Modified Cascaded H-Bridge Multilevel Inverter Using Particle Swarm Optimization

For more than two decades,multilevel inverters in different topologies and control strategies have been involved in many applications.In contrast to conventional three-level inverters,they are more efficient and better suited for applications requiring high power and high voltage levels.The current multilevel inverter topologies available in the market include diode clamped or neutral point clamped (NPC),capacitor clamped or flying capacitor (FC), and cascaded H-bridge (CHB).It is essential to produce an effective power converter from the perspective of cost,efficiency and output quality.These factors have lead to develop a new family of multilevel inverters known as modified CHB-MLIs of a single and three phases for five,nine and thirteen levels.This topology of the modified inverters requires fewer components compared to existing inverters (particularly in the higher levels) and requires fewer carrier signals and gate drives. Therefore,the overall cost and complexity are greatly reduced,particularly for higher output voltage levels.An important issue in the power electronic converters is the modulation control method in order to produce high quality output with a minimum distortion.As there exist many strategies for modulation, still the low-switching frequency technique is widely accepted in higher power applications.There are different optimization aims for different applications utilizing the low-switching frequency technique it is possible to increase the number of output voltage levels and produce a better sinusoidal output waveform and efficiency.The modified CHB-MLIs for five, nine and thirteen levels have a reduced number of DC power supplies and switches when compared to the conventional CHB topologies designed for the same number of voltage levels.The aim of this thesis is to investigate the performance of modified CHB-MLIs of a single and three phases for five,nine and thirteen levels based on cascaded multilevel inverter using low-switching frequency modulation scheme.The modulation method for obtaining the optimum switching angles based on Newton Raphson (NR) and Particle Swarm Optimization (PSO)control techniques have been proposed.A NR and PSO control techniques were presented for selective harmonics elimination (SHE) solution in a modified CHB-MLIs.These control techniques have been implemented through closed-loop control system using DSP TMS320F2812.In this thesis, the complete switching angles of the SHE has been developed by using a heuristic optimization technique namely PSO by solving the non-linear equation of the output voltage waveform and later validated with the conventional method NR.To validity of a low power prototype of the modified CHB-MLIs have been designed and implemented;analytical,simulation,and experimental results have been provided.The relative merits of the proposed modulation scheme based on the NR and PSO have been assessed based on modified inverters output quality and efficiency.Investigations of the proposed modulation scheme based on PSO have been revealed that the switching pattern of the adopted inverters has the capability of producing output voltage with minimal THD and high efficiency of the modified inverters.The results acquired from the simulation results the superiority of PSO over the conventional methods NR,where the THD reduction values in the three developed CHB-MLI namely five-level, nine level,and thirteen level are 15%,7.8%,and 5.2%, respectively

Particle Swarm Optimization (PMO) Algorithm With Reduced Number Of Switches In Multilevel Inverter (MLI)

In this work, a three-phase of multilevel inverter (MLI) with reduced number of switches components based on Newton Raphson (NR) and Particle Swarm Optimization (PSO) techniques were presented. The Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) is a powerful technique for harmonic minimization in multilevel inverter within allowable limits. NR and PSO techniques were used to determine the switching angles by solving the non-linear equation's analysis of the output voltage waveform of the modified CHB-MLI in order to control the fundamental component. A comparison has been made between NR and PSO techniques related to optimization in order minimize harmonic distortion. The main aims of this paper cover design, modeling, construction the modified topology of the CHB-MLI for a three phase five levels inverter. The controllers based on NR and PSO were applied to the modified multilevel inverter. The inverter offers much less THD using PSO scheme compared with the NR scheme. The performance of the proposed controllers based on NR and PSO techniques done by using MATLAB/Simulink of results are compared

Design And Development Of Active Power Filter For Harmonic Minimization Using Synchronous Reference Frame (SRF)

The research for the aimed towards avoiding the waveform of the current from distorted is make the researchers interested to do that.. The controllers used in an active power filter play an important role in determining the current waveform in electrical system will smooth with a minimum of the total harmonic distortion (THD). The main purpose of this paper is to propose the controller of an active power filter based on synchronous reference frame (SRF). A model of the proposed controller has been developed using MATLAB/SIMULINK. The results of the simulation shows that the effectiveness of the proposed controller toward in reducing THD at the acceptable

Aggregated Modelling Analysis Of Power Flow From Wind Power Plant Into Grid System Using MATLAB/ SIMULINK Software

In consistent with the growth in demand, complexity of electric power systems has evolved to meet the requirements of supply. Power is generated from non-renewable, fossil fuels and nuclear fuel while renewable energy resources mainly include solar and wind. Power from Wind plants WP has shown a fast growth in the last decades due to their economic benefits especially at areas with the proper wind speed and the possibility to connect wind generators in distribution or transmission power networks. Conventional power unit generators are of high generation capacities, therefore smaller numbers are required in power plant, in other hand wind turbines WP are of smaller capacities therefore, Wind Power Plants (WPPs) consist of dozens or hundreds of low-power units. Time domain simulations of WPPs may take too much time if detailed models are considered in such studies while reduced order models used in interconnection studies of synchronous machines with full converter technology significantly reduce computational time (1, 2). The performance of all models is evaluated based on time domain simulations in the Simulink/MATLAB environment. The work includes the simulation of 50 MW WPP constructed from 18 MW doubly fed induction generators (DFIGs) aggregated (reduced) to one system of Nx2.78 MW generation capacity interconnected to existing conventional system network through 132 kV grid. The analysis includes active and power flow at the farm and the PCC terminals also power flow at PCC has been assessed for different level of WP penetration. Outputs from the MATLAB/SIMULINK modeling and simulation introduces the level of the grid voltage, current active and reactive power in the PCC and the wind farm terminal

Control Of A Super-Capacitor As Energy Storage With Thirteen-Level Inverter

Control of a super-capacitors as energy storage with thirteen-level inverter is presented in this paper. A NR and PSO techniques are presented for selective harmonics elimination (SHE) solution in a modified Cascaded H Bridge Multilevel inverter (CHB-MLI). The Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) is a powerful technique for harmonic minimization in multilevel inverter. The proposed design is used to charge the energy storage such as battery, super capacitor.NR and PSO techniques are used to determine the switching angles by solving the non-linear equation's analysis of the output voltage waveform of the modified CHB-MLI in order to control the fundamental component. The proposed techniques, based on NR and PSO techniques, are capable to minimize the Total HarmonicM Distortion (THD) of output voltage of the modified CHB-MLI within allowable limits. A comparison has been made between NR and PSO techniques related to optimization in order minimize harmonic distortion based on super capacitor as super capacitor. The main aims of this paper cover design, modeling, construction and testing of a laboratory the modified topology of the CHB-MLI for a single-phase prototype for 13-levels. The experimental results of the prototype are also illustrated. The controllers based on NR and PSO are applied to the modified multilevel inverter based on super capacitor as super capacitor. The Digital Signal Processing (DSP) TMS320F2812 is used to implement these modified inverters control schemes using NR and PSO method. The proposed controller is then coded into a DSP TMS320F2812 board. The inverter offers much less THD using PSO scheme when compared with the NR schem

An Improvement Of Shunt Active Power Filter Using Effective Controller For Different Load Condition

The distorted waveforms due to highly uses of the non-linear load, especially, the current that is considered the main issues need to be addressed seriously. The issues of the distorted waveforms for the current have attracted many researchers to recover them in the electrical system. There are so, many electronic devices that have been used in order to protect the waveform of the current from distorted as it is very dangerous and may cause the main supply to shut down or burnt. The main aims of this project is to design and develop a shunt active power filter for the purposes to mitigate the distorted of current waveform produced by the different types of non-linear loads using the controller of the SRF. The software MATLAB/Simulink will be used to design and develop shunt active power filter and its controller. Finally, the performance of the shunt active power filter and its controller at different types of non-linear loads will be evaluated through the waveforms of the currents produced by different types of non-linear loads and the Total Harmonic Distortion (THD) will be monitored and observed whether meets to the International Electrical Committee (IEC) standard or not

Comparative Studies Of Fuzzy Logic Base Power System Stabilizers In Enhancing Dynamic Stability Of A Generator Connected To Infinite Bus

Power system stabilizers (PSS) are added to excitation system to enhance the damping during low frequency oscillations. This paper presents a study of fuzzy logic power system stabilizer for stability enhancement of a single machine connected to infinite bus (SMIB) power system. Recently fuzzy logic as a novel robust control design method has shown promising results. The emphasis in fuzzy control design center is around uncertainties in the system parameters and operating conditions. Fuzzy logic controller (FLC) has been suggested as a possible solution to overcome this problem, thereby using linguist information and avoiding a complex system mathematical model, while giving good performance under different operating conditions. The proposed approach is found to have stable convergence characteristics and resulted in good voltage regulation and damping characteristics. The stabilizing signals were computed using the fuzzy membership functions with variations of angular speed and acceleration as the inputs. The simulations were tested under different operating conditions, with different membership functions using MATLAB /SIMULINK. The simulation results are quite encouraging and satisfactory

A New Algorithm With Different Modulation Index (Mi) In Cascaded H-Bridge Multilevel Inverters (CHB MLIS)

The output waveforms of the multilevel inverters must be maintained smooth and not highly contents of the harmonics.Due to that the research of the multilevel inverters is still relevant to explore. For maintaining sinusoidal of the output waveforms of the multilevel inverters the design of an appropriate controller is crucial, hence the best controllers must be chosen. The suitable and its performance of the controllers will determine whether the output waveforms of the multilevel inverters can reduce the harmonics contains or not. This research aimed to investigate the performance of the Firefly Algorithm (FFA) which is applied to the modified cascaded H-Bridge multilevel inverters (MCHBMLIs) for five levels for harmonics reduction of the MCHBMLIs output waveforms especially for the currents and the voltages with different modulation index (MI). FFA is considered as an easy way which is aims to compute of the switching angle to be optimized for harmonics reduction in the proposed inverters.The concept is based on the Selective Harmonics Elimination (SHE) and the FFA is capable to reduce the lower order harmonics in the output voltages and currents of the waveforms. In order to validate the effectiveness of the proposed algorithm a simulation model has been built up. The parametric model of the simulation to be a benchmark to build up a prototype. Finally the experimental results are a good agreement with the simulation result

Stability Studies Of Fuzzy Logic Based Power System Stabilizer In Enhancing Dynamic Stability Of A Two Generators Tie-Line System

Electro-mechanical oscillations are created, in the machines of an interrelated power network, followed by a trouble or due to high power transfer through weak tie lines. These oscillations should be damped as quickly as possible to guarantee the reliable and stable operation of the network. This research presents the analysis of change of speed, change of angle position and tie - line power flow, fuzzy logic controller (FLC) two area symmetrical systems connected via tieline are measured to show via performance of these controllers using Simulink/MATLAB. Simulation results described by fuzzy logic based controller having dual inputs of rotor speed deviation and generator’s accelerating power there shown better solutions for damping the inter area (tie-line) oscillations

Design And Development Of Dc-Dc Boost Converter Based On Dsp Tms320f2812 For Pv Application

Objective: In this paper, we reported experiment control voltage signal of Pulse Width Modulation (PWM) design circuit of closed loop implemented of dc-dc boost converter for application Photovoltaic (PV) simulator. Methods/Statistical Analysis: In this design, the converter provides step-up voltage from the PV generating systems as an interface between the load and PV panel and let the follow-up of the Findings: The operation was performed obased on a specifically associated converter to the PV panel which is controlled via the observed P&O and Maximum Power Point Tracking (MPPT) perturb. The regulation is achieved by PWM at a fixed frequency and the switching device is generally Insulated Gate Bipolar Transistor IGBT. Application/Improvements: The feedback path is established with a control circuit such that a proper duty cycle is achieved for the desired output voltage (Vo) for the application photovoltaic generating systems. The proposed scheme is modelled to utilise MATLAB/SIMULINK and verified through simulation result, and prototype experiment for the purpose of utilising the Digital signal processing (DSP) TMS320F2812 control PWM