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In recent years, while energy consumption is still increasing, system peak load is decreasing due to deregulation in power systems, application of demand response programmes, microgrids and smart grids implementation, and so on. Thus, transmission system operators (TSOs), which are usually a public entity, must reinforce the transmission systems to maintain power system reliability. They are not interested in investing transmission network because of high investment costs. In this regard, this study presents a new bi-level model for co-planning of transmission system and merchant distributed energy resources (DERs). The upper level takes the TSOs perspective and aims to minimise the line... 

This paper provides a novel bad data detection processor to identify false data injection attacks (FDIAs) on the power system state estimation. The attackers are able to alter the result of the state estimation virtually intending to change the result of the state estimation without being detected by the bad data processors. However, using a specific configuration of an artificial neural network (ANN), named nonlinear autoregressive exogenous (NARX), can help to identify the injected bad data in state estimation. Considering the high correlation between power system measurements as well as state variables, the proposed neural network-based approach is feasible to detect any potential FDIAs.... 

Uncertainty and variability in the supply sector of renewable-penetrated power systems is becoming a new challenge for secure operation of these systems which if not responded properly may cause large amounts of load and supply curtailments. To meet this challenge, some ISOs recently have employed a new product named Flexible Ramping Product (FRP) into their markets which enhances the capability of the system to overcome such uncertainties by reserving additional ramp rates. In this regard, a new framework for implementing FRP in real-time market is proposed here. The proposed framework provides a proper opportunity for participation of thermal generating units in procuring FRP requirements.... 

This study presents a novel framework to incorporate the uncertainties associated with load fluctuations and components' availability in a day-ahead joint energy-reserve payment cost minimisation (PCM). The payments are calculated based on locational marginal prices (LMPs). Considering these uncertainties, appropriate definitions are not available for energy and reserve LMPs (RLMPs) that suit the probabilistic PCM formulation and reflect the market characteristics. A tri-level optimisation framework is proposed. The optimisation variables in the first-level optimisation include commitment status. In the second-level optimisation, the production schedule and allocated reserves are the... 

Secure operation of protective intelligent electronic devices (IEDs) has been recognized as a crucial issue for power grids. By gaining access to substation IEDs, intruders can severely disrupt the operation of protection systems. This paper develops an analytical reliability assessment framework for quantifying the impacts of the hypothesized integrity attacks against protection systems. Petri net models are used to simulate possible intrusion scenarios into substation networks. The cyber network model is constructed from firewall, intrusion prevention system (IPS), and password models, which are three types of defense mechanisms for protecting substation networks. In this paper, two main... 

The high penetration of residential air conditioners (RACs) poses a growing concern in emerging fault-induceddelayed voltage recovery (FIDVR) in power systems. FIDVR is expected to be a significant threat to the stability and reliability offuture power grids. Hence, the system planners should carry out appropriate simulation studies to mitigate the severeconsequences of FIDVR events. A key question to implement these studies is how to determine the worst condition whichresults in FIDVR. Most of the actual FIDVR events have been experienced in the hot hours of the day and this issue makes onecurious to think about the relationship between the FIDVR events and the ambient temperature. In this... 

This paper evaluates the reliability impact of UPFC application in power system. The paper proposes a new reliability model for the UPFC which is capable of considering different operating states of UPFC. The model is then applied to a test system to study the reliability impacts of UPFC. The impacts of operating points of different states of the model on the system reliability are analyzed. The role of model parameters in reliability impacts of UPFC is analyzed through the sensitivity analysis. A comparative study is finally conducted to illustrate the applicability of the proposed model compare to that of existing UPFC reliability models. The abilities and deficiencies of the proposed... 

This paper presents a modified particle swarm optimization (MPSO) algorithm for solving the optimal power flow (OPF) problems. The main distinction of this approach is in using particle's worth experience in stead of the best previous experience. The proposed approach is evaluated on the IEEE 30-bus test system which minimizes the total fuel cost considering operational constraints such as power flow equations, transmission flow limits, bus voltages and reactive power of generators. The results obtained using the proposed approach are compared with results of other optimization methods  

In the new environment of power system, generating units dispatch problem plays an important role inasmuch as it is used to clear power market transactions. That is, market operator solves an optimization problem in order to find the energy and capacity reserve quota of each generating units participating in the power market. There are different techniques for solving this problem which differ in many aspects, including the objective function, optimization algorithm, and feasibility, so using an efficient technique is vital. In the real competitive electricity market, the components of generating units dispatch problem are faced with the uncertainties; therefore, due to the presence of... 

With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to the utilization of distributed generation. Since the integration of DG units has been known as an alternative for main grid as a resource for energy supply, the determination of optimal sizing and sitting is an important issue in the planning procedure of DG. This work presents a comprehensive multi-objective model for integration of distributed generations into a distribution network, regarding various technical, economical and environmental issues such as reduction of carbon dioxide emissions and investment & running costs while the bus voltages shall be kept within... 

In the new deregulated environment of electric power utility industry, new system reliability criteria and analytical tools are required. This paper proposes an analytical probabilistic model for reliability evaluation of competitive electricity markets. The market reliability is evaluated by using Markov state space diagram. Since the market is a continuously operated system, the concept of absorbing states is applied to it in order to evaluate the reliability. The market states are identified by using market performance indices and the transition rates are calculated by using historical data. To illustrate interesting feature of the proposed methodology, a case study is carried out over a... 

One of the most important applications of phasor measurement units (PMUs) is power system state estimation. Some models have been proposed for including phasor measurements in the state estimation. But, all of these models have treated transformer tap settings (voltage transformer turns ratio and phase-shift transformer angle) as fixed parameters of the network. The accuracy of state estimation may decrease when a tap changes or the true value is unknown. In this paper, each transformer tap setting is added as a new state variable to the states vector, converting the linear PMU based state estimation to a nonlinear one. Also, the network observability is analyzed including the observability... 

Considering the high level of interactions between energy and reserve markets, simultaneous clearing of these markets has been shown to provide more efficient solutions, than a sequential market clearing process. In addition, determining reserve requirements based on probabilistic approaches results in more economical efficiency, while maintaining an acceptable level of reliability, compared to deterministic approaches. This paper proposes a new method for clearing energy and spinning reserve markets simultaneously, while at the same time, spinning reserve requirements are determined based on a cost/benefit analysis as a probabilistic-based approach. This cost/benefit analysis considers both... 

In this paper we investigate the effects of superconducting shielded core reactor (SSCR) on the operation of induction generators. Large number of induction generators used in wind power plants generally increase the short circuit current level of the system. The reason is that they provide parallel reduced-impedance paths for the fault currents. Taking advantage of SSCR in wind power plants allows for using these generating units in large numbers with no concerns about the system fault current increments. The study is performed on a test system using the conventional model of an induction generator and a new effective model for SSCR based on its shielding behavior. Mathematical equations... 

A reasonable amount of spinning reserve is essential to satisfy system security constraints when the power system encounters a contingency. Most ofthe methods previously developed for spinning reserve assessment ignore the probabilistic aspects of system components. This paper presents the design of a market for energy and spinning reserve services. This dispatching method has been developed to minimize the cost associated with theses services while maintaining the system security. Particle swarm optimization (PSO) is used for determining the global optimal solution for this dispatch problem. The effectiveness of the proposed approach is examined by application to the IEEE Reliability Test... 

This paper presents an optimal phasor measurement units (PMUs) placement algorithm for the purpose of power system observability and also increasing the performance of secondary voltage control scheme. The optimal placement problem (OPP) is formulated such that to minimize the number of PMU installations subject to full network observability and monitoring pilot buses of the system to improve secondary voltage control performance. The branch and bound optimization method is adopted to solve the OPP problem which is suitable for problems with integer and boolean variables. Topology-based algorithm is used for observability analysis. Constraint functions considering adjacent zero-injection... 

This paper presents a method for the optimal allocation of Distributed generation in distribution systems. In this paper, our aim would be optimal distributed generation allocation for voltage profile improvement and loss reduction in distribution network. Genetic Algorithm (GA) was used as the solving tool, which referring two determined aim; the problem is defined and objective function is introduced. Considering to fitness values sensitivity in genetic algorithm process, there is needed to apply load flow for decision-making. Load flow algorithm is combined appropriately with GA, till access to acceptable results of this operation. We used MATPOWER package for load flow algorithm and... 

This paper is concerned about the optimal placement of phasor measurement units (PMUs) so as to make a system completely observable. Observability assessment is done by the aid of the topological observability rules. Moreover a new rule is added which can decrease the number of required PMUs for complete system observability. A modified binary particle swarm is used as an optimization tool for obtaining the minimal number of PMUs and corresponding configuration. In order to improve the speed of convergence, an initial PMU placement is provided by graph-theoretic procedure. The simulation results of proposed approach are presented for several IEEE test systems  

The participants in auction-based electricity markets need to take part in a competition way, which operates, based on the concept of supply and demand theory to buy or sell the electricity. However, to have a feasible market solution, reactive power services are necessary to support the transmission of power from generation to end-users. This paper presents a methodology for optimal reactive power procurement, consistent with the auction-based electricity market mechanism. The proposed reactive power market is run in subsequence of the primary electricity market, allowing active power modification in light of available transmission capacity and reactive power resources. The IEEE 30-bus test... 

Uncoordinated adoption of plug-in electric vehicles (PEVs) imposes further load on the distribution network, and therefore may result in disruptive impacts on the grid. Transactive coordination of PEVs has been introduced as an effective approach to mitigate these negative consequences. This paper furthers efforts enabling PEVs to participate in a real-time retail electricity market under a transactive energy (TE) paradigm. In this regard, PEV owners will estimate their willingness to pay/accept using a user-friendly strategy and submit the estimated values to the retail market operator. Then using a network-constrained market clearing mechanism, the clearing prices, i.e., dual variables of...