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One-line diagram of the IEEE 118-bus system with four communities partitioned by proposed partitioning method.
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The contributions of this article include a new concept, a new question, and a new method. This article proposes the concept of functional community, which is different from conventional topological community. Functional community is defined with two meanings: (1) tighter internal coupling for better efficiency within the same community; (2) more i...
Contexts in source publication
Context 1
... proposed in this article is applied to the IEEE-118 bus system. The proportion coefficients (ω, ξ, δ, and λ) are equal to 0.5 in (2) and (7). Fig. 3 shows the relationship between the number of communities and power supply modularity. Fig. 3, the Q P S reaches the maximum value (0.08477) when the network is partitioned into four communities. Fig. 4 displays the one-line diagram of the IEEE-118 bus system with these four communities. In Fig. 4, the different colors are utilized to represent diverse communities. Additionally, to further analyze the performance of the proposed partitioning method in large-scale power networks, Fig. 5 shows the relationship between the number of ...
Context 2
... 4 displays the one-line diagram of the IEEE-118 bus system with these four communities. In Fig. 4, the different colors are utilized to represent diverse communities. Additionally, to further analyze the performance of the proposed partitioning method in large-scale power networks, Fig. 5 shows the relationship between the number of communities and power supply modularity of the IEEE-300 bus system and an Italian power network. ...
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Renewable energy such as wind power, hydro-power and photovoltaic are connected to the power system as distributed power sources will increase the instability of power system operation. To ensure the stable operation of the power system after renewable energy and load access, it is necessary to properly partition the power grid. A grid partition me...
Citations
... To cope with this limitation, reference [11] investigated the power flow relation between the generator bus and the load bus. Adding the power supply strength model to the ECS formed the proposed Electrical Functional Strength (EFS) network to use with the FNA for network partitioning. ...
... C sr is the transmission capacity between the source bus s, and the sink bus r. Similarly, Z sr is the equivalent impedance between the two buses, calculated as follows [11]: ...
... Where z ss is the internal impedance of bus s, z rr is the internal impedance of bus r, and z sr is the equivalent impedance between bus s and r. While this study considers the admittance defined in equation (6) to simplify the calculations [11], where Z E sr is the equivalent capacity defined as in (5): ...
As the current calculation method of voltage/var sensitivity (VVS) could not reflect the temporal variations of power sources and load, the paper proposes a novel VVS calculation method to partition the distribution network containing renewable energy. Firstly, the defects of the existing VVS calculation methods are analyzed, and a novel VVS calculation method is proposed by adding reactive power output perturbation to the reactive power source. Secondly, the VVS matrix is fuzzified to obtain the membership matrix between each node. Based on the membership relationship between the reactive power source nodes, the nodes with a strong coupling relationship are merged to determine the initial number of partitioning. Then, the final partitioning result is determined according to the affiliation between each load node and each reactive power source. Finally, the partitioning result is evaluated based on the partitioning membership indexes. The proposed approach is tested on the IEEE 33-node distribution test system, and numerical simulations verify the high efficiency of partitioning. The simulation results show that the proposed method can reflect the temporal variations of power sources and load, and ensure the reasonable distribution of voltage and reactive power in each zone.
Background
The voltage/var control of the power system is an important means to ensure the safe and economically stable operation of the system.
Objective
The paper proposes a novel VVS calculation method to partition the distribution network containing renewable energy.
Method
Firstly, the existing problems of electrical distance index are analyzed. A novel VVS matrix calculation method is proposed, which calculates the VVS of each reactive power source to the remaining nodes by adding voltage/var output perturbation to the reactive power source. Secondly, the VVS matrix is fuzzified to obtain the membership matrix between each node. Based on the membership relationship between the reactive power source nodes, the power supply nodes with strong coupling relationship are merged to determine the initial number of the partitioning. Then, the final partitioning result is determined according to the affiliation between each load node and each reactive power source. Finally, the partitioning result is evaluated based on the sensitivity index of membership degree.
Results
The proposed approach is tested on the IEEE 33-node distribution test system and numerical simulations verify high efficiency of the partitioning. The simulation results show that the proposed method can reflect the temporal variations of power sources and load, and ensure the reasonable distribution of voltage and reactive power in each zone.
Conclusion
The proposed method can reflect the temporal variations of power sources and load, and ensure the reasonable distribution of voltage and reactive power in each zone. This paper proposed a fuzzy clustering partitioning based on a novel calculation method of VVS, which is suitable for the problem of variable voltage /var running state of the system under high-proportion DG access.
The Virtual Microgrid (VM) method is a solution for addressing challenges in Conventional Distribution Network (CDN), such as power fluctuations or load mismatches, by actively partitioning the CDN into interconnected Microgrid-style VMs. Previous studies have fewer discussions about the mutual interaction between the grid’s partition performance and Distributed Energy Resources (DERs) allocation. This paper proposes a new approach for dividing a large power grid into clusters by using the complex network theorem. The approach integrates power flow dynamic, line impedance, generator-load relations and power generator cost-efficiency into a single static weighted adjacency matrix. Meanwhile, a multi-objective Genetic Algorithm (GA) planning structure is also denoted for transforming a CDN to VMs with mutual interaction between partition and DER allocation. The proposed metric is tested in both transmission and distribution networks. The IEEE 118-bus system test shows that even with a higher value of the proposed indicator, there are fewer power exchanges between sub-networks. Meanwhile, in the 69-bus radial system tests, the GA-based co-planning method outperforms previous methods in forming more self-sufficient and more efficient interconnected VMs. An intermediate solution is suggested by implementing a trade-off between inter-VM power exchange and the operation cost.
