Rob Armstrong

An investigation of the total radiated power of pantograph arcing measured in a reverberation chamber

Pantograph arcing is the main electromagnetic interference source in electric railways. A series of measurements of the radiated power of pantograph arcing has been taken in a reverberation chamber by using a laboratory replica designed to simulate the arcing pantograph. The radiated power properties are investigated in different resolution bandwidths, arc gap lengths and train speeds. The results show that pantograph arcing is a broadband signal compared to GSM-R bandwidth; the radiated power decreases when the arc gap gets bigger or the speed of train goes higher.

Recommendations for mitigating low frequency magnetic field exposure in hybrid/electric vehicles

The need to assess the possible exposure of vehicle occupants to low frequency magnetic fields is an emerging vehicle design requirement that is of particular significance for hybrid and electric vehicles. This paper outlines the nature of the potential threats, methods for their evaluation, and practical mitigation measures that could be adopted to limit the exposure.

An EMC study on the interopability of the European railway network

The research presented here deals with the electromagnetic compatibility in the railway environment. In particular it focuses on four research areas: the spot signalling systems, the track circuits, the GSM-R and the broadcasting services. A review of the current railway standards is followed by a research on the immunity limits, the worst case scenarios and cross acceptance EMC tests for the four areas.

The effect of fully electric vehicles on the low frequency electromagnetic environment

The rapid development of fully electric vehicles, their charging systems and their increasing availability to the general public presents both the automotive industry and consumers with some new challenges. Electromagnetic compatibility has been well understood by the industry, but the deployment of high power inverter drives as part of the powertrain is currently not covered by automotive EMC standards. Of particular concern are potentially high levels of low frequency magnetic field emissions both when the vehicle is in use, and when using some charging systems. This leads to the possibility that levels set for the protection of persons exposed to low frequency electromagnetic fields are exceeded. This paper concludes that additional requirements are required for radiated emission testing of electric vehicles and that low frequency emissions can be high enough to merit consideration in the design stage of the vehicle and during installation of the drive train. In addition, it provides some guidance on installation of in-vehicle high power electronics to mitigate emissions effects on the electromagnetic environment.

HEMIS Project (Electrical Powertrain HEalth Monitoring for Increased Safety of FEVs): Limitations of Electromagnetic Standards for Vehicles Equipped with Electrical Powertrain

The HEMIS project is concerned with health monitoring of electrical powertrain in order to enhance the maintainability and safety of electric vehicles. Electromagnetic emissions from electrical powertrain will change the electromagnetic environment in vehicles, which may have implications for electromagnetic compatibility and, because of the high electrical power levels, human exposure to electromagnetic fields. This paper outlines some of the electromagnetic issues under investigation in the project, including limitations of existing test methods for electromagnetic compatibility, and a lack of test methods for the assessment of in-vehicle human exposure, as well as for both electromagnetic compatibility and human field exposure issues relating to wireless charging of traction batteries.