PERFORMANCE ANALYSIS FOR SHUNT ACTIVE FILTER BASED ON P-Q AND SDM THEORY

B.Indhumathi¹ , R.Beula²

¹PG student- Department of EEE - G.K.M College of Engineering and Technology, Chennai, India

²Assistant Professor- Department of EEE - G.K.M College of Engineering and Technology, Chennai, India

            The Intensive use of Power Converters and other non-linear loads, result in an increasing deterioration of the power systems voltage and current waveforms. The presence of harmonics in the power lines results in greater power losses in distribution. To suppress the harmonics, filters are used. The Active Power Filter uses a voltage source inverter to produce the harmonic current components that cancel the harmonic components due to non-linear loads. The switching of the power electronics devices in the shunt active power filter is based on reference   compensation   current,   which   is   determined   by different algorithms. In this project, simulation setup has been developed  using  MATLAB    and  performance  of  three-phase shunt active power filter   is studied using different control techniques that are used to generate the reference compensation current, namely instantaneous active and reactive (p-q) theory and synchronous detection method for the control of reactive power and harmonics. Reference current generated by each of the above method is compared with the actual current fed by the VSI circuit and gate pulses of the VSI are modified so that the actual current is equal to the reference current. A comparison is given for different values of load. Capacitor voltage is kept constant by another closed loop with PID controller. Simulations results are obtained for the two methods. From the simulation result it is observed that the total harmonic distortion factor has been decreased nearly to10%  as compared to system without shunt active power filter and the power factor is also improved.

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MULTI SCALE DECOMPOSITION AND EDGE PRESERVING FILTER BASED SATELLITE IMAGE RESOLUTION ENHANCEMENT

K.R.Manikandan¹, Mallikarjuna Nandi²

¹PG student- Department of CSE - Velammal college of Engineering and technology, Madurai, Tamilnadu, India.

²Assistant Professor- Department of CSE - Velammal college of Engineering and technology, Madurai, Tamilnadu, India.

                Resolution enhancement (RE) schemes (which are not based on wavelets) suffer from the drawback of losing high frequency contents (which results in blurring). The discrete wavelet transform- based (DWT) RE scheme generates artifacts (due to a DWT shift-variant property). A wavelet-domain Handled based on dual-tree complex wavelet transform (DT-CWT) and nonlocal means (NLM) is proposed for RE of the satellite images. Satellite input Picture is decomposed by DT-CWT (which is nearly shift invariant) to obtain high-frequency subbands. The high-frequency subband and the low-resolution (LR) input image are interpolated using the Lanczos interpolator. The high frequency subband are passed through an NLM filter to cater for the artifacts generated by DT-CWT (despite of it’s nearly shift invariance).This Is The filtered high-frequency subbands and the LR input image are combined using inverse DT-CWT to obtain a resolution-enhanced image. Objective and subjective analyses reveal superiority of the proposed technique over the conventional and state of- the-art RE techniques.

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PERFORMANCE IMPROVEMENT OF BOOST CONVERTER USING INTERLEAVING TECHNIQUE AND ZERO VOLTAGE SWITCHING

A.R.Siva Priya

PG student- Department of EEE – K.S.Rangasamy College of Technology, Namakkal Tamilnadu, India.

            To achieve high-power density in power supplies, it is desirable to minimize the physical size of the energy storage capacitor. The capacitance is determined by the energy storage requirement for line outage ride-through and also the ripple current handling capability of the capacitor. Interleaving is well known as an effective method to reduce the capacitor ripple current and in cases where ripple current considerations dominate, it could reduce capacitor size. High frequency operation of converters results in high switching losses. Several soft-switching techniques have been proposed in recent literatures to substantially reduce the switching loss. In this paper, a soft-switching interleaved boost converter composed of two shunted elementary boost conversion units and an auxiliary inductor is proposed. Simulation results reveal that the performance of this proposed converter is better than that of conventional boost converter.

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