A.R. Shirani

Bio: A.R. Shirani is an academic researcher. The author has contributed to research in topics: AC power & Electricity market. The author has an hindex of 2, co-authored 5 publications receiving 44 citations.

A comprehensive method for available transfer capability calculation in a deregulated power

Abstract: In this paper we discuss an improved method for the calculation of available transfer capability (ATC) in a restructured power system. The ATC calculation is performed through an optimal power flow approach. The objective function is to maximize the sum of the receiving-end load in a specified area as well as to send generation to other control areas while a minimum cost of generation is continuously achieved. The constraints are AC power flow equations and system operation limits. It is assumed that the generation cost curve of each generator is available. A genetic algorithm is used for the optimization process. An IEEE 30 bus test system is used for testing the proposed algorithm and the results are compared with those forms the methods calculated ATC value without considering optimal power dispatch between available generators.

Reactive power management in a deregulated power system with considering voltage stability: Particle Swarm optimisation approach

Abstract: During past two decades electric utilities have faced the upheaval of moving toward deregulation. It has always been its ambition of creating a clear structure in which rivals are allowed to do free enterprise in trading of electricity. Accordingly, in this new era economical rules and electricity market legislations have a big effect on secure operation of power systems. This means that, presense of a market independent entity is vital while it should only be in charge of security and stability of power system operation. This entity, called ISO, which is acronym for Independent System Operator [1]. Major task of ISO corresponds to prospect ancillary services requirments which are necessary for reliability enhancement of the system. ISO is also responsible for ancillary services procurement [2,3]. Reactive power is one kind of ancillary service that have significant effectcs on active power trading indirectly. Reactive power is utilized for different purposes e.g voltage profiles amelioration, power loss reduction and lessening occupied capacity of the transmission network. In general, a good reactive power management system increase the performance of transmission lines as unique paths for physical operation of electric power transactions. From Economical points of view, ancillary services had better be provided in a market structure than obligatory as it is operated in vertically integrated system. In recent years many researches are carried out concerning reactive power management and pricing in restructured power systems. In [4,5] applicale methods for determination of reactive power costs are discussed. In [6] a security constraint optimal power flow (SCOPF) is presented for reactive power management of NGC power system. In proposed method reactiv epower cost is modeled as a quadratic function of generators' reactive power outpus and linear programming is used to solve model and determination the reactive power shared among participatns along with prices. Considering social welfare objective for active power market in [7] it tries to dispatch reactive power in such a way power market get better performance as much as possible. It also assumes that active power consumptions are propotional to the price and obey an exponential function. Based on this strategy one can easily distinguish that reactive power price is determined indirectly and it depends on active power activities. Lagrangeian multiplyers are used for settlements of active / reactive power commodity. Reference [8] exploits an OPF based structure to show that reactive power pricing extremely depends on chosen objective for its dispatching purposes. Data analysis of [8] declares that it had better reactive power price be determined in a separate structure and independent of active power market objectives. Investigation of methods presented in above articles reveals that in all cases, reactive power is optimised around current operating point of power system after clearing active power market or simultaneous with it. In other words there is less attention to reactive power reserve necessary for perventing of voltage collapse occurance following perturbation in loads or other events. This paper presents a method in which providing of efficient reactive power reserve is also considered in price determination. Therefore, conventional OPF formulation is modified in somehow, voltage stability criterion can be modeled within reactive power market equations. In proposed structure, reactive power costs is to be minimized independently of active power activites. Particle Swarm Optimization Algorithm is used for solving OPF based market structure implemented on WSCC 9 bus test system to show capabilites of the procedure into a market based power system managenet.

A New Structure for Electricity Market Scheduling

Abstract: On pool market structure, the generating units are typically dispatched in order of lowest to highest bid as needed to meet demand requirement as well as considering network constraints Generally, no account is taken of generating unit's reliability when scheduling them This paper proposes a new structure for electricity market to consider generating unit's reliability in the scheduling problem GAMS (general algebraic modeling system) language has been used to solve the social welfare maximization problem using CPLEX optimization software with mixed integer programming

Computing Optimum Bidding Strategy of Gencos Using Simulated Annealing Method

Abstract: This paper describes a new method that uses simulated annealing (SA) method for analyzing the competition among Generating Companies (Gencos) where they have incomplete information about their opponents. Each Genco models its opponents with their generating cost coefficients. The proposed methodology employs the supply function equilibrium (SFE) for modeling a Genco's bidding strategy. Gencos change their bidding strategies until Nash equilibrium points are obtained. Nash equilibrium constitutes a central solution concept in game theory. The task of detecting the Nash equilibria of a finite strategic game remains a challenging up-to-date. This paper uses SA to compute Nash equilibria strategies of Gencos and then the obtained results are compared with another computational intelligence technique (Genetic Algorithm) and a mathematical method (GAMS/DICOPT).

Using Market Simulation to Recognize The Price Maker Firms

Abstract: This paper proposes a new method for recognizing the price maker firms in the Independent System Operator (ISO)'s point of view. In the proposed methodology, at the first, all firms are supposed to be as price takers. Then the state of each firm will be changed from price taker to price maker and the obtained profit in either of cases is compared. In the proposed methodology the Supply Function Equilibrium (SFE) model is used for modeling a price maker firm's bidding strategy. If a price maker firm changes the market clearing price (MCP) noticeably, that firm is realized as a price maker. GAMS (general algebraic modeling system) language has been used to solve the market simulation model using MINOS optimization software with non-linear programming.

Reactive Power Management in Islanded Microgrid—Proportional Power Sharing in Hierarchical Droop Control

Abstract: A microgrid (MG) is a local energy system consisting of a number of energy sources (e.g., wind turbine or solar panels among others), energy storage units, and loads that operate connected to the main electrical grid or autonomously. MGs provide flexibility, reduce the main electricity grid dependence, and contribute to changing large centralized production paradigm to local and distributed generation. However, such energy systems require complex management, advanced control, and optimization. Moreover, the power electronics converters have to be used to correct energy conversion and be interconnected through common control structure is necessary. Classical droop control system is often implemented in MG. It allows correct operation of parallel voltage source converters in grid connection, as well as islanded mode of operation. However, it requires complex power management algorithms, especially in islanded MGs, which balance the system and improves reliability. The novel reactive power sharing algorithm is developed, which takes into account the converters parameters as apparent power limit and maximum active power. The developed solution is verified in simulation and compared with other known reactive power control methods.

Congestion Management using Demand Response programs in power market

Abstract: Congestion Management (CM) plays a significant role in power system operation under todaypsilas deregulated environment. Its two major functions are maintaining power system within security limits and collecting money from market participants paying back to transmission grid investors. This paper compares two market-clearing procedures for CM in terms of economic efficiency of the solution attained. The first method implements Demand Response (DR) programs, especially Emergency Demand Response Program (EDRP) and the other one re-dispatches the production of generators to avoid transmission congestion in a least-cost manner. Numerical studies based on IEEE 30-bus system are performed for the evaluation of the methods.

ATC-Based System Reduction for Planning Power Systems With Correlated Wind and Loads

Abstract: Simulations of production costs, flows, and prices are crucial inputs to generation and transmission planning studies. To calculate average system performance for many alternatives over long time p ...