Load Flow Based Voltage Stability Indices for Voltage Stability and Contingency Analysis for Optimal Location of STATCOM in Distribution Network with Integrated Distributed Generation Unit

Electrical power system is growing rapidly with the current increasing demand. One of many important issues being faced in power system is the voltage instability. With that being said, this work investigates the voltage stability indices with contingency analysis used in order to determine the voltage stability of the network system. These approaches are used to detect and avoid voltage instability in the distribution network. The behavior of the distribution network is determined based on the contingency analysis. STATCOM is injected into selected buses in the distribution network of the system to determine the system’s stability during the contingency condition. Distributed generation (DG) is utilized to enhance the network stability. Different scenarios have been assumed in order to test the proposed technique under different conditions. The work has been implemented in Digsilent power factory environment. The proposed technique has been tested on IEEE 30 bus system. Promising results have been obtained with respect to previous published literature, in term of identifying the weak buses and enhancing the overall stability of the network

Optimal placement of DSTATCOM in distribution network based on load flow and voltage stability indices studies

The power utilities are experiencing a new challenge as the demand for electrical power is increasing on a regular basis. This forced the existing networks operates closed to its stability limits. The ability of a power system to remain acceptable magnitude voltages at all bus under both normal and contingency conditions, known as voltage stability is the major concern for both transmission and distribution network to ensure that a secure and reliable electrical power is able to transmit from generation to load side. This can be mitigated by integrating Custom Power (CP) device on the existing transmission system. However, the location of CP device is significantly important to ensure adequate investment of CP device in networks that will enhance the voltage stability margin, reduce power loss and improve voltage profile. In this paper, the optimal location of Distribution Static Synchronous Compensator (DSTATCOM) is introduced by analyzing results obtained from two studies; load flow and voltage stability indices. The studies were examined using the modified IEEE 30 bus system which is modelled and tested using DigSILENT PowerFactory 16 as simulation tools

Voltage stability indices studies on optimal location of wind farm in distribution network

The increasing demand for electrical power contributes major challenges especially in power utilities as one of the main issues is voltage instability. The voltage instability occur in both transmission and distribution network may weaken the whole operation of power system that will significantly limit the growth of load. As a result, voltage collapse blackout occurs in the power system whereas at this point the voltage become uncontrollable. The penetration of Wind Power Plant (WPP) in distribution system may be a good alternative to accommodate this challenge. However, the location of WPP play the important role to fully utilize the power generated by WPP that will not only improve the voltage stability margin but also reduce the power losses and enhance voltage profile. This paper presents the analysis for the selection of the optimal location of WPP integration from voltage stability, voltage profile and total system losses overview. The study was conducted using IEEE 30 Bus test system as the benchmark system and DigSILENT PowerFactory 16 as simulation tools

Dynamic modeling of power network-integrated wind turbine

This paper presents the performance investigation of voltage and current for dynamic model of the wind turbine. In this study, the various numbers of wind turbine speed are applied in the simulation. This treatment is intended to see how much influence the turbine speed has on the voltage and current output. IEEE 14 bus system is integrated to the wind turbine in order to observe the impact of on-grid connection to the voltage and current performance. How to model wind turbine in PSCAD simulation software also discussed in this paper. The detail of supporting components in designing a wind turbine system and their functions are also explained. Several values of turbine speed are also considered in this paper as a study material in seeing the performance of wind turbines. The relationship between wind speed and pitch angle will also be discussed to ensure that the wind turbine is not damaged. In order to prove the accuracy of the simulation model, the obtained measurement generation of active power from the wind turbine is matched with the manual calculation. Based on the various wind speed values that have been tested, this can be the basis for the application of wind turbine (renewable energy) design development for further research

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Genomic insights into rapid speciation within the world’s largest tree genus Syzygium

Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification