An Investigation of Zeta Converter on Power System

Abstract

Worldwide about 1.5 billion people live without access to electricity. With lack in effort, the number of people denied from getting electricity. Extension of national grids is often prohibited by high cost and non-feasible in isolated rural areas. The generation of power using non-renewable energy sources like coal, diesel, and gas will be available over a short span of time. Use of renewable energy sources like solar, wind, tidal is becoming emerging trends as they are the alternate sources after the advent of power electronic components. Basically, converters and inverters are incorporated while the power generation is done using renewable energy sources. Development in technology led to increasing demand for high power switched mode converters in telecommunication equipment s, satellite and so on. A DC/DC converter generally needs to work under high switching frequency when used as an adjustable power supply to reduce the size of magnetic elements such as inductors, transformers, and capacitors. With the increase of switching frequency, the switch losses will increase which in turn increases the output voltage ripple and reduces the efficiency of the converter. Ripple voltage is a small unwanted residual periodic variation of the Direct Current (DC) output of a power supply which is undesirable in many electronic circuit applications which tends to undesired noise in audio and video applications thereby dropping their performance. Recent studies in reducing this output voltage ripple content focus on two distinct fields: one is various topologies and the newlinevii newlineother one is various controlling techniques employed for these topologies. In past few decades, several DC-DC converter topologies have been proposed to address this issue, namely CuK converter, SEPIC converter, Zeta converter, Luo converter and so on. In spite of all available converters zeta converter hold good for low ripple and continuous output current. newlineThe proposed work has the objective to regulate the output DC voltage. For the investigation, an Enhanced Zeta Converter (EZC) is structured which includes basic ZETA converter and a high gain voltage converter so that the voltage stress felt by the components in the basic zeta can be reduced. By properly changing the duty ratio of zeta converter, the output voltage can be varied. Simulation is carried out by considering a load of 400and#937; with the input voltage of 20V and the output voltage is obtained as 200V with the basic Zeta converter. Similarly, for the same load, the output voltage is obtained as 240V with the input voltage of 20V for Enhanced zeta converter. This proposed topology is compared with the available other topologies and observed that it gives a constant output voltage even the load is changed to 13%. The simulation is carried out by MATLAB software and the results are discussed in proposed work. newlineFor integrating the output voltage to an AC grid, a basic zeta converter with a multilevel inverter (MLI) is proposed. The simulation result reveals that newlineviii newlinethe proposed system can be used for grid-connected systems. The result is verified by the simulation of the proposed structure and is given in the thesis. newlineA novel hybrid power system comprising of a photovoltaic system and wind power system is proposed. The output voltages of the proposed system increased by incorporating the zeta converter whose duty cycle is controlled by Fuzzy Logic Controller (FLC) and the output is verified by MATLAB which gives a regulated output voltage. The simulated results and analysis are given in the thesis. newline