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 Residential Customer Commercial/ Industrial Customer Residential Customer Distribution Pole Urban Customers Primary Distribution 66 kV Transmission Distribution Transformer (11/0.415 kV) Secondary Grid (66/11 kV) Primary Grid (220/66 kV) Secondary Distribution Underground Cable To Other 66Kv Substations POWER SYSTEM COMPONENTS Primary Transmission(132/220/400/765KV) Secondary Transmission(66/132KV) CBX’mer (11/220kV) Sending end SS Bus-bar Steel Tower CB Dhuvaran Karamsad V V Nagar GCET

Generation :: Heart RLDC::Brain Sub-Transmission :: Sub-Arteries Transmission :: Main Arteries Distribution :: Capillaries An Analogy – Power System vs Human Body USER

Human Body Power System Blood Pressure Voltage Heart Beat Frequency The Pulse 72 Beats/Minutes 50 Cycles/Seconds CauseStress/AnxietyLoad-Gen.-Mismatch Risk Heart Beat Deviation Frequency Deviation The 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 – 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 QUALITY Definition Power quality refers to maintaining a sinusoidal waveform of bus voltages at rated voltage and frequency. The waveform of electric power at generation 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 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