Research on Development Strategies of Distributed Generation Based on Micro Grid Technology

Qishun Zhu,Jinsong Liu,Minghao Zhang,Xin Sun 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.3

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.

농형 유도발전기의 계통 연계시 전압 변동 및 전력 흐름 분석

김종겸(Jong-Gyeum Kim) 한국조명·전기설비학회 2014 조명·전기설비학회논문지 Vol.28 No.6

Synchronous generators and induction generators are mainly used in hydroelectric power generation. Synchronous generator is mainly applied to large hydroelectric plants but induction generator is applied to the small hydro power plants. Stability of induction generator is slightly less than the synchronous generator. However, induction generator has many advantages rather than a synchronous generator in terms of price and maintenance. So Induction generator is used primarily in small hydroelectric power station less than 1,000㎾ recently. Squirrel cage induction generator generates a high inrush current at the grid-connection. This high inrush current causes a voltage drop on the grid. In order to reduce the voltage drop and to analyze the power flow, the analysis for operating characteristics of the induction generator should be reviewed in advance. In this study, we analyzed the voltage drop and power flow analysis when a 1500㎾ induction generator is connected to the grid. The voltage drop is slightly higher than the acceptable range of distributed power supply voltage and the power flow of the generator is performed well.

Stabilization of a power system with a distributed generator by a virtual synchronous generator function

K. Sakimoto,Y. Miura,T. Ise 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

The power capacity of distributed generators such as photovoltaic and wind turbine is growing, many of distributed generators are connected to a grid by inverters. The inverters are controlled by a PLL (Phase Locked Loop) in order to be synchronized with power system frequency. Power system will become unstable, if the capacity of inverter-connected-type distributed generators becomes larger and larger, because inverter frequency is controlled to follow the grid frequency. The concept of “Virtual Synchronous Generator” (VSG), which is to control inverters to behave like a synchronous generator, has been proposed. VSG has virtual inertia which is realized by an energy storage device to pretend rotor’s inertia. In this paper, the control scheme of VSG is investigated which is based on the swing equation of a synchronous generator. Numerical simulation results show both ride-through capability of voltage dip and enhancement ability of grid stability.

혼합 정수 선형 계획법 기반의 최적 경제 급전을 활용한 분산형 열병합 발전원의 송전선로 건설비용 회피 편익계산

권욱현(Wook Hyun Kwon),박용기(Yong-Gi Park),노재형(Jae Hyung Roh),박종배(Jong-Bae Park),이두희(Duehee Lee) 대한전기학회 2019 전기학회논문지 Vol.68 No.4

We calculate the benefit of distributed combined heat power generators from avoiding a transmission expansion cost by building distributed generators near electricity demand centers. We determine a transmission expansion plan by solving a mixed integer linear problem, where we modify capacities of existing transmission lines and build new transmission lines. We calculate the benefit by comparing the sum of generation and transmission expansion costs with or without distributed generators through two simulation frames. In the first frame, for the current demand, we substitute existing distributed generators for non-distributed generators and measure an additional cost to balance the generation and demand. In the second frame, for increased future demand, we compare the cost to invest only in distributed generators to the cost to invest only in non-distributed generators. As a result, we show that the distributed generators have at least 5.8 won/kWh of the benefit from avoiding the transmission expansion cost.

Distribution System Reconfiguration Considering Customer and DG Reliability Cost

Sung-Min Cho,Hee-Sang Shin,Jin-Hyun Park,Jae-Chul Kim 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.4

This paper presents a novel objective function for distribution system reconfiguration for reliability enhancement. When islanding operations of distributed generators is prohibited, faults in the feeder interrupt the operation of distributed generators. For this reason, we include the customer interruption cost as well as the distributed generator interruption cost in the objective function in the network reconfiguration algorithm. The network reconfiguration in which genetic algorithms are used is implemented by MATLAB. The effect of the proposed objective function in the network reconfiguration is analyzed and compared with existing objective functions through case studies. The network reconfiguration considering the proposed objective function is suitable for a distribution system that has a high penetration of distributed generators.

Analysis of the System Impact of Distributed Generation using EMTP

Yeo, Sang-Min,Kim, Il-Dong,Kim, Chul-Hwan,Aggarwal, Raj The Korean Institute of Electrical Engineers 2004 KIEE International Transactions on Power Engineeri Vol.a4 No.4

With the advent of distributed generation, power systems in general are impacted in regards to stability and power quality. Distributed generation has positive impacts on system restoration following a fault, higher reliability, and mitigation of effect due to voltage sag. However, distributed generation also has negative impacts on the decrease of reliability such as changes of protective device setting and mal-operation. Because bulk power systems consist of various sources and loads, it is complicated to analyze power systems that have distributed generation. The types of distributed generation usually are classified as the rotating machinery system and the inverter-based system. In this paper, distributed generation is designed as a synchronous generator, and the distribution system with its distributed generation model is simulated using EMTP. In addition, this paper shows the simulation results according to the types of distributed generation

Operational Analysis of DC Micro-grid using Detailed Model of Distributed Generation

J. Lee,B. Han,Y Seo 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This paper describes operational analysis results of the DC micro-grid using detailed model of distributed generation. Detailed model of wind power generation, photo-voltaic generation, fuel cells generation was implemented with the user-defined model of PSCAD/EMTDC software that is coded with C-language. The operation analysis was carried out using PSCAD/EMTDC software, in which the power circuit is implemented by built-in model and the controller is modeled by user-defined model that is also coded with Clanguage. Various simulation results confirm that the DC micro-grid can operate without any problem in both the grid-tied mode and the islanded mode. The operational analysis result confirms that the DC micro-grid make it feasible to provide power to the load stably. And it can be utilized to develop an actual system design and building.

수용가의 신뢰도 평가를 위한 분산전원 모델링

조종만,배인수,심헌,김진오,Jo, Jong-Man,Bae, In-Su,Shim, Hun,Kim, Jin-O 한국조명전기설비학회 2005 조명·전기설비학회논문지 Vol.19 No.8

본 논문은 분산전원이 연계된 배전계통의 신뢰도를 평가할 수 있는 해석적 기법과 그에 맞는 분산전원의 모델을 제시한다. 분산전원은 송전계통에 연계된 대규모 발전기와는 다른 운영방식을 가지기 때문에 기존의 기법과는 다른 해석기법과 모델을 필요로 한다. 제시되는 신뢰도 해석기법은 Monte-Carlo 시뮬레이션에 비해 간단하면서도 피크부하를 사용하는 해석기법에 비해 정확하기 위해 Load Duration Curve를 사용하였고, 최종적으로는 사례연구를 통해 제시된 기법의 정확성을 입증하였다. Unlike the large sized generations of transmission system, the distributed generations have complexities in analyzing and determining model. This paper resents an analytical method for the reliability evaluation of distribution system, including the distributed generations. The method using Load Duration Curve model is simpler than the Monte-Carlo Simulation and is more accurate than that using peak load model. The modeling of distributed generation to analysis reliability of customers using LDC is proposed in this paper, and is compared with the MCS method as a result of case studies.

Analysis of System Impact of the Distributed Generation Using EMTP with Particular Reference to Voltage Sag

Yeo, Sang-Min,Kim, Chul-Hwan The Korean Institute of Electrical Engineers 2004 KIEE International Transactions on Power Engineeri Vol.a4 No.3

With the advent of distributed generation, power systems are fundamentally impacted in regards to stability and power quality. Distributed generation has a positive impact on system restoration following a fault, higher reliability, and mitigation of effect due to voltage sag. However, distributed generation also has a negative impact on decrease of reliability such as changes of protective device setting and mal-operation. Because bulk power systems consist of various sources and loads, it becomes complicated to analyze a power system with distributed generation. The types of distributed generation are usually classified by both rotating machinery and the inverter-based system. In this paper, distributed generation is designed by rotating machinery, and the distributed system having a model of the distributed generation is simulated using EMTP. In addition, this paper presents the simulation results according to the types of distributed generation.

Distribution System Reconfiguration Considering Customer and DG Reliability Cost

Cho, Sung-Min,Shin, Hee-Sang,Park, Jin-Hyun,Kim, Jae-Chul The Korean Institute of Electrical Engineers 2012 Journal of Electrical Engineering & Technology Vol.7 No.4

This paper presents a novel objective function for distribution system reconfiguration for reliability enhancement. When islanding operations of distributed generators is prohibited, faults in the feeder interrupt the operation of distributed generators. For this reason, we include the customer interruption cost as well as the distributed generator interruption cost in the objective function in the network reconfiguration algorithm. The network reconfiguration in which genetic algorithms are used is implemented by MATLAB. The effect of the proposed objective function in the network reconfiguration is analyzed and compared with existing objective functions through case studies. The network reconfiguration considering the proposed objective function is suitable for a distribution system that has a high penetration of distributed generators.