZnO ZnO

Sw1 Sw2

ipp

ipniap

ian

ZfZf

AlternativeSource

Iz1Iz2

Is1Is2

Ia

Tpp

Thyristor based STS topology

Tpn

Tan

Tap

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NaMPET: National Mission on Power Electronics Technology

• NaMPET is a national mission programme launched in November 2004 by the Department of Information Technology(DIT) under Ministry of Communications & Information Technology, Government of India.

• This five year programme is implemented through the Nodal Centre at the Centre for Development of Advanced Computing, Thiruvananthapuram.

• Premier Academic Institutions in the country, Manufacturing Industries and User Industries of Power Electronics Systems participate in this programme.

• A National Steering Committee comprising of eminent experts from different agencies and institutions in India guides the activities of

NaMPET.

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NaMPET: Vision

• To provide the country with capability to become a dominant player in Power Electronics Technology at the international level.

• This is a National level R&D Programme facilitating Research, Development, Deployment and Commercialization of Power Electronics Technology by enhancing the indigenous R&D expertise and infrastructure in the country with active participation from academic institutions and industries.

NaMPET: Focus Areas

• Power Quality Improvement / Smart power for Digital Economy. •Electric traction / Electric & Hybrid Electric Vehicles / Automotive Electronics. •Distributed power generation / Renewable energy and Micro generator control. •Advanced Magnetics / Energy Storage Systems. •New topologies for Converter / Inverter applications. •New generation sensors for PE applications. •Modeling / Simulation packages. •Standard PE module with the state of the art developments

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Conclusions

• Protection both appliance and life against Fault and unhealthy conditions of Electrical Energy System

• Mitigation of voltage sags and swells• Power supply of different reliability

The main contributions of the Power Electronics and FRIENDS Devices for Safety, conservation and improving the power quality can be summarized as follows:

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Conclusions contd.

• Interface to dispersed generation systems• Flexibility in Configuration of the System• Load Leveling and Energy Conservation• NaMPET: Vision

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