Mohammad Reza Hesamzadeh

An Advanced Optimal Approach for High Voltage AC Bushing Design

This paper proposes a new and advanced methodology for finding the optimum electrical design of high voltage ac capacitive graded bushings using an improved genetic algorithm approach as an effective meta-heuristic method. A case study has been conducted on a 145 kV oil impregnated paper (OIP) bushing and the IEC 60137 tests have been performed to evaluate its performance. Condenser-bushings contain concentric conductive foils which are isolated from each other. The partial capacitances between conducting cylinders can be modified by adjusting the number, diameter, place and length of these cylinders as well as the thickness of insulating material between foils. As a result, the voltage drop and also the electrical stress in the core and along the surface will change. This paper finds optimal value of bushing design parameters to achieve well-distributed electric stress with the lowest possible maximum value and also a constant voltage drop for different layers by using an improved genetic algorithm optimization method subject to practical and technological constrains. The proposed method of this research work has been applied to a 145 kV OIP bushing. The performance of optimal designed 145 kV OIP bushing under IEC 60137 tests is very promising.

Transmission System Augmentation Based on the Concepts of Quantity Withheld and Monopoly Rent for Reducing Market Power

This paper proposes two mathematical structures for considering the market power effect of transmission capacity in transmission augmentation assessment. These mathematical structures use the concepts of monopoly rent and quantity withheld in economics for market power modeling in the assessment process of transmission augmentation. The simultaneous-move and sequential-move games in applied mathematics are used to model the interactions of the transmission network service provider, generating companies, and the market management company in the proposed mathematical structures. The solution concept of Nash equilibria is reformulated as an optimization problem, and the multiple Nash equilibria is tackled through an introduced concept termed worst Nash equilibrium. A numerical solution is developed to solve the proposed mathematical structures. The numerical solution is an island parallel genetic algorithm nested in a standard genetic algorithm. The six-bus Garvers example system and the IEEE 14-bus test system are modified and studied. The results prove the strong mechanism of the developed structures for modeling the market power effect of transmission capacity in the assessment of transmission augmentation.

Economic Transmission Augmentation With Explicit Modeling of the Competition Benefit

This paper derives and evaluates a mathematical structure for identifying economically-efficient transmission augmentations. The mathematical structure is based on the concepts of sequential-move and simultaneous-move games in applied mathematics. The Nash equilibrium solution concept has been reformulated as an optimization problem in the proposed structure. The problem of multiple Nash equilibria is managed by introducing the concept of the worst-case Nash equilibrium. Both the economic concepts of the “efficiency benefit” and “competition benefit” of the transmission capacity are explicitly modeled in the proposed structure. A simple three-bus example system and Garvers example system are employed and modified to suit the purpose of analysis. A thorough economic study of these example systems is presented to highlight the concept and operation of the proposed mathematical structure from different perspectives. The results demonstrate the utility of the proposed structure for measuring the total economic efficiency benefit of additional transmission capacity.

A course in power system analysis based on project based learning methodology

A growing need in the electrical power industry for engineers who can perform professionally both in technical aspects and generic engineering skills has put a demand on universities to modify their programs and course structures. To address this demand, a course in power system analysis which used project based learning (PBL) methodology was developed. As a part of this development a power system laboratory was established, which gave students access to professional software packages. Projects were defined in the areas of power system operation and planning. These projects were used as stimuli for student learning. Portfolio assessment was used to assess students learning outcome. The course was delivered for the first time in 2008. The feedback from students was very positive and promising.

Economic assessment of transmission expansion projects in competitive electricity markets - an analytical review

Restructuring of the electricity market has changed many aspects of the transmission system operation and planning. Reliability-Driven and Economic-Driven transmission expansion planning by regulated and private utilities are the substitutes of the traditional Cost-Driven transmission expansion planning. Reliability-based criteria for assessment of the transmission projects are almost well-developed while there exists a lack of a comprehensive framework for the economic evaluation of the transmission projects. Definition of a quantitative and monetary framework for economic evaluation of future transmission projects demands a detailed market analysis. In addition, specific characteristics and responsibilities of the transmission system in the open access structure must be understood comprehensively. To reaching the aforementioned goal, an analytical review on the existing economic assessment methodologies would be highly beneficial for the researchers in this area. Moreover, most of the review literatures on transmission investment in competitive electricity markets are general. These review literatures have tried to address all aspects of this challenging issue with devoting only few paragraphs to economic assessment of transmission projects. Given the aforementioned shortcomings, this article would bridge the gap by the following contributions: Firstly, reviewing available approaches for economic assessment of transmission projects based on research papers and industrial reports .Secondly, analysing the reviewed criteria critically by applying them to a modified Wood and Wollenberg 6-bus case study and Finally, summarizing the key components of a successful Economic Assessment Framework for transmission expansion or upgrade projects. Practical experiences of California Electricity Market, New England Electricity Market, Pennsylvania, New Jersey, and Maryland (PJM) and National Electricity Market, Australia have been accommodated in the article.

THe Nodal Market Power index (NMP index) for modelling and visualising market power

This paper deals with a systematic way for modelling and visualising market power in liberalised electricity markets. The paper first introduces a new index termed the “Nodal Market Power” index, the NMP index. The NMP index is calculated based on the concept of “social welfare” in economics and the game theory in applied mathematics. The oligopoly electricity market is modelled through a non-cooperative game and the solution concept of the Nash equilibrium. The solution concept of Nash equilibrium is reformulated as an optimisation problem. To tackle the multiple Nash equilibria problem, the worst Nash equilibrium in terms of the social cost to the society is selected. Then after, the NMP index is calculated for each node of power system. A colour contour map is used for visualising the market power using the NMP index.

Design and study of a switch reactor for Central Queensland SWER system

Single wire earth return (SWER) systems are a widely applied, low cost electrification method used in many rural areas. In central queensland a single SWER system supplying approximately 100 kW may extend more than 300 km. Many SWER systems include shunt reactors to control the effects of the line charging capacitance. One effect, the Ferranti effect, causes the line voltage to rise with the distance. In three phase distribution systems this effect is not visible but in SWER systems, this effect makes it difficult to maintain the consumers supply within the acceptable regulation range. As the second effect, the loading of the SWER system supply transformer increases. Controllable shunt reactors are used as one solution to the aforementioned problems. Stanage Bay feeder in central queensland area has been chosen for the installation of the designed shunt reactor. Stange Bay feeder is supplied by an isolating transformer with the total capacity of 150 kVA and the voltage level of 22 kV. Using the Stanage Bay feeder, this paper details the process of design and simulation of a suitable switch reactor. This step has been carried out by firstly, the design of the switch reactor and secondly, the proper modelling of the designed reactor for the voltage regulation studies.

A multi-criteria decision framework for optimal augmentation of transmission grid: addressing a tool for sensitive zone detection in electricity market

Transmission system structure has an essential effect on the reliability of the power system and electricity market performance, especially when producers bid strategically. As part of on-going research on the design of a robust algorithm for expansion planning of the transmission grid in the Australian electricity market, this paper presents a framework which addresses: (1) the security of power delivery to the load points of the transmission system in case of single line outages; (2) the minimization of transmission system lost load; (3) an efficient electricity market for market participants; (4) construction and maintenance costs of transmission augmentation options; and (5) operation efficiency of the transmission grid.The suggested algorithm benefits from the dynamic programming and sensitivity analysis approaches along with the aggregation method in its multi-criteria decision-making to locate the optimum configuration of a future transmission system. A set of indices, which account for impacts of the augmentation options of the transmission grid on five aforementioned reliability and market criteria, are proposed and used in the optimum framework for expansion planning of the transmission grid.Although the methodology is promising for expansion planning of the transmission system, considering the sensitivity analysis concept employed, the proposed methodology would be suitable to detect the sensitive areas of the transmission system to be expanded. The tool would be very useful in the case of large scale power systems for a smart reduction of the transmission expansion options.The proposed methodology has been applied to a 6-bus and a modified IEEE 30-bus test system to show the effectiveness of the sensitivity-based algorithm.

Derivation of a mathematical structure for market-based transmission augmentation in oligopoly electricity markets using multilevel programming

In this paper, we derive and evaluate a new mathematical structure for market-based augmentation of the transmission system. The closed-form mathematical structure can capture both the efficiency benefit and competition benefit of the transmission capacity. The Nash solution concept is employed to model the price-quantity game among GenCos. The multiple Nash equilibria of the game are located through a characterisation of the problem in terms of minima of the R function. The worst Nash equilibrium is used in the mechanism of transmission augmentation. The worst Nash equilibrium is defined as the one which maximises the social cost, total generation cost + total value of lost load. Thorough analysis of a simple three-node network is presented to clearly highlight the mechanism of the derived mathematical structure from different perspectives.

Derivation of a new mathematical framework for transmission system augmentation using von Stackelberg game

The market-based augmentation of the high voltage transmission systems as a legacy of the previous regulated regimes has been a challenging issue for the central transmission entities. The economic assessment framework for transmission upgrades or expansion projects, considering the interaction of the central transmission entity (CTE) with the electricity market management (MMC) company both as independent players needs to be addressed appropriately at least in the National Electricity Market, Australia. To assist in bridging this gap, this paper introduces a novel metric, namely, the L-Shape Area, for the economic assessment of the transmission expansion options. The proposed methodology employs a von Stackelberg game for the interaction modelling of the central transmission entity and the market management company. The upper subproblem minimises the objective of the CTE as the leader player and the lower subproblem solves the security-constrained economic dispatch as the follower subproblem. The bi-level programming problem has been solved by applying the Kuhn-Tucker optimality conditions to the follower subproblem and the use of a gradient search method to solve the resultant single level non-linear programming problem. A modified IEEE 14-bus test system has been used to show the effectiveness of the proposed formulation.