Limitation of fossil energy reserves in the world and increasing level of energy consumption, have always challenged human to replace new energy sources. Meanwhile, wind power as one of the new aspects of energy is of...Limitation of fossil energy reserves in the world and increasing level of energy consumption, have always challenged human to replace new energy sources. Meanwhile, wind power as one of the new aspects of energy is of a special place. Due to the topography of the Sistan and Baluchistan province and its relative position, it is one of the best places to build wind farms. The aim of this study was to determine suitable locations for the construction of wind farms in the province. The following criteria were considered for various standards and due to the importance of data integration, Analytic Hierarchy Process (AHP) method was selected and implemented to weight the layer through Expert choice software. ArcGIS was used for layers spatial analysis and overlapping. After data analysis, the studied region, in terms of the susceptibility to build wind farms, was divided into four levels: excellent, good, fair, weak. Results indicated that GIS as a supportive and decision making system is helpful preparing data and modeling priorities and experts comments regarding various factors and help designers selecting a suitable place to build wind farms. In this study, we determined three priorities for the construction of wind farms, taking into account the limited overlap and conformity of limitations map and locating, the area of prioritized region, climate and the field observations;the priority order is excellent, good, average, including Zabol, central regions in Zabol and Chabahar.展开更多
The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, lo...The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.展开更多
This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control lo...This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control loops where the coefficients of PI controller are regulated by the adaptive sliding law.This method is used to regulate the output voltage of the inverter under different load conditions and uncertainty,and adapts the output to the reference model to reduce the total harmonic distortion(THD).In this paper,the stability of the proposed controller is proven by using Lyapunov's theory and Barbalet’s lemma.The proposed controller performs well in voltage regulation such as low THD under sudden load change and uncertainty.Also,the results of the proposed controller are compared with PI controller to show the effectiveness of the presented control system.展开更多
In recent years, urban rail systems have developed drastically. In these systems, when induction electrical machine suddenly brakes, a great package of energy is produced. This package of energy can be stored in energ...In recent years, urban rail systems have developed drastically. In these systems, when induction electrical machine suddenly brakes, a great package of energy is produced. This package of energy can be stored in energy storage devices such as battery, ultra-capacitor and flywheel. In this paper, an electrical topology is proposed to absorb regenerative braking energy and to store it in ultracapacitor and battery.Ultra-capacitor can deliver the stored energy to DC grid and charge the battery for auxiliary applications such as lighting and cooling systems The proposed system is modeled based on large signal averaged modeling, which leads to the simplicity of calculations. The control system is based on Lyapunov stability theorem which guarantees system stability. Also, an energy management algorithm is proposed to control energy under braking and steady-state conditions. Finally,the simulation results validate the effectiveness of the proposed control and energy management system.展开更多
文摘Limitation of fossil energy reserves in the world and increasing level of energy consumption, have always challenged human to replace new energy sources. Meanwhile, wind power as one of the new aspects of energy is of a special place. Due to the topography of the Sistan and Baluchistan province and its relative position, it is one of the best places to build wind farms. The aim of this study was to determine suitable locations for the construction of wind farms in the province. The following criteria were considered for various standards and due to the importance of data integration, Analytic Hierarchy Process (AHP) method was selected and implemented to weight the layer through Expert choice software. ArcGIS was used for layers spatial analysis and overlapping. After data analysis, the studied region, in terms of the susceptibility to build wind farms, was divided into four levels: excellent, good, fair, weak. Results indicated that GIS as a supportive and decision making system is helpful preparing data and modeling priorities and experts comments regarding various factors and help designers selecting a suitable place to build wind farms. In this study, we determined three priorities for the construction of wind farms, taking into account the limited overlap and conformity of limitations map and locating, the area of prioritized region, climate and the field observations;the priority order is excellent, good, average, including Zabol, central regions in Zabol and Chabahar.
文摘The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.
文摘This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control loops where the coefficients of PI controller are regulated by the adaptive sliding law.This method is used to regulate the output voltage of the inverter under different load conditions and uncertainty,and adapts the output to the reference model to reduce the total harmonic distortion(THD).In this paper,the stability of the proposed controller is proven by using Lyapunov's theory and Barbalet’s lemma.The proposed controller performs well in voltage regulation such as low THD under sudden load change and uncertainty.Also,the results of the proposed controller are compared with PI controller to show the effectiveness of the presented control system.
文摘In recent years, urban rail systems have developed drastically. In these systems, when induction electrical machine suddenly brakes, a great package of energy is produced. This package of energy can be stored in energy storage devices such as battery, ultra-capacitor and flywheel. In this paper, an electrical topology is proposed to absorb regenerative braking energy and to store it in ultracapacitor and battery.Ultra-capacitor can deliver the stored energy to DC grid and charge the battery for auxiliary applications such as lighting and cooling systems The proposed system is modeled based on large signal averaged modeling, which leads to the simplicity of calculations. The control system is based on Lyapunov stability theorem which guarantees system stability. Also, an energy management algorithm is proposed to control energy under braking and steady-state conditions. Finally,the simulation results validate the effectiveness of the proposed control and energy management system.
