Sharif Digital Repository

Congestion management is one of the most important issues for secure and reliable system operations in deregulated electricity market. This paper presents a cost/worth analysis approach for optimal location and sizing of Distributed Resources (DRs) to mitigate congestion and increase security of the system. In order to reduce the solution space a priority of candidate buses is formed, then optimal location and sizing problem is discussed. To increase the accuracy of results, load duration curve is constituted and based on this curve different load levels are incorporated into this study. Proposed method considers economical factors such as congestion rent, deferred upgrading investment and... 

Reactive market power assessment is an important issue for ISOs and the regulators of the reactive power market. Due to the localized characteristics of reactive power as a technical support and its monopsonistic nature as an economic commodity, a vivid reactive market power index including market share, demand side and cost is not achieved yet. In this paper, a new reactive market power index is presented which is based on bidding strategy deviation of the GENCOs after establishing a uniform price auction reactive market. Not knowing others' offers to ISO, each unit faces a bidding strategy problem that is solved using game theory. Considering its production costs, the unit uses the... 

Transmission line congestion in electricity market is lead to increase the energy cost and change in local marginal prices. So, it is probable that the market power is manifested. Market power may prevent the full competition in Electricity Market. Moreover, in this condition, with operating of power system in its boundary conditions, the system may be damaged and the security of the system may be disturbed. On the other hand, decreasing the line flows from their optimal value, cost and consequently, price of energy are increased. So, there is need to have a compromise between the line flow decrease and the cost those impose. In this paper, a framework for compromising between social cost... 

Distribution systems management is becoming an increasingly complicated issue due to the introduction of new technologies, new energy trading strategies, and new deregulated environment. In the new deregulated energy market and considering the incentives coming from the technical and economical fields, it is reasonable to consider Distributed Generation (DG) as a viable option to solve the lacking electric power supply problem. This paper presents a mathematical distribution system planning model considering three planning options to system expansion and to meet the load growth requirements with a reasonable price as well as the system power quality problems. DG is introduced as an... 

Distribution systems management is becoming an increasingly complicated issue due to the introduction of new technologies, new energy trading strategies and new deregulated environment. In the new deregulated energy market and considering the incentives coming from the technical and economical fields, it is reasonable to consider Distributed Generation (DG) as a viable option to solve the lacking electric power supply problem. This paper presents a mathematical distribution system planning model considering three planning options to system expansion and to meet the load growth requirements with a reasonable price as well as the system power quality problems. DG is introduced as an attractive... 

This paper investigates the effects of service quality regulation on investing in distribution automation. Among different regulatory instruments for quality regulation, the Reward-Penalty Scheme (RPS) has been selected to evaluate the effect of monetary incentive on behavior of Electric Distribution Utility (EDU) for service reliability. By implementing different automation strategies, the value of enhancing reliability indices and consequently the value of rewards and penalties are calculated for each strategy. For achieving to more realistic outcome, ten years horizon is considered. Furthermore, in the calculation of reliability indices, the time varying failure rate of components is... 

Congestion management is one of the most important functions of independent system operator (ISO) in the restructured power system. This paper presents two new methodologies for optimal sitting and sizing of distributed generations (DGs) in the restructured power systems for congestion management. The proposed methodologies are based upon locational marginal price (LMP) and congestion rent that forms a priority list of candidate buses to reduce the solution space. The proposed priority list facilitates the optimal placement as well as the level of output power of DGs. The proposed methods are implemented on the IEEE 14-bus and IEEE 57-bus test systems to illustrate their effectiveness. An... 

This paper discusses various aspects of unified power flow controller (UPFC) control modes and settings and evaluates their impacts on the power system reliability. UPFC is the most versatile flexible ac transmission system device ever applied to improve the power system operation and delivery. It can control various power system parameters, such as bus voltages and line flows. The impact of UPFC control modes and settings on the power system reliability has not been addressed sufficiently yet. A power injection model is used to represent UPFC and a comprehensive method is proposed to select the optimal UPFC control mode and settings. The proposed method applies the results of a contingency... 

This paper proposes a stochastic mixed-integer programming (SMIP) model for the reliability-constrained unit commitment (RCUC) problem. The major objective of the paper is to examine both features of accuracy and efficiency of the proposed SMIP model of RCUC. The spinning reserve of generating units is considered as the only available reserve provision resource; however, the proposed formulation can be readily extended to comprise the other kind of reserve facilities. Expected load not served (ELNS) and loss of load probability (LOLP) are accommodated as the reliability constraints. Binding either or both reliability indices ensures the security of operation incorporating the stochastic... 

Integration of wind power generation creates new concerns for operation engineers in a power system. Unlike conventional power generation sources, wind power generators supply intermittent power due to uncertainty in parameters of wind such as its velocity. This paper presents probabilistic model for load and wind power uncertainty which can be used in operation planning (with durations up to one or two years). A stochastic model is proposed to simulate the status of units that are directly affected by the load and wind power generation uncertainties. This paper develops a solution method for generation scheduling of power system, while taking into account the stochastic behavior of the load... 

This paper propose a particle swarm optimization based algorithm for locating Unified power flow controller (UPFC), as well as set its parameters, with static point of view in deregulated electricity markets in order to reduce generation cost, voltage violation and manage congestion. The modeling of UPFC has been adapted based on power injection method. In order to verify and validate the effectiveness of the proposed method, it was applied to 24-bus Reliability Test System (RTS) and the results have been discussed  

This Paper presents a model for optimal locating and sizing of Distributed Generation (DG) for congestion management in deregulated electricity market. For reducing the solution space a priority list of candidate buses is formed and then optimal placement and sizing of DG in potential buses is discussed. In order to incorporate stochastic nature of power system in this study, Monte-Carlo method is used to simulate the effect of uncertainty of loads and system on the optimal location and size of the DGs in the network. The proposed method is applied to IEEE Reliability Test System (RTS). The impacts of load uncertainty on optimum DG size and location are studied  

Considerable developments in the real-time telemetry of demand-side systems allow independent system operators (ISOs) to use reserves provided by demand response (DR) in ancillary service markets. Currently, many ISOs have designed programs to utilize the reserve provided by DR in electricity markets. This paper presents a stochastic model to schedule reserves provided by DR in the wholesale electricity markets. Demand-side reserve is supplied by demand response providers (DRPs), which have the responsibility of aggregating and managing customer responses. A mixed-integer representation of reserve provided by DRPs and its associated cost function are used in the proposed stochastic model.... 

Reliability of energy supply is one of the most important issues of service quality. On one hand, customers usually have different expectations for service reliability and price. On the other hand, providing different level of reliability at load points is a challenge for system operators. In order to take reasonable decisions and obviate reliability implementation difficulties, market players need to know impacts of their assets on system and load-point reliabilities. One tool to specify reliability impacts of assets is the criticality or reliability importance measure by which system components can be ranked based on their effect on reliability. Conventional methods for determination of... 

To improve power system reliability, it is important to reduce the amount of curtailed load when a contingency occurs. While comparing the conventional methods in load shedding, this paper presents a new approach based on sensitivity between line flows and bus power injections. The proposed method selects a set of buses for alleviating the overloaded transmission lines. The RBTS, IEEE-RTS79, and IEEE 118-bus test systems are used to examine the applicability of the proposed method. The results obtained are compared with those of global optimization and heuristic approach from the amount of curtailed load and the computational burden points of view. It will be shown that the proposed method... 

As the electricity market undergoes continuous evolutions, along with the outdated nature of the grid, system operators would have to be able to more effectively manage the operation costs since waves of maintenance costs and equipment investments would be anticipated in the years to come. Strategic implementation of cost-effective reliability centered maintenance (RCM) approaches seems to be a key solution. This paper proposes an efficient method to assess the component criticality for the system overall reliability and further maintenance focuses. A solution concept of game theory, called Shapely Value, that is able to fairly identify the contribution of each single equipment to the system... 

With the rapid evolution of electricity markets and the need for higher economic efficiency of power industry, attempts for lowering down the maintenance costs as a large portion of system operation expenses seem imperative. Recognised as a crucial step in practical implementation of modern maintenance paradigms, e.g. reliability-centred maintenance, this study proposes an efficient method to quantify the generating units' criticality on the bulk power system reliability performance. The proposed approach utilises a solution concept of game theory and evaluates the contribution of each generating unit on the overall system reliability when a higher-order contingency occurs. The suggested... 

The main focus of this study is on reserve market settlement in an electricity market with marginal pricing scheme as the pricing mechanism. Following a day-ahead market clearing, the marginal prices are found using the appropriate Lagrange multipliers as the bi-products of the optimisation process. The payments to energy and reserve providers can then be found based on these prices. However, it is hard to find an appropriate settlement scheme that provides the fair and justifiable consumer payments based on marginal pricing scheme considering the actual reserve functions in power systems. In this study, a reserve marginal pricing that is based on a proper reserve marginal price definition... 

This paper proposes a particle swarm optimization based algorithm for locating series FACTS devices in deregulated electricity markets in order to reduce and manage congestion. Line outage sensitivity factors are used to reduce the solution space and to pinpoint the lines which are more suitable for FACTS device placement. Total congestion cost and total generation cost are the two objective functions that are employed in the optimization process. In order to verify and validate the effectiveness of the proposed method, it was applied to IEEE 14-bus and IEEE 57-bus test systems. The results obtained by the proposed method were compared with those of congestion rent contribution method  

Spinning reserve (SR) is one of the most important ancillary services which are needed for satisfying reliability requirements, including the desired level of security in power systems. By definition, spinning reserve is the unloaded section of synchronized generation that is able to respond immediately to serve load. This paper proposes a hybrid DCOPF and harmony search (HS) optimization method as a novel heuristic approach to the joint dispatch of energy and reserve considering the bottling of reserve due to transmission limits. The effectiveness of the proposed method is examined by applying it to the IEEE 30-bus test system. The results obtained using the proposed method are presented...