• 한국ITS학회 논문지
• /
• 제19권2호
• /
• pp.1-17
• /
• 2020

본 연구는 자율주행 시대에 대비하여 기존의 인간 운전자 대상의 교통규제의 변화를 모색하기 위해, 기존 교통안전시설 규제정보 공공개방을 위한 기초 인식조사 연구를 수행하였다. 이를 위해 자율주행차 관련 정보 수요자 집단, 현행 교통규제정보 관련 정보 관리자 집단을 대상으로 전문가 심층면접(In-depth Interview, IDI)을 수행하여 교통규제정보 공공개방의 방향성을 확인하였다. 분석 결과, 동적 규제정보에 대한 체계적 제공, 정보의 신뢰성 향상, 일원화된 정보 관리 체계에 대한 필요성을 확인하였으며 자율주행차의 주행에 대비한 IoT 기반의 교통안전시설 도입에 대한 요구사항을 도출하였다. 또한 서비스 제공을 위한 관리기관 및 수요기관 간의 유기적인 협업체계가 필요함을 확인하였다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집B
• /
• pp.656-661
• /
• 2000

In the recent trend of electric power supply market, a variable pressure operation supercritical once-through steam generator is highlighted as a thermal power plant for cycling load because of its superiority in load regulation. Almost all thermal power plants of the future are expected to be variable pressure operation supercritical once-through units. APESS(Advanced Plant Engineering & Simulation System) is a dynamic simulation software for power plant which is under being developed by Korea Heavy Industries & Construction Co., Ltd. This paper present the introduction of APESS and the result of simulation for variable pressure operation supercritical once-through steam generator.

• Journal of Communications and Networks
• /
• 제18권4호
• /
• pp.658-669
• /
• 2016

The tremendous increase in mobile data traffic coupled with fierce competition in wireless industry brings about spectrum scarcity and bandwidth fragmentation. This inevitably results in asymmetric-valued long term evolution (LTE) spectrum allocation that stems from different timing for twice improvement in capacity between competing operators, given spectrum allocations today. This motivates us to study the economic effects of asymmetric-valued LTE spectrum allocation. In this paper, we formulate the interactions between operators and users as a hierarchical dynamic game framework, where two spiteful operators simultaneously make spectrum acquisition decisions in the upper-level first-price sealed-bid auction game, and dynamic pricing decisions in the lower-level differential game, taking into account user subscription dynamics. Using backward induction, we derive the equilibrium of the entire game under mild conditions. Through analytical and numerical results, we verify our studies by comparing the latest result of LTE spectrum auction in South Korea, which serves as the benchmark of asymmetric-valued LTE spectrum auction designs.

• 융합신호처리학회 학술대회논문집
• /
• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
• /
• pp.183-187
• /
• 2003

When a flexible arm is rotated by a motor about an axis through the arm's fixed end, transverse vibration may occur. The motor torque should be controlled in such a way that the motor rotates by a specified angle, while simultaneously stabilizing vibration of the flexible arm so that it is arrested at the end of rotation. In this paper, we propose nonlinear observer for one-link flexible am. Then based on the error dynamic equation between the plant dynamic equation and the nonlinear observer dynamic equation of the flexible one-link am, Lyapunov candidate function is applied to achieve a stable deterministic nonlinear feedback controller for the regulation of joint angle.

• Journal of Power Electronics
• /
• 제18권3호
• /
• pp.944-953
• /
• 2018

This paper proposes an analysis method based on the magnitude-phase dynamic theory for isolated power systems with static synchronous compensators (STATCOMs). The stability margin of an isolated power system is greatly reduced when a load is connected, due to the disadvantageous features of the self-excited induction generators (SEIGs). To analyze the control process for system stability and to grasp the dynamic characteristics in different timescales, the relationships between the active/reactive components and the phase/magnitude of the STATCOM output voltage are derived in the natural reference frame based on the magnitude/phase dynamic theory. Then STATCOM equivalent mechanical models in both the voltage time scale and the current time scale are built. The proportional coefficients and the integral coefficients of the control process are converted into damping coefficients, inertia coefficients and stiffness coefficients so that analyzing its controls, dynamic response characteristics as well as impacts on the system operations are easier. The effectiveness of the proposed analysis method is verified by simulation and experimental results.

• 한국철도학회논문집
• /
• 제19권6호
• /
• pp.777-784
• /
• 2016

본 연구에서는 도시철도에 사용되는 방진체결장치가 현장에서 부담하는 하중의 체계적 평가를 통하여 방진체결장치의 성능시험하중에 대한 기준이 정립되었다. 방진체결장치가 가질 수 있는 동적 강성 범위를 알아보기 위하여 국내에서 공급 가능한 3가지 유형의 방진체결장치들에 대하여 동적 시험을 수행하였다. 이들 방진체결장치에 작용하는 하중을 평가하기 위하여 동적 강성을 변화하면서 차량-궤도 상호작용해석을 수행하였다. 해석의 중요 입력요소인 궤도틀림은 측정자료를 토대로 도출된 궤도틀림 PSD(Power Spectral Density) 회귀 함수로 고려하였다. 도시철도의 다양한 운영환경을 고려하여 방진체결장치에 작용하는 하중을 평가한 후, 평가된 하중을 토대로 방진체결장치의 성능시험하중에 대한 기준을 제시하였다.

• 자원ㆍ환경경제연구
• /
• 제18권1호
• /
• pp.75-103
• /
• 2009

'Porter Hypothesis'는 환경규제가 강한 국가에서 재생에너지 및 환경규제 관련 산업의 기술개발이 촉진되어 해당산업의 수출이 증가한다고 환경규제와 무역의 관계를 설명하고 있다. 이점에 착안하여 수입국의 환경규제가 우리나라의 재생에너지 및 에너지절감산업의 수출에 미치는 영향을 중력모형을 이용한 실증분석을 통하여 분석한다. 또한 환경선진국인 일본의 경우에도 같은 분석을 시행하여 우리나라와 비교한다. 추정 결과에 의하면 도출된 환경변수의 계수값이 부분적으로는 유의하지 않은 결과가 나왔지만 전반적으로 한국 및 일본의 재생에너지 및 에너지절감산업에 있어 환경과 수출과의 관계에서 'Porter Hypothesis'가 성립됨을 보였다. 또한 한국과 일본의 환경변수의 계수값을 비교한 결과, 본 연구에서 적용한 세 가지 환경변수의 계수에 대한 한국의 절대값이 일본의 것보다 연도와 환경변수의 종류에 관계없이 크게 나왔다. 이는 재생 에너지 및 에너지절감 분야에서 우수한 기술력을 바탕으로 국제경쟁력을 갖춘 일본 기업들의 제품과 기술력이 환경규제가 강한 국가의 시장에서도 활용되고 있기 때문이다. 반면 한국 기업은 아직 일본에 비하여 국제시장에서 다소 경쟁력이 떨어지기 때문에 수입국의 환경규제가 강할수록 수출의 감소폭이 일본에 비하여 클 수밖에 없다. 이러 한 실증분석 결과는 우리의 기술 수준이 아직 선진국 수준에 이르지 못하고 있음을 보여주는 간접적인 증거이다.

• Journal of Power Electronics
• /
• 제5권2호
• /
• pp.109-119
• /
• 2005

This paper deals with the performance analysis of static compensator (STATCOM) based voltage regulator for self­excited induction generators (SEIGs) supplying balanced/unbalanced and linear/ non-linear loads. In practice, most of the loads are linear. But the presence of non-linear loads in some applications injects harmonics into the generating system. Because an SEIG is a weak isolated system, these harmonics have a great effect on its performance. Additionally, SEIG's offer poor voltage regulation and require an adjustable reactive power source to maintain a constant terminal voltage under a varying load. A three-phase insulated gate bipolar transistor (IGBT) based current controlled voltage source inverter (CC- VSI) known as STATCOM is used for harmonic elimination. It also provides the required reactive power an SEIG needs to maintain a constant terminal voltage under varying loads. A dynamic model of an SEIG-STATCOM system with the ability to simulate varying loads has been developed using a stationary d-q axes reference frame. This enables us to predict the behavior of the system under transient conditions. The simulated results show that by using a STATCOM based voltage regulator the SEIG terminal voltage can be maintained constant and free from harmonics under linear/non linear and balanced/unbalanced loads.

• Journal of Electrical Engineering and Technology
• /
• 제11권2호
• /
• pp.300-308
• /
• 2016

Application of demand-side resources to automatic generation control (AGC) has a great significance for improving the dynamic control performance of power system frequency regulation. This paper investigates the possibility of providing regulation services by demand-side energy storage in electric vehicle battery swapping stations (BSS). An interaction framework, namely station-to-grid (S2G), is presented to integrate BSS energy storage into power grid for giving benefits to frequency regulation. The BSS can be regarded as a lumped battery energy storage station through S2G framework. A supplementary AGC method using demand-side BSS energy storage is developed considering the vehicle user demand of battery swapping. The effects to the AGC performance are evaluated through simulations by using a two-area interconnected power grid model with step and random load disturbance. The results show that the demand-side BSS can significantly suppress the frequency deviation and tie-line power fluctuations.

• 전기학회논문지
• /
• 제56권10호
• /
• pp.1731-1737
• /
• 2007

The Korea electricity wholesale market is operated under the cost-based-pool system and the government regulation to the new generation capacities in order to insure the resource adequacy. The goal of government's regulation is the electricity market stability by attracting proper generation investment while keeping the reliability of system. Generation companies must mandatory observe that government plan by now. But if the restructuring is to be complete, generation companies should not bear any obligation to invest unless their profitability is guaranteed. Namely the investors' behavior will be affected by the market prices. In this paper, the system dynamics model for Korea wholesale electricity market to examine whether competitive market can help to stabilize is developed and analyzes the investors behavior. The simulation results show that market controlled by government will be operated stable without resulting in price spike but there is no lower price because of maintaining the reasonable reserve margin. However, if the competition is introduced and the new investment is determined by the investor's decision without government intervention, the benefits from lower wholesale price are expected. Nevertheless, the volatility in the wholesale market increases, which increases the investment risks.