• 한국정보통신학회논문지
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• 제2권4호
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• pp.473-484
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• 1998

현재 우리나라의 상호접속제도는 기본적으로 전부비용배부방식에 의해 접속료를 산정하고 있으나 비용배부기준 등 이 방식의 기본적인 문제점뿐만 아니라 실제발생비용을 전부 보상하므로 효율적인 사업운영을 유도할 수 없다는 문제점을 가지고 있다. 또한 전면경쟁환경의 조성과 대외개방압력의 임박 등 통신환경변화는 경쟁활성화를 촉진하는 새로운 규제방식을 요구하고 있다. 이에 본 논문에서는 미국, 영국, 일본 등 통신선진국의 접속료규제방식의 동향분석과 주요 접속료산정방식 및 인센티브규제방식들에 대한 비교분석을 통하여 기본적으로 효율성이념을 보다 반영한 장기증분비용방식의 도입을 추진함과 아울러 기존사업자에 대한가격상한규제방식의 도입을 병행할 것을 제시하고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.867-870
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• 1997

This paper presents application of battery energy storage system(BESS) for interconnection with power distribution system. We configured interconnection model using PSCAD/EMTDC program. The simulation for voltage regulation on BESS interconnection with power distribution analyzes transient voltage variation, steady state voltage variation, and voltage of reverse power flow at interconnected feeder and nearby feeder.

• 인터넷정보학회논문지
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• 제15권5호
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• pp.123-132
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• 2014

본 논문은 비대칭적 규모를 가진 인터넷망사업자간의 인터넷망 접속대가 정산모형에 관한 분석적 모형을 통해 중계접속료 규제의 필요성을 제시하고자 한다. 일반적으로 인터넷망 상호접속은 사업자간 상업적인 계약에 기반하여 이루어지고 있으며, 대부분의 국가에서 별도의 사전적 규제가 적용되지 않고 있다. 하지만 최근 ICT생태계 환경의 변화로 인해 국내외적으로 인터넷 상호접속에 대한 사전규제의 필요성과 방법 등에 대한 논의가 활발히 진행 중이다. 국내의 경우 초고속인터넷 시장의 경쟁 심화로 사업자간 분쟁이 지속적으로 발생하자 이의 해결을 위한 최소한의 조치를 마련하는 차원에서 '05년 인터넷 상호접속에 직접적 규제 방안을 마련한 바 있다. 본 논문에서는 사업자간 네트워크 규모의 차이로 인하여 동일계위간 일방정산이 이루어지고 있는 국내 인터넷 정산모형하에서 네트워크 규모가 큰 사업자의 가격압착 행위 및 이에 따른 시장쏠림 현상의 발생 가능성을 검토하고 이에 대한 정책적 해결방안으로 중계접속료 규제가 필요함을 제시하였다. 이러한 분석결과는 인터넷 상호접속 규제정책에 대한 학술적, 실무적 논의의 기초자료로 활용될 수 있을 것이다.

• 한국통신학회논문지
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• 제31권12B호
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• pp.1099-1111
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• 2006

최근 국내 주요 이동통신사들이 W-CDMA R5(HSDPA)망을 본격 상용화함에 따라, 이에 알맞은 새로운 3G 이동통신 접속료 산정방안의 조속한 도입에 대한 필요성이 제기되고 있으나, 이에 대한 체계적인 연구사례를 찾기 힘들다. 본 연구에서는 새로운 접속료 산정방안 도입의 타당성을 검증하기 위하여 3G 이동통신과 관련된 기술, 시장, 규제 측면에 대한 통합적인 분석을 수행한다. 연구결과, 합리적인 접속료 산정과 관련한 3G 망 특성상의 여러 가지 기술적 한계, 이동통신 시장의 발전속도의 가변성, 사전규제의 타당성 검증문제, 그리고 수집 가능한 해외사례 등을 고려했을 때, 즉각적인 원가기반 접속료 산정방안 마련 및 적용은 합리적이지 못하며, 해당 시장의 성숙 또는 All-IP망으로의 진화 이후로 접속료 산정방안 개선시기를 미루는 것이 효율적임을 제안한다.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.712-718
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• 2013

With the development of industry and the improvement of living standards, better quality in power electric service is required more than ever before. This paper deals with the optimal algorithms for voltage regulation in the case where Distributed Storage and Generation (DSG) systems are operated in distribution systems. It is very difficult to handle the interconnection issues for proper voltage managements, because the randomness of the load variations and the irregular operation of DSG should be considered. This paper proposes the optimal on-line real time voltage regulation methods in power distribution systems interconnected with the DSG systems. In order to deliver suitable voltage to as many customers as possible, the optimal sending voltage should be decided by the effective voltage regulation method by using artificial neural networks to consider the rapid load variation and random operation characteristics of DSG systems. The simulation results from a case study show that the proposed method can be a practical tool for the voltage regulation in distribution systems including many DSG systems.

• 제어로봇시스템학회논문지
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• 제20권11호
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• pp.1118-1124
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• 2014

This paper proposes a novel controller design scheme for multimachine power systems based on the explorized policy iteration. Power systems have several uncertainties on system dynamics due to the various effects of interconnections between generators. To solve this problem, the proposed method solves the LQR (Linear Quadratic Regulation) problem of isolated subsystems without the knowledge of a system matrix and the interconnection parameters of multimachine power systems. By selecting the proper performance indices, it guarantees the stability and convergence of the LQ optimal control. To implement the proposed scheme, the least squares based online method is also investigated in terms of PE (Persistency of Excitation), interconnection parameters and exploration signals. Finally, the performance and effectiveness of the proposed algorithm are demonstrated by numerical simulations of three-machine power systems with governor controllers.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.2125-2133
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• 2018

To achieve high performance speed regulation, a robust adaptive speed controller is proposed for the permanent magnet synchronous motor (PMSM) subject to parameter uncertainties and input saturations in this paper. A nonlinear adaptive control is introduced to compensate the PMSM speed tracking errors due to uncertainties, disturbances and control input saturation constraints. By combining the adaptive control and the nonlinear robust control based on the interconnection and damping assignment (IDA) strategy, a new robust adaptive control is designed for speed regulation of PMSM. Stability and robustness of the closed-loop control system involved with the constrained control inputs rather than unconstrained control inputs are validated. Simulations for PMSM control in the presence of uncertainties and saturations nonlinearities show that the proposed approach is effective to regulate speed, and the average tracking error using the proposed approach is at least 32% smaller than the compared methods.

• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.192-201
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• 2011

The optimal evaluation algorithms for voltage regulation in the case where new dispersed sources are operated in distribution systems are studied. Handling the interconnection issues for proper voltage managements are often difficult and complicated because professional skills and enormous amounts of data during evaluations are needed. Typical evaluation algorithms mainly depend on human ability and quality of data acquired, which inevitably cause the different results for the same issue. Thus, unfair and subjective evaluations are unavoidable. In order to overcome these problems, we propose reasonable and general algorithms based on the standard model system and proper criterion, which offers fair and objective evaluation in any case. The proposed algorithms are divided into two main themes. One is an optimal algorithm for the voltage control of multiple voltage regulators in order to deliver suitable voltage to as many customers as possible, and the other is a proper evaluation algorithm for the voltage management at normal and emergency conditions. Results from a case study show that proposed methods can be a practical tool for the voltage management in distribution systems including dispersed sources.

• Advances in nano research
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• 제15권3호
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• pp.263-275
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• 2023

The electron transport properties of Y-type zigzag branched carbon nanotubes (CNTs) are of great significance for micro and nano carbon-based electronic devices and their interconnection. Based on the semi-empirical method combining tight-binding density functional theory and non-equilibrium Green's function, the electron transport properties between the branches of Y-type zigzag branched CNT are studied. The results show that the drain-source current of semiconducting Y-type zigzag branched CNT (8, 0)-(4, 0)-(4, 0) is cut-off and not affected by the gate voltage in a bias voltage range [-0.5 V, 0.5 V]. The current presents a nonlinear change in a bias voltage range [-1.5 V, -0.5 V] and [0.5 V, 1.5 V]. The tangent slope of the current-voltage curve can be changed by the gate voltage to realize the regulation of the current. The regulation effect under negative bias voltage is more significant. For the larger diameter semiconducting Y-type zigzag branched CNT (10, 0)-(5, 0)-(5, 0), only the value of drain-source current increases due to the larger diameter. For metallic Y-type zigzag branched CNT (12, 0)-(6, 0)-(6, 0), the drain-source current presents a linear change in a bias voltage range [-1.5 V, 1.5 V] and is symmetrical about (0, 0). The slope of current-voltage line can be changed by the gate voltage to realize the regulation of the current. For three kinds of Y-type zigzag branched CNT with different diameters and different conductivity, the current-voltage curve trend changes from decline to rise when the branch of drain-source is exchanged. The current regulation effect of semiconducting Y-type zigzag branched CNT under negative bias voltage is also more significant.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1088-1090
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• 1998

The cogeneration facilities (COGN) into the power distribution system can cause operational problems - reenergization of distribution feeders under repair by utility personnel, voltage variation and regulation because of output power of COGN, and lost of coordination at emergency state - on an electrical utility system. This paper deals with momentary voltage dips as the parallel interconnection operation of COGN in the power distribution system. PSCAD/EMTDC simulation tool is used to show the behavior of momentary voltage dips. In addition, restraint solution for momentary voltage variation is presented.