Control of power electronic interfaces in distributed generation.

Renewable energy has gained popularity as an alternative resource for electric power generation. As such, Distributed Generation (DG) is expected to open new horizons to electric power generation. Most renewable energy sources cannot be connected to the load directly. Integration of the renewable energy sources with the load has brought new challenges in terms of the system’s stability, voltage regulation and power quality issues. For example, the output power, voltage and frequency of an example wind turbine depend on the wind speed, which fluctuate over time and cannot be forecasted accurately. At the same time, the nonlinearity of residential electrical load is steadily increasing with the growing use of devices with rectifiers at their front end. This nonlinearity of the load deviates both current and voltage waveforms in the distribution feeder from their sinusoidal shape, hence increasing the Total Harmonics Distortions (THD) and polluting the grid. Advances in Power Electronic Interfaces (PEI) have increased the viability of DG systems and enhanced controllability and power transfer capability. Power electronic converter as an interface between energy sources and the grid/load has a higher degree of controllability compared to electrical machine used as the generator. This controllability can be used to not only overcome the aforementioned shortfalls of integration of renewable energy with the grid/load but also to reduce THD and improve the power quality. As a consequence, design of a sophisticated controller that can take advantage of this controllability provided by PEIs to facilitate the integration of DG with the load and generate high quality power has become of great interest. In this study a set of nonlinear controllers and observers are proposed for the control of PEIs with different DG technologies. Lyapunov stability analysis, simulation and experimental results are used to validate the effectiveness of the proposed control solution in terms of tracking objective and meeting the THD requirements of IEEE 519 and EN 50160 standards for US and European power systems, respectively

Designing a model and historical cost calculation of services by ABC method and budgeting By ABB method

This study deals with the design of the historical cost calculation model by Activity Based Costing (ABC) method and budgeting model based on the Activity Based Budgeting (ABB) in the municipality of Sirik Port. The present study is a descriptive-survey type with operating approach and applied results. The activity and output cost were calculated by using activity-based costing method and then budget was anticipated based on the activity. First, the historical cost of services was calculated by (ABC) method and then was compared to the historical cost of the current municipal accounting systems that was calculated by traditional (conventional) methods to determine whether there is a significant difference between these two costing methods or not. Also, the budget anticipated by (ABB) method is compared to the budget compiled by conventional method to determine whether there is a significant difference between these two methods of budgeting or not. Finally, whether the Activity Based Costing and Activity Based Budgeting can be used in the municipality of Sirik Port or not. The results indicate that there is significant difference between the activity-based historical cost with available traditional costing methods and also between activity-based budgeting with budgeting by traditional (conventional) method. Also there is the calculating possibility of the historical cost of service by (ABC) method and budgeting by (ABB) method in the municipality of Sirik Port

Designing a model and historical cost calculation of services by ABC method and budgeting By ABB method

This study deals with the design of the historical cost calculation model by Activity Based Costing (ABC) method and budgeting model based on the Activity Based Budgeting (ABB) in the municipality of Sirik Port. The present study is a descriptive-survey type with operating approach and applied results. The activity and output cost were calculated by using activity-based costing method and then budget was anticipated based on the activity. First, the historical cost of services was calculated by (ABC) method and then was compared to the historical cost of the current municipal accounting systems that was calculated by traditional (conventional) methods to determine whether there is a significant difference between these two costing methods or not. Also, the budget anticipated by (ABB) method is compared to the budget compiled by conventional method to determine whether there is a significant difference between these two methods of budgeting or not. Finally, whether the Activity Based Costing and Activity Based Budgeting can be used in the municipality of Sirik Port or not. The results indicate that there is significant difference between the activity-based historical cost with available traditional costing methods and also between activity-based budgeting with budgeting by traditional (conventional) method. Also there is the calculating possibility of the historical cost of service by (ABC) method and budgeting by (ABB) method in the municipality of Sirik Port

Determining effective criteria on sustainable development of fluting paper making industry

Fluting paper industry seems to be significant from environmental view point. Accordingly, study on sustainable development criteria in this sector of Iran’s industry is regarded as a national necessity. The intent of the current study is to determine and prioritize the indices affecting sustainable development of Iran’s fluting paper industry by benefiting from Analytical Hierarchy Process (AHP) method. After the conducted investigations, 55 indices were identified and categories in eight general groups namely, technical & human, cultural-social, economic, materials & products, rules and regulations, environmental, infrastructure and sale & marketing . Analytical Hierarchy Process was applied in the form of adjusting and distributing questionnaires among professional experts. Results show that the highest priorities for attaining sustainable development in this industry respectively belong to sub-criteria of economic stability increase in the country, a continuous relation between university and industry, privatization, training man force, paper recycling, foreign investment, increasing productivity and reducing greenhouse gas emissions

The study of relationship between earnings quality and investment in capital assets on Tehran stock exchange companies

This study examines the relationship between earnings quality and investment in capital assets of accepted companies in Tehran Stock Exchange. For this purpose, 109 sample companies with required information for 4-year period (2007-2010) of study were selected in judgmental form and based on the defined limitations. The investigated variables of this study included the earnings quality, investment in capital assets and the returns on capital asset. The results of the data analysis and hypotheses testing indicated that there is a significant relationship between earnings quality and investment in capital assets in both retrospective approach and the prospective approach

The study of relationship between earnings quality and investment in capital assets on Tehran stock exchange companies

This study examines the relationship between earnings quality and investment in capital assets of accepted companies in Tehran Stock Exchange. For this purpose, 109 sample companies with required information for 4-year period (2007-2010) of study were selected in judgmental form and based on the defined limitations. The investigated variables of this study included the earnings quality, investment in capital assets and the returns on capital asset. The results of the data analysis and hypotheses testing indicated that there is a significant relationship between earnings quality and investment in capital assets in both retrospective approach and the prospective approach