K. Pavankumar Reddy ¹, M. Venu Gopala Rao ¹

Affiliations
1 Department of EEE, K L University, Vaddaswaram, Guntur - 522502, Andhra Pradesh, IN

Abstract

The main objective of this paper is to enhance the power transfer capability of grid interfaced hybrid generation system. Generally, this hybrid system is a combination of solar and wind energy systems. In order to get maximum and constant output power from these renewable energy systems at any instant of time, this paper proposes the concept of maximum power tracking techniques. The main concept of this maximum power point tracking controller is used for controlling the Direct Current (DC) to DC boost converter. Finally, the performance of this Maximum Power Point Tracking (MPPT) based Hybrid system is observed by simulating using Matlab/Simulink.

Keywords

MPPT Technique, Solar Energy System, Wind Turbine System

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T.J.V. Subrahmanyeswara Rao ¹, M. Venu Gopala Rao ¹, T. V. N. L. Aswini ¹, K. Asha ¹, S. Bhanu Harika ¹

Affiliations
1 Department of ECE, KL University, Vaddeswaram, Guntur, Andhra Pradesh- 522502, IN

Abstract

Background/Objectives: The popularity of Wireless technologies, for applications that urges high bandwidth, increases the demand of Radio frequency (RF) spectrum which leads to scarsity in the spectrum resources. Hence it is required to sense the spectrum of a wideband signal at low sampling rates compared to the Nyquist rate. Methods/Statistical analysis: If the wide band signal is Sparse in frequency domain, then it is used to get over the problem of high sampling rates under the compressive sensing framework. Two different efficient schemes called Modulated Wideband Converter (MWC) and Asynchronous Multi-rate (AMR) are proposed here for wideband spectrum sensing at sub-Nyquist rates. The key features of these methods are also compared with the traditional sub-Nyquist sampling approach called Multi-Coset (MC). Findings: The MC sampling is capable of sampling at different time offsets, but unable to poses channel synchronisation. In MWC sampling, the sparse multiband signal is multiplied by a periodic waveform to shift the spectral components of the band of interest to the origin, then filtered and sampled at low rate. This also makes the computational time to reduce greatly. In AMR sampling, the sparse signal is under sampled at different sampling frequencies to produce sample sets with different aliasing spectra. Later these spectra are compared on a common frequency grid to detect the active bands. This mechanism takes fewer samples there by reduces thee computational cost. The simulation results exhibit these advantages over the traditional sampling techniques for wide band spectrum sensing. Application/Improvements: The trade-off between the selection of MWC for less computational time and MR for low complexity in design makes these sub Nyquist schemes suitable for wide band spectrum sensing in cognitive radio like applications.

Keywords

Cognitive Radio, Compressive Sensing, Sensing Algorithms, Wideband Signal

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B. Jyothi ¹, M. Venu Gopala Rao ¹, T. Karthik ¹

Affiliations
1 EEE Department, KL University, Greenfields, Vaddeswaram, Guntur (District) - 522502, Andhra Pradesh, IN

Abstract

Output total harmonic distortion of the five phase inverter topologies and corresponding dynamic performance of five phase induction motor are investigated in this paper. Four types of five phase inverter topologies are simulated by using direct pulse and sinusoidal pulse width modulation methods for the inverter control. Arbitrary reference frame method has been employed to model a five phase induction motor. Special transformer connection can be used to transform the available three phase grid supply to five phases but it requires more space, frequent maintenance and high cost so inverters are preferred. Four types of five phase inverter topologies and induction motor modeling are implemented by MATLAB/Simulink. These multi-phases (more than three phases) find applications where reliability and high output power are main concern for example: ship propulsion systems, hybrid electric vehicles.

Keywords

Diode Clamped Multilevel Inverter, Five Phase Induction Motor, Five Phase Supply, Reversing Voltage Multilevel Inverter, Switching Sequence, SPWM Technique, Ten-Step VSI, Total Harmonic Distortion, 1800 Pulses.

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