Bahador Fani Articles List

Open Access Article

1 - Investigation and improvement of high step- up converters for pv module applications
Hamed moradmand jazi Ehsan Adib Bahador Fani

20.1001.1.23223871.1395.7.28.4.9

Abstract- sun is of the clean and cheapest sources of energy. Charging slight energy to electricity is carried out by PV modules. Since most electric consumers need Ac input voltage, the PV modules output voltage should be changed into Ac form. But, the voltage level of More

Abstract- sun is of the clean and cheapest sources of energy. Charging slight energy to electricity is carried out by PV modules. Since most electric consumers need Ac input voltage, the PV modules output voltage should be changed into Ac form. But, the voltage level of PV modules is much lower than the voltage needed in input stage of inverters. Because of large voltage level. Difference it is not possible to use the basic boost and buck-boost converters. The basic boost and buck-boost converters definitely can not be used in this applications, for, they will face extreme drop in efficiency in duty cycles closer to unity.In this paper The proposed converter is presented in order to decrease the voltage stress of coupled inductors based high step-up converters. The voltage stress in the proposed converter is lower than the high step-up boost converter with coupled inductors in identical condition. Also, soft switching condition for switches and diodes is realized by active clamp circuit, and with this technique and proper selection of duty cycle, large gain and high efficiency could be achieved ultimately. . In this paper theoretical analysis is used for analyzing the performance of the proposed converters, and in order to verify the theoretical analysis, simulated results from pspice software is provides. Manuscript profile

Open Access Article

2 - Adaptive Coordination of Fuse – Recloser in a Distribution System with High PV Penetration
Farzad Hajimohammadi Bahador Fani

20.1001.1.23223871.1396.8.30.3.9

Employment of photovoltaic (PV) distributed Generation in the distribution system, leads to improvement of network voltage profile and power quality. On the other hand, it cause miscoordination between fuses and recloser. In this paper an adaptive method is presented to More

Employment of photovoltaic (PV) distributed Generation in the distribution system, leads to improvement of network voltage profile and power quality. On the other hand, it cause miscoordination between fuses and recloser. In this paper an adaptive method is presented to maintain coordination between fuse and recloser. This method is based on a modification of fast operation curve of recloser, proportional to the lateral fuse maximum fault current to recloser current which is located at the beginning of the feeder. Simulation results show the performance of the proposed methods for different fault scenarios, variation of PV penetration and different fault resistance. Based on the presented method, proportional to PVs penetration the protection coordination index (PCI) determined in fault period. Then, according to this index, time dial setting (TDS) of recloser fast operation modified adaptively. Finally, new recloser trip time calculated in this conditions for fuse saving. Simulation results show the performance of the proposed methods for different fault scenarios, variation of PV penetration and different fault resistance. Manuscript profile

Open Access Article

3 - Coordinated Protection Scheme Based on Virtual Impedance Control for Loop-Based Microgrids
Hamed Karimi Bahador Fani Ghazanfar Shahgholian

20.1001.1.23223871.1400.12.2.2.0

The presence of the inverter distributed generations in the power systems can bring about incoordination in the protection system performance while enjoying various advantages. In this paper, a suitable solution, independent of relay settings, is presented in order to s More

The presence of the inverter distributed generations in the power systems can bring about incoordination in the protection system performance while enjoying various advantages. In this paper, a suitable solution, independent of relay settings, is presented in order to solve the protection problems of inverter island microgrids with circular arrangement. The presence of distributed inverter generation sources causes a change in the direction and amplitude of the fault current at the microgrid level. This problem is more visible in microgrids with circular arrangement. Therefore, conventional protection schemes that consider a single path and a high fault current level compared to load current may be problematic. An important factor for the proper design of a protective system for microgrids is the contribution of the injecting fault current of the inverter sources. In this paper, a protection strategy based on the inverter control of sources is presented and ordinary overcurrent relays with the same characteristic curve are used. When a short circuit fault occurs in the microgrid, an adaptive current limiting strategy is applied using the virtual impedance loop. In this case, the share of fault current of each source is controlled according to the position of the fault, and sources closer to the fault produce a larger fault current. Therefore, the current passing through the protective equipment is closer to the fault than other equipment in the micro grid. And without the need for making connection between protective equipment, the protective coordination is guaranteed. Manuscript profile

Open Access Article

4 - Harmonic Compensation and Micro-Grid Voltage and Frequency Control Based on Power Proportional Distribution with Adaptive Virtual Impedance Method
Monir Kamali Bahador Fani Ghazanfar Shahgholian Gevork B. Gharehpetian Masoud Shafiee

20.1001.1.23223871.1402.14.53.3.7

Due to the different distances and complexity of micro-grids, the lines impedance varies between the feeders of the distributed generation and the loads. Therefore, conventional droop control method does not have good efficiency in power distribution between distributed More

Due to the different distances and complexity of micro-grids, the lines impedance varies between the feeders of the distributed generation and the loads. Therefore, conventional droop control method does not have good efficiency in power distribution between distributed generation (DG) units. Generally, due to simplification, the impedance of the lines is not considered in a complex. The stated conditions greatly reduce the accuracy and speed of the dynamic response of the control system. In this paper, harmonic compensation, voltage and frequency control of micro-grid with adaptive virtual impedance method based on proportional power distribution are presented. In the proposed method, reducing the error coefficient of active power and reactive power, control of voltage and currents’ harmonic in two modes of connection to the main grid and islanded, as well as voltage and frequency control for optimal operation of the micro-grid is presented. The proposed method, without the need to update the impedance information of the feeders, has the capability of optimal operation and power distribution under different operating conditions, taking into account the complex impedance. To validate, the proposed method is simulated in MATLAB/Simulink software environment and the results are presented along with stability and sensitivity analysis. Manuscript profile

Open Access Article

5 - Coordination of Protection Equipment in Synchronous Generator-Based Microgrids with Regard to Maintaining First Swing Stability
Hassan Fayazi Majid Moazzami Bahador Fani Ghazanfar Shahgholian

20.1001.1.23223871.1402.14.54.2.8

With the addition of distributed generation resources to the structure of distribution networks, at the time of the fault, the amount and direction of flow through the main and backup protections changes and disrupts the coordination between them. Synchronous generator- More

With the addition of distributed generation resources to the structure of distribution networks, at the time of the fault, the amount and direction of flow through the main and backup protections changes and disrupts the coordination between them. Synchronous generator-based sources, meanwhile, are more sensitive to error fixing times and their stability may be compromised. Since the troubleshooting time depends on the performance of the protection system, this paper proposes the most suitable protection combination for systems with synchronous generators by examining the types of combinations for protection elements (relay-relay, relay-recloser and recloser-fuse). Slowly On the other hand, this paper presents a solution by which, while maintaining the stability of the first oscillation of synchronous generators in the distribution network, the coordination between the main protection and the backup in the event of an error and in the presence of these sources can be maintained. There is no need to change or redesign the protection system in this solution. The proposed method, by activating the instantaneous characteristic along with the characteristic curve of the relay in the system, was able to establish coordination between the protections and transient stability of the synchronous generators in the distribution system for a penetration coefficient of 0 to 100%. The results of the implementation of the proposed method on the standard 33-bus IEEE test system in the ETAP software environment confirm its capability. Manuscript profile

Open Access Article

6 - Distributed Generations Management to Restore Protective Coordination Using Multi-Agent Systems
Saeed Soltaniyan Bahador Fani

20.1001.1.23223871.1403.15.59.6.9

Utilizing the structure of multi-agent systems is one of the methods proposed today to improve the performance of network protection systems. Given that the presence of distributed generation resources as well as network restructuring has always been a concern for netwo More

Utilizing the structure of multi-agent systems is one of the methods proposed today to improve the performance of network protection systems. Given that the presence of distributed generation resources as well as network restructuring has always been a concern for network managers, so it is expected that with the introduction of smart equipment and capabilities that provide network managers, better performance and maintenance They help. Intelligent devices are able to exchange information by communicating on a telecommunications platform. The purpose of this paper is to coordinate the protection relays in the presence of distributed generation sources by removing the connection between the relay agents and the information collected from the entire network by the central controller. The proposed method, in addition to improving the speed of the traditional multi agent system protection system, increases the security of the protection system and eliminates the need for information from one agent of one section to the agents of another sections. Manuscript profile

Open Access Article

7 - Adaptive Coordination of Fuse – Recloser in a Distribution System with High PV Penetration
Bahador Fani Alireza Karbaschi

20.1001.1.23223871.1397.9.35.2.5

The use of Distributed Generations in the distribution system, has been lead to improve both network voltage profile and power quality. But it can probably create miscoordination between protective devices. In this paper a new Time – Curent – Voltage charact More

The use of Distributed Generations in the distribution system, has been lead to improve both network voltage profile and power quality. But it can probably create miscoordination between protective devices. In this paper a new Time – Curent – Voltage characteristic is presented in order to return coordination between fuse and recloser. This method is based on a adaptive modification of fast operation curve of recloser, which is related to a voltage term that is infact the Perunit voltage amplitude of recloser at fault accurance point. Based on the presented method, relate to the fault location, the Time Dial Setting (TDS) modification index (MI) is determined in fault location. Thus, according to this index, TDS of recloser fast operation is modified adaptively. Finally, new recloser trip time is calculated in this conditions for fuse saving. Simulation results show the performance of the proposed methods for both different types of fault scenarios and variation of PV penetration. Manuscript profile

Open Access Article

8 - Transient Performance Improvement of Wind Turbines with Doubly Fed Induction Generators Using Active Damping Control Strategy
Saeed Soleymani Bahador Fani Mohammad Reza Yousefi

20.1001.1.23223871.1394.6.24.1.1

This paper Analytically investigates the effects of system and controller parameters and operating conditions on the dynamic and transient behavior of wind turbines (WTs) with doubly-fed induction generators (DFIGs) under voltage dips and wind speed fluctuations. Also, More

This paper Analytically investigates the effects of system and controller parameters and operating conditions on the dynamic and transient behavior of wind turbines (WTs) with doubly-fed induction generators (DFIGs) under voltage dips and wind speed fluctuations. Also, it deals with the design considerations regarding rotor and speed controllers. The poorly damped electrical and mechanical modes of the system are identified, and the effects of system parameters, and speed/rotor controllers on these modes are investigated by modal and sensitivity analyses. The results of theoretical studies are verified by time domain simulations. It is found that the dynamic behavior of the DFIG-based WT under voltage dips is strongly affected by the stator dynamics. Further, it is shown that the closed loop bandwidth of the rotor current control, rotor current damping, DFIG power factor and the rotor back-emf voltages have high impact on the stator modes and consequently on the DFIG dynamic behavior. Moreover, it is shown that the dynamic behavior of DFIG-based WT under wind speed fluctuation is significantly dependent on the bandwidth and damping of speed control loop. Manuscript profile

Open Access Article

9 - Design and Implementation of a New Current Fed Converter With Zero Current Switching Conditions
Bahador Fani Majid Delshad

20.1001.1.23223871.1389.1.3.2.5

In this paper a new soft switching current-fed converter for high voltage high power applications is presented. This converter utilizes parasitic components of high voltage transformers as resonant elements and employs fixed frequency phase shift PWM control to implemen More

In this paper a new soft switching current-fed converter for high voltage high power applications is presented. This converter utilizes parasitic components of high voltage transformers as resonant elements and employs fixed frequency phase shift PWM control to implement soft switching condition, so the implementation of control circuit is easy and cheap. Every six switches turn on at zero current condition (ZCS) and it has high efficiency. The detailed steady state analysis of the converter is presented by computer simulation and analytical method. Finally the experimental results certificate analysis and simulation results of this converter. Manuscript profile

Open Access Article

10 - Reliability Evaluation of Power System SVC Types Using a Markov Chain
Ali Behdan Bahador Fani Ehsan Adib

20.1001.1.23223871.1394.6.22.2.8

Static reactive power compensator (SVC) plays an important role in power system reliability stems. In evaluations of reliability, only reactive power is considered as a constraint network is placed in the SVC Brrsy‌Ha impact on power system reliability evaluation techni More

Static reactive power compensator (SVC) plays an important role in power system reliability stems. In evaluations of reliability, only reactive power is considered as a constraint network is placed in the SVC Brrsy‌Ha impact on power system reliability evaluation techniques are still not considered. This type of SVC, the TCR-FC, TSC and TCR-TSC examined and the information wrong or repair parts of the states of the user. μ) is expressed.This type of SVC, the TCR-FC, TSC and TCR-TSC examine the error occurs and information Halt‌Hay or repair parts used by our participants .Static reactive power compensator (SVC) plays an important role in power system reliability stems. Thus it is clear that λ is a parameter that indicates the error to each component, and μ is a parameter which indicates the service or go into the same circuit components and repair goes wrong. After the static reactive power compensator (SVC) plays an important role in power system reliability. Manuscript profile

Open Access Article

11 - Transient Performance Improvement of Wind Turbines with Doubly Fed Induction Generators Using Fractional Order Control Strategy
Samaneh Jenab Bahador Fani Hossein Ghasvari

20.1001.1.23223871.1392.4.16.3.3

Application of fractional order proportional integral (FOPI) controller to improve transient performance of wind turbine (WT) with Doubly fed induction generator (DFIG) is presented and studied in this paper. By small signal analysis, it is found that the dynamic behavi More

Application of fractional order proportional integral (FOPI) controller to improve transient performance of wind turbine (WT) with Doubly fed induction generator (DFIG) is presented and studied in this paper. By small signal analysis, it is found that the dynamic behavior of the DFIG based WT, during the variation of operating conditions, is strongly affected by the stator dynamics. Since the DFIG electrical dynamics are nonlinear, the linear control (PI) scheme cannot work properly under change in wind speed and stator modes are not damped appropriately. The proposed fractional order controller generalizes the conventional integer order PI controller whose integral order are fractional number rather than integer. This expansion can provide more flexibility in achieving control objectives. By time domain simulations, a comparative analysis is made with respect to the standard PI controller to demonstrate effectiveness of the fractional order PI ( ) controller during wind speed perturbation. Manuscript profile

Open Access Article

12 - Short-Term Load Forecasting of Distribution Power System for Weekdays Using Old Data
Bahador Fani Soleyman Fehresti Sani Ehsan Adib

20.1001.1.23223871.1393.5.18.4.5

Estimation of daily load in distribution companies which is performed to present the results to the DMS, is necessary. Daily load forecasting of power systems has traditionally been considered. Because load patterns are influenced by several factors such as climate, eco More

Estimation of daily load in distribution companies which is performed to present the results to the DMS, is necessary. Daily load forecasting of power systems has traditionally been considered. Because load patterns are influenced by several factors such as climate, economy and society, it is difficult to predict the load exactly. That's why in recent years the use of intelligent algorithms to predict it, is growing. In this project, the short-term load forecasting is performed in a hybrid approach. Due to the different behavior in different days, various methods have been used to predict the load. With studying different methods of load prediction, finally, finally exponential smoothing algorithm was used to predict the exact load in the weekdays. Manuscript profile

Open Access Article

13 - Coordinated Control of FACTS Devices by Using ADALINE Neural Network to Enhance the Transient Stability of Power System
Mehdi Ghasemi Ali Reza Roosta Bahador Fani

20.1001.1.23223871.1391.3.9.4.3

In order to improve transient stability and increase the system damping, this paper introduces a specific way of coordination between FACTS devices (TCSC and SVC). In order to improve the performance and use all the features of TCSC and SVC (presented in this article), More

In order to improve transient stability and increase the system damping, this paper introduces a specific way of coordination between FACTS devices (TCSC and SVC). In order to improve the performance and use all the features of TCSC and SVC (presented in this article), it is necessary a controller be used in which does not have the limitations of other controllers and simply be also able to quickly respond and adapt to the power system model. Hence, these features can be found in the intelligent controllers in which the ADALINE network is one of them. To better understand the performance of the ADALINE network controller; this controller will be compared with a controller which is designed by the optimal control parameters (LQR). The instruments used for FACTS are from the injection type and therefore, it is possible to use a fixed factorization ybus matrix in the calculations. Simulation results using non-linear network show that the ADALINE neural network controller has better performance than the LQR controller and can cause significant improvement on damping and transmission ability in the power system. Manuscript profile

Open Access Article

14 - Stability Analysis and Control of DFIG Based Wind Turbine Using FBC Strategy
Majid Tavoosi Bahador Fani Ehsan Adib

20.1001.1.23223871.1392.4.15.4.2

Doubly fed induction generator has numerous advantages in wind power generation over other types of generators. Once a DFIG is subjected to a large voltage dip, a large rotor voltage induces in the rotor windings. This leads to a large transient current in rotor circuit More

Doubly fed induction generator has numerous advantages in wind power generation over other types of generators. Once a DFIG is subjected to a large voltage dip, a large rotor voltage induces in the rotor windings. This leads to a large transient current in rotor circuit and the dc-link overvoltage, and may block power electronic converter operation. This paper first discusses dynamic modeling of  DFIG wind turbines with the stator ﬂux orientation. Then, by small signal analysis, it is found that the dynamic behavior of the DFIG based WT during voltage dip, is strongly affected by the stator dynamics. Next, a nonlinear control strategy based on flatness is proposed to improve the DFIG transient performance. The main interest of this control method is the possibility to deﬁne the behavior of the state variable system in the steady state as well as in transients. Since the DFIG electrical dynamics are nonlinear; better control performance is achieved with nonlinear control, compared with the linear control scheme. The proposed approach stabilizes the stator dynamics through rotor and grid side filter voltage control. The results of time domain simulations validate the effectiveness the nonlinear control strategy during voltage dip of generator terminal. Manuscript profile

Open Access Article

15 - Evaluation of the Trajectory Sensitivity Analysis of the DFIG Control Parameters in Response to Changes in Wind Speed and the Line Impedance Connection to the Grid DFIG
Mehdi Fooladgar اسمعیل Rokrok Bahador Fani Ghazanfar Shahgholian

20.1001.1.23223871.1393.5.20.4.9

Economic and environmental conditions often make large stations and transmission lines, restrictions are placed. Small and medium-sized production units connected to existing systems as a strategy is in progress. These units are usually near the center of the load place More

Economic and environmental conditions often make large stations and transmission lines, restrictions are placed. Small and medium-sized production units connected to existing systems as a strategy is in progress. These units are usually near the center of the load placed and distributed generators (DG) famous are the DG are allowed types vary, such as induction generators rack squirrel-connected wind turbines, generators fed induction double mounted wind turbines, fuel cells connected to the system by power electronic converters or synchronous generator connected to the turbine combustion [10]. This way sensitivity analysis in systems of distributed generation (DG) is assessed. It is shown that the method can detect the effect of control parameters listed wind turbine connected to a double-fed induction generator (DFIG) Badoou the impedance of the changing the speed of on the stability of the transmission line useful system invested. The control parameters of the importance of influencing the behavior of DFIG are divided. Manuscript profile

Open Access Article

16 - Stability of nonlinear load electric arc furnaces in the presence of reactive power sources
Pegah Sagha Bahador Fani

20.1001.1.23223871.1393.5.17.5.4

This paper first discusses about Electric arc.the model used in this paper is a dynamic model shown with a differential equation. Then, this model is placed with power system model which is considered as a thevenin equivalent model,and whole dynamical system is derived. More

This paper first discusses about Electric arc.the model used in this paper is a dynamic model shown with a differential equation. Then, this model is placed with power system model which is considered as a thevenin equivalent model,and whole dynamical system is derived. With linearization around the work places, Jacobian Matrix of the system was extracted and the stability of equilibrium points specificed. Infollow, restricted equation to the central manifold for system intended is achieved and using that, possible events in the system the critical values of the bifurcation parameter is investigated. At the end, the analytical result is compared with the simulation results obtained with the help of Auto software. Finally, we will conclude that, using one type of the analytical method, one split of power system is characterized, but with using Auto software, all bifurcation are identified in the power system. Manuscript profile

Open Access Article

17 - A New Hard Switching Bidirectional Converter With High Power Density
Bahador Fani Majid Delshad Daryoosh Nazarpour

20.1001.1.23223871.1389.1.1.6.5

In this paper, a new isolated dc-dc bidirectional converter is proposed. This converter consists of two transformers (flyback and forward) and only one switch in primary side and one switch in secondary side of transformers. In this converter energy transfers to the out More

In this paper, a new isolated dc-dc bidirectional converter is proposed. This converter consists of two transformers (flyback and forward) and only one switch in primary side and one switch in secondary side of transformers. In this converter energy transfers to the output in both on and off switch states so power density of this converter is high This converter controlled by PWM signal. Also this converter operates over a wide input voltage range.  Theoretical analysis is presented and computer simulation and experimental results verify the converter analysis. Manuscript profile

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