Dr Ambedkar Institute of Technology Bangalore
REPORT On
“INDUSTRIAL VISIT TO VARAHI HYDEL POWER PLANT”
MASTER OF TECHNOLOGY
In POWER ELECTRONICS
Submitted by
ANAND REDDY B.R. (1DA10EPE01)
CONTENTS KPCL OVERVIEW, OBJECTIVES OF KPCL, UNDERGROUNG POWER PLANT, TECHNICAL DETAILS OF THE VARAHI UNDER GROUND POWER PLANT, PELTON TURBINE, Oil-Filled Cable, VERTICAL MOUNTED ALTERNATOR – TURBINE, CONTROL OPERATION OF POWER PLANT, CONCLUSION
KPCL OVERVIEW For over three decades, the Karnataka Power Corporation has been a prime mover and catalyst behind key power sector reforms in the state - measures that have spiraled steady growth witnessed in both industrial and economic areas. Right from the year of inception, in 1970, KPCL set its sights on “growth from within” meeting growing industry needs and reaching out to touch the lives of the common man, in more ways than one. KPCL today has an installed capacity of 5975.91 MW of hydel, thermal, solar and wind energy, with 9500 MW in the pipeline. The 1720 MW Raichur Thermal Power Station located in Raichur dist is accredited with ISO 14001-2004 certification for its environment protection measures. From an industry vantage point, KPCL has raised the bar on the quality of deliverables and is constantly working at lowering the cost per megawatt - a commendable cost-value equation that has become a benchmark on the national grid. KPCL’s stock in trade is industry proven - well-established infrastructure & modern, progressive management concepts and a commitment to excel, helping it meet the challenges of the rising energy demands of Karnataka. The leverage point of KPCL initiatives are its resource management strengths – right across planning, financing and project engineering. KPCL also has a high rating in terms of project completion and commissioning within the implementation calendar.
OBJECTIVES OF KPCL KPCL seeks to touch higher vantage points in the world of power engineering. Our formula for achieving this - start with a world class organization, build-in efficiency and cost control and ensure that progress is in harmony with the environment.
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Exploring, identifying and developing opportunities in power generation.
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Devising innovative ways of setting up and operating power plants.
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Investing in a resource base of technical competence, systems, processes and capability.
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Empowering people, work teams and the support network to achieve these objectives.
UNDER GOROUND HYDEL POWER PLANT The river Varahi takes its birth at a height of 730 m in the Western Ghats at Hebbagilu, near Agumbe in Shimoga District. It joins the Arabian Sea near Kundapur. After a 25 Km initial run, this swift and powerful river falls 455 m in cascades to form the bellowing Kunchikal falls. Varahi is Karnataka’s first underground powerhouse – a key milestone in the corporate history of KPCL. Initially conceived as a surface power house at the blueprint stage, Varahi was later converted into an underground Powerhouse. The decision for the change-over was based on three key parameters : technical, economical and our concern for environment protection. Stage I of the Varahi Hydro Electric Project has a total installed capacity of 230 MW contributing 1100 MU annually. This consists of 2 x 115 MW Generating Units at Varahi underground Powerhouse and two 4.5 MW units in the power house at the Mani Dam site. Provision was made to add two more Units at this power house of similar capacity (115 MW) & the excavation works were completed during Stage I works only. Now the construction works of units 3 & 4 each of 115 MW capacity is under progress. These units are commissioned during November 2008
VARAHI HYDEL POWER PLANT An underground power station is a type of hydroelectric power station constructed by excavating the major components (e.g. machine hall, penstocks, and tailrace) from rock, rather than the more common surface-based construction methods. Often underground power stations form part of pumped storage hydroelectricity schemes, whose basic function is to level load: they use cheap or surplus off-peak power to pump water from a lower lake to an upper lake, then, during peak periods (when electricity prices are often high), the power station generates power from the water held in the upper lake
UGHPP LAYOUT
TECHNICAL DETAILS OF THE VARAHI UNDER GROUND POWER PLANT INSTALLED CAPACITY: 460MW PEAK LOAD: 215MW PLANT LOAD FACTOR: 20.59%
CUMMULATIVE MONTHLY GENERATION: 2.273 NO UNITS INSTALLED: 4 EACH UNIT CAPACITY: 115MW ALTERNATOR: 11KV POWER TRANSFORMERS: LV SIDE-11KV HV SIDE-220KV
Load centers:2 n.o.shimoga, 2 n.o.mangalore Generator voltages, current, line voltages and number of transmission lines:
Station: varahi Rated current generator terminals: 6715A Rating of generator transformer:2*130mw No of line bays: 5 (1 under construction) Type of turbine: vertical pelton Rated turbine speed: 250 RPM WATER CONSUMPTION:MCft/MU:32 Design discharge MCft/MU:77 cuecs per unit
PELTON TURBINE The water flows along the tangent to the path of the runner. Nozzles direct forceful streams of water against a series of spoon-shaped buckets mounted around the edge of a wheel. As water flows into the bucket, the direction of the water velocity changes to follow the contour of the bucket. When the water-jet contacts the bucket, the water exerts pressure on the bucket and the water is decelerated as it does a "u-turn" and flows out the other side of the bucket at low velocity. In the process, the water's momentum is transferred to the turbine. This "impulse" does work on the turbine. For maximum power and efficiency, the turbine system is designed such that the water-jet velocity is twice the velocity of the bucket. A very small percentage of the water's original kinetic energy will still remain in the water; however, this allows the bucket to be emptied at the same rate it is filled, (see conservation of mass), thus allowing the water flow to continue uninterrupted. Often two buckets are mounted side-by-side, thus splitting the water jet in half (see photo). This balances the side-load forces on the wheel, and helps to ensure smooth, efficient momentum transfer of the fluid jet to the turbine wheel.
PELTON TURBINE
CROSS SECTION
Oil-Filled Cable A high-voltage power cable in which the paper insulation is impregnated with mineral oil under pressure. An increase in the electric strength of insulation is achieved in oil-filled cables through the elimination of gas inclusions (voids) within the insulation, which are potential sites of breakdown, by filling them with oil. During operation of the cable the oil pressure is maintained by make-up equipment. Oil-filled cables are used to lead power lines from large power plants or underground hydroelectric power plants to distribution equipment, where power transmission lines cross water obstacles, in densely builtup areas, and where power lines extend far into cities with high power
consumption
VERTICAL MOUNTED ALTERNATOR – TURBINE
CONTROL OPERATION OF POWER PLANT The hydroelectric power stations are undergoing a modernization process for operating optimization. One of the main ways to improve a hydropower development (hydropower station) is to equip it with SCADA-type acquisition and control systems the system is based on an architecture distributed and two hierarchical levels: the process, local level (located in the HPS) and the territorial dispatching level (located in Hydropower Dispatcher level). The system includes programmable automatic equipments, intelligent electronic devices, data transmission system and computers. The monitoring system connects three distinctly different environments. The substation, where it measures, monitors, controls and digitizes; the Control Room, where it collects, stores, displays and processes substation data; the Dispatcher Center, where it stores and displays incoming data. A communications pathway connects the three environments
CONCLUSION The industrial visit was highly informative and an experience to know the complexities involved in generation and transmission of electric power.
