Earticle

점차 스마트그리드 기술이 발전됨에 따라서 에너지의 효율성에 이목이 집중되고 있다. 그래서 스마트그리드를 구성하고 있는 마이크로그리드 내의 에너지를 독립적으로 관리하기 위해서는 신재생에너지에 대한 연구를 필요로 한다. 그중에서도 소수력 에너지는 마이크로그리드내의 사용자가 사용하는 물의 양에 따라서 그 어디에도 설치 할 수 있는 장점을 가지고 있다. 사용자들이 주거하는 아파트, 공동주택에서 사용하고 있는 하수량을 기반으로 전기 발전량과 발전기의 가동률을 측정하여 측정값이 소수력 발전에 적합한지 알아본다. 적합한 아파트, 공동주택에서는 위치에너지를 활용하여 발생한 하수를 소수력 발전기로 전기를 생산 한다. 마이크로그리드의 에너지 관리 시스템과 전기 저장 장치를 도입하여 보다 효율적인 관리를 제안하고자 한다.

As smart grid techniques developed, public attention is concentrating on energy efficiency. So it is necessary to study on new renewable energy in order to manage the energy within micro grid consisting smart grid. Among them, small hydro energy has the advantage of being installable anywhere depending the amount of water used by the users within micro grid. This study examines if the measured value is appropriate for small hydro power generation by measuring generation quantity and operation rate of generator based on the sewage flow used by apartments and multi-unit dwellings where those users live. Some appropriate apartments and multi-unit dwellings generate electricity with small hydro generator using sewage as potential energy. This study intends to suggest more effective management by introducing energy management system and electricity storage device of micro grid.

This study shows an application method of Micro Grid integrating Solar Energy Seasonal Storage (SESS) based on the analysis of time-variant load characteristics of electric railway. Micro Grid includes various renewable energy generation plants as like wind farm, photovoltaic, small hydro, fuel cell, etc. and some energy storage systems to meet the balance between generation production and demand. The essential concept of this paper is the connection and integration between electric railway and Micro Grid including SESS which is able to control power system frequency. This new concept for power system stabilization would be tested in an independent Micro Grid site and some detail application methods would be evaluated for the commercialization.

This paper presents an operating and cost optimization model for Micro Grid (MG). This model takes into account emission costs of CO2, SO2 and NOx, together with the operation, maintenance and startup costs. Photovoltaic (PV) arrays, Wind Turbine (WT), Fuel Cell (FC), Micro Turbine (MT) and Diesel Generator (DG) with different capacities are considered in this model. The aim of the optimization is minimizing operation cost according to constraints, supply demand and safety of system. The proposed Bender’s Decomposition (BD) is used to optimize the micro grid operation.

This paper provides discussion of multimedia system infrastructure and database management for the micro grid. The micro grid is energy system that has power generator with renewable energy resources and load. The micro grid is an ideal power system for using renewable energy resources for isolated area. This paper provides a brief overview of micro grid and discussion of communication system infrastructure and database management for the micro grid. The Energy Management System (EMS) interacts with all subsystems through communication channel and status information like metering data from all subsystems is stored at data base system in the EMS. With this information EMS manages and operates the micro grid. The Powerline communication and ZigBee are one of ideal communication infrastructure for local communication and the cellular network like MiMAX and LTE can be a good choice for the backhaul of the micro grid.

본 연구는 기존 풍력 터빈의 한계와 문제점을 극복하기 위해 블레이드리스 풍력 발전을 위한 선형 발전기의 모델링 및 해석에 중점을 두고 있다. 블레이드리스 풍력 발전 시스템은 블레이드 풍력 발전 터빈에 비해 설치 및 유지관 리에 필요한 토지 요구량이 낮다는 장점이 있다. 그러나 블레이드리스 풍력 발전을 위한 발전기에 관한 종합적인 연구는 아직까지 부족한 실정이다. 특히, 발전기의 토플로지에 관한 질문의 답변이 만족스럽지 않다. 연구의 목표는 원통형 블레 이드리스 풍력발전기의 수평 및 수직 구조에 대해 비교 분석하는 것이다. 제안된 토플로지는 자기력을 이용해 2차원 등가 자기회로 네트워크 방식으로 해석한 후 유한요소법으로 비교 평가하였다. 최종적으로, 본 연구의 결과는 풍력 발전 시스템을 위한 새로운 발전기 구조에 대한 상세한 정보와 블레이드리스 풍력 발전 특성에 대한 통찰을 제공할 것이다.

This study focuses on the modeling and analysis of the linear generator for a bladeless wind power generation to overcome the limitations and drawbacks of conventional wind turbines. A bladeless wind power generation system has the advantages of low land requirement for installation and maintenance cost compared to a blade wind power turbine. Nevertheless, question concerning the generator topology are not satisfying answered. The goal of the research is to compare and analyze the characteristics of horizontal and vertical structures of linear generator for bladeless wind power systems. The proposed topology will be analyzed using magnetic energy by equivalent magnetic circuit method, and then it has been compared and evaluated by finite element method. The results of this project will give elaborate information about new generator structures for wind power system and provide insights into the characteristics of bladeless wind power generation.

Optimal allocation of distributed generations (DGs) integrated into micro grids can significantly improve the stability and benefit the economy of micro grid operation. However, optimal micro grid planning is a kind of multi-dimensional and non-linear optimization problem. In this study, a multi-objective model is established by adopting the objective function which minimizes network loss, electricity price and operation cost; an improved particle swarm optimization (IPSO) algorithm with better optimizing performance is proposed by improving the initializing method and parameter control as well as average minimum and mutation factor are introduced. The proposed IPSO algorithm is then applied to a 29-node micro grid network structure. The comparison between different optimization schemes demonstrates the significance of optimal placement of DGs in micro grids. And it is also clear that the IPSO algorithm proposed in this study can effectively solve such problems.

In the micro-grid, power storage converter is played as a interface between the battery pack and grid electricity storage device, to achieve a two-way exchange of energy. In this paper, the research and development of power storage converter can realize multiple sets of independent control of the battery, flexible configuration of the system capacity and flexible cutting of the battery pack. Structural design uses multi-level topology. It contains 15 non-isolated half-bridge parallel bi-directional DC / DC converter. Control strategy designed to be grid inverter adopts SVPWM control technology. DC / DC converter designed to improve the droop control strategy based on environmental design. The high-power energy storage converter product this paper designed have completed the charge and discharge related droop control and Full power grid experiment. The charge and discharge currents accurately track the current instruction and the grid efficiently is more than 95%. It verified the rationality and effectiveness of the design and is the important part of the optical storage and solar power generation systems.

Micro-grid is the significant part of the distribution network in the future of smart grid, which has advanced and flexible operation and control pattern, and integrates distributed clean energy. It is a study of the direction of the grid in the future. In the paper, it gives an account of the operation and control of micro-grid. First, the concept of micro-grid, the structure and characteristics of the typical micro-grid and the significance of the development of micro-grid are analyzed. Second, it introduces typical control strategy which contains the integrated control strategy of Micro-grid and a typical control mode of Micro-power. At last, based on a comprehensive control strategy, it proposed the operation mode of Micro-grid.

This paper proposes a multi-agent technology to energy management of the distributed generations in a micro-grid (MG) system. An introduction and analysis of the distributed intelligent multi-agent technology are presented, including its architecture and operation mechanism. Then, the objective function about minimizing the operating cost and environment losses taking in electricity trading is given. An implementation of Central Force Optimization (CFO) utilizing variable initial probes and decision space adaptation is presented, and Compare it to particle swarm optimization (PSO) method. The daily load forecast of electric power system is presented. The simulation results demonstrate that the proposed multi-agent technology is successfully monitored, controlled and operated for the energy management of the distributed generations in micro-grid system.

The recent interests in the IoT-applied Smart Homes have also affected other areas of IT technology. In addition to hardware and software developments, it is required to establish some sort of intelligent power grids which enable low-cost and efficient communications. The Smart grid and its sub-network, the micro grids, have been considered to be suitable for such a goal but the logic which would bring out more efficiency in the power networks was not easily found as there were many tradeoffs to be dealt with. Thus, in this paper, we’ve proposed the Hybrid Advanced Metering Infrastructure (AMI) through the mathematical model which adopts a pool model of the game theory to show a systemic relationship between the electricity (power) prices that have been determined by the management policy and power output of the micro grids. We expect that the Hybrid AMI will become a fundamental technology for the micro grids.

Micro-grid control is the key technology in the process of accessing micro-grid into regular grid. This paper summarizes several ways on coordination control in micro-grid and introduces some domestic researches on micro-grid control strategies. It is written on the basis of the achievements on micro-grid control in some developed countries and current situations on domestic micro-grid control. Firstly, the paper introduces the objects of micro-grid control study and describes the control processes of each object thoroughly on different micro-grid control structures. Then the paper states the researches among the world on micro-grid control generally. In the end, the paper discusses the research orientation on micro-grid control which based on the existing problems of micro-grid control and current situations on regular grid.

It is facing resource shortage and environmental pollution around the globe, until the emergence of new renewable energy technology has reinvigorated traditional techniques. Development of renewable energy generation in China needs the joint efforts of all social sectors from policy to technique. Distributed generation combining with battery applied in micro-grid relieves a problem of resource shortage, and ensures load operation when power grid fault urgently. In this paper, photovoltaic is described briefly first. Then photovoltaic-battery-diesel micro-grid is established according to the situation about geographical environment, what is more workflow of the system is analyzed. Control strategy is shown according to condition of micro-grid. At last, micro-grid containing distributed generation established in Liaoning Province is quantitative illustrated in economic benefit. Distributed generation is added into micro-grid enhance the reliability of micro-grid even power grid. That makes a contribution to resource and environmental problem.

With the continuous development of economy and social progress, the social requirement of power network is more and more high. This paper, as a basis research of distributed generation, proceed mainly from the impact of distributed generation on power grid, detailed fine analysis of the influence of all kinds of distributed generation on power network adverse, including power system stability, power quality, power supply reliability effect. In order to avoid these adverse effects, we combining the distributed grid technology and smart micro grid, put distributed generation as a branch of the micro grid that can be ideal to connect grid and can avoid most of the problems mentioned above. Distributed intelligent micro grid system uses variety of new energy supply, it is a comprehensive model of power electronic technology, distributed generation, renewable energy power technology and energy storage technology .The paper provides a reference for the use of future distributed power generation.

Renewable energy resources for electric power generation have got the spotlight by industry and academia as greenhouse effect has become more severe. Micro Grid is an isolated power system that has generators and power loads. For isolated area Micro Grid is an ideal power system for generating electrical power with renewable energy resources like the solar and wind energy. However generations with renewable energy resources cannot meet the demand of loads securely. So smart applications with communication infrastructure are required to control and monitor the power system. The communication infrastructure for smart power grid can be classified as Home Area network (HAN), Neighborhood Area Network (NAN) and Wide Area Network (WAN). Many technologies including cellular network and PLC are competing for communication in Micro Grid. This paper provides discussion of power line communication technologies for Micro Grid.

The uncertainty and fluctuation brought by distributed type of intermittent power generation in micro grid bring huge challenges to power quality of micro grid in isolating operation and power control in parallel operation. Nevertheless energy storage is able to well solve this problem. Hybrid energy storage integrates the respective advantages of storage battery and supercapacitor to have improved the performance of energy storage system. Service life of storage battery is tightly related to its charging/discharging times and problem of frequent charging/discharging storage battery still exists in current hybrid energy storage technology. In this paper, it respectively puts forward control strategies for storage battery and supercapacitor. As to control strategy for storage battery, it uses double-layered control strategy, namely, single loop control and power hysteresis control, to feedback low-frequency fluctuation of power and reduce charging/discharging frequency of storage battery. As to control strategy for supercapacitor, it uses inner loop current with power to control voltage in outer loop so as to feedback high-frequency fluctuation of power and it is able to well maintain stability of DC bus voltage. Simulation results suggest the validity of aforesaid control strategies.

With the rapid growth of the electricity demand, UHVAC and UHVDC transmission and the distributed generation with the renewable energy become the key point of the development of power industry based on the goal of the harmonious development in the power industry at home. According to the certain topological structure, the micro grid is the network including the distributed power supply, energy storage power supply, and load-control devices. It is linked with the grid through the switch devices, realizing the effective management of the distributed generation. We can also find the value and benefits of the distributed generation for the power grid and the user. This paper discusses that the micro grid is the effective approach to solve the integration between distributed generation and power grid. It also summaries its concept and research status of the micro grid deeply. Then it knows the current application of photovoltaic power generation technology. Finally it concludes that the operation characteristic of the photovoltaic power generation system has the important research value in the micro grid.