Yannick Maret

Vibration Sensitivity Reduction of Photoacoustic Gas Analyzers

Optical gas analyzers are devices for measuring gas concentrations with high precision in industrial environments. Unfortunately mechanical shocks and vibrations can impact the measurement accuracy if the analyzer is installed in noisy environments, e.g. near rotating machines. In this paper, we propose two methods to remove the influence of vibrations by using an auxiliary signal measured via an accelerometer. In the first method, the mechanoelectrical transfer function between the vibration and its effects on the microphone is estimated before installation of the analyzer. In the second method, the mechanoelectrical transfer function is updated continuously under normal sensing operations. The two methods have been implemented within an ABB URAS gas analyzer and corrections are executed in real time. Tests on a vibrating table have confirmed the effectiveness of both methods: a reduction in vibration sensitivity up to a factor twenty is achieved.

Automatic detection of transmission towers

The detection of electrical transmission towers in digital images is an essential component of future, automated power networks inspection solutions. In this paper, a novel detection method is proposed. It is composed of two phases: training and detection. In the training phase, the characteristic model of transmission towers is learned from a training set. The training set consists of images with known locations for all transmission towers. In the detection phase, meaningful image features are compared with the model in order to detect likely locations of transmission towers. Experimental results with images downloaded from the Internet show accurate detection even in the presence of background clutter and multiple objects.

VHDL-AMS virtual prototyping of a generator circuit breaker ablation monitoring system

Generator Circuit Breakers (GCBs) are commonly used in electrical power generation systems to protect key equipment such as transformers and generators from damage due to overload or short-circuit. However the interruption and feeding of high currents lead to the ablation of the electrical contact system of the breaker. This deterioration process needs to be monitored in order to guarantee the healthy condition of the breaker. In this paper, we propose a virtual prototype of a GCB fitted with an ablation monitoring system. This is an early model of the complete system, which is highly desired before the physical implementation, since it facilitates the study of detection methods and the exploration of system limitations. The virtual prototype is implemented in VHDL-AMS with certain low-level models described in SPICE. The virtual prototype has been validated by measurements performed on the real system. It is therefore adequate for performing design optimization and to obtain useful observations for further usage of the monitoring system.

A mobile app for reporting damaged electrical equipment

A mobile app is proposed for collecting data about damaged electrical equipment. I.e. location, description, pictures. This is an essential stage of reliable, coordinated and fast power outage management. The app runs on tablet computers and smart phones, and it is specifically intended for electric utility customers. The essential advantage of relying on end customers with respect to professional maintenance personnel, is fast reaction time. First, the general architecture of the app is discussed. Then, its implementation on an Android tablet computer is outlined by means of screen shots. Finally, subjective quality evaluation results show that the proposed app has been found easy to handle even for first-time users.