In a transmission line, sag is intentionally provided to relax the tension on the wire when placed between two terminals. However, thermal stress and extreme weather conditions can cause increases in transmission line sag, which can eventually damage transmission line infrastructure. In this regard, this paper examines a number of sag measurement techniques based on physical or optical properties and integrated with signal processing and communication technologies. The performance of different sag measurement methods is compared in terms of accuracy, precision and key feature. Several challenges and limitations of the existing sag measurement mechanisms are reported. A number of recommendations to address the identified challenges are made. Moreover, an efficient communication framework for sag related information exchange is proposed. This comprehensive review of the sag measurement techniques will facilitate the evolution of new and efficient real-time sag measurement and monitoring methods.

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Demand of electrical energy is growing day by day worldwide. To meet this increasing demand, generation is needed to be increased subsequently. Increasing generation is not an easy task as it may require setting up new generating units, changing transmission lines, control equipments, etc. Moreover, increased generation also causes increased environment pollution. An alternate approach that can create balance between demand and supply of electricity without increasing generation is demand side management (DSM). Furthermore, demand side management has the potential to reduce the use of energy resources resulting in less environment pollution. In this paper, three DSM techniques: using solar system, load limiting, deliberate load reduction are applied for residential users of Dhaka, Bangladesh and the results are compared with two traditional techniques: energy efficiency, direct load control. It has been found that by using solar system at home significant amount of electrical energy can be saved.

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Reliable and efficient power flow in the electrical grid is crucial given network expansion and the incorporation of numerous renewable sources. Microgrids are becoming more and more important in the global energy sector due to its numerous benefits. The variable nature of distributed energy resources (DER) in microgrid makes large-scale DER integration potentially unstable for system voltage. Grid regulations place restrictions on the voltage control of DER unit, which raises the need for reactive power support. Proper placement of flexible AC transmission system (FACTS) under post-fault conditions may enable faster voltage recovery. In this work, battery energy storage system (BESS) and static synchronous compensator (STATCOM) have been considered for improving the post-fault voltage in DER integrated weakly grid-connected microgrid system. Two operation scenarios have been considered for analyzing the behavior of BESS and STATCOM individually at post-fault situation. According to the results of the simulation, BESS requires lesser rating than STATCOM for faster recovery of post-fault voltage of the system.