Apr 2018 / by Shaikh Shamser Ali and Ruchi Tyagi
TANGEDCO (Tamil Nadu Generation & Distribution Corporation Ltd.) – distribution utility for Tamil Nadu State has issued a regulation regarding harmonic mitigation, under direction of tariff order by Tamil Nadu Electricity Regulatory Commission (TNERC), wherein any HT consumer/ generator needs to meet the specified harmonic limits as per norms stipulated in CEA (Central Electricity Authority) regulation on grid code (GOI, 2013).
TANGEDCO measures the level of harmonics and issues a notice if the value exceeds the CEA specified limit and if the consumer is unable to mitigate harmonics within the specified limit after notified period, penalty is imposed every month. Due to above tariff penalty mechanism the HT consumers started looking at mitigation techniques wherever the harmonic distortion is reportedly high. Most of these facilities already had reactive power compensation in terms of capacitor banks installed. These capacitor banks too suffered from failure like other electrical equipment failure due to high harmonic distortion levels.
In some cases based on harmonic spectrum, installed capacitor banks can be used to mitigate harmonics. After detailed and proper analysis of harmonics in the system mitigation techniques like tuned harmonic filters or capacitor with reactor can also be used as harmonic filtration technique (Campos BP, Sousa LAR&Ribeiro PF, 2016).
This case study explores such possibility that can be beneficial for industry to look at available resources for addressing harmonic mitigation and optimizing their expenses in deploying fresh investment to avoid harmonic penalty.
Mar 2018 / by Weijun Wang, Haoyue Wang, Yong Sun and Wei Luo
While the wind energy resources of northern China are quite abundant, the abandoned wind rate keeps up at a high level due to the electric energy and heat coupling of the cogenerator during heating period. Consuming abandoned wind power heating facilitates degrading the abandoned wind power amount of northern China, developing consumption wind power ability and reduction of the pollution. Whilst the economical efficiency of wind power heating is relatively poor due to the high construction costs, the pollutant discharge amount is low. The environmental costs are calculated, shifted into monetary costs, and then added with economic costs. The costs of consuming abandoned wind power heating include the decrement of the generation cost of wind power plant and the economic and environmental costs of thermal storage type electric heating. Taking the environmental conservation of wind power and the decrement of the generation cost of wind power plant into consideration, not only the comparison between consuming abandoned wind power heating and cogeneration heating is more comprehensive and reasonable, but also the joint programming of wind power heating and traditional modes of heating.
Keywords: Consumingabandoned wind power heating; thermal storage type electric heating; economic costs; environmental costs
Mar 2018 / by Zhiwen Luo, Xingzhong Yuan, Xing Wang and Kun Le
Wetland ecosystem is considered as one of the important ecosystems for life and human society sustainability, and also one of the most important terrestrial carbon stocks on the earth. Therefore, conservation of wetland soil carbon stock may play a significant role in mitigation of increasing greenhouse gas in the atmosphere. The Three Gorges reservoir as an important hydraulic project of Yangtze river, the environmental issues attracts worldwide attention, and the environmental problems of littoral wetlands of the Three Gorges reservoir are more important aspect. Total organic carbon (TOC) and nitrogen content in soil of downstream of the Three Gorges reservoir in Fengjie, Kaixian, Wushan regions were determined. Then the organic carbon content of the soil classification comparison, analysis of the causes of soil organic carbon content of the various main reasons for differences, soil classification: the same region, same altitude, different species; the same area, the same species, different altitudes. Finally, by calculating the content of these regions of the average total organic carbon is about 10.43g/kg and average ammonium-N is about 28.47mg/kg.
Keywords: Three Gorges reservoir; littoral wetland; total organic carbon; ammonium-N; soil
Mar 2018 / by Amartya Kumar Bhattacharya
The present paper gives an overview of saline water intrusion into coastal Nigeria. The paper places saline water intrusion into coastal Nigeria in the context of geology, hydrogeology, meteorology and land use of coastal Nigeria. The paper suggests ways and means to manage the problem of saline water intrusion into coastal Nigeria.