A Hybrid Model of Photovoltaic Power Stations for Model Ling Tasks of Large Power Systems

2021 ◽  
Vol 69 (4) ◽  
pp. 43-49
Author(s):  
Nikolay RUBAN ◽  
◽  
Vladimir RUDNIK ◽  
Igor RAZZHIVIN ◽  
Anton KIEVEC ◽  
...  

Renewable energy sources are being actively penetrated in the global energy sector, with the main growth being achieved by new photovoltaic power stations. At the same time, the influence of photovoltaic power stations on the operation of power systems is known. This is primarily due to the inconstancy of the weather, which leads to a decrease in the output of each specific photovoltaic panel and power station as a whole. To study the effect of partial shading of photovoltaic panels on the parameters of its operation, various models of the current-voltage characteristics of photovoltaic cells are used in the world, while detailed two-diode models show the best results. The use of detailed models allows to get complete information about the processes in a variety of photovoltaic panels of a power station, as well as other elements of it, such as a voltage converter. This makes it possible to assess the impact of these processes on the external power system. However, for detailed modelling of large photovoltaic power stations as part of power systems, it is necessary to use powerful software and hardware systems. Such systems include the Hybrid real-time power system simulator. This simulator is a multiprocessor installation that provides a solution to the aggregate model of the power system through the use of three approaches to modelling: digital, analogue and physical. The article presents the results of experimental studies of software and hardware tools for modelling a photovoltaic power station, developed on the basis of a hybrid approach to modelling electric power systems.

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6742
Author(s):  
Yongshi Jie ◽  
Xianhua Ji ◽  
Anzhi Yue ◽  
Jingbo Chen ◽  
Yupeng Deng ◽  
...  

Distributed photovoltaic power stations are an effective way to develop and utilize solar energy resources. Using high-resolution remote sensing images to obtain the locations, distribution, and areas of distributed photovoltaic power stations over a large region is important to energy companies, government departments, and investors. In this paper, a deep convolutional neural network was used to extract distributed photovoltaic power stations from high-resolution remote sensing images automatically, accurately, and efficiently. Based on a semantic segmentation model with an encoder-decoder structure, a gated fusion module was introduced to address the problem that small photovoltaic panels are difficult to identify. Further, to solve the problems of blurred edges in the segmentation results and that adjacent photovoltaic panels can easily be adhered, this work combines an edge detection network and a semantic segmentation network for multi-task learning to extract the boundaries of photovoltaic panels in a refined manner. Comparative experiments conducted on the Duke California Solar Array data set and a self-constructed Shanghai Distributed Photovoltaic Power Station data set show that, compared with SegNet, LinkNet, UNet, and FPN, the proposed method obtained the highest identification accuracy on both data sets, and its F1-scores reached 84.79% and 94.03%, respectively. These results indicate that effectively combining multi-layer features with a gated fusion module and introducing an edge detection network to refine the segmentation improves the accuracy of distributed photovoltaic power station identification.


2021 ◽  
Vol 11 (3) ◽  
pp. 914
Author(s):  
Yang Si ◽  
Laijun Chen ◽  
Xuelin Zhang ◽  
Xiaotao Chen ◽  
Tianwen Zheng ◽  
...  

Hot dry rock (HDR) power stations have the potential to serve as an energy storage system for large-scale photovoltaic (PV) plants. For flexible operation, thermal storage (TS) power stations are required to coordinate with HDR power stations. In this study, a hybrid power system is constructed by combining the HDR, TS, and PV plants. Game theory is then introduced into the optimal dispatch of the hybrid power system. Considering HDR, TS, and PV as players, non-cooperative and cooperative game dispatching models are established and verified by a case in the Gonghe basin of Qinghai. Finally, the stability of the coalitions and the rationality of allocation of the hybrid power system is verified, and the sensitivity of critical parameters is analyzed. The results demonstrate that the overall payoff of the hybrid power system is increased by 10.15%. The payoff of the HDR power station is increased by 16.5%. The TS power station has obtained 50% of the total extra profits. The PV plant reduces the impact on the grid to obtain the priority of grid connection. Based on these results, a theoretical basis can be provided for developing generation systems based on the HDR resources in the Gonghe Basin.


The paper presents a classification of solar tracking systems used in photovoltaic power stations (PVS) and their operating principles. A simulation model of a grid-connected 5-kW PVS has been developed in PVsyst, to which end the researchers selected PVS equipment and optimized the PV cell tilt angles. The paper further analyzes a grid-connected PVS in Orenburg Oblast in PVsyst under the following configurations: static PV cells, not tilted vs seasonally varied tilts; single-axis solar trackers with vertical and horizontal axes of rotation vs a dual-axis solar tracker. The analysis is based on solar insolation data for 2019 obtained from the research team’s HP-2000 weather station. Dual-axis solar tracker and single-axis vertical trackers are shown to have the best year-round generation, providing an increase of 13.2% and 11.5%, respectively, against the static PV cells (no change in tilt).


2020 ◽  
Vol 209 ◽  
pp. 07014
Author(s):  
Tulkin Gayibov ◽  
Bekzod Pulatov

Optimal planning of short-term modes of power systems is a complex nonlinear programming problem with many simple, functional and integral constraints in the form of equalities and inequalities. Especially, the presence of integral constraints causes significant difficulties in solving of such problem. Since, under such constraints, the modes of power system in separate time intervals of the considered planning period become dependent on the values of the parameters in other intervals. Accordingly, it becomes impossible to obtain the optimal mode plan as the results of separate optimization for individual time intervals of the period under consideration. And the simultaneous solution of the problem for all time intervals of the planning period in the conditions of large power systems is associated with additional difficulties in ensuring the reliability of convergence of the iterative computational process. In this regard, the issues of improving the methods and algorithms for optimization of short-term modes of power systems containing thermal and large hydroelectric power plants with reservoirs, in which water consumption is regulated in the short-term planning period, remains as an important task. In this paper, we propose the effective algorithm for solving the problem under consideration, which makes it possible to quickly and reliably determine the optimal operating modes of the power system for the planned period. The results of research of effectiveness of this algorithm are presented on the example of optimal planning of daily mode of the power system, which contains two thermal and three hydraulic power plants..


Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 38 ◽  
Author(s):  
Bouzounierakis ◽  
Katsigiannis ◽  
Fiorentzis ◽  
Karapidakis

Greece has a large number of islands that are isolated from the main interconnected Greek power system; however, a majority of them are to be interconnected in the mainland grid over the next decade. A large number of these islands present a significant amount of wind and solar potential. The nature of load demand and renewable production is stochastic; thus, the operation of such isolated power systems can be improved significantly by the installation of a large-scale energy storage system. The role of storage is to compensate for the long and short-term imbalances between power generation and load demand. Pumped hydro storage (PHS) systems represent one of the most mature technologies for large-scale energy storage. However, their advantages have not been proven in practice for cases of medium and small-sized isolated insular systems. Regarding Greece, which contains a large number of isolated insular systems, a PHS system in the island of Ikaria started its test operation in 2019, whereas in Europe only one PHS system operates in El Hierro (Canary Islands). This paper studies the effect of installing a wind-PHS hybrid power station in the operation of the insular power system of Samos, Greece, according to the latest regulatory framework. The implemented analysis uses real hourly data for a whole year, and examines the effects of such an installation considering investors’ and power system operators’ viewpoints. More specifically, the economic viability of this project under different billing scenarios is compared, and its impact on the insular power system operation for various PHS sizes is examined.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3310 ◽  
Author(s):  
Ignacio Blanco ◽  
Daniela Guericke ◽  
Anders Andersen ◽  
Henrik Madsen

In countries with an extended use of district heating (DH), the integrated operation of DH and power systems can increase the flexibility of the power system, achieving a higher integration of renewable energy sources (RES). DH operators can not only provide flexibility to the power system by acting on the electricity market, but also profit from the situation to lower the overall system cost. However, the operational planning and bidding includes several uncertain components at the time of planning: electricity prices as well as heat and power production from RES. In this publication, we propose a planning method based on stochastic programming that supports DH operators by scheduling the production and creating bids for the day-ahead and balancing electricity markets. We apply our solution approach to a real case study in Denmark and perform an extensive analysis of the production and trading behavior of the DH system. The analysis provides insights on system costs, how DH system can provide regulating power, and the impact of RES on the planning.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3365 ◽  
Author(s):  
Lukas Wienholt ◽  
Ulf Müller ◽  
Julian Bartels

The paradigm shift of large power systems to renewable and decentralized generation raises the question of future transmission and flexibility requirements. In this work, the German power system is brought to focus through a power transmission grid model in a high spatial resolution considering the high voltage (110 kV) level. The fundamental questions of location, type, and size of future storage units are addressed through a linear optimal power flow using today’s power grid capacities and a generation portfolio allowing a 66% generation share of renewable energy. The results of the optimization indicate that for reaching a renewable energy generation share of 53% with this set-up, a few central storage units with a relatively low overall additional storage capacity of around 1.6 GW are required. By adding a constraint of achieving a renewable generation share of at least 66%, storage capacities increase to almost eight times the original capacity. A comparison with the German grid development plan, which provided the basis for the power generation data, showed that despite the non-consideration of transmission grid extension, moderate additional storage capacities lead to a feasible power system. However, the achievement of a comparable renewable generation share provokes a significant investment in additional storage capacities.


1999 ◽  
Vol 23 (1B) ◽  
pp. 117-127
Author(s):  
R. Lykins ◽  
M. Ramalingam ◽  
B. Donovan ◽  
E. Durkin ◽  
J. Beam

A computerized analytical program is being developed to help investigate the impact of power system requirements on aircraft performance. The program has an user interface that operates in MS-EXCEL, linking several subsystems analysis programs for execution and data transfer in the power systems analysis. The program presently includes an encoded propulsion engine cycle code, which allows the inspection of power extraction effects on engine performance. To validate the results of the encoded engine program, a study was conducted to investigate the separate effects of shaft power extraction and pneumatic bleed. The selected engine cycle was that for a standard tactical fighter, with a flight condition of varied altitude (sea level to 40,000 ft) and constant Mach Number (0.9). As expected the resultant data showed that the engine performance was more sensitive to pneumatic bleed than to shaft power extraction. The paper’s efficiency comparisons between shaft power and bleed air power helps indicate the higher efficiency for the power system of a more-electric type aircraft. Present efforts on the analytical interface are to incorporate a fuel thermal management analysis capability.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2268 ◽  
Author(s):  
Dong-Hee Yoon ◽  
Sang-Kyun Kang ◽  
Minseong Kim ◽  
Youngsun Han

We present a novel architecture of parallel contingency analysis that accelerates massive power flow computation using cloud computing. It leverages cloud computing to investigate huge power systems of various and potential contingencies. Contingency analysis is undertaken to assess the impact of failure of power system components; thus, extensive contingency analysis is required to ensure that power systems operate safely and reliably. Since many calculations are required to analyze possible contingencies under various conditions, the computation time of contingency analysis increases tremendously if either the power system is large or cascading outage analysis is needed. We also introduce a task management optimization to minimize load imbalances between computing resources while reducing communication and synchronization overheads. Our experiment shows that the proposed architecture exhibits a performance improvement of up to 35.32× on 256 cores in the contingency analysis of a real power system, i.e., KEPCO2015 (the Korean power system), by using a cloud computing system. According to our analysis of the task execution behaviors, we confirmed that the performance can be enhanced further by employing additional computing resources.


2019 ◽  
Vol 112 ◽  
pp. 02011
Author(s):  
Cristian-Gabriel Alionte ◽  
Daniel-Constantin Comeaga

The importance of renewable energy and especially of eolian systems is growing. For this reason, we propose the investigation of an important pollutant - the noise, which has become so important that European Commission and European Parliament introduced Directive 2002/49/CE relating to the assessment and management of environmental noise. So far, priority has been given to very large-scale systems connected to national energy systems, wind farms whose highly variable output power could be regulated by large power systems. Nowadays, with the development of small storage capacities, it is feasible to install small power wind turbines in cities of up to 10,000 inhabitants too. As a case study, we propose a simulation for a rural locality where individual wind units could be used. This specific case study is interesting because it provides a new perspective of the impact of noise on the quality of life when the use of this type of system is implemented on a large scale. This option, of distributed and small power wind turbine, can be implemented in the future as an alternative or an adding to the common systems.


Sign in / Sign up

Export Citation Format

Share Document