M. Kowsalya

Bio: M. Kowsalya is an academic researcher from VIT University. The author has contributed to research in topics: Inverter & Low voltage. The author has an hindex of 1, co-authored 3 publications receiving 5 citations.

Power quality improvement features on photovoltaic grid connected dual voltage source inverter

Abstract: In this paper the Dual Voltage Source Inverter (DVSI) is used for improving the reliability and the microgrid system quality Here, proposed system includes two inverter, which allows the microgrid to replace the energy generated by the source of energy distribution ie the PV system, and more than to compensate local and non-linear load conditions The DVSI is enabled in the network sharing modes and the injection mode conditions for the algorithms of control which are constructed by using the instantaneous symmetric component theory (ISCT) The proposed design provides improved reliability, low bandwidth requirements for the inverter source, filter size reduces the cost and power consumption of the microgrid large powers while using a dc connection reduction Voltage for the main inverter The factors make the design option of DVSI for the small grid can provide load sensitivity The algorithm of topology control and approved by many consequences caused by MATLAB/Simulink

Design a high-efficiency and high voltage gain DC-DC converter for photo voltaic systems

Abstract: Renewable sources such as photovoltaic modules, fuel cells or energy storage devices, such as super capacitors or batteries provide an output voltage supply in the range of about 12–70 VDC. In order to connect grid systems, the voltage level must be adjusted in accordance with the rules of the electricity grid in the country. For applications such as attached to network systems, it is necessary to increase the voltage level resulting in reduced efficiency. To deal with this problem, this article proposes a new high-voltage gain, the DC-DC converter based on the high-efficiency inductor coupled, an intermediate condenser and the regenerative leak recovery system. The input power source is first stored in the inductor field and a capacitor coupled magnetic in an intermediate time loss. A passive retention network around the primary inductor ensures the recovery of the trapped energy in the leakage inductance, it leads to an improvement in the voltage gain and the efficiency of the system. It is necessary to increase the duty cycle values to obtain a high voltage gain, which avoids problems such as reverse diode recovery. Due to the presence of a passive voltage-locking network reduces the voltage on the switch. This allows the use of a low voltage switch (with a low “ON-state” resistance), improving the overall efficiency of the system.

Zero current switching high frequency isolated Dc-Dc converter

Abstract: It's been a challenging task to distribute power in subsea oil and gas stations. In such high power applications ZCS based converters are more preferable as it uses switches like IGBT, GTO etc. This paper deals with the zero current switching full bridge dc-dc conversion. At the input side each modules are connected in series and at output side all bridge connections connected parallel. Input side inductances and output capacitances minimize ripple contents present in the system. The proposed system minimizes the losses due to diodes in the output side by replacing switches and also provides flexibility in the output voltage.

Low-Stress and Optimum Design of Boost Converter for Renewable Energy Systems

Abstract: This paper examines the design and analysis of DC–DC converters for high-power and low-voltage applications such as renewable energy sources (RESs) and comparisons between converters based on switch stresses and efficiency. The RESs including photovoltaic arrays and fuel cell stacks must have enhanced output voltages, such as 380 V DC in the case of a full bridge inverter or 760 V DC in the case of a half bridge inverter, in order to interface with the 220 V AC grid-connected power system. One of the primary difficulties in developing renewable energy systems is enhancing DC–DC converters’ efficiency to enable high step-up voltage conversion with high efficiency and low voltage stress. In the present work, the efficiency, current, and voltage stress of switches of an isolated Flyback boost converter, simple DC–DC Boost converter, and an Interleaved boost converter, are explored and studied relatively. The most suitable and optimized options with a high efficiency and low switching stress are investigated. The more suitable topology is designed and analyzed for the switch technology based on the Silicon-Metal Oxide Semiconductor Field Effect Transistor (Si-MOSFET) and the Gallium Nitride-High Electron Mobility Transistor (GaN-HEMT). The Analytical approach is analyzed in this paper based on efficiency and switching stress. It is explored that GaN HEMT based Flyback boost converter is the best. Finally, the future direction for further improving the efficiency of the proposed boost converter is investigated.

A Digital Controller IC for High-Frequency DC-DC Switching Converters

Abstract: A digital controller IC for DC-DC converters with high switching frequency is described and implemented by CSMC 0.18um CMOS process in this paper. The designed digital controller IC consists of a reference-voltage-programmable delay-line window type ADC, a current-mode compensator using Adjacent Cycle Sampling (ACS) control strategy, and a hybrid digital pulse-width modulator (DPWM) using the structure of counter comparator and delay-locked-loop delay line. The simulation results indicated that, a Buck DC-DC switching converters using the designed controller IC can convert an input from 5V to 1.8 V with 1Mhz switching frequency. The slew rate of the transient responses as load variation of 500 mA is 20mV/μs, at most.

A comprehensive review of various isolated DC-DC converters topologies associated with photovoltaic applications

Abstract: Environmentally friendly renewable energy sources showed substantial development over the most recent couple of years. Compared with other RES, extracting power from solar has become the most beneficial and profitable source because of its environmental friendly nature. In the process of extraction of power, DC-DC converters has given conspicuous interest due to their broad use in various applications. Although a lot of advancements, research work, and continuous tuning of circuits of photovoltaic systems, still remarkable efficiency and stability has not been achieved yet. In this paper, exhaustive research and development of DC-DC converters are identified and studied. It surveys the difficulties associated with implementing new converter topologies in photovoltaic applications. Presented new topologies that have simpler control, less number of components, economical, and suitable for solar applications. Various types of isolated converter are explained such as different bidirectional converters, high step- up converters, zero current switching, high frequency isolated converter, isolated converter with discontinuous input, quasi-Z-source converter, multiport converter, high efficient converter, single-switch converter and single-switch resonant converter. Different types of structure characteristics and operation of the converters are presented. Based on the distinct features, a comparison of the converters has been carried out. From the review, a single converter topology does not fulfill all requirements in the industry. Future scopes of the research trend are suggested. The current survey is to update the research carried out during the time gap.