PERBEDAAN KENAIKAN TEMPERATUR DAN JUMLAH ENERGI PANAS YANG DIHASILKAN INTI TEMBAGA TERHADAP BEBAN ARUS PADA 3 MERK KABEL NYM

Seiring berkembangnya industri, penggunaan kabel pada instalasi listrik turut meningkat. Salah satu komponen yang memiliki peran penting dalam menghantarkan arus listrik adalah inti tembaga kabel. Tembaga banyak digunakan karena memiliki resistivitas listrik terendah dan nilai konduktivitas terbaik. Arus yang mengalir pada inti tembaga akan menghasilkan energi panas dan sejumlah panas yang berpindah. Selain itu, dalam memilih kabel yang digunakan perlu memperhatikan kemampuan inti tembaga dalam menghantarkan arus listrik karena akan mempengaruhi temperaturnya. Penelitian dilakukan untuk mempelajari perbedaan kenaikan temperatur dan jumlah panas yang dihasilkan inti tembaga kabel NYM pada beban arus tertentu dengan menggunakan tiga merk berbeda. Sampel kabel NYM yang digunakan menggunakan ukuran 2 x 1,5 mm2 dengan tiga merk berbeda, yaitu merk A, merk B, dan merk C. Seluruh sampel diuji perbedaan peningkatan temperaturnya menggunakan trafo uji dengan diberi beban arus sesuai KHA kabel (22 Ampere) dan dua kali KHA kabel (44 Ampere). Temperatur akhir dilihat dari hasil grafik perubahan temperatur hingga mencapai keadaan setimbang. Berdasarkan hasil penelitian, dapat disimpulkan bahwa inti tembaga kabel merk B memiliki kenaikan temperatur paling rendah saat diberi beban arus sesuai KHA yang mencapai 54,3ºC maupun saat beban arus dua kali lipat KHA yang mencapai 144,4ºC. *** With the development of the industry, the use of cables in electrical installations is increasingly being used. One of the important parts in conducting electric current is the copper conductor of the cable. Copper is widely used because it has the lowest electrical resistivity and the best conductivity values. The current flowing in the copper conductor will generate heat energy and some heat transfer. In addition, in choosing the cable used, it is necessary to pay attention to the ability of the copper conductor to conduct electric current because it will affect its temperature. This research was conducted to study the differences in temperature rise and the amount of heat generated by the copper conductor of NYM cables at certain current loads using three different brands. The NYM cable samples used were 2 x 1.5 mm2 in size with three different brands, namely brand A, brand B, and brand C. All samples were tested for differences in temperature rise using an electrical apparatus with current load according to the current carrying capacity of the cable (22 Amperes) and twice the current carrying capacity of the cable (44 Amperes). The final temperature is seen from the results of the temperature change graph until it reaches a steady state condition. Based on the results of the research, it can be concluded that the copper conductor of cable brand B has the lowest temperature rise when given a current load according to the current carrying capacity which reaches 54.3ºC and when the current load is twice as high as the current carrying capacity of the cable which reaches 144.4ºC

Optimal SSSC-based power damping inter-area oscillations using firefly and harmony search algorithms

The static synchronous series compensator (SSSC) can add a series reactance to the transmission line, and when it is fed using auxiliary signals, it can participate in damping inter-area oscillations by changing the series reactance. In this paper, the effect of the SSSC on small-signal stability is investigated. The design of a controller for damping oscillations is designed and discussed. Moreover, using the firefly and the harmony search algorithms, the optimal parameters controlling SSSC are addressed. The effectiveness of these two algorithms and the rate of SSSC participation in damping inter-area oscillation are also discussed. MATLAB software was used to analyse the models and to perform simulations in the time domain. The simulation results on the sample system, in two areas, indicated the optimal accuracy and precision of the proposed controller

Otimização de layout e sistema coletor de parques eólicos offshore

The integration of energy generation systems from renewable and alternative sources became possible with the advent of new technologies. Wind energy is one of the sources that has been showing significant growth over the past few years and with good prospects for the coming years. This growth is verified for onshore projects, when installed on the continent, or offshore, when installed on the ocean. The absence of obstacles, which provide better use of the wind farm, and less visual and noise pollution have led to a growing interest on the part of investors in the construction of offshore projects. The technologies used for the deployment of wind farms in offshore environments require a greater investment when compared to onshore technologies. This fact makes the planning stage even more necessary, in which the objective is to obtain a wind farm that extracts the maximum power and, at the same time, is economically viable, presenting a reduction in cabling costs and electrical losses. Jensen’s wake effect model was used to define the optimum positioning of the turbines (layout). The model determines the incident wind speed in a turbine that is located in regions that have interference due to the interaction between the wind and a turbine located upstream. The optimization of the collector system aimed to reduce electrical losses and costs with the acquisition of cables. Cable crossings, the occurrence of wind turbines very close to connections, the ampacity limits and the positioning of the offshore substation were considered as restrictions of the problem. PSO, GWO, Bat Algorithm (BA) and a modified version of BA were the techniques used to solve both problems. The results obtained showed that the modifications implemented on BA make the technique perform better in obtaining solutions to these problems. In addition, the results demonstrated that all techniques were effective in obtaining viable solutions according to the objectives of each simulation. Thus, the techniques are great strategies for solving problems of this nature and assist decision making in the planning stage of wind farms.A integração de sistemas de geração de energia proveniente de fontes renováveis e alternativas se tornou possível com o advento de novas tecnologias. A energia eólica é uma das fontes que vêm apresentando um expressivo crescimento ao longo dos últimos anos e com boas perspectivas para os próximos anos, tanto em empreendimentos onshore, quando instalados sobre o continente, ou offshore, quando instalados no mar. A ausência de obstáculos, que proporcionam melhor aproveitamento do parque, e a menor poluição visual e sonora proporcionaram um crescente interesse por parte de investidores na construção de empreendimentos offshore. Devido ao local de instalação, as tecnologias necessárias para a implantação de parques eólicos em ambientes offshore requerem um investimento maior, quando comparado ao das tecnologias onshore. Este fato torna ainda mais necessária a etapa de planejamento que vise à obtenção de um parque que consiga extrair o máximo de potência possível e, ao mesmo tempo, seja viável economicamente, apresentando redução de custos com cabeamento e de perdas elétricas. Para a definição do posicionamento ótimo das turbinas (layout) foi considerado o wake effect para a determinação da velocidade de vento incidente em uma turbina e naquelas que estão localizadas em regiões que sofrerão interferência devido a essa interação. Para a otimização do sistema coletor, buscou-se a redução das perdas elétricas e dos custos com aquisição de cabos e restringiu-se o problema para que não houvesse cruzamentos de cabos e aerogeradores muito próximos a conexões. Além disso, também foram considerados os limites de ampacidade e o posicionamento da subestação offshore. Para a resolução de ambos os problemas foram utilizados o PSO, o GWO, o Bat-Algorithm (BA) e uma versão deste algoritmo com modificações propostas. Os resultados obtidos demonstraram que as modificações realizadas sobre o BA fizerem com que a técnica apresentasse um melhor desempenho na obtenção de soluções desses problemas. Além disso, os resultados demonstraram que as técnicas foram eficazes na obtenção de soluções viáveis de acordo com os objetivos de cada simulação, que são ótimas estratégias para a resolução de problemas dessa natureza e que auxiliam a tomada de decisão na etapa de planejamento de parques eólicos