PREMAID · Predictive maintenance and diagnostics of railway power trains

Final Activity Report Summary - PREMAID (Predictive maintenance and diagnostics of railway power trains)

For the rail transportation system to offer a higher level of performance, the reliability and consequently availability of power trains have to be improved since the failure of any of its component results in traffic perturbations. The PREMAID Marie-Curie TOK programme, gathering five research centres, one from a large European industrial company (Alstom Transport) and four from academics in Spain (University of Oviedo), Portugal (University of Coimbra), Italy (University of Bologna) and Poland (Gdansk University of Technology) focused on the following topics: - the development of early stage diagnostic tools / methodologies of mechanical and electrical failures of key components of the power train (motor, inverter, power capacitor, power transformer); - based on those diagnostic tools / methodologies, the development of a predictive maintenance system integrated into the train monitoring system. Regarding the motors, the main failure mode studied was the detection of broken bars of the rotor following three different approaches. One needs the installation of a special flux coil in the stator. The results of these methods at the simulation level were impressive. However, for industrial reason, it is not easy to install such a specific coil. So it has been decided not to implement it in a real motor. The two others methods are not invasive and use only the variables of the motor control. They give good results at the simulation level and have been validated thanks to a reduced power test bench. At the scientific level these diagnostic methods show the possibility to detect failure in a rotor even in time varying conditions. At the industrial level, considering the operation conditions of a traction motor, the problem of the broken rotor bars is not so frequent. The decision to implement one of these two methods on a real motor control is still pending. Linked to the motor control, a methodology using the theory of the state observers has been develop to diagnose the health status of the transmission. This methodology is very promising and is currently tested on a real train. Regarding the power electronic, the main activity was focused on the ageing evaluation of the power semi-conductors. A high resolution board has been developed, able to measure some parameters as close as possible from the semiconductor. Results seem to be promising. A lot of work has been done also on the power capacitors. Although very reliable, these components have some failure mode wanted to be avoided. A diagnosis method based on the capacitance evaluation has been developed with a good enough accuracy to detect faulty capacitors. The algorithm is currently tested on a tramway. Regarding the transformer, the focus was the insulation faults. A method based on the comparison between the internal losses measurement and the evaluation as if the transformer was healthy has been developed. The method has been tested on a reduced scale traction transformer, replica of a real traction transformer. The method detects magnetic core faults, increased resistance of the connections and inter-turn short circuits but could also detect cooling and open circuit problems. A transverse study concerning the insulation materials was also a part of the project. It has been possible to study the partial discharge activity of a piece of motor using a special tool developed by one of the universities. The work is being continued applying an accelerated ageing process. Finally, the last subject studied was in relation with the capacitor health status monitoring, demonstrating the possibility to do an on-line monitoring of a capacitor using a cheap DSP from the market. As a conclusion on this project, we can say that some experts have been surprised by the results achieved so far. Some study must be continued to get final conclusion on the efficiency of the diagnosis methods. It has been an exciting adventure for the researchers who participated to the project.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз