Electrical

Estimating observability matrices or state sequences is the central component of existing subspace identification methods. In this paper a different approach, in which Markov parameters are first estimated under general input excitation, is proposed. The prominent difference of this approach is that a three-block arrangement of data matrices is used. It is shown that one advantage of this approach over other subspace algorithms is that several unbiased estimating procedures can be carried out. One immediate application is to obtain balanced or nearly balanced models directly from the estimated Markov parameters. Another application is that with the estimated Markov parameters, consistently initialized Kalman filter state sequences can be obtained, from which the system matrices can be easily determined without bias.

Recently, the renewable energy such as Wind, solar, ocean, Biomass and geothermal powers are getting more attention with the increasing demand on energy, high oil prices and concern of environment impacts increased. Among them Photovoltaic (PV) generation getting more importance due to absence of fuel cost, low maintenance, no noise, no moving parts and long life time. However, the power of PV module is unstable and strongly dependent on Solar insolation and load. Hence, to ensure high efficiency despite these variations, Maximum Power Point Tracking controller is introduced. Traditionally, a maximum power point locus was used to provide a fast response with minimum losses which required extra control loop or intermittent disconnection of PV module. Hence, this report presents a improved maximum power point tracking for standalone PV system with will be simpler Fast Converging and comparatively MPPT technique, in which Perturb and Observe and Particle Swarm Optimization is use. This...

This paper presents feasibility study of hybrid power system. Rapid depletion of fossil fuel resources necessitated research on alternative energy sources. A windsolar hybrid system is a reliable alternative energy source because it uses solar energy combined with wind energy to create a stand-alone energy source that is both dependable and consistent. Solar power or wind power alone can fluctuate, when used together they provide a reliable source of energy. The perfect solution is to combine these two forms of energy sources to create a constant energy flow. Main objective of this paper is to study feasibility of standalone solar-wind hybrid power system with respect to their sizing and cost analysis, to maximize use of renewable energy generation system while minimizing the total system cost.

In recent years, industry has begun to demand higher power equipment, which now reaches the megawatt level. Controlled ac drives in the megawatt range are usually connected to the medium-voltage network. Today it is hard to connect a single power semiconductor switch directly to medium voltage grids. For these reasons a new family of multilevel inverters has emerged as the solution for working with higher voltage levels. They can generate output voltages with extremely low distortion and lower dv/dt, they draw input current with very low distortion, they generate smaller common mode voltage and they can operate with a lower switching frequency. Because of these features worldwide research and development of multilevel inverters is occurring. In this report the simulation results and its comparison of diode clamped 3 levels and 5 level inverter has been shown.