Diagnóstico automático de eventos e distúrbios em unidades geradoras e usinas utilizando lógica fuzzy

The electric power systems are getting more complex and covering larger areas day by day. This fact has been contribuiting to the development of monitoring techniques that aim to help the analysis, control and planning of power systems. Supervisory Control and Data Acquisition (SCADA) systems, Wide Area Measurement Systems and disturbance record systems. Unlike SCADA and WAMS, disturbance record systems are mainly used for offilne analysis in occurrences where a fault resulted in tripping of and apparatus such as a transimission line, transformer, generator and so on. The device responsible for record the disturbances is called Digital Fault Recorder (DFR) and records, basically, electrical quantities as voltage and currents and also, records digital information from protection system devices. Generally, in power plants, all the DFRs data are centralized in the utility data centre and it results in an excess of data that difficults the task of analysis by the specialist engineers. This dissertation shows a new methodology for automated analysis of disturbances in power plants. A fuzzy reasoning system is proposed to deal with the data from the DFRs. The objective of the system is to help the engineer resposnible for the analysis of the DFRs’s information by means of a pre-classification of data. For that, the fuzzy system is responsible for generating unit operational state diagnosis and fault classification.

A altura de dossel e a adubação nitrogenada da pastagem podem afetar a nutrição nitrogenada do milho, num sistema de integração lavoura pecuária?

We conducted a field experiment near Abelardo Luz, Santa Catarina, from October 2012 to April 2014, to evaluate the effect interaction of nitrogen fertilization and height of canopy over the N nutrition of corn subsequently grown to pasture. The data belonging to this thesis are related to the first two production cycles obtained in sorghum pasture (2012/2013), oat (2013) and corn crop (2013/2014). In the evaluation of forage sorghum and oat it was used the same experimental design, consisting of randomized complete block in a factorial arrangement (2 x 2) with three replications. The first factor was considered canopy height (Low and High) and the second factor was the fertilization of cover crop pasture (0 and 200 kg N.ha-1). In phase I and II, the combination of factors evaluators were prepared in the same experimental unit. For corn crop the design was a randomized complete block in a factorial design (2X2X4X6) with three replications. Factors considered in corn were: canopy height of pasture (Low and High), nitrogen application times (NG - nitrogen in the grains and NP - nitrogen in pasture), nitrogen fertilization in corn (0, 100, 200 and 300 kg N.ha-1) and time (46, 53, 60, 67, 76 and 103 days after sowing the maize). In phases I and II, in general the use of N in the pasture increased the productive potential of the pasture and animal management and canopy height has changed the dynamics of structural components and botanical pasture. In cold conditions for long periods and not acclimatized plants the adoption of high nitrogen fertilization and height high grazing pasture leave vulnerable to damage caused by the freezing of plants. The anticipation of nitrogen fertilization on pasture positively affects the corn crop by increasing the accumulated dry matter and N content in the plant. Nitrogen nutritional content of corn with the anticipation of fertilization in pasture is suitable for obtaining high crop production in integrated crop-livestock system. When used nitrogen only coverage in corn sufficiency level in the nitrogen nutrition is achieved with the use of 100 kg N.ha-1. With the use of 200 kg N ha -1 NG and NP no difference in nitrogen content and nitrogen nutrition index.