Technovations of Electrical Engineering in Green Energy System: 11 (3)

Open Access Article

1 - A Single-Switch DC-DC High Step-Up Converter with Soft Switching for Photovoltaic Applications
Tayebeh Shamsi Majid Delshad Ehsan Adib Mohammad Rouhollah Yazdani

A single-switch DC-DC high step-up converter is presented in this paper. There are soft switching conditions in the proposed converter for switching on and off time, which increases efficiency. In order to increase the gain, two coupled inductors have been used, and the More

A single-switch DC-DC high step-up converter is presented in this paper. There are soft switching conditions in the proposed converter for switching on and off time, which increases efficiency. In order to increase the gain, two coupled inductors have been used, and the leakage inductance of the coupled inductors has been used to create a soft switching condition, and the minimal auxiliary element has been used in the proposed converter. In the proposed converter, only one switch is used, and the condition of the converter is no different from a basic converter in terms of the control circuit. Therefore, the converter does not need to design a new control circuit. The auxiliary circuit added to the converter with a minimal element, provides soft switching conditions for the switch at turn-on, under zero current and at turn-off, under zero voltage, which, in addition to increased efficiency, the circuit has a simple structure. Therefore, the innovation of the paper is to present a switching converter high step-up soft without imposing an additional switch and with a low number of elements. The proposed converter is simulated after full theoretical analysis at 400 W output power, which shows the efficiency of 97.2 percent, in addition to proving the theoretical analysis. Also, the prototype of the converter is made and the experimental results obtained prove the theoretical and simulation results. Manuscript profile

Open Access Article

2 - Short-Term Forecasting of Wind Farm Power Production Using a Modified Artificial Neural Networks Based Algorithm in Python: A Case Study in Manjil
Hamid Jabari Ardalan Shafiei-Ghazani Farkhondeh Jabari

This paper presents a new approach for short-term forecasting of wind farm power generation using artificial neural networks under Python programming language. In this method, weather conditions such as wind speed, wind direction, temperature and air pressure are select More

This paper presents a new approach for short-term forecasting of wind farm power generation using artificial neural networks under Python programming language. In this method, weather conditions such as wind speed, wind direction, temperature and air pressure are selected as key features affecting the power production of the wind farm. To achieve a relatively accurate estimate, the root mean squared error of the predicted values is calculated and minimized as the objective function. The speed and accuracy of the proposed algorithm have been evaluated by conducting a case study on a wind farm located in Manjil, Iran. The power production of the wind power plant is predicted for a time horizon of one week and hour by hour using the wind speed, wind direction, temperature and air pressure during 8592 hours (total hours of a year minus hours of a week). The root mean squared error, the highest relative error percentage, the time resolution of the forecasts and the calculation time of the proposed algorithm are compared with other algorithms published in recent years, which shows the effectiveness and high accuracy of the results in a short calculation time. The power production of the wind farm was predicted hour by hour during a week and 168 data points were obtained, the root mean squared error in the optimal scenario is equal to 0.010817. The calculation time of the forecasting algorithm is less than 1 minute, and the maximum relative error in the proposed method is 2.3%, which demonstrates that the uncertainties associated with the power production of the wind farm can be reduced by using this short-term forecasting approach. Manuscript profile

Open Access Article

3 - Parameters Estimation of Photovoltaic Cell Using Cuckoo Search Algorithm
Vahdat Nazerian Mehran Hosseinzadeh Dizaj Alireza Salehi

In this paper, an electrical equivalent circuit model based on the photovoltaic effect has been presented with the studies done on the simulation of the solar energy system. This linear model, which consists of two diodes, shows the behavior of a solar cell to produce e More

In this paper, an electrical equivalent circuit model based on the photovoltaic effect has been presented with the studies done on the simulation of the solar energy system. This linear model, which consists of two diodes, shows the behavior of a solar cell to produce electricity. We have done the desired simulations using MATLAB software. Our goal in this research is to calculate the minimum error value for the unknown parameters of the circuit, which is obtained by the root-mean-square error (RMSE). In order to accurately and reliably determine the parameters of the double-diode model, an optimization method based on collective intelligence called the Cuckoo search algorithm is presented in this article. According to the desired model that we intend to study with the proposed algorithm, to obtain the minimum error value, we calculate the unknown parameters of the circuit and compare them with other methods. The results show that the RMSE value of the proposed algorithm with the initial population value of 50 and the number of iteration rounds of 1000 is equal to 3.56*10-2, which provides better results than other algorithms. The average execution time of this algorithm is 15.81 milliseconds per every iteration round. Manuscript profile

Open Access Article

4 - Reliability Investigation with the New Architecture of the Backup Node Markov Model with a Better Repair and Replacement Rate and More Monitoring in Avoiding the Failure of Industrial Wireless Sensor Networks
Ahmadreza Zamani Mohammad Ali Pourmina Ramin Shaghaghi Kandovan

Sensor nodes are prone to failure due to the various applications of operating environments. This paper presents a new architecture with a Markov model to improve reliability. In the modification of the previous ideas, due to work fatigue, energy consumption and high ma More

Sensor nodes are prone to failure due to the various applications of operating environments. This paper presents a new architecture with a Markov model to improve reliability. In the modification of the previous ideas, due to work fatigue, energy consumption and high maintenance costs, the idea of increasing the repair and replacement rate to avoid failure with the availability of replacement nodes with detailed planning of the support unit.The advantages of this method are reducing the failure rate, increasing reliability, fast implementation and deployment, energy efficiency and economic savings, improving the performance and useful life of the network, reducing delay and system rejuvenation and dynamics.The structure of the proposed method is by using the sleep and wake mode of the hot or cold standby node in such a way that the spare node is placed parallel to the main node and if one or both nodes are damaged, the system is reversible and. the damage can be repaired or replaced. The technique of idle time and the availability of the backup spare sensor play an important role in reducing energy consumption. The experts of the support unit perform the configuration settings so that the equipment goes to sleep or standby mode during idle time. And if one or two nodes are damaged, first the healthy spare¬node is awake and in service, and then the damaged node is repaired and replaced and placed in standby or sleep mode. The results of the innovation, we can mention the emphasis on node health monitoring, failure avoidance, improving repair and replacement rates and efficiency. The simulation results show a better improvement compared to the previous models. Manuscript profile

Open Access Article

5 - Design and Simulation of Low Power Adder Circuits Using MGDI Gate in QCA Technology
Hamidreza Sadrarhami Sayed Mohammadali Zanjani Mehdi Dolatshahi Behrang Barekatain

With the design of circuits at the nano-scale and observation of the problems of CMOS technology, designers are seeking suitable alternatives for this technology. Quantum-dot Cellular Automata (QCA) is one of these proposed technologies, which has attracted researchers' More

With the design of circuits at the nano-scale and observation of the problems of CMOS technology, designers are seeking suitable alternatives for this technology. Quantum-dot Cellular Automata (QCA) is one of these proposed technologies, which has attracted researchers' attention due to its high speed and low power consumption. On the other hand, the Gate Diffusion Input (GDI) method is an approach to improve power and area efficiency, which has led to higher speed, less power loss, and reduced complexity in Boolean functions through the use of fewer transistors. Furthermore, the adder, as a fundamental computational circuit in the design of digital systems, is of special importance. In this paper, a half-adder circuit, a half-subtractor circuit, and three new adder circuits in QCA technology have been designed and improved with the help of the GDI block. Simulation of these circuits using the QCADesigner software in 18-nanometer technology demonstrates the advantages of simultaneously using QCA technology and the GDI method. The results of the comparison and evaluation of the proposed circuits relative to the best existing adder indicate a reduction of about 55% in the occupied area, a significant decrease in the number of cells, and a delay that is equal to or less than 28% compared to existing works. Manuscript profile

Open Access Article

6 - A New Ultra High-Gain DC/DC Converter with Full Soft-Switching Performance and Low Voltage Stress
Sara Hasanpour Amard Afzalian Tohid Nouri

This paper presents a new single-switch Ultra High-Gain DC/DC converter for renewable energy applications. This converter is able to provide a high voltage gain in a low-duty cycle, low input current ripple, and low voltage stress. Moreover, a coupled inductor with thre More

This paper presents a new single-switch Ultra High-Gain DC/DC converter for renewable energy applications. This converter is able to provide a high voltage gain in a low-duty cycle, low input current ripple, and low voltage stress. Moreover, a coupled inductor with three windings is utilized to extend the voltage gain, which indicates more converter flexibility. Also, the secondary winding of the coupled inductor acts in a trans-inverse manner. Thus, at a lower number of turn ratios, higher voltage gains can be achieved. A regenerative passive clamp circuit absorbs and recycles the energy of the leakage energy of the coupled inductor. The single-power MOSFET operates at zero current switching conditions with restricted voltage stress. In this circuit, because of the soft-switching operation for the power switch and diodes, the power dissipations have been alleviated considerably. Detailed steady-state and power loss analyses, as well as design considerations, are provided. Finally, to confirm the given theories a sample prototype (200 W, 25 V- 400 V) is implemented. Regarding the experimental results, the proposed converter efficiency is about 96.2%, and the maximum voltage stress across the power switch is limited to about 15% output DC voltage. Manuscript profile

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