Intelligent power supply restoration in power distribution networks with distubuted generation

Author(s):  
L. Jiang ◽  
Q. Yang
Tecnura ◽  
2013 ◽  
Vol 17 (35) ◽  
pp. 12
Author(s):  
José Alexander Martínez ◽  
Fredy Hernán Martínez Sarmiento

We propose a data-analysis-based methodology for maintaining trees that affect power distribution networks. From the information captured in the field, we use fuzzy-logic-based techniques and models together with genetic algorithms so as to focus maintenance activities on the optimal time and place. The strategy is aimed at two key aspects: first, the history of failure events caused by trees on medium-voltage power supply systems; this information is used to calculate quality indicators such as energy-not-supplied (ENS) and number-of-users (NU) affected due to falling trees only. In this case we use a fuzzy-logic-based system to weight and find the critical circuits on which forest maintenance should be performed. Second, we construct an objective function based on tree-to-network distances and growth patterns of trees (classified per species) in order to simulate forest maintenance; this is achieved using a genetic algorithm to determine optimum pruning cycles for a given power supply system. We use real historical data of medium voltage circuits for system setting as well as for performance evaluation.


Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1158 ◽  
Author(s):  
Sun ◽  
Zhang ◽  
Yang ◽  
Liu ◽  
Zhang

Massive electric vehicle (EV) integration has been an inevitable trend for future power distribution networks. However, the spatial-temporal randomness of EV charging behavior may cause insufficiency of power supply capability. This paper simulates the charging loads with massive EV integration, proposes a probabilistic evaluation index to evaluate the probability of insufficient power supply capability, and gives improvement measures for power distribution networks without hardware upgrading. First, the spatial-temporal distribution of EV charging loads is simulated via Monte Carlo method, which particularly divides EVs into three categories, private cars, buses, and taxis. Then, aggregated with conventional loads, total supply capacity of a power distribution network can be calculated on different time periods. Second, for the uncertainty of EV charging loads both in time and space, a probabilistic evaluation index is addressed to evaluate the probability of power supply capability insufficiency. After that, several improvement measures of the charging strategy are given to relieve the insufficiency of power supply capability. Finally, taking the simplified distribution network of a typical power supply mode in China’s Fujian province as an example, three scenarios with different vehicle quantities and parameters are designed, and the effectiveness of the evaluation index and improvement measures proposed are identified. The results can provide evidences for constraining EV charging behaviors with massive integration.


Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Fei Xue ◽  
Yingyu Xu ◽  
Huaiying Zhu ◽  
Shaofeng Lu ◽  
Tao Huang ◽  
...  

Structural analysis based on complex network theory has been considered promising for security issues of power grids. At the same time, modern power distribution networks with more Distributed Generations (DGs) and Energy Storage Systems (ESS) have taken on more challenges in operation and security issues. This paper proposed a dedicated metric named as Power-Supply-Ability for power distribution networks based on net-ability. Special features of DGs, such as relations of capacities, identification of effective supply area, and limitation in continuous power supply, have been considered in definition. Furthermore, a novel opinion is proposed that the extent of improvement for operation and security by adding DGs also depends on the original structure of the distribution networks. This is an inherent ability of the original networks and could be quantitatively analyzed. Through case studies, this method has been proved to be effective in identifying potential structural vulnerabilities of distribution networks; particularly the impact of DGs on security has been studied. Furthermore, it can help in site selection for DGs by providing different priorities of locations compared with results of other works. This can help to complement other methods to construct a more comprehensive methodology by considering aspects of security, economy, and quality.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2405
Author(s):  
Samar Fatima ◽  
Verner Püvi ◽  
Ammar Arshad ◽  
Mahdi Pourakbari-Kasmaei ◽  
Matti Lehtonen

Power distribution networks are transitioning from passive towards active networks considering the incorporation of distributed generation. Traditional energy networks require possible system upgrades due to the exponential growth of non-conventional energy resources. Thus, the cost concerns of the electric utilities regarding financial models of renewable energy sources (RES) call for the cost and benefit analysis of the networks prone to unprecedented RES integration. This paper provides an evaluation of photovoltaic (PV) hosting capacity (HC) subject to economical constraint by a probabilistic analysis based on Monte Carlo (MC) simulations to consider the stochastic nature of loads. The losses carry significance in terms of cost parameters, and this article focuses on HC investigation in terms of losses and their associated cost. The network losses followed a U-shaped trajectory with increasing PV penetration in the distribution network. In the investigated case networks, increased PV penetration reduced network costs up to around 40%, defined as a ratio to the feeding secondary transformer rating. Above 40%, the losses started to increase again and at 76–87% level, the network costs were the same as in the base cases of no PVs. This point was defined as the economical PV HC of the network. In the case of networks, this level of PV penetration did not yet lead to violations of network technical limits.


Author(s):  
Xin Shen ◽  
Hongchun Shu ◽  
Min Cao ◽  
Nan Pan ◽  
Junbin Qian

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.


Sign in / Sign up

Export Citation Format

Share Document