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Prasada Rao K.,Christu Jyothi Institute of Technology and Science
International Journal of Applied Engineering Research | Year: 2015

This paper proposes a MPPT based Photovoltaic fed Dynamic Voltage Restorer (DVR) and DSTATCOM using multilevel converter with reduced number of switches. The DVR is used to mitigate deep voltage sags and voltage swells on distribution system. In addition to the harmonic reduction due to non linear load, the reactive power compensation is done by DSTATCOM. Further the use of cascaded multilevel converter with reduced number of switches will reduce the switching losses and increases the power rating of both devices. Maximum Power Point Tracking (MPPT) based PV will maintain constant voltage across DC side of the multilevel converter. Matlab/Simulink results are presented to validate proposed system. © Research India Publications. Source


Prasada Rao K.,Christu Jyothi Institute of Technology and Science
International Review on Modelling and Simulations | Year: 2014

In this paper a cascaded multilevel converter with reduced number of switches is proposed for standalone hybrid solar wind power generation system to improve the waveform quality of the output voltage and current. Renewable energy sources such as solar and wind power generation systems play important role in energy generation. However, the output power of solar are usually fluctuant due to the uncertainty and intermittence of solar and wind energy, which requires a large capacity of energy storage to satisfy the load demand when the system works in grid connected mode. Storage systems are used to compensate or absorb the difference between load demand and generation. This paper also presents improvement of power system at different variable load and wind profile conditions. The main advantage of the proposed technique is the closed loop control system which has a vector PI controller which ensures optimal power delivery from solar is matched with the wind energy. The system is employed on a multilevel converter, DC-DC boost converter, photovoltaic system, PMSG and Battery storage system. The performance of the proposed system has been evaluated by Matlab/Simulink. The proposed system can not only improve the power supply reliability, but also reduces the cost of the system. © 2014 Praise Worthy Prize S.r.l. - All rights reserved. Source


Madhuri G.,Christu Jyothi Institute of Technology and Science
Proceedings - 2013 IEEE International Multi Conference on Automation, Computing, Control, Communication and Compressed Sensing, iMac4s 2013 | Year: 2013

In cellular networks, blocking occurs when a base station has no free channel to allocate to a mobile user. One distinguishes between two kinds of blocking, the first is called new call blocking and refers to blocking of new calls, and the second is called handoff blocking and refers to blocking of ongoing calls due to the mobility of the users. There are many methods of allocating a channel upon a new call arrival or handoff attempt. A good channel allocation is the one that yields high spectral efficiency for a specified grade of service (including link quality, probability of new call blocking, and the probability of forced terminations) and given degree of computational complexity It also keeps the planned cell boundaries intact, allocates a channel to MS quickly, maintains the best speech quality for the MS at any instant, and relives undesired network congestions. In this paper a simple and dynamic mobile controlled handoff based on quality of service is proposed which initiates a handoff procedure when RSS (Received signal strength) from serving BS falls below the threshold level. By using DCA (Dynamic Channel Assignment) info regarding the GOS (grade of services) and Quality of Service parameters at BS's whose RSS is greater than the serving BS is acquired by MS. By examine the parameters MS will choose the best BS to make a successful handoff with good voice quality. Forced terminations are generally perceived to severely degrade the quality of service. For this reason first priority of allocating channel is given to the handoff requests more readily then to new cell arrivals. This reduces the probability of forced termination at the expense of a (slight) increase in probability of new call blocking. These results are represented graphically in the paper. © 2013 IEEE. Source


Polimetla P.,Christu Jyothi Institute of Technology and Science | Sailu Ch.,Osmania University
Proceedings of the 2014 IEEE International Conference on MOOCs, Innovation and Technology in Education, IEEE MITE 2014 | Year: 2014

With the recent signing of Washington accord, India demonstrated the commitment to move to the outcome based education (OBE). This paper elaborates the process and the assessment methodology by adopting various parameters, tools and rubrics for successful paradigm shift towards OBE for the existing engineering programs. This paper also discusses the challenges to be addressed by various stakeholders. © 2014 IEEE. Source


Prasada Rao K.,Christu Jyothi Institute of Technology and Science | Sao S.,Bharath Institute of Engineering and Technology
International Review of Automatic Control | Year: 2014

In this paper a cascaded multilevel converter with reduced number of switches is proposed for grid connection of a direct-drive Permanent magnet synchronous generator (PMSG) based variable speed wind turbine to improve the waveform quality of the converter output voltage and current. Therefore, the bulky passive grid filters can be reduced or even removed. The basic topology and control strategy of the proposed converter are presented in detail. The generator is connected to the grid by means of a diode rectifier, an intermediate buck-boost dc-dc converter, and a multilevel converter with reduced number switches. The grid side multilevel converter is controlled to obtain high efficiency under different load conditions. Vector control of the grid-side multilevel converter featured with output voltage and frequency controller that is capable of handling variable load conditions. The operation and performance of the proposed system have been evaluated by Matlab/simulink. Simulation results shows that the controller regulate magnitude and frequency of voltage to match with the grid under varying wind and load conditions. © 2014 Praise Worthy Prize S.r.l. - All rights reserved. Source

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