Power Distribution Control Scheme for a Three-phase Interleaved DC/DC Converter in the Charging and Discharging Processes of a Battery Energy Storage System

Xie, Bing,Wang, Jianze,Jin, Yu,Ji, Yanchao,Ma, Chong The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4

This study presents a power distribution control scheme for a three-phase interleaved parallel DC/DC converter in a battery energy storage system. To extend battery life and increase the power equalization rate, a control method based on the nth order of the state of charge (SoC) is proposed for the charging and discharging processes. In the discharging process, the battery sets with high SoC deliver more power, whereas those with low SoC deliver less power. Therefore, the SoC between each battery set gradually decreases. However, in the two-stage charging process, the battery sets with high SoC absorb less power, and thus, a power correction algorithm is proposed to prevent the power of each particular battery set from exceeding its rated power. In the simulation performed with MATLAB/Simulink, results show that the proposed scheme can rapidly and effectively control the power distribution of the battery sets in the charging and discharging processes.

고효율 고역률 LED 조명장치용 전원공급장치

정강률(Gang-Youl Jeong) 한국정보기술학회 2018 한국정보기술학회논문지 Vol.16 No.11

This paper presents the high efficiency and high power-factor power supply for LED lighting equipment. The proposed power supply is the single-stage power structure consisted of the full-bridge diode rectifier and flyback converter, and thus the power-factor correction and output voltage regulation are performed simultaneously using only one controller IC and one power semiconductor switch. Furthermore, the proposed power supply reduces the voltage stress and switching loss of main switch using the regenerative snubber, and it improves the system efficiency using the synchronous rectifier. The applied synchronous rectifier is the new voltage-driven type and its operation and construction are simple. In this paper, the operation principle of proposed power supply is explained through the operation analyses of its power-factor correction and main power conversion parts and the operation of synchronous rectifier is described, briefly. Also, a design example of the power circuit of 40W-class prototype is shown and the operation characteristics of proposed power supply are validated through the experimental results of the implemented prototype by the designed circuit parameter.

무산소성 파워 측정을 위한 윈게이트 검사 변인과 등속성 검사 변인의 상관관계

윤재량,임승길 대한운동사협회 2010 아시아 운동학 학술지 Vol.12 No.1

[INTRODUCTION] The purpose of this study was to investigate the correlation between Wingate test and isokinetic test for anaerobic power and to identify which isokinetic test variable can best predict anaerobic power. [METHOD] The subjects were 14 college male golfers. Anaerobic power was assessed by 30-second Wingate test and isokinetic test at 60, 180, 240°/s. In order to analyze collected data, pearson product moment and multiple regression analysis were utilized. The statistical significance was accepted at .05 levels. [RESULT] There was significant correlation between mean power in isokinetic knees extension at 60°/s and mean power of wingate test(r=.862, p<.01; R2=.743, p<.001). There was significant correlation between peak torque % body weight in isokinetic knees extension at 60°/s and mean power of Wingate test(r=.785, p<.05; R2=.775, p<.001). There was significant correlation between total work in isokinetic knees flexion at 60°/s and mean power per body mass of Wingate test(r=.762, p<.01; R2=.581, p<.01). And there was significant correlation between mean power in isokinetic knees extension at 60°/s and total work of Wingate test(r=.862, p<.01; R2=.743, p<.001). Although there was significant correlation between time to peak torque in isokinetic knees flexion at 60°/s and time to peak power of Wingate test(r=.-533, p<.01), time to peak torque could not precisely predict time to peak power. There was significant correlation between total work in isokinetic knees extension at 240°/s and peak power of Wingate test(r=.880, p<.01; R2=.775, p<.001), There was significant correlation between total work in isokinetic knees extension at 240°/s and fatigue index of Wingate test(r=.853, p<.01; R2=.728, p<.001). [CONCLUSION] Knee extension peak torque % body weight, average power at 60°/s, and total work at 240°/s were best important variables that can predicts anaerobic power when evaluated by using isokinetic test. Also total work at 60, 240°/s should be considered as anaerobic power variable. Time to peak torque of Wingate test was not proper variable to predict anaerobic power. [서론] 본 연구의 목적은 슬관절의 등속성 검사 변인 중 어떤 변인이 무산소성 파워를 가장 잘 대변할 수 있는지를 분석하는 것이다. [방법] 본 연구의 피험자는 K대학 소속의 골퍼 14명을 대상으로 하였다. 자료 분석은 윈게이트 검사의 측정 변인과 등속성 검사의 측정 변인 간의 상관분석, 다중 회귀분석을 이용한 단계적 방법으로 윈게이트 검사 변인들에 대한 등속성 근력 변인의 영향력을 검증하였다. 유의수준은 α= .05로 설정하였다. [결과] 각속도 60°/s에서의 신전 평균 파워와 윈게이트 검사의 평균 파워 간에 유의한 상관관계와 높은 설명력(r=.862, p<.01; R2=.743, p<.001)을 가지고 있었으며, 신전 단위체중당 피크 토크와 윈게이트 검사의 단위체중당 평균 파워 간에도 유의한 상관관계와 높은 설명력(r=.785, p<.01; R2=.616, p<.01)을 가지고 있었고, 굴곡 전체 일량과 윈게이트 검사의 단위체중당 최대 파워 간에도 유의한 상관관계와 높은 설명력(r=.762, p<.01; R2=.581, p<.01)을 가지고 있었다. 그리고 각속도 60°/s에서의 신전 평균 파워와 윈게이트 검사의 전체 일량 간에도 유의한 상관관계와 높은 설명력(r=.862, p<.01; R2=.743, p<.001)을 가지고 있었다. 각속도 60°/s에서의 굴곡 피크 토크 발현까지 소요시간이 윈게이트 검사의 최대 파워가지 소요시간과 가장 높은 상관관계(r=-.533, p<.05)를 가지고 있기는 했지만 정확하게 추정할 수 없는 것으로 나타났다. 각속도 240°/s에서의 신전 전체 일량과 윈게이트 검사의 최대 파워 간에 유의한 상관관계와 높은 설명력(r=.880, p<.01; R2=.775, p<.001)을 가지고 있었으며, 신전 전체 일량과 윈게이트 검사의 피로 지수 간에도 유의한 상관관계와 높은 설명력(r=.853, p<.01; R2=.728, p<.001)을 가지고 있었다. [결론] 등속성 검사로 슬관절 신전근과 굴곡근의 파워를 평가할 때는 60°/s에서 슬관절 신전 시 단위체중당 피크 토크, 평균 파워와 240°/s에서 슬관절 신전 시 전체 일량은 등속성 검사의 많은 변인 중에 파워를 평가하기 위한 가장 중요한 변인이다. 등속성 장비를 이용하여 파워를 평가할 때는 60°/s와 240°/s를 중요하게 해석해야 하며, 전체 일량도 파워를 평가하는 변인으로 함께 고려되어야 하며, 윈게이트 검사에서 최대 파워까지의 소요시간은 파워를 평가하기 위한 변인으로는 적절하지 못한 것으로 사료된다.

영장류의 사회적 행위를 통한 ‘권력’의 의미와 기원에 관한 연구

박성진 한국정치사상학회 2020 정치사상연구 Vol.26 No.1

본 연구의 목적은 영장류의 정치적 행위를 통해 ‘권력’의 기원과 생태 및 권력에 관한 일반이론을 검토해 보는 것이다. 즉 ‘권력’이 발생하게 된 이유와 양식 그리고 권력을 쟁취하려고 하는 생래적 의지의 원인을 영장류의 사회적 행위를 통해 살펴보고 권력의 원시적 형태를 분석하는 것이 본 연구의 목적이다. 지금까지 권력은 복잡한 인간의 역사와 함께하며 인간만이 가진 고유의 특성으로 인식되어 왔다. 하지만 권력은 침팬지와 보노보를 비롯한 무리생활을 하는 영장류에게 공통적으로 나타나는 현상이다. 이러한 사실은 정치철학의 핵심주제라 할 수 있는 ‘권력’의 기원과 원시적 모습을 탐구하기 위해서는 이들의 사회적 행위에 대해 살펴볼 필요가 있다는 것을 의미한다. 하여 본 연구는 침팬지의 사례를 통해 권력을 분석하였으며 그 결과 권력은 기존의 이론에서 말하는 것처럼 한 개인이나 개체가 가진 능력들의 우월성으로부터 기인하는 것이 아니라 여러 개체들의 연결접속으로 구성된 연맹이나 연합 등 네트워크에 의해서 발생하는 것으로 나타났다. 그리고 무리 동물들은 철저하게 네트워크에 의해서 서열을 구성하며 어떤 네트워크에 연결접속을 가지고 있느냐에 따라서 생존의 기반이 되는 먹이와 자손을 가질 확률이 높아지는 것으로 나타났다. 생존에 대한 생래적 욕구가 네트워크를 구성하며 그 네트워크는 권력을 생산하고 다시 네트워크와의 연결접속을 만들려고 하는 개체들을 통제하며 가치를 생산하여 개체들의 행위를 제약한다. 고도의 정치적 기법으로 자신들만의 관계와 서열을 그물처럼 엮어가는 침팬지들의 행동은 우리에게 권력에 대한 욕망과 그것에 대한 추구가 인간의 기원보다 더 오래되었음을 통찰하게 한다. The purpose of this study is to examine the origin of 'power' and general theory of power through the political behavior of primates. In other words, the purpose of this study is to examine the reasons, styles, and the causes of the natural will to gain power through the social behavior of primates and analyze the primitive form of power. Until now, power has been recognized as a unique characteristic of only humans, along with complex human history. But power is a common phenomenon for primates living in groups, including chimpanzees and bonobos. This means that it is necessary to look at their social behaviors in order to examine the origin and primitive aspects of 'power', which is the core theme of political philosophy. As a result of analyzing power through the case of chimpanzees, power is not caused by the superiority of the abilities of an individual or an individual as mentioned in the existing theory, but by a network such as a federation or a coalition composed of connections of various objects. And it is analyzed that the group animals are thoroughly sequenced by the network and have a higher probability of having prey and offspring that are the basis of survival depending on which network they have connections. The natural desire for survival constitutes a network, which controls individuals who produce power and try to make connections with the network again. And the network produces value and constrains the behavior of individuals. The behavior of chimpanzees, who weave their own relationships and sequences into nets with highly political techniques, gives us insight into the desire for power and the pursuit of it being older than human origins.

Exercises of Power in Marketing Channel Dyads - Power Advantage versus Power Disadvantage

Guijun Zhuang,Neil C,Herndon Jr,Nan Zhou 한국마케팅과학회 2005 한국마케팅과학회 학술대회 발표 논문집 Vol.- No.-

Taking the channel dyad as the unit of analysis, this study investigated the impact of channel members’ power on their uses of power in two distinct conditions: in power advantage and in power disadvantage. The study found that channel members" power has a positive impact on their uses of noncoercive power regardless of their relative position in channel dyads; their uses of coercive power are sensitive negatively to their own power in the condition that they are in power advantage, and sensitive negatively to the target members’ power in the condition that they are in power disadvantage. It also finds that the predictions of deterrence theory are partially supported in both the case of power advantage and power disadvantage, while no evidence supports the predictions of conflict spiral theory in either case. One contribution of this study is that the research method and research findings provide a possible explanation for the inconsistent or contradictory empirical findings on the relationship between power and exercises of power.

전력계통의 전압안정도향상을 위한 감시제어시스템 개발

이현철(Hyun-Chul Lee),정기석(Ki-Suk Jeoung),박지호(Ji-Ho Park),백영식(Young-Sik Baek) 대한전기학회 2013 전기학회논문지 Vol.62 No.4

This paper was developed a monitoring and control system to use reactive power control algorithm. This algorithm could be improved voltage stability in power system. This method was controlled the voltage for stability improvement, effective usage of reactive power, and the increase of the power quality. PMS(Power Management System) has been calculate voltage sensitivity, and control reactive power compensation device. The voltage control was used to the FACTS, MSC/MSR(Mechanically Switched Capacitors/Reactors), and tap of transformer in power system. The reactive power devices in power system were control by voltage sensitivity ranking of each bus. Also, to secure momentary reactive power, it had been controlled as the rest of reactive power in the each bus. In here, reactive power has been MSC/MSR. The simulation result, First control was voltage control as fast response control of FACTS. Second control was voltage control through the necessary reactive power calculation as slow response control of MSR/MSR. Third control was secured momentary reactive reserve power. This control was method by cooperative control between FACTS and MSR/MSC. Therefore, the proposed algorithm was had been secured the suitable reactive reserve power in power system.

『폭풍우』에 나타난 권력 정치학

서용득 ( Yong Deuk Suh ) 한국드라마학회 2004 드라마연구 Vol.- No.22

The Tempest was one of Shakespeare`s last plays. The Tempest is a play with so many layers of meaning that no single interpretation can do it justice. One of the interpretations of The Tempest is the power politics. Because The Tempest is a play about power relation. It has a large vocabulary of power, relation such as conspiracy, treachery, betrayal, rebellion, deposition, authority, and usurpation. Especially Prospero exercises his absolute power on the island; All of the characters except Miranda and Ferdinand are preoccupied with the will to power. Shakespeare was concerned with problems of government, with the tensions between power and virtue. It is striking that all the characters are involved in this problem in one way or another. Prospero has absolute power. So he can control the destinies of all the people on the island and he seems to be using his power for benigh ends. But there are Anthonio and Sebastian`s treachery to depose Alonso and make Sebastian king of Naples. Stepano and Trinculo`s conspiracy with Caliban to depose Prospero and make Stepano king of the island. But Prospero handles the end like a master playwright, suddenly weaving together all the plotlines to bring about the denouement he desires. Shakespeare suggests that power must never operate out of fear, out of terrible vengeance which is destructive of all justice. Power must be used to liberate man from hate. Acting so power becomes pure justice and society ethical and human. The Tempest deals with sinfulness past and present, and that the conclusion is characterized by repentance, forgiveness and reconciliation. It seems to be a kind of struggle for power remains the same. Miranda and Ferdinand will be rulers in the future by marriage. Especially Ferdinand is conscious of his political position.

Consumed-Power and Load Characteristics of a Tillage Operation in an Upland Field in Republic of Korea

김정길,김영주,김정훈,신범수,남주석 한국농업기계학회 2018 바이오시스템공학 Vol.43 No.2

Purpose: This study derived the consumed power and load characteristics of a tillage operation performed in an upland field located in Seomyeon, Chuncheon, Rep. Korea, where potatoes and cabbages were cultivated in two crops. Methods: A plow and rotavator were mounted on a tractor with 23.7 kW of rated power to perform the tillage operation. The work conditions were determined, considering the actual working speed of the tillage operation performed by the local farmers. The power consumption of the rear axle, engine, and power take-off (PTO), PTO torque, and tractive force were measured under each work condition. The consumed power and load characteristics were analyzed using their average values. Results: The rotary-tillage operation consumed more engine power than the plow operation for the same tractor-transmission gear condition. The PTO in the rotary-tillage operation and the rear axle in the plow operation consumed the most power. The power consumption of the engine and the PTO for the rotary-tillage operation tended to increase as the transmission gears of the tractor and the PTO became higher. In contrast, the rear-axle power consumption was insignificant. In addition, the PTO torque tended to rise as the tilling pitch increased. For the plow operation, the drawbar power and the rear axle power accounted for 68–90% of the engine power. The engine and rear axle power, drawbar power, and tractive force tended to rise as the working speed increased. Conclusions: The power consumption and load characteristics differed for the plow and rotary-tillage operations. They may also differ depending on the soil conditions. Therefore, the power consumption and load characteristics in various work environments and regions should be analyzed, and reflected in the design of tractors and working implements. The results derived from this study can be used as a reference for such designs.

Consumed-Power and Load Characteristics of a Tillage Operation in an Upland Field in Republic of Korea

Kim, Jeong-Gil,Kim, Young-Joo,Kim, Jung-Hun,Shin, Beom-Soo,Nam, Ju-Seok Korean Society for Agricultural Machinery 2018 바이오시스템공학 Vol.43 No.2

Purpose: This study derived the consumed power and load characteristics of a tillage operation performed in an upland field located in Seomyeon, Chuncheon, Rep. Korea, where potatoes and cabbages were cultivated in two crops. Methods: A plow and rotavator were mounted on a tractor with 23.7 kW of rated power to perform the tillage operation. The work conditions were determined, considering the actual working speed of the tillage operation performed by the local farmers. The power consumption of the rear axle, engine, and power take-off (PTO), PTO torque, and tractive force were measured under each work condition. The consumed power and load characteristics were analyzed using their average values. Results: The rotary-tillage operation consumed more engine power than the plow operation for the same tractor-transmission gear condition. The PTO in the rotary-tillage operation and the rear axle in the plow operation consumed the most power. The power consumption of the engine and the PTO for the rotary-tillage operation tended to increase as the transmission gears of the tractor and the PTO became higher. In contrast, the rear-axle power consumption was insignificant. In addition, the PTO torque tended to rise as the tilling pitch increased. For the plow operation, the drawbar power and the rear axle power accounted for 68-90% of the engine power. The engine and rear axle power, drawbar power, and tractive force tended to rise as the working speed increased. Conclusions: The power consumption and load characteristics differed for the plow and rotary-tillage operations. They may also differ depending on the soil conditions. Therefore, the power consumption and load characteristics in various work environments and regions should be analyzed, and reflected in the design of tractors and working implements. The results derived from this study can be used as a reference for such designs.

고조파 왜곡 환경에서 향상된 역률 계측 알고리즘 개발

이현우,박영균,이진한,정상현,박철우 대한전자공학회 2016 전자공학회논문지 Vol.53 No.7

We propose a algorithm to calculate power factor of fundamental waveform in an environment where the voltage and current have been distorted by harmonics. In the proposed power factor computation algorithm, voltage and current are converted to rotating DQ reference frame, and power factor is calculated from active power and reactive power. We compare the proposed method with the conventional power factor measurement method as mathematically. In a condition that voltage and current are distorted by harmonics, the proposed method accurately measure the power factor of fundamental wave, and it is confirmed by simulation using MATLAB. If the proposed power factor measurement method is applied to an automatic power factor control system, a power factor compensation performance can be maximized in harmonic distortion environment. As a result, it is possible to reduce electricity prices, reduce line loss, increase load capacity, ensure the transmission margin capacity, and reduce the amount of power generation. 본 논문에서는 고조파로 전압과 전류가 왜곡된 상황에서 정확하게 기본파의 역률을 측정할 수 있는 방법을 제안한다. 제안한 역률 계측 방법에서는 전압과 전류를 DQ회전좌표계로 변환한 후 유효전력과 무효전력을 계산하여 역률값을 구하게 된다. 기존의 역률 계측방법과 제안한 방법을 수식적으로 비교하여 제시하고, 제안한 방법은 전압과 전류 모두 고조파 왜곡된 상황에서도 기본파의 역률을 정확하게 계측할 수 있는 것을 MATLAB을 이용한 모의실험에서 확인한다. 제안한 역률 계측방법을 자동역률제어장치에 적용할 경우 고조파 왜곡 환경에서 역률 보상 성능을 최대화 할 수 있다. 그 결과 수용가에서는 역률 개선을 통한 전기료 감소, 선로손실 감소, 부하 용량 증대 효과가 기대된다. 특히 발전 사업가 측에서는 역률 보상 성능의 향상으로 송전 여유 용량 확보와 발전량 절감이 가능하다.