Suchergebnisse

Model reference adaptive system(MRAS) based techniques are one of the best method to estimate the rotor speed due to its performance and straight forward stability approach.These techniques use two different models which have made the speed estimation a reliable scheme especially when the variations.The scheme use the stator equation and rotor equation as the reference model and the adjustable model respectively.The output error from both models is tuned using a PI controller yielding the estimated rotor speed.It presents the identification and parameter estimation of an induction motor model with parameters varying as functions of the operating conditions. A Sensorless torque control system for induction motors is developed. The system allows for fast and precise torque tracking over a wide range of speed.The induction motor is controlled through field orientation techniques that require knowledge of the rotor speed.Since speed sensors decrease the reliability of a drive system (and increase its price), a common trend in motor control is to use an observer to estimate speed.

Digital change detection is the process that helps in determining the changes associated with Land use and Land cover properties with reference to geo-referenced multi-temporal remote sensing data. It helps in identifying change between two or more dates that is uncharacterized of normal variation. This work is an attempt to assess the district-wise changes in land use/land cover in Delhi, India. The study made use of LISS -III imageries of 2008 and 2012 year. The images were classified using Maximum Likelihood classification method. The output can be useful in many applications such as Land use changes, habitat fragmentation, rate of deforestation, urban sprawl and other cumulative changes through spatial and temporal analysis. The study shows that Delhi land cover from 2008 to 2012 a major rapid changes in the landscape as there is high growth in the fallow and built up area. Agriculture land and forest area has reduced marginally and water body is showing almost stagnant condition over time.