Rup Narayan Ray

An application of PSO technique for harmonic elimination in a PWM inverter

Harmonic elimination problem in PWM inverter is treated as an optimization problem and solved using particle swarm optimization (PSO) technique. The derived equation for computation of total harmonic distortion (THD) of the output voltage of PWM inverter is used as the objective function in the PSO algorithm. The objective function is minimized to contribute the minimum THD in the voltage waveform and the corresponding switching angles are computed. The method is applied to investigate the switching patterns of both unipolar and bipolar case. While minimizing the objective function, the individual selected harmonics like 5th, 7th, 11th and 13th can be controlled within the allowable limits by incorporating the constraints in the PSO algorithm. The results of the unipolar case using five switching angles are compared with that of a recently reported work and it is observed that the proposed method is effective in reducing the voltage THD in a wide range of modulation index. The simulated results are also validated through suitable experiments.

A PSO based optimal switching technique for voltage harmonic reduction of multilevel inverter

Selected lower order harmonics of multilevel inverter are eliminated while the overall voltage THD is optimized by computing the switching angles using particle swarm optimization (PSO) technique. The discontinuity in the solution of selected harmonic elimination (SHE) problem at certain modulation indices is avoided by optimizing the individual harmonics to allowable limits. While choosing the set of solution leading to minimum THD, the abrupt changes in the switching angles are discarded by limiting the voltage THD within allowable limits. Also the selected higher order harmonics are eliminated by additional switching along with the lower order harmonics. In order to reduce the computational burden for online application, the switching angles computed by the proposed PSO technique for optimum THD at varying modulation indices are stored as a look-up table in the DSP memory. The simulated results are also validated through suitable experiments.

Harmonic elimination in multilevel inverter using GA and PSO: A comparison

The Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) is an effective method for harmonic elimination in multilevel inverter. This paper presents the solutions of Selective Harmonic Elimination (SHE) problem based on Genetic algorithm (GA) and Particle Swarm Optimization (PSO) techniques. Total Harmonic Distortion (THD) of output voltage is minimized maintaining selected harmonics within allowable limits. A comparison has been drawn between GA and PSO techniques related to optimization.

Performance improvement of microbial fuel cell (MFC) using suitable electrode and Bioengineered organisms: A review

ABSTRACT There is an urgent need to find an environment friendly and sustainable technology for alternative energy due to rapid depletion of fossil fuel and industrialization. Microbial Fuel Cells (MFCs) have operational and functional advantages over the current technologies for energy generation from organic matter as it directly converts electricity from substrate at ambient temperature. However, MFCs are still unsuitable for high energy demands due to practical limitations. The overall performance of an MFC depends on microorganism, appropriate electrode materials, suitable MFC designs, and optimizing process parameters which would accelerate commercialization of this technology in near future. In this review, we put forth the recent developments on microorganism and electrode material that are critical for the generation of bioelectricity generation. This would give a comprehensive insight into the characteristics, options, modifications, and evaluations of these parameters and their effects on process development of MFCs.

3D modeling of high temperature superconducting hysteresis motor using COMSOL multiphysics

This paper presents 3D modeling of hysteresis motor with high temperature superconducting material in the rotor using Finite Element based solver software COMSOL Multiphysics. Due to the anisotropic property of HTS material, magnetic flux distributions are non-uniform in different axes. Therefore, analysis of HTS hysteresis motor using two dimensional modeling cannot provide high degree of accuracy. Thus, three dimensional modeling is developed for more accurate, precise and realistic results. The magnetic fields around and inside the motor can be computed accurately with the help of proposed three dimensional modeling of motor. To improve the performance in comparison of conventional hysteresis motors such type of motors are developed. The measured parameters are compared with the experimental results. Simulations are done with the help of MATLAB and COMSOL Multiphysics software.

Studies on hunting of hysteresis motor with HTS element on rotor

Hunting is an important phenomenon where the speed of synchronous motor fluctuates slightly above and below the normal synchronous speed. This paper presents an investigation of hunting of hysteresis motor with high temperature superconducting element. Both loaded and unloaded conditions are considered for analysis. All the simulations are performed using Matlab/Simulink and COMSOL Multiphysics.