scholarly journals TIME-BASED DEVELOPMENT PLANS FOR DISTRIBUTION NETWORKS IN THE PRESENCE OF DISTRIBUTED GENERATORS AND CAPACITOR BANKS

2020 ◽  
Vol 4 (4) ◽  
pp. 245-254
Author(s):  
Ebadollah AMOUZAD MAHDIRAJI

In this paper, a time-based model for distribution network development planning is proposed, considering the possibility of using distributed electricity generation technologies and the existence of capacitor banks. The proposed model specifies the location, capacity, and timing of the use of distributed generation technologies and capacitor banks as well as the schedule for increasing the capacity of the grid lines. The Genetic Enhanced Algorithm is used to solve the stated problem to optimize the network development plan including the time, location and capacity of DG and capacitor banks in the distribution network as well as to optimize the investment cost and operating cost. It was also implemented in a MATLAB programming environment to validate and evaluate the effectiveness of the proposed solution to the problem of distribution network development planning on a 17-bus radial distribution network.

The power loss in the radial distribution network is appreciable as compared to transmission network. To reduce the power loss in distribution network which is radial in nature, the solution methodology adopted in this paper is optimal placement of distributed generators (DG). The optimization incorporated is Multi-objective Grey Wolf Optimization (MOGWO). The optimization is accomplished for three different cases. In each case two objective functions are simultaneously optimized to obtain non-dominated solutions using Multi-objective Grey Wolf Optimization. Case (1): To minimize the real power loss and maximize the savings obtained due to DG installation. Case (2): To minimize real power loss and maximum voltage deviation in the network. Case (3): To minimize real power loss and rating of DG installed. MOGWO method maintains an archive which contains pareto-optimal solutions. The archive mimics the behaviour of grey wolves. MOGWO method is verified on radial distribution networks. The effectiveness of the optimization method is proven by comparing the results with other optimization methods available in the literature.


2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Haoran Chen ◽  
Xin Lin ◽  
Guanhua Li ◽  
Jianyuan Xu ◽  
Hui Li ◽  
...  

Among the distribution network faults, single-phase grounding faults have the greatest probability. The faults are often accompanied by arcs in the grounding point soil. This type of fault current has a small amplitude and seldom can obtain field record data. A soil arc grounding fault is tested on a realistic-distribution-network-experimental-platform (RDNEP), and it is concluded that the soil-arc-grounding-fault (SAGF) has three main characteristics: hysteresis, nonlinearity, and asymmetry. By comparing with the characteristics of common arc models, it is pointed out that common arc models cannot accurately fit the characteristics of SAGF. This paper proposes and establishes a double exponential function arc model. Through the comparison of simulation waveforms with experimental data, it is verified that the numerical simulation method proposed in this paper can simulate the development process of SAGF more accurately. Furthermore, the equivalence of RDNEP is verified on the real distribution network system (RDNS). On this basis, analyzed the arc characteristic changes of different SAGF development cycles. Finally, by studying the applicability of the proposed model in simulating ground faults in grass and gravel roads, it is verified that the model proposed in this paper has a strong generalization capability. The research has laid a theoretical foundation for a detection algorithm that is based on the characteristics of SAGF.


2014 ◽  
Vol 909 ◽  
pp. 428-432 ◽  
Author(s):  
Ioan Sarbu ◽  
Gabriel Ostafe

Distribution networks are an essential part of all water supply systems. Distribution system costs within any water supply scheme may be equal to or greater than 60% of the entire cost of the project. The reliability of supply is much greater in the case of looped networks. The pipe networks have concentrated outflows or uniform outflow along the length of each pipe. In some pipes with variable discharge of a looped distribution network, water velocity could be reversed between its extremities. Thus, it is a water stall point denominated neutral point in which the discharge is null. In this paper a mathematical model for the determination of water stall point location in the pipes with distributed consumption is developed. This model has been implemented in a computer program for PC microsystems. Numerical example will be presented to demonstrate the accuracy and efficiency of the proposed model.


2018 ◽  
Vol 8 (10) ◽  
pp. 1888 ◽  
Author(s):  
Chengsi Yong ◽  
Xiangyu Kong ◽  
Ying Chen ◽  
Zhijun E ◽  
Kai Cui ◽  
...  

With the development of active distribution networks, the means of controlling such networks are becoming more abundant, and simultaneously, due to the intermittency of renewable energy and the randomness of the demand-side load, the operating uncertainty is becoming serious. To solve the problem of source–network–load coordination scheduling, a multiobjective scheduling model for an active distribution network (ADN) is proposed in this paper. The operating cost, renewable energy utilization rate, and user satisfaction are considered as the optimization objectives, and the distributed generation (DG) output power, switch number, and incentive price for the responsive load are set as the decision variables. Then the probabilistic power flow based on Monte Carlo sampling and the chance-constrained programming are used to deal with the uncertainty of the ADN. Moreover, the reference point–based many-objective evolutionary algorithm (NSGA3) is used to solve this nonlinear, multiperiod, and multiobjective optimization problem. The effectiveness of the proposed method is verified in the modified IEEE 33-bus distribution system. The results show that the proposed scheduling method can effectively improve the system status.


2021 ◽  
Vol 11 (19) ◽  
pp. 8916
Author(s):  
Zhiwen Xu ◽  
Changsong Chen ◽  
Mingyang Dong ◽  
Jingyue Zhang ◽  
Dongtong Han ◽  
...  

By constructing a DC multi-microgrid system (MMGS) including renewable energy sources (RESs) and electric vehicles (EVs) to coordinate with the distribution network, the utilization rate of RESs can be effectively improved and carbon emissions can be reduced. To improve the economy of MMGS and reduce the network loss of the distribution network, a cooperative double-loop optimization strategy is proposed. The inner-loop economic dispatching reduces the daily operating cost of MMGS by optimizing the active power output of RESs, EVs, and DC/AC converters in MMGS. The outer-loop reactive power optimization reduces the network loss of the distribution network by optimizing the reactive power of the bidirectional DC/AC converters. The double-loop, which synergistically optimizes the economic cost and carbon emissions of MMGS, not only improves the economy of MMGS and operational effectiveness of the distribution network but also realizes the low-carbon emissions. The Across-time-and-space energy transmission (ATSET) of the EVs is considered, whose impact on economic dispatching is analyzed. Particle Swarm Optimization (PSO) is applied to iterative solutions. Finally, the rationality and feasibility of the cooperative multi-objective optimization model are proved by a revised IEEE 33-node system.


2020 ◽  
Vol 213 ◽  
pp. 03004
Author(s):  
Litong Dong ◽  
Yinghua Chen ◽  
Yanqin Ge ◽  
Xuesong Xu

With the orderly advancement of power system reform and the rapid development of incremental power distribution pilots, the investment process of power grid companies has become more and more transparent and standardized. However, in the current fierce environment, how to maintain certain economic benefits in various regional distribution networks has become a problem of concern. This paper establishes a distribution network asset economic index system from the three dimensions of investment cost, operating cost, and economic benefit. The hierarchical structure of indicators is clarified based on the interpretative structural model, and the economic level is measured based on the improved analytical hierarchy process AHP-fuzzy evaluation model. Finally, the analysis of calculation examples shows that: (1) The investment cost and operating cost of the distribution network indirectly affect the economic benefits of the power grid by affecting the electricity sales. (2) The economic levels of the distribution network in the three regions of X, Y, and Z are good, medium, and poor. The region X needs to strengthen the management of distribution network investment, and the region Y continues to improve the economy from all aspects of cost and income. The first thing in region Z is to improve the level of economic efficiency.


The Distributed generation and fast operating power electronic devices are attracting more attention due to their effective solution for improvement in the voltage profile, to meet the increasing power consumption, reduction in the power loss, enhancement in the power transfer capacity of the transmission lines, reducing the overloading of the entire network. The optimal placement of DG and FACTs devices plays key role in improvement of the network reliability and voltage stability. In this paper exhaustive load flow analysis is carried out for optimal placement of DG and UPFC. The proposed method is tested on 40 bus distribution network. The obtained results are satisfactory in terms of improvement in the overall performance of the distribution network.


2020 ◽  
Vol 12 (6) ◽  
pp. 2167 ◽  
Author(s):  
Javad Najafi ◽  
Ali Peiravi ◽  
Amjad Anvari-Moghaddam

An earthquake, as one of the natural disasters, can damage vital infrastructures including the power distribution network (PDN) and water distribution network (WDN). The dependency of WDN on PDN is the other challenge that can be highlighted after the earthquake. In this paper, the resilience improvement planning of integrated PDN and WDN against earthquakes is solved through stochastic programming. Power lines and substation hardening in PDN and water pipes rehabilitation with better material are the candidate strategies to minimize the expected inaccessibility value of loads to power and water as the resilience index and to minimize the cost of strategies. The proposed model is tested on the modified IEEE 33-bus PDN with a designed WDN and its performance is evaluated under different cases where the impacts of using distributed generations (DG) in PDN, equipping the water pumps to back-up generators, and the value of loads accessibility to water on the system resilience are investigated.


2021 ◽  
Vol 11 (2) ◽  
pp. 627
Author(s):  
Walter Gil-González ◽  
Alejandro Garces ◽  
Oscar Danilo Montoya ◽  
Jesus C. Hernández

The optimal placement and sizing of distributed generators is a classical problem in power distribution networks that is usually solved using heuristic algorithms due to its high complexity. This paper proposes a different approach based on a mixed-integer second-order cone programming (MI-SOCP) model that ensures the global optimum of the relaxed optimization model. Second-order cone programming (SOCP) has demonstrated to be an efficient alternative to cope with the non-convexity of the power flow equations in power distribution networks. Of relatively new interest to the power systems community is the extension to MI-SOCP models. The proposed model is an approximation. However, numerical validations in the IEEE 33-bus and IEEE 69-bus test systems for unity and variable power factor confirm that the proposed MI-SOCP finds the best solutions reported in the literature. Being an exact technique, the proposed model allows minimum processing times and zero standard deviation, i.e., the same optimum is guaranteed at each time that the MI-SOCP model is solved (a significant advantage in comparison to metaheuristics). Additionally, load and photovoltaic generation curves for the IEEE 69-node test system are included to demonstrate the applicability of the proposed MI-SOCP to solve the problem of the optimal location and sizing of renewable generators using the multi-period optimal power flow formulation. Therefore, the proposed MI-SOCP also guarantees the global optimum finding, in contrast to local solutions achieved with mixed-integer nonlinear programming solvers available in the GAMS optimization software. All the simulations were carried out via MATLAB software with the CVX package and Gurobi solver.


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