Lecture 1 – Power Quality INTRODUCTION TO POWER QUALITY Power Quality phenomenon-Terms and definitions-Various Power events in power quality - causes for reduction in power quality.

VOLTAGE SAGS Sources of sags - Magnitude & duration of sag-effect of sag on computer and consumer Electronics- Monitoring and mitigation of voltage sag.

INTERRUPTIONS Origin of Long & Short interruption -influence on various equipments-Basic reliability indices related interruption monitoring and mitigation of interruption.

HARMONICS Harmonic distortion: Voltage and current distortion- harmonic indices- harmonic sources from commercial and industrial loads- Effects of harmonics on various equipments- harmonic distortion evaluation- Devices for controlling harmonic distortion.

POWER QUALITY MONITORING Monitoring considerations: Power line disturbance analyzer, power quality measurement equipment, harmonic / spectrum analyzer, flicker meters, disturbance analyzer.

Indian Power Sector Overview

A Prelude to course on Power quality

Power : The Building Block of Economy

• Electricity- the most imp. Infrastructural input in the dev. & growth of economy.

• Consumption of electricity- imp. Index of advancement of the country & standard of living.

• Economic growth rate of 8-9% on a sustained basis is necessary for us to catch up with the rest of the world.

220 kV Power Plant

Generation

ResidentialCustomer

Commercial/IndustrialCustomer

ResidentialCustomer

DistributionPole

UrbanCustomers

Primary Distribution

66 kVTransmission

Distribution Transformer(11/0.415 kV)

Secondary Grid(66/11 kV)

Primary Grid (220/66 kV)

Secondary Distribution

Underground Cable

To Other 66KvSubstations

POWER SYSTEM COMPONENTSPrimary Transmission(132/220/400/765KV)

Secondary Transmission(66/132KV)

CBX’mer(11/220kV)Sending end SS Bus-bar

Bus-bar Steel Tower

CB

Dhuvaran

Karamsad

V V Nagar

GCET

Generation :: HeartRLDC::Brain

Sub-Transmission :: Sub-Arteries

Transmission :: Main ArteriesDistribution :: Capillaries

An Analogy – Power System vs Human An Analogy – Power System vs Human BodyBodyAn Analogy – Power System vs Human An Analogy – Power System vs Human BodyBody

USER

Human BodyHuman Body Power SystemPower SystemBlood PressureBlood Pressure VoltageVoltage

Heart BeatHeart Beat FrequencyFrequencyThe PulseThe Pulse 72 Beats/Minutes72 Beats/Minutes 50 Cycles/Seconds50 Cycles/Seconds

CauseCause Stress/AnxietyStress/Anxiety Load-Gen.-MismatchLoad-Gen.-MismatchRiskRisk Heart Beat DeviationHeart Beat Deviation Frequency DeviationFrequency Deviation

The GenerationThe Generation……The GenerationThe Generation……

GENERATION

• Thermal Power Plant• Hydro Power Plant• Nuclear Power Plant• Diesel Power Plant• Gas Power Plant• Combine Cycle plant

• Solar• Tidal• Wind• Geothermal• Bio-mass• Fuel cells

Coal

Hydro• Hydro potential in North

east and upper part of Northern Region

• Coal reserves mainly in Eastern Region

• Distribution of energy resources and consumption centres are extremely unbalanced

• Necessitate power transfer over long distances

Energy Resource Map Of India

Development of the Electricity Industry in the last 50 yrs.

• The industry has mainly developed through State controlled instruments.

• Until 1975 – dev. mainly through SEBs/electricity deptts. controlled by the respective state govts.

• 1975 – The Electricity (supply) Act was amended. Intervention of the central govt in development of generation facilities led to the formation of NTPC, NHPC

• Effect of this intervention started being felt in early 80’s.

INDIAN POWER SCENARIO

10

MAJOR REASONS FOR POWER SECTOR ILLS

Inadequate power generation capacity; Lack of optimum utilization of the existing

generation capacity; Inefficient use of electricity by the end consumer; Inadequate inter-regional transmission links; Huge T&D losses (theft) and skewed tariff

structure, making SEBs unviable.

POWER QUALITYDefinition

• Power quality refers to maintaining a sinusoidal waveform of bus voltages at rated voltage and frequency. The waveform of electric power atgeneration stage is purely sinusoidal and free from any distortion.

• A Utility may define power quality as reliability and show statistics demonstrating that its system is 99.98 percent reliable.

• A manufacturer of load equipment may define power quality as those characteristics of the power supply that enable the equipment to work properly. These characteristics can be very different for different criteria.

• Any power problem manifested in voltage, current, or frequency deviations that result in failure or misoperation of customer equipment