Modeling and Simulation of Five-Phase Induction Motor Fed With Pulse Width Modulated Five-Phase Multilevel Voltage Source Inverter Topologies

This paper presents modelling and simulation of five-phase induction motor fed with pulse width modulated five-phase multilevel voltage source inverter. The conventional and diode clamped multilevel five-phase inverter configurations are reviewed with pulse width modulation (PWM) techniques. A hybrid three-level inverter topology with less number of components count is proposed for five-phase induction motor drive. The dynamic analysis of five-phase voltage equations in d-q axis of the induction motor are stated and modelled usingMatlab/Simulink/Simscape blocks. The simulation results based on conventional and threelevel five-phase inverters are displayed while the hybrid inverter topology showed some better performance based on the following: : at 0.0127secs maximum torque of 34.54Nm occurred, maximum stator current occurred for 0.18secs with a value of 10A, 9.99% total harmonic distortion was obtained and 15KW power rating was obtained

Modelling of down-draft gasification of biomass - An integrated pyrolysis, combustion and reduction process

A gasification model is developed and implemented in Matlab to simulate a downdraft gasifier using wood as feedstock. The downdraft gasifier was conceptually divided into three zones: the pyrolysis zone, the combustion/oxidation zone and the reduction zone. A typical tar composition and its mole fraction, as reported in the literature was supplied as an input parameter in the model. The concentration of syngas and profiles of temperature along the reduction zone length were obtained by solving the mass and energy balances across each control volume and taking into account the rate of formation/consumption of the species according to different gasification kinetics. The simulation results from the model agreed closely with the experimental results. The syngas concentration was found to be about 1.1%, 17.3%, 22.8%, 9.0% and 49.8% for CH4, H2, CO, CO2, and N2 respectively and the corresponding LHV, CGE, CCE and yield were 4.7 MJ/N m3, 59.9%, 85.5% and 2.5 N m3/kg-biomass respectively at ER of 3.1 and fuel moisture content of 18.5 wt% Sensitivity analysis was carried out with this validated model for different air-fuel ratios, moisture contents and inlet air temperature. The analysis can be applied to produce specific design data for a downdraft biomass reactor given the fuel composition and operating conditions

Twin Synchronous Motor Grinding Mill Drives: Performance Comparison of Two Options

The major challenge of twin synchronous motor drives, as seen in the large grinding mills of the mineral and cement industries are motor overheating and gear wearing, due to certain inevitable manufacturing errors/tolerances on the gear which prevents the two motors from sharing the mill load equally. This paper models a typical gear-driven grinding mill load which accommodates the manufacturing error located on the girth gear circumference, and applies it to two twin synchronous motor drive configurations, namely two three-phase series-connected six-winding synchronous motors (Drive A) and two conventional three-phase synchronous motors (Drive B). The motor equations were mentioned, and the drives simulated in the MATLAB/SIMULINK environment. Results obtained for the two configurations were compared. It was observed that while the risk of motor overheating was removed in Drive A, it was obvious in Drive B. However there is a risk of motor shaft breakage due to the mechanical coupling of the motor