Manoj R. Ramteke

Unity-Power-Factor Operation of Three-Phase AC–DC Soft Switched Converter Based On Boost Active Clamp Topology in Modular Approach

In this paper, a three-phase ac-dc converter using three single-phase pulse width modulated active clamped, zero-voltage-switched boost converter in modular approach is presented. The active clamp technique is used for zero-voltage-switching of the main and auxiliary switches. The operating modes, analysis, and design considerations for the proposed converter are explained. To evaluate the performance of the proposed converter, finally simulation and experimental results for a 500-V, 1.5-kW prototype converter are presented. The proposed converter operates at almost unity power factor with reduced output filter size. The output voltage is regulated without affecting zero-voltage-switching, even under unbalanced three-phase input voltages.

Multilevel Inverter to Eliminate Common Mode Voltage in Induction Motor Drives

Common mode voltage (CMV) is responsible for premature failure of bearing of induction motor when supplied from fast switching devices. In this paper, five level diode clamped multilevel inverter is proposed to eliminate CMV by selecting specific switching states. In addition to eliminate CMV, proposed inverter reduces switching losses, dv/dt and gives high quality output. MATLAB simulation shows the validity of proposed scheme.

Grid Interfaced Distributed Generation System With Modified Current Control Loop Using Adaptive Synchronization Technique

This paper presents real-time implementation of a grid interfaced distributed generation (DG) system with modified current control loop using three phase amplitude adaptive notch filter (AANF) based synchronization tool. A grid current feedback based modified

Control of D-STATCOM under unbalanced and distorted voltages using Synchronous Detection method for load compensation

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An Isolated Multi-Input ZCS DC–DC Front-End-Converter Based Multilevel Inverter for the Integration of Renewable Energy Sources

-current control technique for interfacing inverter is developed in order to achieve constant loading on the grid, transient-free operation, and power factor improvement close to unity power factor (UPF) of the utility grid during sudden load variations. This technique does not require separate calculation of reference reactive component and harmonics component of currents hence reduces control circuit complexity. In addition, it requires only three voltage and three current sensors. Three phase AANF is developed and is used for online extraction of utility voltage phase angle to generate synchronized reference current signals for interfacing inverter. AANF is used because of its adjustable accuracy and amplitude adaptability even under unbalanced voltage sag and swell, frequency variation, and distorted grid conditions. Fast and accurate behavior of three phase AANF improves the dynamic response of entire DG system control performance for sudden load variations. The dynamic behavior of the proposed grid interfaced DG system is experimentally evaluated in maintaining constant loading on grid, transient-free operation, and power factor improvement close to UPF operation of the utility grid, by compensating total reactive power and harmonic current demanded by variable linear as well as nonlinear load.

Modeling of split capacitor based dstatcom & voltage balancing scheme for load compensation

This paper presents Distribution Static Compensator (DSTATCOM) configuration in three phase four wire system, using three level Neutral Point Clamped (NPC) inverter operated in current control mode for load compensation to enhance the quality of power. The behavior of shunt compensator is analyzed using Synchronous Detection method. The purpose of this compensating scheme is to provide completely balanced and sinusoidal source currents under unbalanced and distorted source conditions. The chosen control algorithm includes three different approaches-equal current, equal power and modified equal current. The above said criteria are compared graphically and analytically for unbalanced and non-linear load condition. Results obtained show that modified equal current approach is more effective than the other two even if the source voltages are severely distorted and unbalanced. For realization, an extensive digital simulation is done using MATLAB environment.

Electronic Ballast with Unity-Power-Factor Based on Current Injection technique

A new isolated current-fed zero-current switched (ZCS) front-end dc/dc converter based multilevel inverter is proposed for multi-input applications. The proposed front-end converter with only two controllable switches integrates two different renewable energy sources, resulting in an advantageous compact structure and low conduction losses. The ZCS turn-off is achieved in both the controllable switches with the proposed modulation scheme. The converter maintains ZCS turn-off under a wide load, as well as input voltage variations by employing frequency modulation along with a variable duty ratio technique. Simple structure, soft switching, high gain, and automatic load regulation make the converter structure novel for simultaneous power management in multi-input renewable energy applications. Converter operation and design guidelines have been outlined. A laboratory prototype of the proposed converter is developed and tested at 300-W power level. Simulations and experimental results demonstrate the robust performance of the converter under load, as well as input source voltage variations.

Hybrid Control of High-Efficient Resonant Converter for Renewable Energy System

In this paper Distribution static compensator (DSTATCOM) is realized with split capacitor configuration using state space modeling. This inverter topology is able to compensate the zero sequence components as well as achieve the harmonic compensation, power factor correction & load balancing. The significant problem faced by this topology is capacitor voltage unbalance. To overcome this drawback two quadrant chopper control scheme is used. The compensator reference currents are generated using instantaneous symmetrical component theory while the hysteresis pulse width modulation (PWM) is used to control inverter switching. The derived model has been analyzed by simulation studies through MATLAB.

Multiport DC-DC boost converter with zero-current switching

A new combination of power-factor-correction (PFC) and filter components in single-stage electronic ballast is presented in this paper. A symmetrical half-bridge inverter is used to drive the fluorescent lamp. The proposed topology is based on the high frequency current injection technique. The PFC components inject the current at switching frequency into the dc-bus capacitors and keeps the dc-bus voltage above the ac input peak voltage to achieve the ripple-free input current at unity-power-factor and high efficiency over the wide range of input line voltage. The principle of operation and analysis of the proposed electronic ballast is explained, and the experimental results of the laboratory prototype ballast for 2×36 W lamps operating at 50 kHz and 230 V, 50 Hz mains is also presented further.

Closed-loop control of current-fed full-bridge parallel resonant soft-switched dc-dc boost converter for PV applications

This paper presents the hybrid control of a dc–dc resonant converter for a dc micro-grid. The hybrid control is the simultaneous variation of the frequency and the duty ratio, which can provide excellent voltage regulation and maintain zero-voltage switching (ZVS) over a wide load range. Hence, excellent conversion efficiency is also maintained over the wide load range using hybrid control. However, the conventional control methods for a dc–dc resonant converter using either variable switching frequency or duty ratio have their own limitations. The frequency control requires wide variation in switching frequency for output voltage regulation, which leads to higher switching losses at turn-off of switches and lower efficiency particularly at light loads. The duty ratio control has a limitation of loosing of ZVS at light loads. The simulation and experimental results of hybrid control of resonant converter operating above 100 kHz with maximum duty ratio of 0.48 for 3 kW are presented from full load to no load. The maximum efficiency of the resonant converter is found to be 98%, which was achieved at 75% of the full load.