Directional protection of transmission lines is an important feature in situations where short‐circuit direction must be correctly detected. The proper operation of this protection is highly dependent on phasor comparison techniques called polarisation methods. In practice, there are not clearly defined procedures to analyse and set polarisation methods. Hence, these methods are not normally studied in detail, so their effectiveness is often uncertain. For this reason, this work proposes a novel methodology for analysing the performance of polarisation methods, which includes criteria for the selection of the most appropriate methods and their settings according to each application. Particular phasor diagrams and angular statistics are used for the analysis, while a mathematical optimization problem is defined to determine the best settings of these methods. Based on the benefits that can be obtained, the methodology is intended to be considered as an effective strategy to ensure proper use of polarization methods. The methodology is applied in a portion of the Ecuadorian Transmission System which shows the possibility of studying the performance of polarisation methods. The selection and optimal setting criteria of these methods are also analysed providing opportunities to improve the initial performance of the protection system.

No abstract

La Planta de Tratamiento de Aguas Residuales Quitumbe, de la ciudad de Quito, presentó Bulking en su sistema de Lodos Activados mediante Aireación Extendida, lo que formó espumas sobrenadantes en el biorreactor, por lo que para solucionarlo se analizaron estadisticamente datos históricos y experimentales de calidad del agua y parámetros operacionales en contraste con límites permisibles para el “Vertido en cuerpos de agua” de las normativas; Acuerdo Ministerial 097-A y Ordenanza Metropolitana 404, con el fin de evaluar remoción de contaminantes, calculándose además un modelo correspondiente a la revisión del diseño existente, para comparar condiciones operativas actuales y calculadas. Finalmente, concluyéndose que el origen del Bulking es operacional, se determinaron dos propuestas; la primera consiste en la adición de una sustancia estabilizadora (Hidróxido de Calcio) en el reactor biológico y la segunda, basada en la operación eficiente, consistente en la programación de la purga de lodos en exceso.