scholarly journals Hierarchical Multiobjective Dispatching Strategy for the Microgrid System Using Modified MOEA/D

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xiaofeng Wan ◽  
Hai Lian ◽  
Xiaohua Ding ◽  
Jin Peng ◽  
Yining Wu ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Electric Vehicles ◽  
Large Scale ◽  
Load Level ◽  
Energy Output ◽  
Power Fluctuation ◽  
Electricity Cost ◽  
Distributed Solutions ◽  
User Demand ◽  
Grid Load

The large-scale electric vehicles connected to the microgrid have brought various challenges to the safe and economic operation of the microgrid. In this paper, a hierarchical microgrid dispatching strategy considering the user-side demand is proposed. According to the operation characteristics of each dispatch unit, the strategy divides the microgrid system into two levels: source-load level and source-grid-load level. At the source-load level, priority should be given to the use of the renewable energy output. On the basis of considering the user demand, energy storage, electric vehicles, and dispatchable loads should be utilized to maximize the consumption of the renewable energy and minimize the user’s electricity cost. The source-grid-load level can smooth the tie-line power fluctuation through dispatching of the power grid and diesel generators. Furthermore, the study presents a modified MOEA/D algorithm to solve the hierarchical scheduling problem. In the proposed algorithm, a modified Tchebycheff decomposition method is introduced to obtain uniformly distributed solutions. In addition, initialization and replacement strategies are introduced to enhance the convergence and diversity. A wind-photovoltaic-diesel-storage hybrid power system is considered to verify the performance of the proposed dispatching strategy and the modified algorithm. The obtained results are compared with other dispatching approaches, and the comparisons confirm the effectiveness and scientificity of the proposed strategy and algorithm.

scholarly journals Optimizing operation of a large-scale pumped storage hydropower system coordinated with wind farm by means of genetic algorithms

2019 ◽  
Keyword(s):  
Genetic Algorithms ◽  
Renewable Energy ◽  
Wind Energy ◽  
Large Scale ◽  
Wind Farm ◽  
Closed Loop ◽  
Open Loop ◽  
Energy Output ◽  
Reservoir System ◽  
Pumped Storage

<p>Due to the intermittent and fluctuating nature of wind and other renewable energy sources, their integration into electricity systems requires large-scale and flexible storage systems to ensure uninterrupted power supply and to reduce the percentage of produced energy that is discarded or curtailed. Storage of large quantities of electricity in the form of dynamic energy of water masses by means of coupled reservoirs has been globally recognized as a mature, competitive and reliable technology; it is particularly useful in countries with mountainous terrain, such as Greece. Its application may increase the total energy output (and profit) of coupled wind-hydroelectric systems, without affecting the availability of water resources. Optimization of such renewable energy systems is a very complex, multi-dimensional, non-linear, multi modal, nonconvex and dynamic problem, as the reservoirs, besides hydroelectric power generation, serve many other objectives such as water supply, irrigation and flood mitigation. Moreover, their function should observe constraints such as environmental flow. In this paper we developed a combined simulation and optimization model to maximize the total benefits by integrating wind energy production into a pumped-storage multi-reservoir system, operating either in closed-loop or in open-loop mode. In this process, we have used genetic algorithms as the optimization tool. Our results show that when the operation of the reservoir system is coordinated with the wind farm, the hydroelectricity generation decreases drastically, but the total economical revenue of the system increases by 7.02% when operating in closed-loop and by 7.16% when operating in open-loop mode. We conclude that the hydro-wind coordination can achieve high wind energy penetration to the electricity grid, resulting in increase of the total benefits of the system. Moreover, the open-loop pumped-storage multi-reservoir system seems to have better performance, ability and flexibility to absorb the wind energy decreasing to a lesser extent the hydroelectricity generation, than the closed-loop.</p>

scholarly journals Design and Implementation of Probabilistic Transient Stability Approach to Assess the High Penetration of Renewable Energy in Korea

2021 ◽  
Vol 13 (8) ◽  
pp. 4205
Author(s):  
Young-Been Cho ◽  
Yun-Sung Cho ◽  
Jae-Gul Lee ◽  
Seung-Chan Oh
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Transient Stability ◽  
Stability Index ◽  
Energy Output ◽  
Effective Capacity ◽  
Stability Assessment ◽  
Energy Capacity ◽  
Electric System ◽  
The Many

Recently, because of the many environmental problems worldwide, Korea is moving to increase its renewable energy output due to the Renewable 3020 Policy. Renewable energy output can change depending on environmental factors. It is for this reason that institutions should consider the instability of renewables when linked to the electric system. This paper describes the methodology of renewable energy capacity calculation based on probabilistic transient stability assessment. Probabilistic transient stability assessment consists of four algorithms: first, to create probabilistic scenarios based on the effective capacity history of renewable energy; second, to evaluate probabilistic transient stability based on transient stability index, interpolation-based transient stability index estimation, reduction-based transient stability index calculation, etc.; third, to implement multiple scenarios to calculate renewable energy capacity using probabilistic evaluation index; and finally, to create a probabilistic transient stability assessment simulator based on Python. This paper calculated renewable energy capacity based on large-scale power system to validate consistency of the proposed paper.

scholarly journals Multiobjective Joint Economic Dispatching of a Microgrid with Multiple Distributed Generation

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3264 ◽  
Author(s):  
Hui Hou ◽  
Mengya Xue ◽  
Yan Xu ◽  
Jinrui Tang ◽  
Guorong Zhu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Operating Cost ◽  
Clean Energy ◽  
Load Level ◽  
Power Fluctuation ◽  
Load Fluctuation ◽  
Multiobjective Particle Swarm Optimization ◽  
Grid Load ◽  
Grid Operation ◽  
Net Load

Based on the operation characteristics of each dispatch unit, a multi-objective hierarchical Microgrid (MG) economic dispatch strategy with load level, source-load level, and source-grid-load level is proposed in this paper. The objective functions considered are to minimize each dispatching unit’s comprehensive operating cost (COC), reduce the power fluctuation between the MG and the main grid connect line, and decrease the remaining net load of the MG after dispatch by way of energy storage (ES) and clean energy. Firstly, the load level takes electric vehicles (EVs) as a means of controlling load to regulate the MG’s load fluctuation using its energy storage characteristics under time-of-use (TOU) price. Then, in order to minimize the remaining net load of the MG and the COC of the ES unit through Multiobjective Particle Swarm Optimization (MPSO), the source-load level adopts clean energy and ES units to absorb the optimized load from the load level. Finally, the remaining net load is absorbed by the main grid and diesel engines (DE), and the remaining clean energy is sold to the main grid to gain benefits at the source-grid-load level. Ultimately, the proposed strategy is simulated and analyzed with a specific example and compared with the EVs’ disorderly charging operation and MG isolated grid operation, which verifies the strategy’s scientificity and effectiveness.

Charging and Discharging Control of Plug-In Electric Vehicle Based on Immune Clone Algorithm

2013 ◽  
Vol 805-806 ◽  
pp. 1672-1677
Author(s):  
Min Wang ◽  
Yang Zhang ◽  
Yong Qing Li ◽  
Cheng Fei Zhang ◽  
Yue Yuan
Keyword(s):  
Electric Power ◽  
Electric Vehicle ◽  
Electric Vehicles ◽  
Large Scale ◽  
Power Lines ◽  
Stable Operation ◽  
Load Curve ◽  
Scheduling Scheme ◽  
Grid Load

When a large scale of plug-in electric vehicles connected to the grid,which will be bound to deteriorate the load curve and will affect the safe and stable operation of the grid without a reasonable means of control. Immune clone algorithm is applied to control the electric vehicles charging and discharging strategy and to develop a optimized scheduling scheme throughout the day. In this way not only can it avoid electric vehicles disorderly charging and discharging disorderly so that to optimize grid load curve, but also can reduce the loss of electric power lines and delay investment.

scholarly journals Optimal Charging/discharging Strategy of Electric Vehicles in Residential Area Considering User Comprehensive Satisfaction

2018 ◽  
Vol 53 ◽  
pp. 02012
Author(s):  
Jilong Liu ◽  
Ping Li ◽  
Wentao Zhong ◽  
Lihua Wang ◽  
Yang An ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Large Scale ◽  
Case Analysis ◽  
Residential Area ◽  
Optimization Strategy ◽  
Load Fluctuation ◽  
Grid Load ◽  
Load Peak ◽  
The Impact ◽  
Satisfaction Model

At present, the research on charging/discharging of electric vehicles (EVs) lacks consideration of the user experience, particularly with the aspects of user's convenience and profitability. Therefore, this paper analyses the travelling characteristics and travelling demand of EV users in a residential area and establishes the user comprehensive satisfaction model considering travel convenience and charging/discharging economy. Based on this model, a genetic algorithm is used to optimize the charging/discharging strategy of EVs with the aim of maximizing user comprehensive satisfaction, the validity of the proposed optimization model is verified by results of example. The model is also used to study the impact of large-scale EVs charging/discharging optimization strategy on grid load fluctuation. Based on the load data of a residential area, the simulation is carried out, and the influence of different peak-valley prices on EVs charging/discharging strategy is analysed. Our case analysis shows that the load peak-valley difference is reduced. With the increase of peak-valley electricity price, more users discharge during the peak hours and charge during the peak-off hours, the load peak-valley difference and the load fluctuation decrease accordingly.

scholarly journals The Synergies of Shared Autonomous Electric Vehicles with Renewable Energy in a Virtual Power Plant and Microgrid

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2016 ◽  
Author(s):  
Riccardo Iacobucci ◽  
Benjamin McLellan ◽  
Tetsuo Tezuka
Keyword(s):  
Renewable Energy ◽  
Power Plant ◽  
Electric Vehicles ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
Transport Sector ◽  
Virtual Power ◽  
Virtual Power Plant ◽  
Vehicle Charging ◽  
Autonomous Electric Vehicles

The introduction of shared autonomous electric vehicles (SAEVs), expected within the next decade, can transform the car into a service, accelerate electrification of the transport sector, and allow for large scale control of electric vehicle charging. In this work, we investigate the potential for this system to provide aggregated storage when combined with intermittent renewable energy sources. We develop a simulation methodology for the optimization of vehicle charging in the context of a virtual power plant or microgrid, with and without grid connection or distributed dispatchable generators. The model considers aggregate storage availability from vehicles based on transport patterns taking into account the necessary vehicle redistribution. We investigate the case of a grid-connected VPP with rooftop solar and the case of a isolated microgrid with solar, wind, and dispatchable generation. We conduct a comprehensive sensitivity analysis to study the effect of several parameters on the results for both cases.

CREATION OF REED CADASTRES

2017 ◽  
Vol 1 ◽  
pp. 70
Author(s):  
Edgars Čubars
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Legal Status ◽  
Natural Habitat ◽  
Energy Resource ◽  
Water Reservoir ◽  
Energy Output ◽  
Renewable Energy Resource ◽  
Lack Of Information ◽  
Reed Plants

In Latvia the total renewable energy resource volume has not been fully evaluated. Reed exploitation for energy output has not been developed on a large scale. One of the factors for this is the lack of information about to reed resource spread and characteristics. Therefore, there arises the need for a united inventory system – the formation of a reed cadaster. The study contains information on basic principles of reed cadastre creation and research methodologies. The reed cadaster is a list of the reed researches which contains information about the reed areas in Latvia, the volume and locations, the legal status, possibilities for exploitation, as well as the biomass qualities, in each specific water reservoir. For each water reservoir, which is included in the reed cadaster, a certificate and chart have been produced. Information about the reed locations in each specific lake have been shown on the cadaster chart; the boundaries of the water reservoir, the boundaries of the reed plants and areas, the natural habitat protected area boundaries, the district boundaries, as well as the access roads. The data for reed characteristics and accessible volumes is compiled in the water reservoir cadaster passport. Development for reed exploitation in the conditions of Latvia is dependent on the location, accessible volumes and existing infrastructure. Reeds are a long term renewable energy resource, with the spread of reeds increasing every year.

scholarly journals Strategy of Large-Scale Electric Vehicles Absorbing Renewable Energy Abandoned Electricity Based on Master-Slave Game

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Dunnan Liu ◽  
Lingxiang Wang ◽  
Weiye Wang ◽  
Hua Li ◽  
Mingguang Liu ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Electric Vehicles ◽  
Large Scale
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