Renewable Energy
M. Nurgul; A.A. Ibrahim; A. Al Mansor; A.A. Almulla; M.S. Hamza; A.A. Ali; N.Q. Mohammed; M.A. Hussein
Abstract
A micro-grid consists of loads, power generation, and energy storage. There are residential and commercial micro-grids. Active is the distributed micro-network. The production resources of micro-grids are either based on fossil fuels or renewable energy. Micro-grids can be independent or connected to ...
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A micro-grid consists of loads, power generation, and energy storage. There are residential and commercial micro-grids. Active is the distributed micro-network. The production resources of micro-grids are either based on fossil fuels or renewable energy. Micro-grids can be independent or connected to the grid. This study investigates the viability and optimal design of a micro-grid based on renewable energy sources, taking pollution control into account, for the iron and steel production project of Mass Group Holdings (MGH) in Sulaymaniyah, Bazian, Iraq. After modeling the considered micro-grid in two modes, grid-connected and grid-independent, and entering the required data, such as weather data, Net Pure Cost (NPC) and pollution are used to calculate the consumption load of the superior plans. Multi-objective optimization utilizing the proposed optimization model yields an objective function value of 0.5237, whereas the PSO algorithm yields 0.5279, demonstrating that the proposed grid-connected method is superior. For off-grid mode, however, the objective functions in the proposed model and PSO optimization are 0.7241 and 0.7282, respectively. In the event that a battery is connected to the network, the diesel generator works for 620 hours less, saving fuel and making the diesel generator more economical from an economic standpoint. In this regard, the network-connected mode produced superior results to the mode that was not connected to the network.
Renewable Energy
S.M. Hashemzadeh; M. Hejri
Abstract
This paper presents a model-based approach for the global maximum power point (GMPP) tracking of solar strings under partial shading conditions. In the proposed method, the GMPP voltage is estimated without any need to solve numerically the implicit and nonlinear equations of the photovoltaic (PV) string ...
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This paper presents a model-based approach for the global maximum power point (GMPP) tracking of solar strings under partial shading conditions. In the proposed method, the GMPP voltage is estimated without any need to solve numerically the implicit and nonlinear equations of the photovoltaic (PV) string model. In contrast to the existing methods in which first the locations of all the local peaks on the P-V curve are estimated and next the place of the GMPP is selected among them, the suggested method estimates directly the GMPP without any need for the evaluation of the other local peaks. The obtained GMPP voltage is then given as a reference value to the input voltage controller of a DC-DC boost converter to regulate the output voltage of the solar string at the GMPP voltage in various irradiation conditions. Furthermore, the values of the temperature and irradiation level of each PV module within the PV string are estimated, and therefore, the proposed method does not need to thermometers and pyranometers. This makes it as a reliable and low-cost GMPP tracking method. The theoretical aspects on which the proposed GMPP algorithm is established are also discussed. The comparison of the numerical results of the suggested GMPP tracking scheme with the existing methods at different environmental conditions shows the satisfactory operation of the proposed technique from the speed and accuracy point of views.
Renewable Energy
R. Aghaie; M. Farshad
Abstract
The performance of photovoltaic (PV) systems is highly dependent on environmental conditions. Due to probable changes in environmental conditions, the real-time control of PV systems is essential for exploiting their maximum possible power. This paper proposes a new method to track the maximum power ...
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The performance of photovoltaic (PV) systems is highly dependent on environmental conditions. Due to probable changes in environmental conditions, the real-time control of PV systems is essential for exploiting their maximum possible power. This paper proposes a new method to track the maximum power point of PV systems using the moth-flame optimization algorithm. In this method, the PV DC-DC converter’s duty cycle is considered as the optimization parameter, and the delivered power of the PV system is maximized in real time. In the proposed approach, some schemes are also employed for detecting condition changes and ignoring small fluctuations of the duty cycle. The results of performance evaluation confirm that the proposed method is very fast, robust, and accurate in different conditions such as standard irradiance and temperature, irradiance and temperature variations, and partial shading conditions. The obtained steady-state efficiency and response time for the introduced method under the standard conditions of the test PV system are 99.68% and 0.021 s, respectively. Indeed, in addition to a relatively good efficiency, the faster response of the introduced tracker is also evident in comparison with other methods.
