• 전력전자학회논문지
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• 제9권4호
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• pp.341-349
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• 2004

본 논문에서는 전체 시스템의 용량 증대와 부하 중요도에 따른 신뢰성 향상을 위해 사용되는 UPS 병렬 운전시 발생하는 문제점을 해석하고, 이를 해결하기 위해 기존에 연구되어온 다양한 제어기법들을 조사하였다. 또한 기존의 연구방법에서 적용할 수 없었던 다른 정격의 병력 운전 적용시 L, C 출력필터에 의한 문제점을 해결하기 위해 주종 제어를 이용한 3상 UPS의 전류 분달 제어기법이 연구되었다. 제안된 제어 알고리즘의 타당성을 검증하기 위해 시뮬레이션 및 실험을 수행하였다.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.106-109
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• 2013

It is desirable and advantageous to feed parallel propulsion with induction motors by a single voltage source inverter. However, effects of deviation of the wheel diameters on motor current, rotor speed and torque should be also considered for parallel operation. In order to understand the behavior and characteristics, a simple simulation model is developed by using a commercial Matlab Simulink. From the results, it is clear to manage the diameter deviation of the wheels which are connected to traction motors.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1176-1181
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• 2006

본 연구에서는 병렬구조를 가진 안동댐과 임하댐에 대하여 할당법칙(Allocation rule, AR)을 이용하여 용수공급해석과 신뢰도지표를 산정하였다. 할당계수의 분석결과로는 안동댐이 용수공급의 기여도가 임하댐과 비교해서 Rule(A), Rule(B)에서는 66%이상으로 분석되었으며, Rule(C)의 경우 거의 대등한 기여를 하는 것으로 분석되었다. Rule(C)의 경우는 안동댐과 임하댐의 각각의 저류상태와 공급능력 상태에 따라 저류량과 유입량의 합을 댐의 평균저류량으로 나눈 비에 의해 공급량이 할당되어서 우수한 결과를 나타내었다. 병렬저수지 시스템의 용수공급의 분석기준에 있어 월별로 일정한 양을 기준으로 분석하는 것보다는 월별 용수변화량을 고려한 경우가 용수공급분석에 있어 우수한 결과를 나타나는 것으로 분석되었다. 본 연구를 기초로 하여 용수공급해석을 위한 새로운 기법이 개발되어 병렬저수지에 적용되었으며, 이 운영규칙은 여러 종류의 병렬저수지 시스템의 적용에 있어 효율적인 운영방안을 수립할 수 있을 것이다.

• 한국정보통신학회논문지
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• 제10권9호
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• pp.1538-1544
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• 2006

본 논문은 $GF(2^m)$상의 n차 기 약 AOP를 적용하여 비-시스토릭 병렬 $AB^2+C$ 연산기를 제안한다. 본 논문에서 제안한 연산기 회로는 AND게이트와 EX-OR 게이트만을 사용하여 설계되어지며, 설계된 회로는 기약 AOP의 특성을 이용하여 게이트를 사용하지 않고 결선으로만 연결되어 게이트 및 지 연시간이 없는 순환이동과, m개의 AND 게이트와 m개의 EX-OR게이트를 필요로 하는 승산연산, EX-OR게이트로만 구성되어지는 멱승연산, 승산연산과 멱승연산을 이용한 파워섬연산 및 가산연산 등이 사용된다. 제안된 연산기 법은 AND게이트와 EX-OR게이트만을 사용함으로 고속의 데이터 처리, 저전력 및 집적화 등의 장점이 있으며, $T_A+(1+[log^m_2])T_X$의 연산 지연시간을 갖는다.

• 전력전자학회논문지
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• 제5권2호
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• pp.184-191
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• 2000

기존의 2개의 컨버터를 병렬 운전하기 위해서는 2개의 변류기 (CT)가 필요하였으나, 본 논문에서는 1개의 변류기만으로도 2개의 컨버터를 병렬 운전 가능한 단일 전류센서 방식의 마스터-슬레이브 운전 방법을 제안하였다. 제안된 단일 전류센서 방식의 부하 전류 분배 성능을 확인하기 위하여, 2개의 컨버터를 설계, 제작하였고 기존방법 (예: 최대 전류법)과 부하 전류 분배 성능을 세 가지의 임의 조건하에서 시뮬레이션, 부하 실험을 통하여 비교하였다. 실험 결과 컨버터 2대를 병렬 운전하는 경우, 기존의 방법으로는 2개의 CT가 필요하였으나 제안한 단일 전류센서 방식을 이용한면 1개의 CT만으로도 부하 전류 분배가 잘 이루어짐을 확인할 수 있었다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권4호
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• pp.272-281
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• 2000

This paper deals with the parallel operation of several numbers of PWM converters for a high speed railway train application. Several considerations are made to reduce the transformer interaction which can cause a current control problem in severe case. Also, in this paper, novel control strategy is proposed to achieve a harmonic free primary-side current control under a light load condition using one current sensor independent of the number of converters. In addition, the modified predictive current controller, which is suitable to a digital current controller with a relatively large sampling period, is used. Finally, to verify the system validity, digital control system with TMS320C44 micro-processor and small scale simulator are made and tested.

• 전력전자학회논문지
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• 제28권1호
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• pp.39-47
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• 2023

This paper applies a structural technique with uniform parallel switch characteristics in gates and power loops to minimize the ringing and current imbalance that occurs when a general discrete package (TO-247)-based power semiconductor device is operated in parallel. Also, this propose a heat sink integrated switching module with heat sink design flexibility and high power density. The developed heat dissipation-integrated switching module verifies the symmetry of the parasitic inductance of the parallel switch through Q3D by ansys and the validity of the structural technique of the parallel switch using the LLC resonant converter experiment operating at a rated capacity of 7.5 kW.

• 상하수도학회지
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• 제16권6호
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• pp.670-678
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• 2002

Since Korean government imposed a stricter regulation on effluent T-N and T-P concentrations from wastewater treatment plant, a new process has to be developed to meet these rules and this process should remove T-N and T-P, economically, from weak wastewater that is typical for Korea's combined sewer system sewage. In this study, a computer simulator, BioWin from EnviroSim, Inc. was used. Three processes - A2/O, Modified Johannesburg, UCT- had been simulated under same operational conditions and a new process - Parallel BNR Process - had been developed based on these simulation results. The Parallel BNR process consists of two rows of reactors: One row has anaerobic and aerobic reactors in series, and the other row has RAS anoxic1 and RAS anoxic2 reactors in series. In order to ensure anaerobic state in anaerobic tank, a part of influent is fed to RAS anoxic1 tank in second row. This process had been simulated under same conditions of other three processes and the simulation results were compared. The results showed that three existing processes could not perform biological phosphorus removal when the average influent was fed at any operation temperatures. However, the Parallel BNR process was found that biological phosphorus removal could be performed when both design and average influent were fed at any operation temperatures. This process showed the T-N concentration in effluent had a maximum value of 15mg/L when design influent was fed at $13^{\circ}C$ and a minimum value of 14mg/L when average influent was fed at $20^{\circ}C$. Also, T-P concentrations had a maximum value of 1.3mg/L when average influent was fed at $20^{\circ}C$ and a minimum value of 1.1mg/L when design influent was fed at $13^{\circ}C$. Based on these results, we found that this process can remove nitrogen and phosphorus biologically under any operational conditions.

• 상하수도학회지
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• 제21권2호
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• pp.215-224
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• 2007

The purpose of this study was to estimates water supply reliability indices of the water supply by Allocation Rules(AR) for parallel reservoirs. Rule (A) can be considered it as only current storage, Rule(B) can be considered it as current storage and inflow and Rule(C) can be considered it as current storage, inflow and water supply capacity. First, conditions of water supply are divided by Condition I for the monthly constant water supply and Condition II for the monthly varied water supply. Second, results of allocation coefficients are revealed the smallest different at Rule(C). The analysis of water supply showed that the capability of water supply is superior to the Rule(B), it is superior to the Rule(C) on the base of the balance of water supply. The reliability analysis was highly showed at the Rule(B) and Rule(C). A methodology for the analysis of water supply was developed and applied to the parallel reservoir system from this research, The operation rule for the parallel reservoir can be slightly modified and successfully applied to the different kinds of the parallel reservoir system.

• International Journal of Internet, Broadcasting and Communication
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• 제12권3호
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• pp.87-94
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• 2020

Recently, computer hardware is evolving toward increasing the number of computing cores, not increasing the clock speed. In order to use the performance of parallelized hardware to the maximum, the running program must also be parallelized. However, software developers are accustomed to sequential programs, and in most cases, write programs that operate sequentially. They also have a lot of difficulty designing and developing software in parallel. We propose a method to automatically convert a sequential C/C++ program into a parallelized program, and develop a parallelization tool that supports it. It supports open multiprocessing (OpenMP) and parallel patterns library (PPL) as a parallel framework. Perfect automatic parallelization is difficult due to dynamic features such as pointer operation and polymorphism in C/C++ language. This study focuses on verifying the conditions of parallelization rather than focusing on fully automatic parallelization, and providing advice to developers in detail if parallelization is not possible.