• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.77-83
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• 2001

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.698-704
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• 2012

This paper proposes a new methodology for evaluating the probabilistic reliability based grid expansion planning of composite power system including the Wind Turbine Generators. The proposed model includes capacity limitations and uncertainties of the generators and transmission lines. It proposes to handle the uncertainties of system elements (generators, lines, transformers and wind resources of WTG, etc.) by a Composite power system Equivalent Load Duration Curve (CMELDC)-based model considering wind turbine generators (WTG). The model is derived from a nodal equivalent load duration curve based on an effective nodal load model including WTGs. Several scenarios are used to choose the optimal solution among various scenarios featuring new candidate lines. The characteristics and effectiveness of this simulation model are illustrated by case study using Jeju power system in South Korea.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.540-549
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• 2018

This paper proposes the method of active distribution network expansion planning considering distributed generation integration and distribution network reconfiguration. The distribution network reconfiguration is taken as the expansion planning alternative with zero investment cost of the branches. During the process of the reconfiguration in expansion planning, all the branches are taken as the alternative branches. The objective is to minimize the total costs of the distribution network in the planning period. The expansion alternatives such as active management, new lines, new substations, substation expansion and Distributed Generation (DG) installation are considered. Distribution network reconfiguration is a complex mixed-integer nonlinear programming problem, with integration of DGs and active managements, the active distribution network expansion planning considering distribution network reconfiguration becomes much more complex. This paper converts the dual-level expansion model to Second-Order Cone Programming (SOCP) model, which can be solved with commercial solver GUROBI. The proposed model and method are tested on the modified IEEE 33-bus system and Portugal 54-bus system.

• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.62-69
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• 2005

The optimal design of transmission system expansion planning is an important part of the overall planning task of electric power system under competitive electricity market environments. One of main keys of the successful grid expansion planning comes from optimal reliability level/criteria decision, which should be given for constraint in the optimal expansion problem. However, it's very difficult to decide logically the optimal reliability criteria of a transmission system as well as generation system expansion planning in a society. This paper approaches a methodology for deciding the optimal reliability criteria for an optimal transmission system expansion planning. A deterministic reliability criteria, BRR (Bus Reserve Rate) is used in this study. The optimal reliability criteria, BRR/sup */, is decided at minimum cost point of total cost curve which is the sum of the utility cost associated with construction cost and the customer outage cost associated with supply interruptions for load considering bus reserve rate at load buses in long term forecasting. The characteristics and effectiveness of this methodology are illustrated by the case study using IEEE-RTS.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.237-239
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• 2005

The importance and necessity conducting studies on grid reliability evaluation have been increasingly important in recent years due to the number of black-out events occurring through in the world. Quantity evaluation of transmission system reliability is very important in a competitive electricity environment. The reason is that the successful operation of electric power under a deregulated electricity market depends on transmission system reliability management. Also in Korea it takes places. This paper presents the probabilistic reliability evaluation for 765KV transmission lines of KEPCO grid expansion planning. The Transmission Reliability Evaluation for large-Scale Systems (TRElSS) Version 6.2, a software package developed by Electric Power Research Institute (EPRI) is utilized in determining the improved probabilistic reliability indices of (KEPCO) system.

• Architectural research
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• v.9 no.1
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• pp.19-30
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• 2007

This study explores the issue of campus expansion of an urban university using an in-depth case study of New York University in New York City, USA. It investigates the physical pattern and development mechanism of the campus expansion process on a city grid structure. The three elements that characterize NYU's recent campus expansion, are (1) the university's commitment to building a student community around a public open space on a subway network, (2) four types of property acquisition and building development practiced by the university with private developers for space leasing, building renovation and development under changing local development circumstances, and (3) the city's initiative for attracting the private sector whose development activities influence the university's development dynamics. These findings suggest that the expansion planning of an urban university, due to its location in a city, should be placed on a local planning agenda, which can positively contribute to public goals through the collaborative engagement of the private and public sectors.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.261-265
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• 2004

This paper proposes a fuzzy dual method for analyzing long-term transmission system expansion planning problem considering ambiguities of the power system using fuzzy lineal programming. Transmission expansion planning problem can be formulated integer programming or linear programming with minimization total cost subject to reliability (load balance). A long-term expansion planning problem of a grid is very complex, which have uncertainties fur budget, reliability criteria and construction time. Too much computation time is asked for actual system. Fuzzy set theory can be used efficiently in order to consider ambiguity of the investment budget (economics) for constructing the new transmission lines and the delivery marginal rate (reliability criteria) of the system in this paper. This paper presents formulation of fuzzy dual method as first step for developing a fuzzy Ford-Fulkerson algorithm in future and demonstrates sample study. In application study, firstly, a case study using fuzzy integer programming with branch and bound method is presented for practical system. Secondly, the other case study with crisp Ford Fulkerson is presented.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1369-1377
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• 2021

Nowadays, it is necessary to accelerate the construction of new power plant in face of rising energy demand in such a way that the electricity will be generated at the lowest cost while reducing emissions caused by that generation. The expansion planning is one of the most important issues in electricity management. Nuclear energy comes forward with the low-carbon technology and increasing competitiveness to expand the share of generated energy by introducing Gen IV reactors. In this paper, the generation expansion planning of these new Gen reactors is investigated using the WASP software. Iran power grid is selected as a case of study. We present a comparison of the twenty-one year perspective on the future with the development of (1) traditional thermal power plants and Gen II reactors, (2) Gen III + reactors with traditional thermal power plants, (3) Gen IV reactors and traditional thermal power plants, (4) Gen III + reactors and the new generation of the thermal power plant, (5) the new generation of thermal power plants and the Gen IV reactors. The results show that the Gen IV reactors have the most developing among other types of power plants leading to reduce the operating costs and emissions. The obtained results show that the use of new Gen of combined cycle power plant and Gen IV reactors make the emissions and cost to be reduced to 16% and 72% of Gen II NPPs and traditional thermal power plants, respectively.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1163-1170
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• 2014

Due to global environmental regulations and policies with rapid advancement of renewable energy technologies, the development type of renewable energy sources (RES) in power systems is expanding from small-scale distributed generation to large-scale grid-connected systems. In the near future, it is expected that RES achieves grid parity which means the equilibrium point where the power cost of RES is equal to the power costs of conventional generators. However, although RES would achieve the grid parity, the cost related with development of large-scale RES is still a big burden. Furthermore, it is hard to determine a suitable capacity of RES because of their output characteristics affected by locations and weather effects. Therefore, to determine an optimal capacity for RES becomes an important decision-making problem. This study proposes a method for determining an optimal installed capacity of RES from the business viewpoint of an independent power plant (IPP). In order to verify the proposed method, we have performed case studies on real power system in Incheon and Shiheung areas, South Korea.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.825-836
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• 2019

One of the most challenging safety precautions for workers in dynamic, radioactive environments is avoiding radiation sources and sustaining low exposure. This paper presents a sampling-based algorithm, DL-RRT*, for minimum dose walk-path re-planning in radioactive environments, expedient for occupational workers in nuclear facilities to avoid unnecessary radiation exposure. The method combines the principle of random tree star ($RRT^*$) and $D^*$ Lite, and uses the expansion strength of grid search strategy from $D^*$ Lite to quickly find a high-quality initial path to accelerate convergence rate in $RRT^*$. The algorithm inherits probabilistic completeness and asymptotic optimality from $RRT^*$ to refine the existing paths continually by sampling the search-graph obtained from the grid search process. It can not only be applied to continuous cost spaces, but also make full use of the last planning information to avoid global re-planning, so as to improve the efficiency of path planning in frequently changing environments. The effectiveness and superiority of the proposed method was verified by simulating radiation field under varying obstacles and radioactive environments, and the results were compared with $RRT^*$ algorithm output.