Mohammad Ahmad

Simulation and study of a grid connected multilevel converter (MLC) with varying DC input

Multilevel line commutated inverters for renewable energy systems have gained popularity in recent times, especially in the distributed generation where a number of batteries, fuel cells, solar cell, and micro-turbines can be connected through a MLC to feed the grid. They can synthesize higher output voltage levels and can generate near sinusoidal voltages. This paper presents analysis of a grid connected MLC as an inverter having variable dc sources(which can be the output of wind farms, solar panels etc.). A Computer simulation analysis using SIMULINK/ MATLAB has been done to minimize total harmonic distortion (THD) by increasing the stages and by varying the delay angles for varying dc input to the multilevel inverter. A comparative study of different stages of MLC for different value of dc input has also been studied. The results has been tabulated and discussed.

New approaches for Harmonics reduction in solar inverters

This paper analyzes and compares two approaches for dc to ac power conversion. First approach uses cascaded H-Bridge Inverter and second uses new Multi-level Scheme having Level Modules and H-Bridge. The simulation is done in SIMULINK/ MATLAB Software. The Total Harmonic Distortion in output load voltage, active Power and reactive Power produced by both the approaches are compared. It is shown that THD produced in second scheme is better up to a certain stages of the first scheme. And the available active and reactive powers are larger for the second scheme.

Transport through the peritoneal membrane. I. Evaluation of thermodynamic parameters

Abstract The membrane potential has been measured across a peritoneal membrane separating solutions of sodium chloride, sodium fluoride, potassium chloride, potassium fluoride, potassium nitrate and ammonium chloride. These data have been used to calculate the transference numbers of ions, charge density and permselectivity of the membrane-electrolyte system. The charge density is low. The membrane potential has been found to be negative. It decreases with an increase in the electrolyte concentration across the peritoneal membrane. The peritoneal membrane has consequently been inferred to be anion selective and positively charged.