Artificial Jellyfish Search Algorithm-Based Selective Harmonic Elimination in a Cascaded H-Bridge Multilevel Inverter (original) (raw)
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International Journal of Engineering, 2021
In this paper, the whale optimization algorithm is proposed for harmonics elimination in a cascaded multilevel inverter. In selective harmonic elimination pulse width modulation, the selected low-order harmonics are eliminated by solving nonlinear equations, while the fundamental of output waveform is adjusted to a desired value. In this paper, whale optimization algorithm is applied to a 7-level cascaded H-bridge inverter to solve the equations. Also, it was validated by experimental results, since this algorithm has an ability to search in entire solution space, the probability of catching a global best solution is very high. This method has higher accuracy and probability of convergence than the genetic algorithm. The optimization and comparison of whale optimization algorithm and genetic algorithm have been done in MATLAB software. A 1 kW prototype of this converter is built and the results are presented. The effectiveness and the theoretical analysis of this method are verified through both simulation and experimental results.
Energies
Harmonics worsen the quality of electrical signals, hence, there is a need to eliminate them. The test objects under discussion are single-phase versions of cascaded H-bridge (CHB) multilevel inverters (MLIs) whose switching angles are optimized to eliminate specific harmonics. The Dragonfly Algorithm (DA) is used to eradicate low-order harmonics, and its statistical performance is compared to that of many other optimization techniques, including Particle Swarm Optimization (PSO), Accelerated Particle Swarm Optimization (APSO), Differential Evolution (DE), and Grey Wolf Optimization (GWO). Various scenarios of the algorithms’ search agent population for inverters with seven, nine, and eleven levels of output voltages are comprehensively addressed in this research. No algorithm shows total dominance in every scenario. The DA is least impacted by the change in dimensions of the narrated problem.
Sustainability, 2021
This paper presents the Archimedes optimization algorithm to eliminate selective harmonics in a cascaded H-bridge (CHB) multilevel inverter (MLI). The foremost objective of the selective harmonic elimination (SHE) is to eliminate lower order harmonics by finding the optimal switching angle combination which minimizes the objective function containing Total Harmonic Distortion (THD) and other specific harmonic terms. Consequently, the THD is also reduced. In this study, a recently proposed metaheuristic technique named the Archimedes optimization algorithm (AOA) is used to determine the optimal angles corresponding to the 5, 7 and 9 level CHB-MLI. AOA involves equations related to a physical law, the Archimedes Principle. It is based on the idea of a buoyant force acting upward on a body or object that is partially or completely submerged in a fluid, and the upward force is related to the weight of the fluid displaced. This optimization technique has been implemented on CHB-MLI to ge...
International Journal of Emerging Technology and Advanced Engineering
Harmonics can degrade the power quality of a multilevel inverter by causing the voltage to be distorted and vary from sinusoidal waveforms. Harmonics can be reduced by increasing the number of voltage levels or by employing suitable modulation techniques. In this paper, The Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) modulation method is employed to obtain the optimal switching angles that able to reduce the specific individual harmonic and the Total Harmonic Distortion (THD) in singlephase 7-level Cascaded H-Bridge multilevel inverter. The Animal Migration Optimization (AMO) is proposed to acquire these angles using two difference objective functions. The performance is examined and evaluated. Both objective functions able to determine the optimal switching angles starting from modulation index of 0.34. However, the comparative study demonstratethat objective function number 2 has better performance in term of lowering selective individual harmonics as well as THD.
Harmonic Elimination of Cascaded Multilevel Inverter using Metaheuristic Optimization Methods
International Journal of Engineering & Technology
The harmonic elimination of multilevel inverters is a complicated task that includes nonlinear transcendental equations. With the increase in the level of the multilevel inverter, the no of variables of the equation also increases which makes the problem more complicated. Metaheuristic optimization algorithms play an important role in finding out optimum switching angles required for elimination of harmonics in a lesser computational time avoiding multiple local minima. This paper deals with the harmonic elimination of cascaded multilevel inverter using whale optimization algorithm. The whale optimization method has the ability to escape local minima and it takes less time of computation of results. Results are verified theoretically by taking an example of a 15-level cascaded H-bridge inverter fed from equal d.c.sources. The above scheme well minimizes lower order harmonics and gives better output voltage and a low total harmonic distortion.
Selective Harmonic Elimination of an Eleven Level Inverter Using Whale Optimization Technique
International Journal of Power Electronics and Drive System (IJPEDS), 2018
Reduction of total harmonic distortion in multilevel inverters is a difficult optimization problem that includes nonlinear transcendent equations having more than one local minima.The task becomes difficult as the level of the cascaded multilevel inverter increases.Optimization techniques helps in finding out the solution in a very less span of time giving the best possible results. This paper deals with the harmonic elimination of cascaded multilevel inverter with equal D.C. sources using a new optimization technique called Whale optimization technique. The objective of this paper is to find the best combination of switching angles to minimize the lower order harmonics and the total harmonic distortion is reduced. This aforesaid algorithm is applied to an 11-level cascaded H-bridge inverter.Results shows that Whale optimization algorithm gives better results and effectively performs the above mentioned task. 1. INTRODUCTION Multilevel inverters have gained a lot of interest in the past decade for increasing the voltage to different levels which make it suitable for medium and large power applications like statcom, electric drives, renewable energy, etc.The H bridge inverter previously produces an output voltage of V dc , 0,-V dc. This basic H bridge switching technique is extended to other circuits that can generate added output voltage levels. This multilevel output voltage gives a staircase waveform which is similar to sinusoidal waveform thus reducing the harmonic content in the output. There are different type of multilevel inverter topologies like neutral point clamped, flying capacitor and cascaded inverter out of which the cascaded multilevel inverter has gained a lot of popularity due to its improved quality and connection of independent d.c sources (SDCS) to each of the module so as to attain high power level at the output.[1]-[2]The cascaded multilevel inverter(CMLI) is very efficient in minimizing THD and gives better quality of power.It is animportant topology as it is more simplein obtaining the preferred output voltage from several D.C. sources contrast to diode-clamped and flying capacitors type multilevel inverters. The utility of a multilevel inverter (MLI).[3] It has a modular structure with simple switching method and occupies a lesser space. By connectingadequate number of H-bridges in cascade along with a properly choosen switching scheme, a nearly sinusoidal output voltage waveform can be obtained. Each H Bridge operates with a different switching scheme which is used for harmonic control. If the number of H-bridge given by's' then the no level of output voltage obtained per phase in CMLI is 2s+1. Each H Bridge operates at a different delay angle resulting in a staircase waveform of the output phase voltage where the output voltage is the sum of all voltage generated by H Bridge.[4]-[5] The output phase and line voltage obtained and the efficiency of DC to AC conversion depends on the THD. Normally the output voltage waveform of a single phase inverter contains 33.5 percent of third harmonics, 20 percent of fifth harmonics and 14.5 percent of seventh harmonics approximately. As the output voltage in
Granthaalayah Publications and Printers , 2023
Considering present shortage of fossil fuels and discharges of ozone harming substances, power developed from Renewable Energy Sources (RES) is identified as the excellent choice for producing the electricity. The characteristic of an inverter is to transform the dc power into ac power to fulfill out the requirements of load. Despite its advantage, the presence of harmonics in the output voltage reduces both the efficiency and the performance of the inverter. Several researches have been carried out since last three decades for eliminating the harmonics. Based upon several researches, it reveals that the Selective Harmonic Elimination Pulse-width Elimination technique (SHEPWM) has proven to be the best in eliminating lower order harmonics. But when calculus based methods are used for solving the non-linear transcendental equations, this technique has shown some complications. Artificial Intelligence (AI) techniques appear to be better in solving the above said equations. This review paper provides the performance of some AI techniques used for eliminating the harmonics in inverters. Based upon the information collected from various literatures and its results, conclusion has been made.
Optimum Modulation Index Selection in Multilevel Inverter Using Selective Harmonic Elimination
In this project, a multilevel inverter was designed and implemented to operate a stand-alone solar photovoltaic system. The proposed system uses selective harmonics elimination pulse-width modulation (PWM) in the multilevel inverter to convert DC voltage from battery storage to supply AC loads. In the PWM method, the effectiveness of eliminating low-order harmonics in the inverter output voltage is studied and compared to that of the sinusoidal PWM method. This work also uses SHEPWM to predict the optimum modulation index and switching angels required for a nine-level cascaded H-bridge inverter with improved inverter output voltage. The proposed predictive method is more convincing than other techniques in providing all possible solutions with any random initial guess and for any number of levels of a multilevel inverter. The simulation results prove that the lower-order harmonics are eliminated using the optimum modulation index and switching angles. An experimental system was implemented to demonstrate the effectiveness of the proposed system.
A novel optimization harmonic elimination technique for cascaded multilevel inverter
Bulletin of Electrical Engineering and Informatics, 2019
The main goal of utilizing Selective Harmonic Elimination (SHE) techniques in Multilevel Inverters (MLI) is to produce a high-quality output voltage signal with a minimum Total Harmonic Distortion (THD). By calculating N switching angles, SHE technique can eliminate (N-1) low order odd harmonics of the output voltage waveform. To optimized and obtained these switching angles, N of nonlinear equations should be solved using a numerical method. Modulation index (m) and duty cycle play a big role in selective harmonic elimination technique to obtain a minimum harmonic distortion and desired fundamental component voltage. In this paper, a novel Optimization Harmonic Elimination Technique (OHET) based on SHE scheme is proposed to re-mitigate Total Harmonic Distortion. The performance of seven-level H-bridge cascade inverter is evaluated using PSIM and validated experimentally by developing a purposely built microcontroller-based printed circuit board. 1. INTRODUCTION The rapid development of power electronic devices, better be called renewable energy electronics, has effectively contributed to find more utilization of renewable energy applications in wind and solar energy. DC/AC inverter has become more interesting for interfacing between renewable sources and the grid in order to invert the energy from DC to AC form [1-4]. Recently, Multilevel Inverters (MLIs) have become more popular in photovoltaic (PV) applications. These topologies are mainly utilized in high and medium power practical applications because of their capacity to generate a high-quality output signal with decreased switch loss by power switches employed [5, 6]. However, multilevel inverters include a number of cells of power semiconductor devices which suffer from some challenging issues in more complex topologies [7]. By increasing the number of levels the quality of the output wave shape improves with minimizing THD and making the output closer to a sinusoidal signal [8]. The suitable topology for medium and high power application is Cascaded full bridge multilevel inverter. The control circuit of this kind of inverters is simpler than other topologies [9]. Also, it can be easily extended to higher levels to produce high power by adding more units of H-Bridge on the series connection. The main disadvantage of the cascade multilevel inverter is the large number of DC voltage sources wanted to feed all the H-bridge cells, and hence all these DC sources have to be isolated [10]. However, it can reduce the switching losses and eliminate the effect of harmonic spikes from the output waveform with higher efficiency [11]. The THD of the multilevel inverters output voltage must be a minimum value.
Red deer algorithm-based selective harmonic elimination technique for multilevel inverters
Bulletin of Electrical Engineering and Informatics, 2023
This paper proposed a red deer algorithm (RDA)-based selective harmonic elimination (SHE) method for multilevel inverters (MLIs). To eliminate the desired harmonic orders, the optimum switching angles of the MLI have been calculated using the proposed RDA. The calculated switching angles have been applied to the 3-phase cascaded H-bridged 11-level inverter. In addition, the performance of the proposed RDA method was compared with the results of methods such as the Newton-Raphson (NR) method, LSHADE/EpSin technique (LSHADE), whale optimization algorithm (WOA), and particle swarm optimization (PSO) used for the SHE problem in the literature. The results obtained prove that the proposed RDA optimization solves the SHE problems more effectively than other methods. It has also been observed that RDA produces good solutions in different modulation indexes.