전기추진 선박의 연비 개선을 위한 부하예측 기반의 발전기 스케줄링 기법

정범희,김지안,심재성,정일엽 대한전기학회 2024 전기학회논문지 Vol.73 No.4

In this paper, we propose generator scheduling method using load forecasting to improve the economic efficiency in electric propulsion ship. For efficient generator scheduling, we derive generator cost function using the generator specific fuel consumption (SFC) curves. Next, we classify the ship load into three categories such as propulsion load, service load, and pulse load. According to the load categories, we define the forecasting methods that are suitable for the load characteristics. Then, using the load forecasting results, the proposed generator scheduling algorithms determine the generator unit commitment to prevent repeated turn-on-and-off operations of the specific generators and calculate the generator economic dispatch using the generator fuel cost function. Through simulation case studies, we perform generator scheduling based on various combinations of different sizes of generators and ship operation scenarios. Based on the generator scheduling results, we calculate the total fuel cost and start-up cost, and we analysis an economic efficiency by comparing traditional generator scheduling and proposed generator scheduling method. We also analyze economic efficiency according to generator configuration in electric propulsion ship

A Study on Operation Algorithm of Load Test Device Using Energy Storage System for Field Test in Fire-Fighting Emergency Generator

Choi Seung-Kyou 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

An emergency generator for fi re-fi ghting is a key equipment to supply power sources into fi re-fi ghting facilities which protect property and human in case of fi re accidents. With its necessary role, a rated load test of emergency generator should be mandatorily carried out by connecting emergency load with the generator in accordance with related regulations. However, the no-load test for emergency generator has been performed in general, since serious problems including damage of customer device and shut down of critical load can be occurred when main power is cut off . Therefore, in order to overcome these problems, this paper proposes test method and operation algorithm of load test device with ESS in order to evaluate performance and state of emergency generator without interruption of power supply based on charging mode of ESS with same characteristics of emergency load. In addition, this paper presents a PSCAD/EMTDC modeling of emergency power supply system which is composed of emergency generator, emergency load and load test device with ESS. From the simulation results based on the proposed modeling and algorithm, it is confi rmed that load test method for emergency generator using ESS are useful and practical tools for fi eld load test in fi re-fi ghting facility.

극지해양구조물 성능평가를 위한 스펙트럼 기반 시간역 빙하중 생성에 관한 연구

김영식,김진하,강국진,한소령,김진환 한국해양공학회 2018 韓國海洋工學會誌 Vol.32 No.6

This paper introduces a new method of ice load generation in the time domain for the station-keeping performance evaluation of Arctic offshore structures. This method is based on the ice load spectrum and mean ice load. Recently, there has been increasing interest in Arctic offshore technology for the exploration and exploitation of the Arctic region because of the better accessibility to the Arctic ocean provided by the global warming effect. It is essential to consider the ice load during the development of an Arctic offshore structure. In particular, when designing a station-keeping system for an Arctic offshore structure, a consideration of the ice load acting on the vessel in the time domain is essential to ensure its safety and security. Several methods have been developed to consider the ice load in the time domain. However, most of the developed methods are computationally heavy because they consider every ice floe in the sea ice field to calculate the ice load acting on the vessel. In this study, a new approach to generate the ice load in the time domain with computational efficiency was suggested, and its feasibility was examined. The ice load spectrum and mean ice load were acquired from a numerical analysis with GPU-event mechanics (GEM) software, and the ice load with the varying heading of a vessel was reconstructed to show the feasibility of the proposed method.

소방용 비상발전기의 현장부하시험을 위한 ESS 부하시험장치 운용 알고리즘에 관한 연구

최승규(Seung-Kyou Choi),이후동(Hu-Dong Lee),태동현(Dong-Hyun Tae),이재영(Jai-Young Lee),노대석(Dae-Seok Rho) 대한전기학회 2020 전기학회논문지 Vol.69 No.4

A emergency generator for fire-fighting is a key equipment to supply power sources into fire-fighting facilities which protect property and human in case of fire accidents. With its necessary role, a rated load test of emergency generator should be mandatorily carried out by connecting emergency load with the generator in accordance with related regulations. However, the no load test for emergency generator has been performed in general, since serious problems including damage of customer device and shut down of critical load can be occurred when main power is cut off. Therefore, in order to overcome these problems, this paper proposes test method and operation algorithm of load test device with ESS to evaluate performance and state of emergency generator without interruption of power supply based on charging mode of ESS with same characteristics of emergency load. In addition, this paper presents a PSCAD/EMTDC modeling of emergency power supply system which is composed of emergency generator, emergency load and load test device with ESS. From the simulation results based on the proposed modeling and algorithm, it is confirmed that load test method for emergency generator using ESS are useful and practical tools for field load test in fire-fighting facility.

BTM 발전량을 고려한 평일 단기 전력수요예측 알고리즘

배동진(Dong-Jin Bae),권보성(Bo-Sung Kwon),문찬호(Chan-Ho Moon),우수화(Su-Hwa Woo),송경빈(Kyung-Bin Song) 한국조명·전기설비학회 2020 조명·전기설비학회논문지 Vol.34 No.11

The short-term load forecasting(STLF) is necessary for stable and efficient power system operation. With the spread of renewable energy, solar photovoltaic(PV) capacity is increasing. Most solar PV generator in South Korea is classified Behind-the-Meter(BTM) generator, such as small capacity of solar PV and distributed energy resources(DER). BTM generation is one of the main factors that change the load, and it causes the uncertainty of load forecasting. As a high penetration of BTM solar PV generator, load forecasting error is increased. The load forecasting algorithm using reconstituted load method is proposed to accurate load forecasting considering the BTM generation. The load forecast is performed for weekday excluding special days for the case studies in 2019. The proposed algorithm is improved a lot of the accuracy of STLF compared to the former STLF algorithms that do not considering BTM generation.

Experimental Study on the Optimal Layering Position of the Piezocomposite Electricity Generating Element Built-in an Innovative Traffic Load-Measuring Bridge Bearing

Choo, Jinkyo F.,Ha, Dong-Ho,Lee, Chang Hyung,Jang, Won Seo Scitec Publications 2013 Advanced materials research Vol.811 No.-

<P> The bearings of a bridge are indispensable structural members, which support the superstructure, transfer the loads of the superstructure to the substructure and, accommodate the horizontal and vertical motions of the superstructure caused by all types of loads like traffic. Such traffic loads induce the bridge to vibrate but this energy is wasted. Therefore, a piezocomposite electricity generating element (PCGE) has been introduced in the bearing to exploit effectively this vibrational energy. The bridge bearing with built-in PCGE was seen to be effective for measuring the traffic loads and, detecting eventual overloaded or overspeeding vehicles. In a will to optimize the amount of energy generated by this bearing, this study compares experimentally the amount of electricity produced by the PCGE with respect to its position in the bridge bearing through a series of dynamic loading tests to find out the position of the PCGE providing the most efficient electricity generation. </P>

일사량 가중치를 활용한 평일 전력수요예측 알고리즘

문찬호(Chan-Ho Moon),권보성(Bo-Sung Kwon),배동진(Dong-Jin Bae),송경빈(Kyung-Bin Song) 한국조명·전기설비학회 2020 조명·전기설비학회논문지 Vol.34 No.6

For efficient operation of the electric power system, it is important to increase the accuracy of load forecasting. Recently, small capacity solar photovoltaic(PV) generation in South Korea is the majority of Behind-The-Meter (BTM) generation, which is one of the main factors that change the gross load. Solar radiation is a weather factor that is highly correlated with solar PV generation and closely related to BTM in South Korea. So far, solar radiation is not systematically reflected in the load forecasting algorithm, so the load forecasting error is increasing due to the BTM solar PV generation. Therefore, it is necessary to analyze the impact of the BTM and to study the load forecasting algorithm considering the BTM. As a method to reflect the impact of BTM solar PV generation on the load forecasting, the load sensitivity by cloud amount is calculated. To reflect the characteristics of solar radiation that changes monthly due to earths revolution, the load sensitivity by cloud amount with monthly solar radiation weighting is calculated. The load sensitivity by cloud amount with monthly solar radiation weighting is applied to the weekday load forecasting, and the accuracy is better than the load forecasting result applied only load sensitivity by temperature.

Load Control between PV Power Plants and Diesel Generators

Mohamed Khalil Abdalla MohamedAli,AISHA HASSAN ABDALLA HASHIM,OTHMAN KHALIFA International Journal of Computer ScienceNetwork S 2024 International journal of computer science and netw Vol.24 No.6

Introducing renewable energy sources, such as wind and photovoltaic arrays, in microgrids that supply remote regions with electricity represents a significant leap in electricity generation. Combining photovoltaic panels and diesel engines is one of the most common ways to supply electricity to rural communities. Such hybrid systems can reduce the cost of electricity generation in these remote power systems because they use free energy to balance the power generated by diesel engines. However, the combination of renewable energy sources and diesel engines tends to complicate the sizing and control of the entire system due to the intermittent nature of renewable energy sources. This study sought to investigate this issue in depth. It proposes a robust hybrid controller that can be used to facilitate optimum power sharing between a PV power source and diesel generators based on the dynamics of the available PV energy at any given time. The study also describes a hybrid PV-diesel power plant's essential functional parts that produce electricity for a microgrid using a renewable energy source. Power control needs to be adjusted to reduce the cost of power generation.

The Effects of Generative Concept Map on Science Learning Achievement and Cognitive Load

( Suna Oh ),( Yeonsoon Kim ) 한국교육공학회 2016 Educational Technology International Vol.17 No.2

This study investigated the effect of generative concept maps according to learning achievements and cognitive load. A total of 78 students in the first grade of middle school participated in this study. Before the experimental treatment was implemented, students had to fill out a questionnaire assessing prior knowledge. The study was designed where all the students were presented the same learning contents regarding photosynthesis; however, the two experimental groups were provided with different concept map methods: a learner-generative concept map (GCM) and an instructor-provided concept map (PCM). GCM students were asked to make a concept map by themselves in small groups while they are reading material. PCM students were instructed to study in small groups in order to read the material; however, they were provided a concept map developed by their teacher. The control group (CG) had the teacher present the learning contents in traditional lecture format with no accompanying concept map. The results show that there were significant differences in the achievements among the groups. CG showed higher achievement than both the experimental groups. There was also a significant difference in cognitive load. Although the GCM group did not obtain higher achievement than the other groups, the GCM group showed higher mental effort and lower physical fatigue than the other groups. The GCM group might have invested more effort to find and connect ideas when drawing their concept map with peers which is unlike the conditions for the PCM group and CG. In conclusion, we should consider applying GCM in teaching and learning design in order to increase learning achievement and decrease extraneous cognitive load.

Load Frequency Control of a Synchronous Generator Using a dSPACE DSP-Based State Feedback Controller

Yuttana Kumsuwan,Sitchai Boonpiyathud,Satean Tunyasrirut 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

This paper presents design and implements the state feedback controller to design using Matlab/Simulink for a load frequency control system of the synchronous generator. The proposed controller will be a state feedback controller. The state feedback controller design by pole placement technique is also introduced to the system for regulates and tracking speed response. The overall control system is implemented on dSPACE DSP DS1104 controller board. This scheme leads to be able to adjust the output frequency of the generator by control the input voltage of DC motor drive. The experimental results in testing the 300 watt generator system from no-load to full load show the effectiveness of the proposed control scheme. It is found that the output frequency can be controlled to be constant in the operating range of 40-60 Hz of a resistive, reactive and capacitive load.