Cerca nel sito per parola chiave

pubblicazioni - Presentazione

Application of optical sensors for diagnostic of electrical components of a distribution network

pubblicazioni - Presentazione

Application of optical sensors for diagnostic of electrical components of a distribution network

In questo lavoro di riportano i primi risultati dell¿applicazione di due diverse tipologie di prototipi ottici per la diagnostica di componenti elettrici di una rete di distribuzione

In the framework of the new electrical power system management, a relevant role could be played by sensors and sensor network. The application of low-cost sensors could efficiently provide real time information on the ageing condition or on anomalous operation of electrical components of the new Medium Voltage (MV) network; this could prevent possible dangerous situations affecting the reliability of the distribution network itself [1]. This paper reports two examples of the development of optical sensors based prototypes for the diagnostic and monitoring of MV electrical components. The first one is a predischarge monitoring device for MV switchboards, which is based on three different sensors type (optical, acoustic and chemical sensors). This combined approach is to improve the effectiveness of diagnostic detection [2]. As shown in Fig.1, these sensors are based on optical fibres technology, which guarantees high immunity to electromagnetic interference, chemically inert, and the survival of the sensor probe inside the MV switchboard without the need of its periodic replacement. The simultaneous analysis of three sensors response is managed through a software LabView interface. Sensors were installed in a typical MV switchboard layout in which an artificial corona defect was inserted (Fig.1). Fig.2 shows typical results of a joint analysis of sensors responses in presence of a predischarge activity. Predischarge inception and time evolution are evidenced in the graph when different supply voltage levels are applied to the MV switchboard confirming the effectiveness of this simultaneous detection approach. The second example is an optical prototype assembled for detecting early aging of Medium Voltage/Low-Voltage transformers by means of their vibration fingerprint [3]. As shown in Fig.3 this device consists of Micro Optical Electro-Mechanical System (MOEMS) based accelerometers, an acquisition unit wireless connected to a remote PC and controlled via LabView interface. Preliminary comparative tests were performed with standard piezoelectric accelerometers, used as reference, on a conventional type distribution transformer (30kVA) under open circuit and in shortcircuited configuration. A good agreement with reference vibration spectra was obtained; from the fundamental frequency of vibration it was possible to distinguish between winding and core contributions to transformer tank vibrations. This work has been financed by the Research Fund for the Italian Electrical System under the Contract Agreement between RSE (formerly known as ERSE) and the Ministry of Economic Development – General Directorate for Nuclear Energy, Renewable Energy and Energy Effieciency stipulated on July 29, 2009 in compliance with the Decree of March 19, 2009.

Progetti

Commenti