Harmonic Optimization Of Multilevel Converters Using Big Bang Big Crunch Optimization Method

Fig. 11 shows a comparison of DPWM2O, DPWMLPF2 and GDPWMO at 0.4 modulation index. The inverter is operating with 160 Hz fundamental frequency and 7.68 kHz switching frequency. The output power factor angle is 45°. It can be seen that each strategy produces 32 pulses in one cycle. However, the clamping interval of the GDPWMO strategy is perfectly aligned with the line current peaks, whereas the DPWM2O and DPWMLPF2 strategies incurs switching instances around the current peaks.

The innovative inverter technology produces safe, smooth power, protecting your sensitive electronics (computers, smartphones, etc.) from damage.

Firstly the hybrid HVDC transmission system configuration is given. Next MMC description is given and then the control strategies for the rectifier and inverter is presented. Finally the performance of system under steady state and transient conditions is discussed with the help of MATLAB results.

Haldane, T.G.N. and P.L. Blackstone, Problems of hydro-electric design in mixed thermal¿hydro-electric systems. Proceedings of the IEE - Part A: Power Engineering, 1955. 102(3): p. 311-322.

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Now a days, the switching power supply market is flourishing quickly. The trend is for DC-AC converters with low cost, higher efficiency, power saving that enable maximum features. In this project, a single-stage three-switch buck-boost inverter is designed, where stepping up, stepping down and inversion operation will takes place in single stage. This proposed inverter will overcome all the drawbacks of traditional one. Coupled inductor plays a very important role in energy transfer and eliminates the use of line frequency transformer. As the inverter having only three switches, the controlling of switches also easier than conventional one. And it has also advantages like compact design, reduced switching losses, component size, and cost.

Multilevel inverters have ability to generate low switching frequency high quality output waveforms with several high voltages and higher power applications and the general structure of multilevel converter is synthesizes a sinusoidal voltage from several level of voltages. The multilevel inverter has overcome the limitations of conventional two level voltage converters. The advantages of multilevel inverter are higher power quality, lower switching losses, low electromagnetic interference and higher voltage capability.

Hence, the proposed variable switching frequency PWM reduces the switching instances within a fundamental cycle by lowering the effective switching frequency, while maintaining the output current ripple within a pre-defined range.

This thesis deals with the design and analysis of control system structures for electric drives equipped with permanent magnet synchronous machines (PMSM) in automotive application.With the increasing popularity of multi-level inverters, the room for improvement of the performance of voltage source inverters has continuously been tested for various applications. The rapid development of high switching frequency power electronics in the past decade leads towards wider application of voltage source inverters in AC power generation. Therefore, this prompts the need for a modulation technique with less total harmonic distortion, fewer switching losses, and wider linear modulation range.The present thesis highlights the comparison of the conventional two-level inverter and the three-level diode clamped inverters for the application in automotive industry.

In previous chapters, the advantages and disadvantages of several modulation methods for multilevel converter have been summarized. In this chapter Fourier series and harmonic elimination theory is discussed briefly to derive the transcendental equations for the fundamental frequency switching method for multilevel inverter. In the second part of this chapter a new evolutionary technique Big Bang-Big Crunch optimization is used for solving the transcendental equations for the fundamental frequency switching method for multilevel inverters.

Keywords: — Mathematical model of photovoltaic cell; photovoltaic module; array; boost converter; mppt algorithm; pwm; single phase inverter; three phase inverter; MATLAB/simulink; gate pulse using 555 timer; voltage doubler circuit in hardware.

The objective of the study is to develop a realizable inverter design that would be reliable, cost effective, efficient, and maintainable. The inverter is to be powered from a 12Vdc/40Ah battery source and it is to generate a 220VAC/50Hz with a power rating 500VA. Other objectives of the study include:

L. Hsiu et al. [34] at low output ripple and noise in voltage and current and for this design a model of coupled inductor and transformers on a common core is use that provide Zero-voltage– switched Dual–SEPIC converter with coupled inductor. H. F. Bilgin et al. [35] gave a design criteria, operating feature and characteristic of the buck type PWM rectifier employed in a unity PF dc motor drive. As per this paper single–stage UPF buck –type PWM uses For-low harmonic distortion in Ac supply current and nearly UPF over a wide operating shaft speed Range. And these output voltage and current in limit avoid any type of failure risk in current connection even for oldest motor design, aging in insulation, mechanical failure due to circulation

Abstract— Multilevel inverter used in variable speed drive system is attracting more attention, due to various advantages that they offer when compared to standard 3-phase two level drives. For proper functioning of such systems pulse width modulation (PWM) strategy is of crucial importance. Control complexity of multilevel inverters increases rapidly with an increase in number of phases and the number of levels. The inherent low switching frequency in medium voltage industrial drive presents various challenges. Multilevel inverter topologies are increasingly being used in medium and high power applications due to their many advantages such as low power dissipation on power switches, low harmonic contents and low electromagnetic interference

This project has been carried out at the department of the electrical engineering at S.V.I.T. Vasad. It has been great opportunity to work with this project and get knowledge about this area of the power electronics.