06-02-2013, 04:38 PM
A PROJECT REPORT ON STUDY OF VFD VARIABLE FREQUENCY DRIVES FOR
CROMPTON GREAVES LTD
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VFD Variance frequency Drive
A variable-frequency drive (VFD) is a system for controlling the speed of a rotational or linear alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor. A variable frequency drive is a specific type of adjustable-speed drive. Variable-frequency drives are also known as adjustable-frequency drives (AFD), variable-speed drives (VSD), AC drives, micro drives or inverter drives.
Variable-frequency drives are used in a wide number of applications to control pumps, fans, hoists, conveyors, and other machinery
Energy savings
AC motor-driven applications that do not require full speed can save energy by controlling the motor with a variable speed drive. Energy cost saving with variable torque can be significant, often paying for the cost of VFD within a matter of months. In variable torque applications such as fans and blowers, the torque required varies roughly with the square of the speed, and the horsepower required varies roughly with the cube of the speed, resulting in a large reduction of horsepower for even a small reduction in speed. The motor will consume only 25% as much power at 63% speed than it will at 100% speed. This is referred to as the affinity laws, which define the relationships between speed, flow, torque, and horsepower.
World Economy
Global economic growth prospects are weakened and risk is sharply escalated during the fourth quarter ended December 2011, as euro area crisis entered a new risky phase. US economic growth accelerated in the third quarter as consumers and businesses boosted spending.
The economy has grown by an annual rate of 2.5%, powered by 2.4% growth in consumer spending and 3% rise in spending on services. UK economy grew at better than expected rate of 0.5%, compared to 0.1% growth witnessed in Q2, driven by strength in the service and production sector.GDP growth of euro zone decelerated by 0.3% in the fourth quarter ended December 2011, while growth in third quarter was 0.1%. Germany, euro zone’s biggest economy, witnessed de-growth of 0.2% in fourth quarter, as compared to 0.6% growth in the third quarter, while France witnessed GDP growth of 0.2%, as compared to 0.3% growth in third quarter.
Power Sector
Power is one of the major indicators denoting the success achieved by the economy and in order to sustain the growth level, the economy needs adequate and continuous power supply. As per estimate of Central Electricity Authority, for the economy to grow at the rate of 9%, the power sector must grow at 7.2% annually. India has power generation capacity of 185 GW on November 2011 and as per Government of India, total power generation capacity needs to increase to 960 GW by
2031-32. Power consumption in India is expected to rise in coming years as the population has increased and growing industrial needs will add fuel to it.
Performance of Indian Electrical Industry
Power and its ancillary industry’s growth are expected to rise to new heights on account of various power generation projects and developments expected in power distribution sector. Power sector is amongst the top 10 sectors in India attracting huge FDI inflows. During the period April 2000 to November 2011, power sectors has received FDI of USD 7.08 billion and ranked in 6th position. To understand the growth achieved by the Indian electrical & electronic industry, IEEMA has carried out an analysis of annual performance of selected companies. According the analysis, sector has performed moderately well in 2008-09 despite worldwide recession. However, there was an overall decline in profit margins due to increase in raw material and manpower costs. During the FY 2009-10 industry have performed fairly well. Sales of most of the companies have increased, resulted in overall increase of 10.4%, as against the financial year 2008-09. In most of the sectors cost of raw material and manpower have increased, whereas the export in some cases have gone down.