Reza Sirjani

Karlstads Universitet · Department of Engineering and Physics

The coupling with natural gas networks creates an excellent opportunity for renewable-rich power systems to facilitate the utilisation of renewable energy resources; on the other hand, with the increase in employment of fuel cell vehicles (FCVs), the number of hydrogen refuelling stations (HRSs) is increasing. The integration of HRSs in electric di...

The key role of hydrogen stations (HSs) is to produce hydrogen and deliver it to hydrogen demands. Offering too high prices by HSs decreases their demand and profit; while offering too low prices decreases their revenue and thereby their profit. In literature, optimal pricing of hydrogen has not been done for HSs. In this research, a risk-averse tw...

Wind power uncertainties should be considered in power system operation and planning. Energy storage system (ESS) can facilitate wind power integration in the energy system. However, maximum benefits can be achieved by optimal determination of the location and sizing of ESSs. In this paper, five-point estimation method is utilized to discretise the...

In the power system, economic power dispatch is a popular and fundamental optimization problem. In its classical form, this problem only considers thermal generators and does not take into account network security constraints. However, other forms of the problem, such as economic emission dispatch (EED), are becoming increasingly important due to t...

Herein, we determine the optimal configuration (location and size) of a static Var compensator (SVC) considering the intermittent nature of wind power in the transmission system. A probabilistic load flow (PLF) integrated using a five-point estimation method was used to model the wind power uncertainties by discretizing wind power distribution into...

This study formulated a bi‐level mixed integer non‐linear optimization planning and operation model for the optimal configuration (location, capacity, and power ratings) of energy storage systems (ESSs) in power transmission networks. The model was formulated with consideration for independent and correlated wind farms. The single objective functio...

This paper proposes a Differential Evolution (DE) optimization algorithm and a Pareto-frontier Multi-Objective Differential Evolution (MODE) optimization algorithm for the optimal allocation of Distributed Generation (DG) and Distribution Static Compensator (DSTATCOM) in a radial distribution system. It considers the minimization of active power di...

Despite the increasing utilization of renewable energy resources, such as solar and wind energy, most residential buildings still rely on conventional energy supply by public utility services. Such utility services often use time-of-use energy pricing, which compels residential consumers to reduce their energy usage. This paper presents a wireless...

Wind power uncertainties should be considered in power system operation and planning. Energy storage system (ESS) can facilitate wind power integration in the energy system. However, maximum benefits can be achieved by optimal determination of the location and sizing of ESSs. In this paper, five-point estimation method is utilized to discretise the...

Wind power integration with high penetration in a power system is indispensable. However, wind power integration, especially with high level, raises the power system instability problems due to its natural variability and unpredictability, which increases system uncertainties. Thus, uncertainties and correlations amongst wind farms should be consid...

The growth of demand, the need for economic efficiency and optimal utilisation of electric power networks and the high cost of construction of new power networks result in inevitable challenges, such as overloading and excessive power transfer along transmission lines, high losses, voltage instability, low power quality, reliability problems and vo...

The growth of demand, the need for economic efficiency and optimal utilisation of electric power networks and the high cost of construction of new power networks result in inevitable challenges, such as overloading and excessive power transfer along transmission lines, high losses, voltage instability, low power quality, reliability problems and vo...

Power transmission lines transfer a huge amount of electricity from generation stations to distribution centers. The flow of the large currents causes faults along transmission lines, leading to extended power outages and equipment failure. When a fault occurs along a line at a particular location, a reduction of voltage at that point leads to a hi...

Proton exchange membrane fuel cell is an emerging renewable energy resource for transportation and power generation. Similar to other renewable resources, the performance of proton exchange membrane fuel cell is affected by ambient conditions. However, procedures for analyzing the influences of such conditions on the performance of proton exchange...

Solar energy is a source of free, clean energy which avoids the destructive effects on the environment that have long been caused by power generation. Solar energy technology rivals fossil fuels, and its development has increased recently. Photovoltaic (PV) solar farms can only produce active power during the day, while at night, they are completel...

Currently, many wind farms exist throughout the world and, in some cases, supply a significant portion of energy to networks. However, numerous uncertainties remain with respect to the amount of energy generated by wind turbines and other sophisticated operational aspects, such as voltage and reactive power management, which requires further develo...

With the growth and development of power grids, optimal utilization of electric networks is very important. Because of the high cost of construction and development of power networks, mitigation of existing issues, such as excessive power losses, voltage profile problems, voltage instabilities, reliability problems and etc. is inevitable. To obviat...

The harmonic problem is as a consequence of nonlinear power electronic devices in powering industrial distribution systems. A filter is a necessary equipment in the power system to reduce or eliminate harmonics.In this paper, the optimal design of filters to reduce total harmonic distortion (THD) has been investigated using the Matlab/Simulink. Bee...

Recently, accurate modeling of the differences between the current and voltage (IV) characteristics of solar cells has been the main focus of many research studies. Mostly the results were obtained only for single diode or double diode solar cells, not for both or even for photovoltaic (PV) modules. Moreover, the effect of different shading conditi...

Renewable energy is a fast-growing sector given that it does not cause the pollution produced by nuclear and fossil generation systems. The use of renewable energy for distributed generation (DG) is important worldwide not only because it increases profits but also because integrating it into utility systems ensures power supply at points of consum...

Shunt capacitors are broadly applied in distribution systems to scale down power losses, improve voltage profile and boost system capacity. The amount of capacitors added and location of deployment in the system highly determine the advantage of compensation. A novel global harmony search (GHS) algorithm in parallel with the backward/ forward sweep...

Islanding is a situation in which the distributed generation (DG) unit becomes isolated from the main power system due to inadvertent opening of circuit breakers. Islanding detection is an ongoing challenge because existing methods are not entirely satisfactory. This paper presents a novel islanding detection method in which active and reactive pow...

The benefits of reactive power compensation depend greatly on the placement and size of the compensators. STATCOM is a shunt compensator and one of the important members of the Flexible AC Transmission Systems (FACTS) family that are increasingly being used in long transmission lines in modern power systems. The FACTS devices placement problem is c...

A comparison of the effectiveness of installing reactive power compensators, such as shunt capacitors, static var compensators (SVCs), and static synchronous compensators (STATCOMs), was presented in largescale power networks. A suitable bus was first identified using modal analysis method. The single shunt capacitor, single SVC, and single STATCOM...

In this study, the Ant Colony Optimization (ACO) method is applied to solve the optimal capacitor placement problem in electric distribution systems. An effective and simple power flow method used with the ACO is tested on the 9-bus test system. The obtained capacitor placement results using ACO are compared with other optimization methods.

At the recent years, power system becomes a large complex interconnected network that contains of hundreds of buses and generating stations. In addition, to provide the required power, new installation of power generators and transmission lines are required. Due to the environmental and economic constraints of installation of new generators and inc...

Capacitors in power systems are used to supply reactive power to minimize loss and to improve the voltage profile. The appropriate placement of capacitors is also important to ensure that system power losses and total capacitor costs are minimal. The capacitor placement problem is commonly solved using heuristic optimization techniques which are di...

The Static Var Compensator (SVC) and the Static Synchronous Compensator (STATCOM), as two components of Flexible AC Transmission System (FACTS) devices, play an important role in controlling the reactive power flow to the power network. Because of economic considerations, identifying the best location for installing the SVC and STATCOM is also impo...

This paper presents the application of the improved harmony search (IHS) algorithm for determining the optimal location and sizing of static Var compensator (SVC) to improve the voltage profile and reduce system power losses. A multi-criterion objective function comprising of both operational objectives and investment costs is considered. The resul...

This paper presents a feasibility study of upgrading 63kV double-circuit to 230kV singlecircuit transmission line by minimum changes. The case study in this research is a double-circuit 63kV transmission line in Iran. Different phase coordinations are considered and four alternatives are proposed and compared in mechanical, electrical and structura...

In this paper, the bee colony optimization and harmony search algorithms are combined to form a hybrid algorithm for finding the optimal placement and sizing of static Var compensators (SVC) in transmission systems. A multi-criterion objective function considering both operational objectives and investment costs is considered. The results on the 57...

Capacitors in power systems are used to supply reactive power for the purpose of loss minimization and voltage profile improvement. Besides, appropriate placement of capacitors is also important so as to ensure that system power loss and total capacitor costs is reduced. Most of the capacitor placement techniques assume that the system is balanced...

Capacitors are used to provide reactive power compensation in distribution networks and are widely used to reduce power loss, improve voltage profile and increase system capacity. The benefits of reactive power compensation depend greatly on the placement and size of the added capacitors. Presently, the capacitor placement problem is widely solved...

Shunt capacitors are widely used in distribution systems to reduce power losses, improve voltage profile and increase system capacity. The benefits of compensation depend greatly on the placement and size of the added capacitors. Most of the capacitor placement techniques assume that all loads are linear and ignore the effect of harmonics. The obje...

Capacitors in power systems are generally used to supply reactive power for the purpose of loss minimization and voltage profile improvement. The appropriate placement of capacitors is also important so as to ensure that system power loss and total capacitor costs can be reduced. The main objective of this study is to determine optimal placement of...

This paper presents a Dynamic Programming (DP) methodology for finding optimum preventive maintenance schedule of generating units in a deregulated power system. One part of objective function is to maintain units as earlier as possible. The other part is income from selling electricity in the market. Various constraints such as spinning reserve, d...

This paper presents a Fuzzy Dynamic Programming (FDP) methodology for finding the best preventive maintenance schedule of generating units in a centralized power system. If there is not any feasible solution for crisp model, the Fuzzy model could be a help for finding the best schedule with minimum violation. Objective function is to maintain units...

This paper provides the maintenance schedule of a Generating Company (GenCo) in a deregulated power system. It is shown that the goal of maintenance plan in the new structure is different from the traditional centralized power system. The modeling of maintenance scheduling problem in a competitive environment is demonstrated by taking into account...

Wind power has become the fastest growing renewable energy source around the world, and has become relatively large proportion of total system generation and this procedure will be continuing in future, because of wind power global preference. Because variable speed wind turbine generation (WTG) connects to power system indirectly through converter...

As electricity market participants are prevented from investing in transmission facilities and services in most markets, so transmission expansion may have not sufficient stimulation for competition within the market participators. Therefore an important issue in transmission expansion planning (TEP) is to facilitate competition among GENCOs. In or...

This paper proposes a new method to allocate the power loss for transmission systems. The approach method is developed based on the basic circuit theories, equivalent current injection and bus equivalent admittance. For a given power-flow solution, the relationship between the branch currents and the load/generator voltage is determined using a mod...

An approach to controller design of static var compensator (SVC) device, and its parameter optimization by GA and SA algorithms is proposed In this paper as a power system stability point of view. The implementation of the algorithm for optimizing the controllers¿ parameters is described in detail. In the analysis, the generic dynamic model of SVC...