Alfred Crosby and Richard Grove, the British environmental historians coined the term ‘ecological imperialism’ that refers to ‘the violent appropriation of, indigenous land to ill- considered introduction of, cash crops in colonized terrain. The Indian ecocritic, Ramachandra Guha, argues ‘the need to bring postcolonial and ecocritical issues together as a means of, challenging continuing imperialist mode of, social and environmental dominance. Ghosh synthesizes history, autobiography, imperialism that has great impact on the mind of, the reader. The colonial experiences and distress and miseries of, the people are shown during the colonial period. In this novel, Ghosh presents ecological harm caused to the earth by imperialism and wars. Ghosh indicates how colonialism and wars imperialize and devastate individuals as well as the physical condition.
The growing proliferation of power electronic-based non-linear loads is leading to non-sinusoidal waveforms of currents and voltages in the modern power systems. These non-linear loads inject harmonic components that have a significant impact on low-voltage (LV) distribution transformers. The primary effect of harmonic currents is the amplification of frequency-dependent losses, leading to higher operating temperatures and accelerated thermal degradation of the transformer’s insulation system. This article explores the application of IEEE Std C57.110 in realistic scenarios involving the integration of electric vehicles (EVs) and residential nonlinear loads, based on field measurements of harmonic current injections from both sources. The analysis assesses the resulting harmonic distortion and its impact on LV distribution transformers. The results demonstrate that harmonic distortion can potentially increase transformer losses and thermal stress, particularly under high penetration of EVs and other nonlinear loads. Furthermore, the study underscores the importance of appropriate transformer sizing and strategic over-dimensioning as effective measures to mitigate these adverse effects. These findings suggest that existing harmonic standards and transformer design practices may require revision to account for the evolving composition of modern distribution networks.
The Commission Regulation (EU) 2016/631 of April 2016 establishing a network code on requirements for grid connection of generators (RfG) introduces a framework for building a structural harmonization of technical needs for generation in Europe. RfG entered into force in April 2019. The RfG requires power generating modules (PGM) connected to the system to be compliant with both the RfG technical requirements and its corresponding national implementation throughout its lifetime. In Spain, the Energy Ministry published the national regulation in the Royal Decree 647/2020 and the Ministerial Order 749/2020.The relevant system operator, i.e., the system operator to whose network connects the PGM, i.e. TSO or DSO, is designated by RfG as the responsible body in this compliance monitoring process, which seeks assurance that equipment connected to their network meet the technical requirements. According to the RfG, RSOs can totally or partially delegate, the performance of the compliance testing and simulations to third parties. In Spain, both the TSO and the DSOs associations agreed on adapting the main part of the compliance process to a certification scheme, under the supervision of the national accreditation company, which, for the time being, is not the most common approach followed in European countries with regards to compliance schemes. This scheme seeks to ease the achievement of the Spanish ambitious targets of renewable energy sources (RES) based on increasing the actual capacity more than twice up to 2030, while is ensured the fulfilment of the technical requirements by new PGM.Intending to define the national compliance process in Spain, the TSO and the main DSOs led a working group to draft a technical standard (NTS) for the conformity assessment of the PGM under the RfG. NTS is the guideline associated with the RfG for submitting the PGM conformity certificates by third parties. A first draft was published on the 18th of July 2019 and the final version (version 2) in November 2020, considering the national implementation rules.The NTS is structured in three sections. First, a conformity assessment with general provisions for obtaining the PGM compliance certificate in its commissioning process. Second, the compliance testing and simulations for assessing the technical requirements. Third, the validation of the simulation models used for the compliance simulations.This paper introduces the most relevant aspects of the NTS that will surely be a matter of concern for PGM manufacturers, certification bodies, laboratories, EPCs (Engineering, Procurement, and Construction) and others RSO.
Distributed acoustic sensing using CP-ΦOTDR enables a reliable measurement of vibrations in overhead conductors. A real-time frequency analysis of this vibrations enables for monitoring the sag value allowing dynamic capacity setting for improved line efficiency.
Growing environmental awareness has expanded the integration of a renewable energy source (RES) with renewable portfolio standards or a wide variety of supportive programs, such as feed-in-tariff. As the RES integration proceeded, conventional synchronous generators were gradually replaced with RES. Because early RES did not have sufficient grid support functions that synchronous generators have, RES integration started to cause blackouts across the globe. This article showcases the impact of RES on power grids that we have experienced over the past ten years from various perspectives (power system operation, power system control, power system protection, power system planning, and RES operation and modeling). Countermeasures to combat the aforementioned impact are also briefed with the evolving code/standard. Battery energy storage systems (BESS) are one of the last resorts to cope with the variabilities and uncertainties of RES. Short-duration BESS have been installed in residential areas, often with roof-top PVs, forming a hybrid system. Long-duration BESS has been mostly integrated into transmission grids to serve grid-wide grid support capabilities. Although BESS effectively compensate for intermittent RES output, unprecedented technical challenges have also emerged mainly due to its chemical reaction. Battery technologies, especially for the long-duration BESS, are still in their infancy. Therefore, safety concerns have impacted the power grid from various points of view. This article overviews the impact from broader perspectives.
