This paper presents a new boost inverter topology with nine level output voltage waveform using a single dc source and two switched capacitors. The capacitor voltages are self-balancing and thus is devoid of any sensors and auxiliary circuitry. The output voltage is twice higher than the input voltage, which eliminates the need for an input dc boost converter especially when the inverter is powered from a renewable source. The merits of the proposed topology in terms of the number of devices and cost are highlighted by comparing the recent and conventional inverter topologies. In addition to this, the total voltage stress of the proposed topology is lower and have a maximum efficiency of 98.25%. The operation and dynamic performance of the proposed topology have been simulated using PLECS software and are validated using an experimental setup considering a different dynamic operation.
Energy demand has been overgrowing in developing countries. Moreover, the fluctuation of fuel prices is a primary concern faced by many countries that highly rely on conventional power generation to meet the load demand. Hence, the need to use alternative resources, such as renewable energy, is crucial in order to mitigate fossil fuel dependency, while ensuring reductions in carbon dioxide emissions. Algeria—being the largest county in Africa—has experienced a rapid growth in energy demand over the past decade due to the significant increase in residential, commercial, and industry sectors. Currently, the hydrocarbon-rich nation is highly dependent on fossil fuels for electricity generation, with renewable energy only having a small contribution to the country’s energy mix. However, the country has massive potential for renewable energy generation, such as solar, wind, biomass, geothermal, and hydropower. Therefore, the government aims to diversify away from fossil fuels and promote renewable energy generation through policies and renewable energy-related programs. The country’s Renewable Energy and Energy Efficiency Development Plan focuses on large scale solar, wind generation as well as geothermal and biomass technologies. This paper provides an update on the current energy position and renewable energy status in Algeria. Moreover, this paper discusses renewable energy (RE) policies and programs that aim to increase the country’s renewable energy generation and its implementation status.
17 November 2021 in IEEE Journal of Emerging and Selected Topics in Power Electronics
A multilevel inverter (MLI) with a step-up feature has become significant for connecting a low-voltage PV system with a utility grid. An MLI has been presented in this article with a lower component count. The described structure has achieved nine distinguish voltage levels using 12 switches and a switched capacitor unit having twice voltage boost. A self-balancing of the floating capacitor voltage without any auxiliary circuits and precharging has been obtained. The new topology includes fewer switches, reduced voltage stress, and an inherent reversing polarity without the back-end H-bridge, which has been the additional feature of the proposed circuitry. The topology proposed has been controlled with the nearest level control pulsewidth control technique (NLC-PWM). A comprehensive comparative analysis with several similar topologies has been presented in this article to show the merits of the recommended topology. A number of simulation results using PLECS software have been discussed along with experimental results that have been obtained from a laboratory prototype. The validation of the proposed topology has been carried out using different steady-steady and transient operating conditions.
2 August 2019 in IEEE Journal of Emerging and Selected Topics in Power Electronics
This paper proposes a general mathematical solution for a selected harmonic elimination (SHE) technique. The proposed procedure is valid for both symmetrical and unsymmetrical MLI inverter configurations with a wide range of modulation indexes (mi). The proposed procedure eliminates targeted number of harmonics ’l ’ for switching angles NS= 2l regardless to the MLI output waveform levels. The proposed procedure receives the DC sources values and ratios, and then it calculates the NS values to generate a suitable set of harmonic equations. In this proposed algorithm, the nonlinear transcendental harmonic equations were transformed into a linear system of equations (A X=B); the resulting equations can be solved online easily by formulating matrix A and matrix B, then multiplying the inversion of matrix A in matrix B. It has been found that, only the last element in matrix B needs to be updated for each change in modulation index or in the ac output fundamental component, resulting in reduced computation time. The proposed technique generates the switching angles α1,α2,...,αk based on a preset objective functions. The simulation and experimental results in some selected cases are provided to validate the proposed algorithms.
Recently, photovoltaic (PV) energy has been considered one of the most exciting new technologies in the energy sector. PV power plants receive considerable attention because of their wide applications. Consequently, it is important to study the parameters of the solar cell model to control and determine the characteristics of the PV systems. In this study, an improved bonobo optimizer (IBO) was proposed to improve the performance of the conventional bonobo optimizer (BO). Both the IBO and the BO were utilized to obtain the accurate values of the unknown parameters of different mathematical models of solar cells. The proposed IBO improved the performance of the conventional BO by enhancing the exploitation (local search) and exploration (global search) phases to find the best optimal solution, where the search space was reduced using Levy flights and the sine–cosine function. Levy flights enhance the explorative phase, whereas the sine–cosine function improves the exploitation phase. Both the proposed IBO and the conventional BO were applied on single, double, and triple diode models of solar cells. To check the effectiveness of the proposed algorithm, statistical analysis based on the results of 20 runs of the optimization program was performed. The results obtained by the proposed IBO were compared with other algorithms, and all results of the proposed algorithm showed their durability and exceeded other algorithms.
Optimal reactive power dispatch (ORPD) in a typical power system is a complicated multi-objective optimization problem. The proper modeling of the multi-objective optimization problem has a significant impact on system operation and control. In this paper, an Improved Heap-based optimizer (IHBO) is proposed to improve the performance of a recently published technique called Heap-based optimizer (HBO). In addition, two algorithms based on the original HBO and IHBO are developed for solving OPRD problem. Pareto front approach is utilized in the proposed OPRD algorithm with the aim of solving two or three objective functions simultaneously. The performance of HBO is improved by utilizing the chaotic sequences with the aim of improving its global search capability and avoiding getting stuck in a local optimum. Both original HBO and proposed IHBO are applied to determine the optimal settings of the generator's voltages, shunt capacitor reactive power, and tap settings of transformers. Therefore, this study aims for minimizing three most objective functions of the real power loss, total voltage deviation (TVD) and voltage stability index (VSI), with satisfying different operational constraints. The effectiveness of the IHBO is tested on three test systems IEEE 30-bus, IEEE 57-bus, and IEEE 118-bus test systems. The results of the proposed IHBO are compared with recently published algorithms in the literature. The simulation results proven the superiority and robustness of IHBO in solving the ORPD problem.