scholarly journals Energy Loss Calculation of Low Voltage Distribution Area Based on Variational Mode Decomposition and Least Squares Support Vector Machine

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Keyan Liu ◽  
Dongli Jia ◽  
Fengzhan Zhao ◽  
Qicheng Zhang ◽  
Shuai Hao ◽  
...  

In order to improve the accuracy of theoretical energy loss calculation in low voltage distribution area (LV-area), this paper proposes a new prediction method based on variational mode decomposition (VMD) and particle swarm optimization (PSO) least squares support vector machine (LSSVM). Firstly, the main influencing factors of energy loss calculation in LV-area are determined by the grey correlation method, which reflects the data-driven characteristic of the method and ensures the objectivity of the prediction results and the generalization of the calculation model. Secondly, the trend component and fluctuation component are obtained by VMD of daily energy loss series in the LV-area. The variable set of main influencing factors of energy losses is used as the input variable of LSSVM, and the VMD result of the energy loss sequence is used as the output. The theoretical energy loss training and calculation model of LV-area is established. Compared with the traditional calculation model, this model has more accurate calculation accuracy by taking into account the frequency characteristics of energy losses in different frequency bands. PSO is used to optimize the parameters of LSSVM for the purpose of improving the accuracy of LSSVM. Finally, an example of 252 LV-area in a city in northern China is given to verify the validity of the proposed method. The results indicate that the proposed method generates more accurate results.


2020 ◽  
Vol 190 ◽  
pp. 00033
Author(s):  
Rattanaprapa Charoenwattana ◽  
Umarin Sangpanich

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.



2019 ◽  
Vol 242 ◽  
pp. 674-683 ◽  
Author(s):  
Chenjie Ma ◽  
Johannes Dasenbrock ◽  
J.-Christian Töbermann ◽  
Martin Braun




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