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Author

V. Karthikeyan

Bio: V. Karthikeyan is an academic researcher from National Institute of Technology Calicut. The author has contributed to research in topics: Photovoltaic system & Computer science. The author has an hindex of 12, co-authored 61 publications receiving 455 citations. Previous affiliations of V. Karthikeyan include Motilal Nehru National Institute of Technology Allahabad & Pondicherry University.


Papers
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Journal ArticleDOI
TL;DR: The proposed MIBDC has the benefits of reduction in circulation power and peak current stress in an independent mode of operation, which enhances the efficiency of dual active bridge converter, and offers a wide range of power transmission as compared to the conventional IBDC.
Abstract: This paper proposes a multiple-input configuration of isolated bidirectional dual active bridge dc–dc converter (MIBDC) for power flow control in combinational battery storage It can be operated in an independent source or combinational source mode of operation to control the power transfer, with the capability of bidirectional power flow and smoother transition The proposed configuration has the benefits of reduction in circulation power and peak current stress in an independent mode of operation, which enhances the efficiency of dual active bridge converter It also offers a wide range of power transmission as compared to the conventional IBDC The proposed configuration can also be used with unequal voltage level sources by connecting them in series on multi-input side The operation and investigation of the proposed configuration are presented in detail In addition, the strategy of power flow control with multiple-input sources is discussed The operation of the proposed MIBDC has been verified through simulation studies using PSCAD/EMTDC and experimentally demonstrated using ARM LPC 2148 processor

94 citations

Journal ArticleDOI
TL;DR: A high step-up gain dc-dc converter is proposed by combining the switched capacitor and regenerative boost (SCRB) configuration in this brief, which drastically increases the dc-voltage gain and enhances efficiency.
Abstract: Because of cost, size, and weight, the transformer is the primary burden in grid-connected solar PV-system and it decreases the whole system efficiency. In order to avoid the use of a transformer, a high step-up gain dc-dc converter is proposed by combining the switched capacitor and regenerative boost (SCRB) configuration in this brief. In classic boost type and derived converters, the device stresses and losses associated with the converter are high and result in lower efficiency. In the proposed converter, the SCRB operations take place simultaneously using lossless passive components and a minimum number of semiconductor devices. Thereby, it drastically increases the dc-voltage gain and enhances efficiency. In addition, it also dominates with fewer ripple content, which helps to elongate the lifetime of devices and suppress the electromagnetic interference. This brief describes detailed steady-state waveforms and various modes of operation under continuous conduction mode and discontinuous conduction mode. This brief also presents the performances of the proposed converter and compares with conventional converters characteristics. A 500 W experimental model has been built to validate the operation and confirms the theoretical waveforms with experimental results. The maximum efficiency of 95.60% is obtained at 480 W for the proposed converter.

59 citations

Journal ArticleDOI
TL;DR: A switched capacitor–inductor network (SCLN)-based ultravoltage gain dc–dc converter using a single switch is presented and can achieve ultra dc voltage gain with minimum number of devices when compared with other existing converters.
Abstract: A switched capacitor–inductor network (SCLN)-based ultravoltage gain dc–dc converter using a single switch is presented. The SCLN converter can achieve ultra dc voltage gain with minimum number of devices when compared with other existing converters. Moreover, the voltage gain is significantly improved at entire duty ratios. In addition, due to switched approach of inductor and capacitor, the converter provides lesser ripple content in the output voltage and current. The operation of the converter in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is discussed. The parasitic elements are considered to estimate the dc voltage gain and the efficiency of the converter more precisely. The small-signal model of the converter is derived, and the pole-zero locations are investigated. Moreover, the comparative performances of the SCLN converter with existing converters are reported. A hardware prototype has been developed and tested. To prove the applications of the SCLN converter in solar PV system, the experimental results are observed by considering the output voltages of 650 V for three-phase and 325 V for single-phase applications.

57 citations

Journal ArticleDOI
TL;DR: In this paper, a zero circulating current (ZCC) modulation technique is proposed for isolated bidirectional DC-DC converter (IBDC), which not only reduces the current stress but also eliminates the circulating power flow (CPF).
Abstract: In this study, a zero circulating current (ZCC) modulation technique is proposed for isolated bidirectional DC–DC converter (IBDC). The operating modes of the proposed modulation technique for the bidirectional dual active bridge DC–DC converter have been discussed and analysed. The proposed ZCC modulation not only reduces the current stress but it also eliminates the circulating power flow (CPF). In forward mode, the fixed 50% duty cycle and pulse width modulation signals are applied to the high voltage and low voltage bridges of IBDC converter, respectively. In reverse mode, the switching pattern is interchanged to reverse the power flow. The rising and falling edge phase-shift ratios are introduced for the two waveforms which help in identification of the ZCC switching. Condition on falling edge phase-shift ratio is determined to eliminate the CPF in the IBDC. This study also addresses the impact of the CPF on performance of the IBDC. The simulation and experimental results validate the proposed ZCC modulation for the IBDC.

35 citations

Journal ArticleDOI
TL;DR: The VPAC control proposed in this study effectively manage the power flow control between the battery storage unit and the solar PV fed DC link by continuously varying the phase angle between high voltage and low voltage (LV) bridge voltage of the IBDC.
Abstract: This study proposes a varying phase angle control (VPAC) in isolated bidirectional dc-dc converter (IBDC) for integrating battery storage unit to a DC link in a standalone solar photovoltaic (PV) system. The IBDC is capable of power transfer using high step up/down ratio between DC link and battery. The VPAC control proposed in this study effectively manage the power flow control between the battery storage unit and the solar PV fed DC link by continuously varying the phase angle between high voltage and low voltage (LV) bridge voltage of the IBDC. The solar PV system is incorporated with the maximum power point tracking using DC-DC converter. In order to control the voltage across the AC load a voltage source inverter is used. The study also presents the design aspects of the IBDC converter for the application considered. The performance of the proposed power flow control strategy has been studied through PSCAD/EMTDC simulation and validated using LPC 2148 ARM processor.

34 citations


Cited by
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Journal ArticleDOI
TL;DR: Bargaining with reading habit is no need, reading is not kind of something sold that you can take or not and how can you bargain with the thing that has many benefits for you?

513 citations

Journal ArticleDOI
TL;DR: To improve both steady-state and transient performances, a combination approach to optimize both the efficiency and dynamics for an NSDAB dc–dc converter based on the reviewed methods is presented.
Abstract: The nonresonant single-phase dual-active-bridge (NSDAB) dc–dc converter has been increasingly adopted for isolated dc–dc power conversion systems. Over the past few years, significant research has been carried out to address the technical challenges associated with modulations and controls of the NSDAB dc–dc converter. The aim of this paper is to review and compare these recent state-of-the-art modulation and control strategies. First, the modulation strategies for the NSDAB dc–dc converter are analyzed. All possible phase-shift patterns are demonstrated, and the correlation analysis of the typical phases-shift modulation methods for the NSDAB dc–dc converter is presented. Then, an overview of steady-state efficiency-optimization strategies is discussed for the NSDAB dc–dc converter. Moreover, a review of optimized techniques for dynamic responses is also provided. For both the efficiency and dynamic optimizations, thorough comparisons and recommendations are provided in this paper. Finally, to improve both steady-state and transient performances, a combination approach to optimize both the efficiency and dynamics for an NSDAB dc–dc converter based on the reviewed methods is presented in this paper.

263 citations

01 Jan 2009
TL;DR: In this article, the authors proposed a power flow control between utility and microgrid through back-to-back converters, which facilitates desired real and reactive power flow between the utility and the microgrid.
Abstract: This paper proposes a method for power flow control between utility and microgrid through back-to-back converters, which facilitates desired real and reactive power flow between utility and microgrid. In the proposed control strategy, the system can run in two different modes depending on the power requirement in the microgrid. In mode-1, specified amount of real and reactive power are shared between the utility and the microgrid through the back-to-back converters. Mode-2 is invoked when the power that can be supplied by the DGs in the microgrid reaches its maximum limit. In such a case, the rest of the power demand of the microgrid has to be supplied by the utility. An arrangement between DGs in the microgrid is proposed to achieve load sharing in both grid connected and islanded modes. The back-to-back converters also provide total frequency isolation between the utility and the microgrid. It is shown that the voltage or frequency fluctuation in the utility side has no impact on voltage or power in microgrid side. Proper relay-breaker operation coordination is proposed during fault along with the blocking of the back-to-back converters for seamless resynchronization. Both impedance and motor type loads are considered to verify the system stability. The impact of dc side voltage fluctuation of the DGs and DG tripping on power sharing is also investigated. The efficacy of the proposed control ar-rangement has been validated through simulation for various operating conditions. The model of the microgrid power system is simulated in PSCAD.

258 citations

Journal ArticleDOI
TL;DR: This work surveys the application of WSN in environmental monitoring, with particular emphasis on water quality, taking into account their coverage, energy and security concerns.

156 citations

Chen Gang1
01 Jan 2003
TL;DR: In this paper, a PWM plus phase-shift control bidirectional DC/DC converter is proposed, which combines PWM control and phase shift control to reduce current stress and both conducting and switching loss.
Abstract: A PWM plus phase-shift control bidirectional DC/DC converter is proposed. In this converter, PWM control and phase-shift control are combined to reduce current stress and both conducting and switching loss, to expand ZVS range. The operation principle and analysis of the converter are explained, and ZVS condition is derived. A prototype of PWM plus phase-shift bidirectional DC/DC converter is built to verify analysis.

120 citations