Reduction of the Low Voltage Substation Constraints by Inserting Photovoltaic Systems in Underserved Areas

2019 ◽  
Vol 12 (2) ◽  
pp. 105-112
Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Utilization Rate ◽  
Photovoltaic Systems ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Pv Systems ◽  
Transformer Substation ◽  
Load Pattern

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.

scholarly journals Analysis of Voltage Unbalance and Energy Loss in Residential Low Voltage Distribution Systems with Rooftop Photovoltaic Systems

2020 ◽  
Vol 190 ◽  
pp. 00033
Author(s):  
Rattanaprapa Charoenwattana ◽  
Umarin Sangpanich
Keyword(s):  
Energy Loss ◽  
Distribution Systems ◽  
Low Voltage ◽  
Energy Losses ◽  
Photovoltaic Systems ◽  
Housing Estate ◽  
Voltage Distribution ◽  
Pv System ◽  
Voltage Unbalance ◽  
Pv Systems

This paper investigates effects of voltage unbalance and energy losses due to the connection of rooftop photovoltaic systems in a low voltage distribution system of a housing estate, which has light loads during daytime. The paper presents a case study of a real distribution power system of housing estate in Thailand. Voltage unbalance and energy losses were simulated by using system characteristic and load data from GIS database of PEA with the DIgSILENT Power Factory program. The key findings of our analysis are as follows. Firstly, the number of installable 1-phase rooftop PV systems varies directly with load density. Secondly, the number of installed 1-phase rooftop PV systems can be increased if the installation locations are closer to the transformer. For 3-phase rooftop PV systems, their installations do not have any effects on the voltage unbalance. Furthermore, system energy loss relates to the load density and PV system installation locations in the same way as the voltage unbalance. The key implication of our study is that the installation of 1-phase rooftop PV system should be granted based on a careful consideration of the installation location and the load density.

scholarly journals Operation Modes of HV/MV Substations

2009 ◽  
Vol 25 (25) ◽  
pp. 81-86
Author(s):  
Josifs Survilo ◽  
Antons Kutjuns
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Warm Season ◽  
Electrical Energy ◽  
Cold Season ◽  
Power Losses ◽  
Medium Voltage ◽  
The Third ◽  
Operation Modes ◽  
Mode 3

Operation Modes of HV/MV SubstationsA distribution network consists of high voltage grid, medium voltage grid, and low voltage grid. Medium voltage grid is connected to high voltage grid via substations with HV/MV transformers. The substation may contain one, mostly two but sometimes even more transformers. Out of reliability and expenditure considerations the two transformer option prevail over others mentioned. For two transformer substation, there may be made choice out of several operation modes: 1) two (small) transformers, with rated power each over 0.7 of maximum substation load, permanently in operation; 2) one (big) transformer, with rated power over maximum substation load, permanently in operation and small transformer in constant cold reserve; 3) big transformer in operation in cold season, small transformer-in warm one. Considering transformer load losses and no load losses and observing transformer loading factor β it can be said that the mode 1) is less advantageous. The least power losses has the mode 3). There may be singled out yet three extra modes of two transformer substations: 4) two big transformers in permanent operation; 5) one big transformer permanently in operation and one such transformer in cold reserve; 6) two small transformers in operation in cold season of the year, in warm season-one small transformer on duty. At present mostly two transformers of equal power each are installed on substations and in operation is one of them, hence extra mode 5). When one transformer becomes faulty, it can be changed for smaller one and the third operation mode can be practiced. Extra mode 4) is unpractical in all aspects. The mode 6) has greater losses than the mode 3) and is not considered in detail. To prove the advantage of the third mode in sense of power losses, the notion of effective utilization time of power losses was introduced and it was proven that relative value of this quantity diminishes with loading factor β. The use of advantageous substation option would make it possible to save notable amount of electrical energy but smaller transformer lifetime of this option must be taken into account as well.

scholarly journals ANALISIS DROP TEGANGAN PADA JARINGAN TEGANGAN MENENGAH DENGAN MENGGUNAKAN SIMULASI PROGRAM ETAP

2019 ◽  
Vol 10 (1) ◽  
pp. 26-37
Author(s):  
Redaksi Tim Jurnal
Keyword(s):  
Electric Power ◽  
Power Distribution ◽  
Distribution System ◽  
Low Voltage ◽  
Voltage Drop ◽  
Power Distribution System ◽  
Medium Voltage ◽  
Cable Channel ◽  
Electric Power Distribution ◽  
Manual Calculation

Distribution system is very important in the distribution of electric power to the load. Therefore, a good and efficient distribution system is needed. The underlying cause of poor electric power distribution system is the amount of voltage drop values in the existing system. In the electric power distribution, 20 kV medium-voltage and 380/220V low voltage networks are used. The distribution system of Gandum Feeder in Angke Substation uses medium-voltage network with Underground Cable channel. They are used because of the towering buildings and the dense population in the area. It is known that the longest the channel and the load current are, the greater the voltage drop. From the result of the voltage drop calculation of Feeder Gandum in Angke Substation, which uses manual calculation and ETAP 12.6.0 program, it showed a slight difference in the result. The result of the voltage drop obtained from manual calculation showed that the percentage value of voltage is 1,94%, while the result obtained from ETAP 12.6.0 program showed that the percentage value is 2,01% These results are still in the PLN standard, because it has not exceeded the specified standard that is -10% of its nominal voltage.

scholarly journals Design of power substation placement with GIS tracing tools

Vestnik IGEU ◽  
2019 ◽  
pp. 75-83 ◽  
Author(s):  
А.В. Gadalov ◽  
S.V. Kosyakov
Keyword(s):  
Low Voltage ◽  
Power Grid ◽  
Distribution Networks ◽  
Power Lines ◽  
Electrical Networks ◽  
Voltage Distribution ◽  
Transformer Substation ◽  
Urban Distribution ◽  
Gis Environment

Analytical methods that are currently used to determine transformer substation placement in the process of planning the development of low-voltage distribution networks are based on calculating the lengths of future power lines by Euclidean distance, or methods for comparing several alternative placement options taking into account the routes of power lines. Assumptions made in this case lead to the fact that for the selected location of the substation, the total cost of the power lines connected to it may exceed the possible minimum. The use of modern GIS technologies allows simulating the routes of laying power lines on the map bypassing the existing obstacles or finding the cheapest routes for crossing them. These opportunities can be used to improve the quality of designing urban distribution networks through minimizing the construction cost of new power lines. However, the methods of organizing the solution to such a design problem have not yet found practical applications. The aim of the work is to develop a practical method of designing the placement of power substations in the GIS environment and its verification using real data. The paper uses methods of spatial modeling in the GIS environment, including methods of overlay, finding optimal paths on graphs and power grid inventory, as well as discrete optimization methods. A method of computer-aided design of transformer substation placement in urban distribution low-voltage networks is proposed and implemented as a GIS software module, which allows finding the optimal options of the placement cost at the stages of network scheme selection. The paper presents the results of the method analysis based on studying the design of the power grid scheme of Ivanovo city quarters as an example. The results confirm the possibility of using GIS to improve the quality of decisions on the choice of placement of low voltage distribution substations when designing urban electrical networks and can be used in the electrical networks CAD.

scholarly journals Advanced voltage control method for improving the voltage quality of low-voltage distribution networks with photovoltaic penetrations

2021 ◽  
Vol 4 (S2) ◽  
Author(s):  
Marika Nakamura ◽  
Shinya Yoshizawa ◽  
Hideo Ishii ◽  
Yasuhiro Hayashi
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
Low Voltage ◽  
Distribution Network ◽  
Distribution Networks ◽  
Voltage Distribution ◽  
Power Conditioning ◽  
Pv Systems ◽  
Measurement Period ◽  
Voltage Violation

AbstractAs the number of photovoltaic (PV) power generators connected to the distribution grid increases, applications of on-load tap changers (OLTCs), power conditioning systems, and static reactive power compensators are being considered to mitigate the problem of voltage violation in low voltage distribution systems. The reactive power control by power conditioning systems and static reactive power compensators can mitigate steep voltage fluctuations. However, it creates losses in generation opportunities. On the other hand, OLTCs are installed at the bases of distribution lines and can collectively manage the entire system. However, the conventional voltage control method, i.e., the line drop compensation (LDC) method, is not designed for the case in which a large number of PV systems are installed in the distribution network, which results in voltage violations above the limit of the acceptable range. This study proposes a method to determine the optimal LDC control parameters of the voltage regulator, considering the power factor of PV systems to minimize the magnitude of voltage violations based on the voltage profile analysis of low-voltage (LV) distribution networks. Specifically, during a measurement period of several days, the voltages at some LV consumers and pole transformers were measured, and the optimal parameters were determined by analyzing the collected data. The effectiveness of the proposed method was verified through a numerical simulation study using the actual distribution system model under several scenarios of PV penetration rates. Additionally, the difference in the effectiveness of voltage violation reduction was verified in the case where all the LV consumer’s consumer voltage data measured per minute were used as well as in the case where only the maximum and minimum values of the data within the measurement period were used. The results reveal that the proposed method, which operates within the parameters determined by the voltage analysis of the LV distribution network, is superior to the conventional method. Furthermore, it was found that even if only the maximum and minimum values of the measurement data were used, an effective voltage violation reduction could be expected.

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