Conference Paper

Transient Stability Analysis of an Islanded Microgrid under Variable Load

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Abstract

In this paper, we investigate some aspects related to microgrid (MG) stability. Due to different applications of MG, its structure and deployment topology vary depending upon the nature of application and operating modes (islanded or grid connected). So, the stability of MGs varies accordingly. This paper precisely explains the stability aspects (e.g., phase angle and power losses) of remotely located islanded MG having the capability to integrate distributed energy sources. Initially, the stability of three bus system is assessed under variable load and find some gaps related to stability as MG involves a high penetration of distributed energy sources. These gaps indicate that stability of a MG is not only in the control of generation/load but also in its coordination with other loads. After that, we implement the load coordination technique and analyze the stability against fixed and dynamic loads. For comprehensive analysis, four different cases are considered in which we vary load at different bus bars and check the performance. Lastly, we integrate the distributed energy source to islanded MG and perform the stability analysis. For validation purpose, extensive simulations of the proposed cases are conducted using Matlab. Simulation results depict that load coordination technique is more efficient regarding MG stability.

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... The power flows in distribution grid becomes bidirectional and the conventional protection philosophy gets affected and this necessitates the system to utilize adaptive techniques in protective relaying. Stability issues arise due to small size of DGs in comparison to conventional generators and majorly arise in transient [3][4] and small signal aspects [5][6][7]. ...
... Most of the DG units are of smaller size compared to conventional generators. With low penetration level of DGs, the impact on transient stability of power system is negligible [3][4][5][6][7]. However, if the integration is done on a larger scale then the DGs start influencing the dynamic behaviour of the power system as a whole. ...
... However, if the integration is done on a larger scale then the DGs start influencing the dynamic behaviour of the power system as a whole. Stability issues generally appear in transient [4], small signal [7] and voltage stability [11]. ...
... Recently, the researchers have proposed a wide variant of techniques to reduce the power losses for a betterment of system stability. In (Rasheed et al., 2016), the authors have proposed MG coupling scheme using interconnecting static switch. The neighboring grids have been connected to avoid possible overload conditions due to uneven energy demand. ...
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Coordinated energy management of networked Microgrids in distribution systems
  • Z Wang
  • B Chen
  • J Wang
  • M Begovic
  • C Chen
Z. Wang, B. Chen, J. Wang, M. Begovic and C. Chen, "Coordinated energy management of networked Microgrids in distribution systems," 2015 IEEE Power & Energy Society General Meeting, Denver, CO, 2015, pp. 1-1, doi: 10.1109/PESGM.2015.7286148.