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- 주제어 : Power balance equation (검색결과 6 건)
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확률론과 위상학적 모델링을 이용한 이중 공진구조 내의 PCB 주파수 응답해석
정인환(In-Hwan Jung),이재욱(Jae-Wook Lee),이영승(Young-Seung Lee),권종화(Jong-Hwa Kwon),조춘식(Choon-Sik Cho) 한국전자파학회 2014 한국전자파학회논문지 Vol.25 No.9
최근 전자기기의 활용도가 높아짐에 따라 전자기파에 대한 안정성이 요구되었다. 소형화 전자기기 및 다양한 전자부품들은 맥스웰 방정식 (Maxwell Equation)으로 해석되었으나, 복잡도가 높은 대형 구조물에 대한 전자기파 안정성이 요구되는 현시점에 맥스웰 방정식은 여러 한계점을 가지고 있다. 본 논문에서는 복잡한 대형 구조물을 확률론과 위상학적 모델링을 연동하여 해석하고자 한다. 특히, 확률론을 바탕으로 한 해석 방법인 PWB(Power Balance) Method와 BLT(Baum-Liu-Tesch) 방정식을 연동하여 대형 구조물의 주파수 응답을 풀이할 경우, 해석시간이 상당히 줄어드는 장점이 있다. 본 논문에서는 복잡한 대형구조물의 예로 이중 공진구조 내부에 PCB가 존재하는 경우를 고려해 보았다. In recent, the requirements for the safety to the effects of high power electromagnetic wave have been increased along with the development of electricity and electronic equipments. The small sized electronic devices and the various components have been analyzed by using the full-EM simulation and solving a complete set of Maxwell equation. However, the deterministic approach has a drawback and much limitation in the electromagnetic analysis of an electrically large cavity with a high complexity of the structure. In this paper, statistical theory and topological modeling method are combined to analyze the large cavity with a complex structure. In particular, the PWB(Power Balance) method and BLT(Baum-Liu-Tesche) equation are combined and employed to solve the frequency response to the large-scaled cavity with remarkably reduced time-consumption. For instance, a PCB substrate inside box of box are considered as a large structure with a complexity.
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기상 조건에 따른 선로 저항 변동을 고려한 국내 전력 계통의 유효 전력 손실 분석
이주성,김수배 대한전기학회 2023 전기학회논문지 Vol.72 No.12
In conventional analysis methods for power systems, a static transmission line model has traditionally been used, assuming that the conductor temperature remains constant. However, due to factors such as the amount of current flowing through the conductor and external influences, including weather conditions, the heat energy entering and leaving the conductor fluctuates, leading to changes in transmission line resistance. This paper aims to analyze the impact of weather conditions on conductor temperature and, consequently, the alteration of active power losses within a large power system. The analysis utilizes the heat balance equation to calculate conductor temperature, taking into account diverse weather parameters like ambient temperature, wind speed, wind direction, and solar irradiance. The temperature-dependent resistance is then integrated into the power flow analysis. Subsequently, the active power losses in a power system are determined, considering the influence of weather conditions, and these results are compared with those obtained from conventional power flow analysis. To conduct these calculations with a practical power system, we employ a Korean power system model and consider a range of potential weather conditions specific to Korea. This enables us to calculate conductor temperatures, line resistances for each transmission line, and the corresponding variations in active power losses under different weather conditions
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한준용(Jun-Yong Han),정인환(In-Hwan Jung),이재욱(Jae-Wook Lee),이영승(Young-Seung Lee),박승근(Seung-Keun Park),조춘식(Choon-Sik Cho) 한국전자파학회 2013 한국전자파학회논문지 Vol.24 No.3
고 출력 전자기장(HPEM)의 영향은 시스템의 오작동, 고장 및 장비의 심각한 훼손을 야기시킬 수 있다. 따라서 업무 환경이 각종 전자 장비들로 대체 및 구성되어 가는 요즘, 인명과 재산을 보호하기 위해 고 출력 전자장에 대한 대책 연구가 필요하다. 이에 반해, 위상학적 해석 법(topological analysis)은 해석 대상 구조에 대해 전자장의 이동 경로와 해석을 원하는 지점을 단순화시켜 해석하며, 대표적으로 Baum-Liu-Tesche(BLT) 방정식 기반의 해석법과 구역 설정(zoning)에 기반한 해석 방법 그리고 확률에 기초하고 있는 Power Balance Method(PWB)를 연동시킴으로써 효율적으로 해석할 수 있다. PWB 방법은 기존의 EM 시뮬레이션 방법의 비효율성을 극복하기 위한 하나의 대안으로 제시된 방법이다. 본 논문에서는 기존의 위상학적 해석 방법에 적용되는 기초기술을 바탕으로 대형 구조에 적용될 수 있는 전자파 해석 방법을 제안한다. 그리고 최종적으로 PWB 방법과 full wave analysis 방법을 비교함으로써 PWB 방법의 장점과 이 방법의 도입 필요성에 대해 제안한다. It is generally well-known that the inevitable high power electromagnetic wave affects the malfunction and disorder of electronic equipments and serious damages in electronic communication systems. Hence, it is necessary to take measures against high power electromagnetic(HPEM) wave for protecting electronic devices as well as human resources. The topological analysis based on Baum-Liu-Tesche(BLT) equation simplifying the moving path of electromagnetic and the observation points and Power Balance Method(PWB) employing statistical electromagnetic analysis are introduced to analyze relatively electrically large cavity with little time consumption. In addition to the PWB method, full wave results for cylindrical cavity with apertures and incident plane wave are presented for comparison with time-consumption rate according to the cavity size.
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Li Zeng,Pengcheng Han,Tongyue Huang,Xiaoqiong He 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.5
A bidirectional-friendly control strategy of three-phase NPC rectifier under unbalanced voltage for advanced traction power supply system (ATPSS) is proposed in this study. Negative-sequence current and DC voltage ripple are restrained effectively with very low total harmonic distortions (THDs) on the basis of predictive current control theory. First, power balance equation containing only positive-sequence voltage of the three-phase grid voltage is derived, and the secondary fluctuation of instantaneous active and reactive powers on the grid side is analyzed and calculated. Second, expression of the DC-side voltage fluctuation is deduced to fix the calculation of Pref for the optimization of the control system. Third, command current that can achieve bidirectional-friendly control is calculated according to the power expression and the reference voltage value is obtained on the basis of the predictive current control principle. Finally, simulations and experimental results verify the correctness of the theoretical analysis and the effectiveness of the proposed strategy.
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Numerical Iteration for Stationary Probabilities of Markov Chains
Na, Seongryong The Korean Statistical Society 2014 Communications for statistical applications and me Vol.21 No.6
We study numerical methods to obtain the stationary probabilities of continuous-time Markov chains whose embedded chains are periodic. The power method is applied to the balance equations of the periodic embedded Markov chains. The power method can have the convergence speed of exponential rate that is ambiguous in its application to original continuous-time Markov chains since the embedded chains are discrete-time processes. An illustrative example is presented to investigate the numerical iteration of this paper. A numerical study shows that a rapid and stable solution for stationary probabilities can be achieved regardless of periodicity and initial conditions.
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