http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hwachang Song,Panagis N. Vovos,Kang-Wook Cho,Tae-Sun Kim 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.1
This paper presents a method of decision on where bus splitting is needed to reduce fault current level of power systems and to satisfy the fault current constraints. The method employs a modified fault current constrained optimal power flow (FCC-OPF) with X variables for the candidate locations of splitting and for decision making on whether to split or not, it adopts soft-discretization by augmenting inversed U-shaped penalty terms. Also, this paper discusses the procedure on the adequate selection of bus splitting locations based on the results of the modified FCC-OPF, to reduce the total number of the actions taken.
Hwachang Song,Rodel D. Dosano,Byongjun Lee 한국지능시스템학회 2009 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.9 No.3
This paper presents a methodology for the classification of power system voltage stability, the trajectory of which to instability is monotonic, using an interior point method based support vector machine (IPMSVM). The SVM based voltage stability classifier can provide real-time stability identification only using the local measurement data, without the topological information conventionally used.
Hwachang Song,Ryan Diolata,Young Hoon Joo 대한전기학회 2009 Journal of Electrical Engineering & Technology Vol.4 No.2
This paper presents a methodology for photovoltaic (PV) system allocation in distribution systems using a discrete particle swarm optimization (DPSO). The PV allocation problem is in the category of mixed integer nonlinear programming and its formulation may include multi-valued discrete variables. Thus, the PSO requires a scheme to deal with multi-valued discrete variables. This paper introduces a novel multi-level quantization scheme using a sigmoid function for discrete particle swarm optimization. The technique is employed to a standard PSO architecture; the same velocity update equation as in continuous versions of PSO is used but the particle’s positions are updated in an alternative manner. The set of multi-level quantization is defined as integer multiples of powers-of-two terms to efficiently approximate the sigmoid function in transforming a particle’s position into discrete values. A comparison with a genetic algorithm (GA) is performed to verify the quality of the solutions obtained.
Security Constrained Economic Dispatch (SCED) Considering Load Level Uncertainty
Hwachang Song,BenJeMar-Hope Flores 한국지능시스템학회 2022 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.22 No.2
In power system operation, security constrained economic dispatch (SCED) is used to providea reference point for the next time period for each dispatchable generator, and load forecastingneeds to be involved in the SCED procedure. In real-time operation, forecasting errors and thenonlinearity of the load change might cause undesirable dispatch patterns in terms of systemsecurity. This study presents an SCED that considers the uncertainty of the system load level. For this purpose, a fuzzy model was employed to express the uncertainty in the load levelchange, and a practical two-stage SCED solution method was adopted. In addition, to resolvethe difficulty in determining the reference generation pattern from solutions using this model,a procedure is required to determine the secure upper and lower limits for the dispatchablegenerators as the final SCED outcome. The numerical results were obtained using a 43-bustest system to test the feasibility of the proposed method.
Fuzzy-Enforced Complementarity Constraints in Nonlinear Interior Point Method-Based Optimization
Hwachang Song 한국지능시스템학회 2013 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.13 No.3
This paper presents a fuzzy set method to enforce complementarity constraints (CCs) in a nonlinear interior point method (NIPM)-based optimization. NIPM is a Newton-type approach to nonlinear programming problems, but it adopts log-barrier functions to deal with the obstacle of managing inequality constraints. The fuzzy-enforcement method has been implemented for CCs, which can be incorporated in optimization problems for real-world applications. In this paper, numerical simulations that apply this method to power system optimal power flow problems are included.