The Probabilistic Reliability Assessment of Distribution Network Containing Distributed Generation

2013 ◽  
Vol 448-453 ◽  
pp. 2503-2506
Author(s):  
Xin Zhang ◽  
Hong Liu ◽  
Li Mei Zhou

The access of distributed renewable energy enhances the uncertainty of the distribution network reliability, whereas the distribution network reliability evaluation using existing methods cannot fully reflect the stochastic volatility of islanding power supply and loads. For this reason the approach of active distribution network probabilistic reliability evaluation based on point estimation method was proposed. In the framework of Monte Carlo simulation, the islanding random variable was sampled and processed firstly; then the islanding probabilistic reliability was assessed with a nonlinear transformation method of independent random variables based on point estimate method; finally, system probabilistic reliability indexes can be obtained from the probabilistic superimposing of the results of repeating simulated failures. The simulation on the transformed multi-branch feeder model of the IEEE RBTS Bus6 verifies the validity and accuracy of this assessment approach.

2021 ◽  
Author(s):  
Arnab Pal ◽  
Aniruddha Bhattacharya ◽  
Ajoy Kumar Chakraborty

Abstract Electric vehicle (EV) is the growing vehicular technology for sustainable development to reduce carbon emission and to save fossil fuel. The charging station (CS) is necessary at appropriate locations to facilitate the EV owners to charge their vehicle as well as to keep the distribution system parameters within permissible limits. Besides that, the selection of a charging station is also a significant task for the EV user to reduce battery energy wastage while reaching the EV charging station. This paper presents a realistic solution for the allocation of public fast-charging stations (PFCS) along with solar distributed generation (SDG). A 33 node radial distribution network is superimposed with the corresponding traffic network to allocate PFCSs and SDGs. Two interconnected stages of optimization are used in this work. The first part deals with the optimization of PFCS’s locations and SDG’s locations with sizes, to minimize the energy loss and to improve voltage profile using harris hawk optimization (HHO) and few other soft computing techniques. The second part handles the proper assignment of EVs to the PFCSs with less consumption of the EV’s energy considering the road distances with traffic congestion using linear programming (LP), where the shortest paths are decided by Dijkstra's algorithm. The 2m point estimation method (2m PEM) is employed to handle the uncertainties associated with EVs and SDGs. The robustness of solutions are tested using wilcoxon signed rank test and quade test.


Author(s):  
P. Radha ◽  
K. Rajagopalan

Rational design of stiffened cylindrical shell structures calls for the calculation of reliability. Random variables occur in modelling loads and strengths. The reliability can be evaluated with ‘Monte-Carlo Simulation’ (MCS) which consists of obtaining cumulative distribution functions for each and every random variable and simulating the ultimate strength of stiffened shells for combinations of random variable values. However for MCS to be successful, the sample size should be very large. Hence methods have been proposed to reduce the sample size without however sacrificing any accuracy on reliability. ‘Point Estimation Method’ (PEM), ‘Response Surface Technique’ (RST), ‘Importance Sampling Procedure Using Design points’ (ISPUD), ‘Latin Hypercube Sampling’ (LHS) etc., are some of these methods. In this paper, a method based on ‘Random Polar Sampling Technique’ (RPST) is proposed, in which combinations of variates are obtained using a polar sampling of Latin Hypercube sampled values. A typical example has been worked out using this method.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3242
Author(s):  
Hamid Mirshekali ◽  
Rahman Dashti ◽  
Karsten Handrup ◽  
Hamid Reza Shaker

Distribution networks transmit electrical energy from an upstream network to customers. Undesirable circumstances such as faults in the distribution networks can cause hazardous conditions, equipment failure, and power outages. Therefore, to avoid financial loss, to maintain customer satisfaction, and network reliability, it is vital to restore the network as fast as possible. In this paper, a new fault location (FL) algorithm that uses the recorded data of smart meters (SMs) and smart feeder meters (SFMs) to locate the actual point of fault, is introduced. The method does not require high-resolution measurements, which is among the main advantages of the method. An impedance-based technique is utilized to detect all possible FL candidates in the distribution network. After the fault occurrence, the protection relay sends a signal to all SFMs, to collect the recorded active power of all connected lines after the fault. The higher value of active power represents the real faulty section due to the high-fault current. The effectiveness of the proposed method was investigated on an IEEE 11-node test feeder in MATLAB SIMULINK 2020b, under several situations, such as different fault resistances, distances, inception angles, and types. In some cases, the algorithm found two or three candidates for FL. In these cases, the section estimation helped to identify the real fault among all candidates. Section estimation method performs well for all simulated cases. The results showed that the proposed method was accurate and was able to precisely detect the real faulty section. To experimentally evaluate the proposed method’s powerfulness, a laboratory test and its simulation were carried out. The algorithm was precisely able to distinguish the real faulty section among all candidates in the experiment. The results revealed the robustness and effectiveness of the proposed method.


Author(s):  
Guowei Li ◽  
Qinghui Zeng ◽  
Hao Liu ◽  
Junbo Wang ◽  
Rongbo Luo ◽  
...  

2014 ◽  
Vol 672-674 ◽  
pp. 1441-1446 ◽  
Author(s):  
Yu Qiang Ou ◽  
Le Feng Cheng ◽  
Jian Zhong Wen ◽  
Xuan Yu Qiu ◽  
Tao Yu

Research on reliability of distribution network has very important meaning and function to ensure the quality of power supply. This paper introduces some basic concepts of reliability in distribution network, including distribution network reliability definition, task and index. The classical reliability evaluation method was reviewed, and focused on specific distribution network, an example analysis was given, and specific reliability evaluation indexes were calculated. Finally, the future development of distribution network reliability evaluation was made a simple prospect.


2020 ◽  
Vol 10 (3) ◽  
pp. 971 ◽  
Author(s):  
Xiangyu Kong ◽  
Shuping Quan ◽  
Fangyuan Sun ◽  
Zhengguang Chen ◽  
Xingguo Wang ◽  
...  

With the development of smart grid and low-carbon electricity, a high proportion of renewable energy is connected to the grid. In addition, the peak-valley difference of system load increases, which makes the traditional grid scheduling method no longer suitable. Therefore, this paper proposes a two-stage low-carbon economic scheduling model considering the characteristics of wind, light, thermal power units, and demand response at different time scales. This model not only concerns the deep peak state of thermal power units under the condition of large-scale renewable energy, but also sets the uncertain models of PDR (Price-based Demand Response) virtual units and IDR (Incentive Demand Response) virtual units. Taking the system operation cost and carbon treatment cost as the target, the improved bat algorithm and 2PM (Two-point Estimation Method) are used to solve the problem. The introduction of climbing costs and low load operating costs can more truly reflect the increased cost of thermal power units. Meanwhile, the source-load interaction can weigh renewable energy limited costs and the increased costs of balancing volatility. The proposed method can be applied to optimal dispatch and safe operation analysis of the power grid with a high proportion of renewable energy. Compared with traditional methods, the total scheduling cost of the system can be reduced, and the rights and obligations of contributors to system operation can be guaranteed to the greatest extent.


Sign in / Sign up

Export Citation Format

Share Document