• 전기학회논문지
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• 제57권8호
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• pp.1377-1382
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• 2008

DSTATCOM(distribution static compensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Researches about DSTATCOM are mainly divided two parts, one is the calculation of compensation current and the other part is the current control. Conventional researches use a LPF(low pass filter) to eliminate ripple component at the calculation of compensation current. But this method has a problem that LPF's characteristics restrict the compensation performance of instantaneous active and reactive power. This paper proposes a calculation of compensation current using state observer that can be a counterproposal of conventional methods using LPF. Improved performance of instantaneous active and reactive power compensation was shown by experiments.

• Journal of Power Electronics
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• 제19권5호
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• pp.1315-1325
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• 2019

Aiming at the negative sequence and harmonic problems in the operation of railway static power conditioners, an optimization compensation strategy for negative sequence and harmonics is studied in this paper. First, the hybrid RPC topology and compensation principle are analyzed to obtain different compensation zone states and current capacities. Second, in order to optimize the RPC capacity configuration, the minimum RPC compensation capacity is calculated according to constraint conditions, and the optimal compensation coefficient and compensation angle are obtained. In addition, the voltage unbalance ${\varepsilon}_U$ and power factor requirements are satisfied. A PSO (Particle Swarm Optimization) algorithm is used to calculate the three indexes for minimum compensating energy. The proposed method can precisely calculate the optimal compensation capacity in real time. Finally, MATLAB simulations and an experimental platform verify the effectiveness and economics of the proposed algorithm.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.289-297
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• 2014

This paper proposed a novel high performance sensorless control scheme for IPMSM based on an extended nonlinear state observer. The gain-matrix of the observer has been derived by using state linearization method. Steady state errors in estimated rotor position and speed due to parameter inaccuracy have been analyzed, and an equivalent flux error is defined to represent the overall effect of parameter errors contributing to the wrong convergence of the estimated rotor speed as well as rotor position. Then, an online compensation strategy was proposed to limit the estimation errors in rotor position and speed. The effectiveness of the extended nonlinear state observer is validated through simulation and experimental test.

• Smart Structures and Systems
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• 제14권6호
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• pp.1269-1289
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• 2014

With the sub-stepping technique, the numerical analysis in real-time dynamic hybrid testing is split into the response analysis and signal generation tasks. Two target computers that operate in real-time may be assigned to implement these two tasks, respectively, for fully extending the simulation scale of the numerical substructure. In this case, the integration time-step of solving the dynamic response of the numerical substructure can be dozens of times bigger than the sampling time-step of the controller. The time delay between the real and desired feedback forces becomes more striking, which challenges the well-developed delay compensation methods in real-time dynamic hybrid testing. This paper focuses on displacement prediction and force correction for delay compensation in the real-time dynamic hybrid testing with a large integration time-step. A new displacement prediction scheme is proposed based on recently-developed explicit integration algorithms and compared with several commonly-used prediction procedures. The evaluation of its prediction accuracy is carried out theoretically, numerically and experimentally. Results indicate that the accuracy and effectiveness of the proposed prediction method are of significance.

• 대한의용생체공학회:의공학회지
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• 제18권4호
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• pp.477-484
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• 1997

본 논문에서는 각성도 평가시 초기 각성상태 차이에 따른 보상방법을 제안하고 보상상수를 결정하였다. 각성도는 IRI와 Nz에 의하여 측정되었다. BI는 초기 저각성상태의 영향을 많이 받게 되며 이는 각성도의 지표인 Nz 값에 영향을 주게 되어 각성수준이 실제보다 높게 평가된다. 따라서 본 연구에서는 BI의 과대평가로 인한 오판정 문제를 해결하기 위하여 수정된KSS 측도(mKSS)를 이용한 보상법을 제안하고 각성수준에 따른 수정된 KSS 측도에 대응하는 보상상수를 결정하였다. 이 보상상수를 개발된 휴대형 각성도 측정 시스템에 적용하여, 실시간으로 각성도를 평가 및 제어한 결과, 본 연구에서 제안한 보상법 및 보상상수의 유용성을 확인하였다.

• 한국화재소방학회논문지
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• 제33권5호
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• pp.109-117
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• 2019

화재발생의 직접적인 원인 제공자들이 그 화재로 인한 피해자들에게 손해배상을 할 능력이 없으면 피해자들은 소방기관에 국가배상책임을 물어 피해구제를 받으려는 경향이 있다. 2가지 국가배상 사례 분석에서 화재로 인한 손해와 소방공무원의 화재예방 또는 소방특별조사 활동과 관련된 과실 사이에 인과관계가 있으면, 법원은 소방기관에서 피해자에게 손해를 배상하도록 판결함을 알 수 있었다. 2017년 12월 26일 「소방기본법」이 개정되어 '소방활동에 대한 면책' 조항이 마련되었지만 면책을 받으려면 그 활동의 불가피성이 입증되어야 하는데, 화재예방이나 소방검사 활동은 구조·구급활동과 달리 그 활동의 불가피성을 입증하기가 쉽지 않으므로 화재와 관련된 국가배상 청구 소송은 줄어들지 않을 것으로 예측된다.

• 디지털융복합연구
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• 제14권6호
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• pp.51-60
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• 2016

현대 국가는 과학기술의 발달에 따른 산업화와 정보화 추세 속에서 다양한 위험이 항상 따르게 된다. 이러한 환경하에서, 공무원의 직무수행 중 불법행위로 인하여 국민이 손해를 입은 경우에, 이를 구제해 주기 위해 우리 헌법은 국가배상청구권을 보장하고 있다. 국가배상의 문제는 법치국가의 원리에 따른 피해자의 권리구제, 공무원의 불법행위의 억제, 안정된 공무수행의 보장, 국고의 안정 등의 다양한 가치들을 조화롭게 고려하여야 한다. 그런데 현대 법치국가에서 공무원이 한 행위를 국가가 책임을 지는 이상, 반드시 고의와 과실을 요건으로 하여야만 국가가 책임을 진다는 것에는 의문이 있을 수 있다. 또한 헌법에 합치되는 자기책임설의 이론에 의하게 되면 국가배상법상 과실책임주의는 배제되어야 한다. 국가배상법상 공무원의 배상책임과 관련하여 고의와 과실과 같은 주관적 책임요건은 필요하지 않다고 보아야 한다. 따라서 현행 국가배상법의 개정을 통하여서 국가배상법의 원리를 과실책임주의로부터 무과실책임주의로 전환하여야 할 필요성이 있다.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.121-127
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• 2012

An electric power compensation system for a DC transmission system with an integrated wind turbine generator is proposed. The proposed compensation system consists of a synchronous generator and a duplex reactor. This apparatus is connected to the sending-end circuit of the DC transmission system. A set of steady-state equations of the system is first derived. Then, the effect of the duplex reactor, which can eliminate the sending-end grid current distortion due to commutation of the converter, is explored. The relationships among power at the sending-end circuit are also revealed. It is shown that fluctuations in the sending-end grid power due to changes in wind velocities are compensated with the proposed system. Finally, the effects of the sending-end grid conditions on the steady-state characteristics of the system are studied.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.390-391
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• 2007

We have studied improvement of light leakage of twisted nematic liquid crystal display (TN-LCD) in dark state using the hybrid aligned compensation film made of rod-like LC. When the voltage is applied properly to the TN-LCD, the director tilts up but LC director on the substrate don't tilts up due to surface anchoring energy of the LC cell. Accordingly, LC director from surface to middle LC of TN -LCD become hybrid state such as hybrid aligned film. Consequently, in this paper we achieve wide viewing angle performances of TN mode using developed hybrid aligned film which especially decreases light leakage at vertical direction in dark state.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.30-40
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• 2015

For a shunt power quality controller (SPQC) the DC side voltage value which is closely related to the compensation performance is a significant parameter. Buy so far, very little discussion has been conducted on this in a quantitative manner by previous publications. In this paper, a method to design the DC side voltage of SPQC is presented according to the compensation performance in the single-phase system and the three-phase system respectively. First, for the reactive current and the harmonic current compensation, a required minimal value of the DC side voltage with a zero total harmonic distortion (THD) of the source current and a unit power factor is obtained for a typical load, through the equivalent circuit analysis and the Fourier Transform analytical expressions. Second, when the DC side voltage of SPQC is lower than the above-obtained minimal value, the quantitative relationship between the DC side voltage and the THD after compensation is also elaborated using the curve diagram. Hardware experimental results verify the design method.