A Downsizing Strategy for Combinatorial PMSG Based Wind Turbine and Micro-SMES System Applied in Standalone DC Microgrid

This paper presents a combinatorial standalone permanent magnet synchronous generator (PMSG) based variable speed wind turbine (VSWT) and small-size superconducting magnetic energy storage (SMES) system into the DC microgrid system. The principal purpose of SMES system is to preserve power balance by absorbing power during peak wind generation and to release it during low power generation. This work accomplished by describing the optimized design of the SMES solenoid coil, ensuring the desired energy storage capacity based on the simulated annealing (SA) algorithm. More importantly, the new control technique is developed for bi-directional DC-DC converter to level output power of the wind turbine depending on the demand thereby reducing the capacity of the DC-DC converter system. Detailed simulation studies implemented in PSCAD/EMTDC corroborate the superior robustness and balancing performance of the proposed micro-SMES controller with an optimal coil size under various situations including variable wind speed. This combination will result in “scaling-factors” knowledge through downsizing strategy which will lead to the most efficient system from cost cutting, energy savings, and downsizing viewpoints

An Assessment of Voltage Instability in the Nigerian Power System Network

This paper assesses the trends in voltage instability in the Nigerian Power System Network (PSN). Data of voltage instability were collected for the year (1995-2013) and was analyzed sequentially using simple statistics and the result interpreted graphically. The result shows an average collapse of 5.1% recorded during this period. 50.8%of the voltage collapses are as a result of total grid collapse while 48.4% collapses are as a result of partial grid collapse while 0.9% collapses caused by foreign objects. The paper therefore emphasizes how poor government policies had led to poor power generation hence leading to voltage instability in the Nigeria power system network

Victorian Eco-Spiritualism: Environmental Citizenship and the Occult Revival in Nineteenth-Century Women’s Writing

The purpose of this article is to explore the notion of environmental citizenship in the work of nineteenth-century spiritualist women. By examining female occultist participation in vegetarianism, anti-vivisection, and anti-industrial communalism, it is possible to observe an eco-spiritualist line in women’s writing, one which facilitated a more holistic and respectful approach to non-human subjectivities. Such texts therefore offer useful evidence of how spiritualist beliefs allowed women to influence public policies regarding the human-nature relationship in the long nineteenth century

Achieving inclusive and transformative ICT education practices in rural schools in marginalized communities

Information and Communication Technology (ICT) can do more than benefit teaching and learning in rural schools; it can also be a catalytic and transformative tool that induces knowledge reformation and production amongst learners in an informed society. In this paper our focus is on how ICT education practices in rural schools in marginalized communities can be transformed to develop knowledge that is transformative, empowering, and emancipatory in order for learners to pursue a vision of a good life in a desirable society. The study employs critical research to acquire deeper meanings and insights from in-class teaching events and observations at Alabama High School (a pseudo name) in Eastern Cape of South Africa. Through our critical reflective, the research confirms that current ICT education and curricula practices in rural marginalized schools have failed to develop transformative knowledge that makes rural schools sites of possibility for learners to become active in society from a position of empowerment. Developing transformative ICT educational experiences in rural schools could face challenges in the context of dominant educational practices and structures that in essence also need transformation. Transformative ICT education practices in this study suggest transforming learners’ learning experiences such that the learners question or reframe their assumptions, knowledge, and education experiences in relation to their community life. In this paper we argue that more effective transformative ICT education in rural schools requires a sufficiently longitudinal perspective and action that takes into account the general impact of ideas on education practices in relation to school and community needs

SoC-FPGA systems for the acquisition and processing of electroencephalographic signals

Real-time acquisition and processing of electroencephalographic signals have promising applications in the implementation of brain-computer interfaces. These devices allow the user to control a device without performing motor actions, and are usually made up of a biopotential acquisition stage and a personal computer (PC). This structure is very flexible and appropriate for research, but for final users it is necessary to migrate to an embedded system, eliminating the PC from the scheme. The strict real-time processing requirements of such systems justify the choice of a system on a chip field-programmable gate arrays (SoC-FPGA) for its implementation. This article proposes a platform for the acquisition and processing of electroencephalographic signals using this type of device, which combines the parallelism and speed capabilities of an FPGA with the simplicity of a general-purpose processor on a single chip. In this scheme, the FPGA is in charge of the real-time operation, acquiring and processing the signals, while the processor solves the high-level tasks, with the interconnection between processing elements solved by buses integrated into the chip. The proposed scheme was used to implement a brain-computer interface based on steady-state visual evoked potentials, which was used to command a speller. The first tests of the system show that a selection time of 5 seconds per command can be achieved. The time delay between the user’s selection and the system response has been estimated at 343 µs.Fil: Oliva, Matias Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; ArgentinaFil: Arias García, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; ArgentinaFil: Spinelli, Enrique Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; ArgentinaFil: Veiga, Alejandro Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales. Universidad Nacional de La Plata. Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señales; Argentin