Gholam H. Riahy

Gholam H. Riahy
Amirkabir University of Technology | TUS · Department of Electrical Engineering

PHD

About

55
Publications
12,941
Reads
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1,475
Citations
Citations since 2017
3 Research Items
861 Citations
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
Additional affiliations
March 2000 - present
Amirkabir University of Technology
Position
  • Professor (Associate)

Publications

Publications (55)
Article
Economic nonlinear model predictive control (ENMPC) is a strong candidate for controlling wind turbines (WTs). In the model predictive control (MPC) group, the model is the crucial component for the true controller performance. It is common to use simplified models to reduce the problem complexity. These models neglect some of the underlying dynami...
Article
In this study, economical options to meet the load demand of Hormoz Island as a green Island in future years, located in Iran, are investigated. For this purpose, construction of a new undersea transmission line (UTL) and design of a grid-connected hybrid renewable energy system (RES) are selected as two possible options. Therefore, the optimizatio...
Article
In this paper, a new mechanism is proposed to apportion expected reserve costs between electricity market agents in the power system. The uncertainties of generation units, transmission lines, wind power generation and electrical loads are considered in this model. Hence, a Stochastic Unit Commitment (SUC) is used to apply the uncertainty of stocha...
Article
Contributing in power system expansions, the present study establishes an efficient scheme for optimal integration of wind energy resources. The proposed approach highly concerns the spatial distribution of wind speed at different points of a wind farm. In mathematical statements, a suitable probability distribution function (PDF) is well-designed...
Article
Full-text available
In this paper, a method is presented to control offshore wind farm output power. This method is able to fix the wind farm output power even during wind speed variations. In the proposed method, the offshore wind farm is connected to the onshore grid through the high-voltage dc (HVdc) cable. Moreover, the power control of the wind turbines is achiev...
Conference Paper
Full-text available
In this paper,a hybrid system consisting of wind and solar resources with the battery as a storage is designed in order to supply an off-grid system with a sample load pattern.By using wind density probability function of the region , the capacity factor is estimated for four wind turbines and the turbine with the highest capacity factor is selecte...
Conference Paper
In this paper the performance of a non-isolated DC/DC boost converter is investigated during load variation since unexpected transients frequently happen in power systems. This boost converter is simulated in MATLAB/Simulink and the results are presented under different transient conditions. The simulation shows that the output voltage maintains in...
Article
Abstract This paper presents a novel probabilistic technique so as to estimate the power output of wind farms (WFs). At first, the power output of each wind turbine (WT) is calculated using power probability distribution functions (PPDFs). These PPDFs are acquired from the actual data of an installed WT measured in a particular time horizon, which...
Article
Full-text available
Todays, contingency analysis is being used to predict the effect of line outages in power system operation. This analysis is mostly offline to predict the line outage effects on the blackout of power system. To investigate the grid's sensitivity to each line outage, power flow equations are analyzed. The ranking process of line outage and their eff...
Article
Full-text available
In this paper, IRAN energy balance is investigated to understand the energy flow in IRAN and improve the condition of consumption, production, and transformation of energy with regard to the importance of energy planning. First, the 2011 energy balance for Iran is simulated and the share of different sections such as crude oil, natural gas, coal, b...
Article
This paper studies the rotor-speed stability improvement of dual stator-windings induction generator (DWIG)-based wind farms under power system fault conditions. The characteristics of the DWIG-based wind turbines are described. The factors affecting the rotor-speed stability are analyzed, and a novel control-winding voltage oriented drive together...
Article
Full-text available
Diesel generators are the most common distributed generation (DG) units that are used in distribution networks. Depletion and increasing cost of fossil fuels is an important factor that makes us using renewable energy resources (RES) as DG. Virtual power plant (VPP) as an aggregation of some DGs with own local energy management system and some fixe...
Article
Full-text available
Power quality has become an important issue in recent years due to the sensitivity of new equipment to its variations. Custom power devices are used to overcome power quality problems. Dynamic voltage restorer (DVR) is one of the most efficient and effective custom power devices that can mitigate voltage sags, swells and harmonics coming from suppl...
Article
The majority of the fixed-speed wind turbines are equipped with squirrel-cage induction generators (IG) and ac-connected to the power system. During a fault in power system, voltage and rotor speed instability may occur, especially when the strength of the system compared to the power delivered by the IG is relatively low. This paper investigates a...
Article
Full-text available
Wind and solar (photovoltaic) power generations have rapidly evolved over the recent decades. Efficient and reliable planning of power system with significant penetration of these resources brings challenges due to their fluctuating and uncertain characteristics. In this paper, incorporation of both PV and wind units in the unit commitment of power...
Article
Full-text available
Wind power is site dependent and is by nature partially dispatchable. Furthermore, good wind sites are far from grid. Owing to these problems, and along with the existing limitations in the transmission networks, a comprehensive analysis over an extended time is needed to properly explore all potential wind sites for wind capacity allocation. This...
Conference Paper
Hybrid systems are becoming popular for remote area power generation applications. Any effort to decrease capital and operating costs, contributes to increase penetration of hybrid systems in power generation systems. In this paper combining of hybrid systems and Thermal Energy Storage (TES) has been proposed for lowering the costs of hybrid system...
Article
Wind energy is leading technology among renewable energy resources, and many countries have ambitious wind energy plans for future. Wind-rich sites which are a variable source of energy, are mostly located in remote areas that transmission network in these areas cannot absorb additional power from new wind sites. Therefore, a non-physically firm co...
Article
Full-text available
A new hybrid algorithm using linear prediction and Markov chain is proposed in order to facilitate very short-term wind speed prediction. First, the Markov chain transition probability matrix is calculated. Then, linear prediction method is applied to predict very short-term values. Finally, the results are modified according to the long-term patte...
Article
In this paper, a hybrid wind/photovoltaic/battery generation system is designed. The aim of design is to minimize the annualized cost of the stand-alone system over its 20 years of operation. The optimization problem is subject to economic and technical constraints. System costs involve investments, replacements, operation and maintenance as well a...
Article
In this paper, the size of a stand-alone wind/PV/battery system is optimized. The hybrid system is consisting of three major power sources: wind turbine generator, photovoltaic arrays, and storage batteries that the characteristics of components are commercially available. This study is performed for a region in North-West of Iran. The optimization...
Article
In this paper, a grid-connected hybrid wind/photovoltaic/battery power system is designed. The aim of design is minimization of annualized cost of the hybrid system over its 20 years of operation. The optimization problem is subject to economic and technical constraints. System costs involve investments, replacements and operation and maintenance a...
Conference Paper
Photovoltaic (PV) module produces DC voltage, so it must be connected to the network through an inverter. Considering PV characteristics clear that maximum power is obtained in some specific operating points. These optimal points depend on the solar radiation as well as ambient temperature and vary with their changes. Therefore, DC-DC converter is...
Article
Full-text available
A hybrid wind/photovoltaic/fuel cell generation system is designed to supply power demand. The aim of this design is minimization of annualized cost of the hybrid system over its 20 years of operation. Optimization problem is subject to reliable supply of the demand. Three major components of the system, i.e. wind turbine generators, photovoltaic a...
Conference Paper
Basic in the districts where solar energy and wind energy are naturally complementary, the application of wind-solar hybrid energy systems can reduce the storage capacity of batteries and the total cost of the system compared with stand alone PV or wind generation system. But efficient and reliable operation of wind-solar hybrid generation system l...
Data
A hybrid wind/photovoltaic generation syst em is designed to supply power demand. The aim of this design is minimization of the overall cost of the generation scheme over 20 years of operation. Full demand supply is modeled as constraint for optimization problem. Characteristic equations of the system components and solar radiation and wind speed d...
Article
Full-text available
A hybrid wind/photovoltaic generation system is designed to supply power demand. The aim of this design is minimization of the overall cost of the generation scheme over 20 years of operation. Full demand supply is modeled as constraint for optimization problem. Characteristic equations of the system components and solar radiation and wind speed da...
Article
in this paper, size of stand-alone system is optimized. Hybrid system is consisting of three major power sources: wind turbine generator, photovoltaic arrays, and storage batteries that the characteristics of components are commercially available. This study is performed for the region in south- west of Iran. The optimization problem is subject to...
Conference Paper
Full-text available
Since year 2000, the increase of the installed wind energy capacity all over the world (mainly in Europe and United States) attracted the attention of electricity companies, wind farm promoters and researchers towards the short term prediction, mainly motivated by the necessity of integration into the grid of an increasing dasiaunknownpsila (fluctu...
Conference Paper
Full-text available
A hybrid wind/photovoltaic/fuel cell generation system is designed to supply power demand. The aim of this design is minimization of overall cost of generation scheme over 20 years of operation. Optimization problem is subject to reliable supply of demand. The system components and radiation and wind speed datasets are assumed to be fully determini...
Article
In hybrid systems which include wind turbines, calculation of wind turbine power is based on average wind speed, because considering instantaneous wind speed makes the design of the hybrid system complex and practically impossible. In this paper a new method is presented to determine the optimum generation capacity and storage needed for a hybrid (...
Conference Paper
The instantaneous wind speed variations are ignored in the wind turbine power curves. Hence, the output power of the wind turbines becomes a function of only the average wind speed. In the variable-speed wind turbines, the output power is a function of wind speed as well as the wind dynamics because in order to extract the maximum amount of electri...
Article
A permanent magnet wind turbine is to track a dynamically changing wind from measurements of the wind speed and the rotor speed. Issues of determining the effective wind speed at the turbine rotor are investigated as well as the optimum control strategy to maintain operation at the maximum power point. This is implemented using a hysteresis control...
Article
In this paper a new method, based on linear prediction, is proposed for wind speed forecasting. The method utilizes the ‘linear prediction’ method in conjunction with ‘filtering’ of the wind speed waveform. The filtering eliminates the undesired parts of the frequency spectrum (i.e. smoothing) of the measured wind speed which is less effective in a...
Conference Paper
The Power curve of wind turbine ignores the dynamic behavior of the wind and represents the wind turbine power as a function of the average wind speed. Power curve is not an adequate tool for estimating the power of variable speed wind turbines. Because, in addition to average wind speed, the output power of these turbines is highly dependent on th...
Article
Since the total traffic of the protected network must pass through the firewall to be inspected, the performance of it has a direct effect on the performance of the network behind it. In this paper to increase the efficiency of the firewall, the external attacks against the protected network, which by consuming the network resources, have an improp...
Conference Paper
We have proposed a new design methodology to integrate digital protection relays. We have solved the timing problems involved with the conventional integrated protection systems. The proposed algorithms not only have led to an overall fast protection response, as well as integration advantages, but also have offered possibility of ommitting convent...
Conference Paper
The authors present a model based on the linear prediction method which has been successfully applied to a 400-kV power network with satisfactory results. Because of the presence of the second and higher order harmonic components in the fault cycle, it is necessary to use a digital sharp filter to eliminate these components. The finite impulse resp...
Article
Full-text available
Neither, the annual energy output, nor the power curve of a wind turbine cannot give an exact estimate of the turbine performance in a site. A new performance index is introduced in this paper for the wind turbines in potential sites. That index can be used for evaluation of a wind turbine in a site, where the wind speed information at that site sh...
Article
Full-text available
The growing revolution in wind energy encourages for more accurate models for wind speed forecasting. In this study, a new integrated approach, which contains ANN, Markov chains and linear regression, is used due to very short-term prediction of wind speed. In this method, First ANN is used for primary prediction of wind speed. Then, second-order M...

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Projects (3)
Project
By the end of the project, it is expected that a coherent structure can be achieved in order to optimize both objective functions simultaneously. At the lower level of the optimization program, the cost of purchased energy of microgrids is minimized due to its all different constraints, and at the upper level, various objective functions such as network voltage variance or social welfare of network consumers can be optimized.
Project
Analysis of two smart actuators on a NACA 4412 wind turbine blade regarding its power generation and economic feasibility.