scholarly journals Calculation of Maximum Total Supply Capacity of Three-Phase Unbalance Distribution Network Based on Mixed Integer Second-Order Cone

2019 ◽  
Author(s):  
Jieyun Zheng ◽  
Shiyuan Ni ◽  
Pengjia Shi ◽  
Guilian Wu ◽  
Ri’an Wang ◽  
...  
Keyword(s):  
Power Supply ◽  
Distribution System ◽  
Power Flow ◽  
Flow Model ◽  
Distribution Network ◽  
Second Order ◽  
Mixed Integer ◽  
Power Distribution System ◽  
Second Order Cone ◽  
Three Phase

Considering the fault "N-1" checksum and the power flow, the single-phase power flow model is further transformed into a three-phase power flow model, and the asymmetry of the three-phase power flow is measured by the three-phase unbalance factor. The calculation model is linearized by the second-order cone relaxation and the Big-M method. At the same time, the load response and distribution network reconstruction are used to improve the reliability of the power supply network to cope with the power failure. The relationship between power supply capability and power flow constraints, main transformer capacity and distributed power parameters is analyzed by IEEE 33-node three-phase power distribution system. The feasibility of the proposed model and the accuracy of the second-order cone relaxation are verified by numerical examples, which provides a technical reference for distribution network planning.

scholarly journals A Novel Linear Optimal Power Flow Model for Three-Phase Electrical Distribution Systems

2020 ◽  
Author(s):  
Juan Sebastian Giraldo ◽  
Pedro Pablo Vergara ◽  
Juan Camilo Lopez ◽  
Phuong Nguyen ◽  
Nikolaos Paterakis
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Optimal Power Flow ◽  
Flow Model ◽  
Mixed Integer ◽  
Electrical Distribution Systems ◽  
Optimal Power ◽  
Electrical Distribution ◽  
Three Phase

This paper presents a new linear optimal power flow model for three-phase unbalanced electrical distribution systems considering binary variables. The proposed formulation is a mixed-integer linear programming problem, aiming at minimizing the operational costs of the network while guaranteeing operational constraints. Two new linearizations for branch current and nodal voltage magnitudes are introduced. The proposed branch current magnitude linearization provides a discretization of the Euclidean norm through a set of intersecting planes; while the bus voltage magnitude approximation uses a linear combination of the L1 and the L∞ norm. Results were obtained for an unbalanced distribution system, in order to assess the accuracy of the linear formulation when compared to a nonlinear power flow with fixed power injections, showing errors of less than 4\% for currents and 0.005\% for voltages.

scholarly journals A Novel Linear Optimal Power Flow Model for Three-Phase Electrical Distribution Systems

2020 ◽  
Author(s):  
Juan Sebastian Giraldo ◽  
Pedro Pablo Vergara ◽  
Juan Camilo Lopez ◽  
Phuong Nguyen ◽  
Nikolaos Paterakis
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Optimal Power Flow ◽  
Flow Model ◽  
Mixed Integer ◽  
Electrical Distribution Systems ◽  
Optimal Power ◽  
Electrical Distribution ◽  
Three Phase

This paper presents a new linear optimal power flow model for three-phase unbalanced electrical distribution systems considering binary variables. The proposed formulation is a mixed-integer linear programming problem, aiming at minimizing the operational costs of the network while guaranteeing operational constraints. Two new linearizations for branch current and nodal voltage magnitudes are introduced. The proposed branch current magnitude linearization provides a discretization of the Euclidean norm through a set of intersecting planes; while the bus voltage magnitude approximation uses a linear combination of the L1 and the L∞ norm. Results were obtained for an unbalanced distribution system, in order to assess the accuracy of the linear formulation when compared to a nonlinear power flow with fixed power injections, showing errors of less than 4\% for currents and 0.005\% for voltages.

Flexible Power Flow Algorithm for Distribution Network Including Second-Order Items

2014 ◽  
Vol 521 ◽  
pp. 440-443 ◽  
Author(s):  
Ning Zhou ◽  
Ru Si Chen ◽  
Tao Lin ◽  
Qiang Li ◽  
Xiang He ◽  
...  
Keyword(s):  
Distribution System ◽  
Network Flow ◽  
Power Flow ◽  
Distribution Network ◽  
Static Characteristic ◽  
Second Order ◽  
Electric Power System ◽  
Flow Equations ◽  
Good Convergence ◽  
Flow Algorithm

For intelligent distribution system including Distributed Generations, we take the generator and load static characteristic into account and propose a flexible power flow algorithm for distribution network including second-order items. First, this algorithm modifies the distribution network power flow equations including second-order items in order to meet the static characteristic of generator and load. Moreover, we use the fsolve function of MATLAB to solve the power flow equations. This algorithm makes full use of the characteristic of high accuracy of the distribution network flow equations including second-order items and good convergence of the fsolve function. Compared with conventional distribution power flow algorithm, it does not need to set the trend flexible node type of each one. Not only the voltage amplitude, phase information of each node and the system frequency information can be calculated, as well as the actual power of generator and loads. The result of the algorithm is more in line with the practical electric power system engineering. Improved IEEE33 node system is chosen to verify the correctness of the algorithm.

scholarly journals Two-Stage Stochastic Programming Scheduling Model for Hybrid AC/DC Distribution Network Considering Converters and Energy Storage System

2019 ◽  
Vol 10 (1) ◽  
pp. 181
Author(s):  
Peng Kang ◽  
Wei Guo ◽  
Weigang Huang ◽  
Zejing Qiu ◽  
Meng Yu ◽  
...  
Keyword(s):  
Wind Power ◽  
Reactive Power ◽  
Distribution Network ◽  
Stochastic Scheduling ◽  
Second Order ◽  
Mixed Integer ◽  
Two Stage ◽  
Dc Distribution ◽  
Scheduling Model ◽  
Second Order Cone

The development of DC distribution network technology has provided a more efficient way for renewable energy accommodation and flexible power supply. A two-stage stochastic scheduling model for the hybrid AC/DC distribution network is proposed to study the active-reactive power coordinated optimal dispatch. In this framework, the wind power scenario set is utilized to deal with its uncertainty in real time, which is integrated into the decision-making process at the first stage. The charging/discharging power of ESSs and the transferred active/reactive power by VSCs can be adjusted when wind power uncertainty is observed at the second stage. Moreover, the proposed model is transformed into a mixed integer second-order cone programming optimization problem by linearization and second-order cone relaxation techniques to solve. Finally, case studies are implemented on the modified IEEE 33-node AC/DC distribution system and the simulation results demonstrate the effectiveness of the proposed stochastic scheduling model and solving method.

scholarly journals Increment of Fault Current due to integration of Distributed Generation and its impact on Distribution Network Protection

2021 ◽  
Author(s):  
Haymanot Takele Mekonnen
Keyword(s):  
Power System ◽  
Distributed Generation ◽  
Distribution System ◽  
Distribution Network ◽  
Fault Current ◽  
Power System Protection ◽  
Power Distribution System ◽  
System Protection ◽  
Network Protection ◽  
Three Phase

Abstract BackgroundOne of the new technologies in generating power near the distribution system is called distributed generation which has supportive and destructive characteristics to the power system protection. One of the destructive characteristics of distributed generation is increasing the level of fault current to the protective equipment of the power system. In addition to increment of fault, it also alters the radial nature of the power distribution system and cause the power bidirectional rather than unidirectional. Integration of distributed generation to the distribution network causes increment of fault current effect, reliability drop, and affects security of protection system. The level of failure of protection be contingent on type, size, location and number of distributed generation. This fault current can cause a great damage to the electrical equipment with the miss operations of protective devices. The main aim of this paper is analysis of the fault current level to the protection of distribution network due to the integration of distributed generation which concerns on solar distributed generation, wind distributed generation and combination of solar and wind distributed generations at a time. This paper conducts the analysis for the increment of fault current by the integration of distributed generation and its impact on distribution network protection. ResultsThe analysis and the modeling are conducted on the 15KV distribution network of the radial feeder in Debre Markos town. This paper has covered the ling to ground, line to line and three phase fault analysis and their impact on the protection of distribution system for the wind and solar distributed generation types. After the integration of the distributed generation the fault current is increased by 0.529KA for three phase, 0.74KA for line to ground, 0.467KA for line to line and 0.523KA for line to line to ground. ConclusionsThis paper confirms designing distribution network without forecasting the future demand of electric power users give the protection equipment additional requirement. As the result, the fault current after the integration of distributed generation to the distribution network have great value in terms of power system protection.

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