A Wide Input-Voltage Range Quasi-Z-Source Boost DC–DC Converter With High-Voltage Gain for Fuel Cell Vehicles

 Abstract—

A quasi-Z-source boost dc–dc converter, which uses a switched capacitor, is proposed for fuel cell vehicles. The topology can obtain a high-voltage gain with a wide input-voltage range and requires only a low-voltage stress across each of the components. The performance of the proposed converter is compared with other converters which use Z-source networks. A scaled-down 400-V/400-W prototype is developed to validate the proposed technology. The respective variation in the output voltage is avoided when the wide variation in the input voltage happens, due to the PI controller in the voltage loop, and a maximum efficiency of 95.13% is measured.

Standalone Single Stage PV fed Reduced Switch Inverter Based PMSM for Water Pumping Application

 Abstract—

This paper proposes a standalone single stage PV fed PMSM drive for water pumping. The proposed system aims at reducing the switching losses and overall cost by using reduced switch inverter (RSI). The proposed system comprises of a PMSM drive, fed by PV source through an inverter employing reduced number of switches. The inverter uses only four switches whereas the conventional VSI utilizes six switches. Field oriented control scheme is employed to control the PMSM drive. Perturb and Observe (P&O) MPPT technique is used to generate a speed reference to PMSM drive. Simulation studies for the proposed PV fed PMSM driven water pumping system are performed using MATLAB platform and it is also experimentally verified through FPGA controller based 400 W laboratory prototype PMSM drive and results demonstrates the efficacy of the system.

Grid Synchronization of Wind Based Microgrid

 Abstract-

This paper is on the synchronization of a wind based microgrid with main grid. The wind power is generated using the permanent magnet brush less DC generator (PMBLDCG) and the MPPT (Maximum Power Point Tracking) is executed with P&O (perturb & Observe) approach to extract the maximum power from the wind generation. This power is fed to the AC load using a voltage source inverter (VSI) through the battery bank (BSS) at DC link. The control algorithm operates in standalone mode and grid connected mode. It can switch in islanded and grid connected modes seamlessly according to the wind conditions. In standalone mode, this wind power is fed to the load through a VSI, during low wind conditions, the battery discharges itself to fulfill the load demand. After that, the grid is connected to give power to the load during low wind conditions, and for this, control algorithm operates in grid connected mode. Therefore, the control algorithm switches from voltage control to current control mode to provide smooth synchronization and vise versa at de-synchronization. A MA TLABI Simulink model is developed to simulate the system performance during wind variations, and duringsynchronization and desynchronization.

A 15-Level Asymmetric Cascaded H Bridge Multilevel Inverter with Less Number of Switches For Photo Voltaic System

 Abstract—

This Paper presents a 15 level Asymmetrical Cascaded H bridge multilevel inverter Topology for Photovoltaic system. In this system Symmetrical and Asymmetrical Multilevel inverter (MLI) is utilized. In Symmetrical MLI, the DC source magnitude are equal ie., 50Vdc, 50Vdc & 50Vdc., where as in Asymmetrical MLI the DC source Magnitude are unequal and it is designed with binary form of voltage such as 50Vdc, 100Vdc & 200Vdc.Comparing both the MLI , Asymmetrical MLI generates a number of output voltage level with same number of Power semiconductor switches. The phase Disposition Pulse Width Modulation (PD-PWM) technique is used for controlling the Power semiconductor switches in MLI. The results are verified in both MATLAB and PROTEUS.

High-Reliability Single-Phase Six-Switch Dual-Output Current Source Inverter with Switching-Cell

 Abstract—

This paper proposes a novel single-phase six-switch dual-output current source inverter. The switching-cell structure is implemented into two of three phase legs of the proposed inverter to improve the reliability due to the absence of open-circuit problems. In addition, the overlap-time between switching transition can be minimized or eliminated to enhance output performance, efficiency, and dc-source utilization. Both the number of semiconductor devices and conduction loss of the proposed inverter are reduced in comparison with the conventional dual-output current source inverters. The proposed topology can be applied in dual-output inverters, universal power filter, and uninterruptible power supply, for instance. A 300 W prototype with 35 V dc input was built and tested to verify the performance of the proposed inverter.

A Novel Method of Reducing Commutation Torque Ripple for Brushless DC Motor Based on Cuk Converter

 Abstract—

Based on Cuk converter, a novel commutation torque ripple reduction strategy is proposed for brushless DC motor (BLDCM) in this paper. Output modes (buck-boost mode and boost mode) of the Cuk converter during commutation period and normal conduction period are altered by designing a mode selection circuit, which can reduce commutation torque ripple over the entire speed range. During the commutation period, Cuk converter operates in the boost mode to step up the input voltage of three-phase bridge inverter and then meet the voltage demand of commutation period, such that the commutation torque ripple can be reduced by keeping the non-commutated current steady. In order to improve the utilization rate of the converter, during the normal conduction period, Cuk converter operates in the buck-boost mode and the input voltage of three-phase bridge inverter is regulated by adopting PAM (Pulse Amplitude Modulation) method without the inverter PWM chopping, which can reduce the voltage spike damage to the motor windings caused by turn-on/off of MOSFET in the inverter and simplify the program of modulation method further. The experimental results verify the correctness of the theory and the effectiveness of the proposed approach.

A Grid-Connected Dual Voltage Source Inverter With Power Quality Improvement Features

 Abstract—

This paper presents a dual voltage source inverter (DVSI) scheme to enhance the power quality and reliability of the microgrid system. The proposed scheme is comprised of two inverters, which enables the microgrid to exchange power generated by the distributed energy resources (DERs) and also to compensate the local unbalanced and nonlinear load. The control algorithms are developed based on instantaneous symmetrical component theory (ISCT) to operate DVSI in grid sharing and grid injecting modes. The proposed scheme has increased reliability, lower bandwidth requirement of the main inverter, lower cost due to reduction in filter size, and better utilization of micro-grid power while using reduced dc-link voltage rating for the main inverter. These features make the DVSI scheme a promising option for microgrid supplying sensitive loads. The topology and control algorithm are validated through extensive simulation and experimental results.