A wireless 802.11 condition monitoring sensor for electrical substation environments

The work reported in this thesis is concerned with the design, development and testing of a wireless 802.11 condition monitoring sensor for an electrical substation environments. The work includes a comprehensive literature review and the design and development of a novel continuous wireless data acquisition sensor. Laboratory and field tests were performed to evaluate the data acquisition performance of the developed wireless sensor. The sensor‟s wireless immunity to interference performance was also evaluated in laboratory and field tests. The literature survey reviews current condition monitoring practices in electrical substation environments with a focus on monitoring high voltage insulators and substation earth impedance. The data acquisition performance of the wireless sensor was tested in a laboratory using two artificially polluted insulators, in a fog chamber that applied clean fog. Analysis of the test results were found to be in good agreement with those recorded directly through a data acquisition card and transmitted via coaxial cable. The wireless impedance measurement of a 275kV transmission earth tower base field test was also performed and was found to be in agreement with previous published results from standard earth measurements. The sensor‟s wireless interference performance was evaluated at a field test site when no high voltage experiments were taking place. The sensors wireless interference performance was then tested in a laboratory environment before and during high voltage tests taking place. The results of these tests were compared to each other and to published results. These tests demonstrate the suitability of the sensor‟s design and its immunity to interference. The experimental work conducted using the developed wireless sensor has led to an understanding that continuous wireless data acquisition is possible in high voltage environments. However, novel condition monitoring systems that make use of such wireless sensors, have to take into account data losses and delays adequately. Furthermore, a solar power source was designed and constructed to be used for outdoor substation applications and the solar battery charging performance of the wireless sensor was tested in a solar laboratory