Modelling Eddy Current Brake emissions for electromagnetic compatibility with signaling devices in high speed railways

This paper presents a model that anticipates the emissions from eddy current brakes (ECBs) installed in high-speed trains. The emissions are computed in the 10 KHz-1.3 MHz range, where trackside signaling devices operate and issues related to electromagnetic compatibility have arisen, hindering ECB's promise of full deployment. The electromagnetic model provides a transfer function in the frequency domain between the nondesired harmonic currents produced by the train power supply and the subsequent radiated emissions by the ECBs at the trackside. The model includes the influence of the on-board ECB system's electric circuitry on the three-dimensional field computation of the electromagnets by a cosimulation approach (circuit and electromagnetic cross talk). After the data are postprocessed, the simulated results are compared with the results of an extensive measurement campaign on board a high-speed ICE 3 train equipped with ECBs. The high correlation makes it possible to anticipate ECB emissions in order to save costly on-track test runs, to suggest ECB design strategies and to provide safe limits when the worst cases occur

Modeling the impact on wheel sensor readouts by Eddy Current Brakes installed in high-speed trains

This paper presents a model to anticipate the impact of Eddy Current Brakes (ECBs) installed in high-speed trains on the readouts of rail-side wheel sensors. The purpose is to anticipate false positive readouts of train wheels when traversing, one of the main obstacles for full ECB deployment. The ECB type EWB 154 from Knorr-Bremse and Wheel Sensor types RSR180 and RSR123 from Frauscher Sensor Technology are represented in a comprehensive model, integrating LTSpice and CST Microwave Studio. The wheel sensor predicted readout error is 4% compared to measurements when DC current is not applied to the ECB (passive case). It is demonstrated that the RSR180 is not compatible with ECBs, whereas the RSR123 is. The impact of active (DC current fed) brakes is analyzed when performing running tests with a high-speed ICE 3 train equipped with ECBs. The model is adjusted to study the saturation of the rail and ECB pole cores. The extra damping of the wheel sensor fingerprint is modeled by an extra 6% drop that may well be applicable to passive tests in a laboratory setting to shift to active tests without actually performing them. In this way, cost and time would be saved. Based on the model outcomes, a test bench is recommended for laboratory tests to emulate active behavior

Cranial and ventricular size following shunting or endoscopic third ventriculostomy (ETV) in infants with aqueductal stenosis: further insights from the International Infant Hydrocephalus Study (IIHS)

Purpose The craniometrics of head circumference (HC) and ventricular size are part of the clinical assessment of infants with hydrocephalus and are often utilized in conjunction with other clinical and radiological parameters to determine the success of treatment. We aimed to assess the effect of endoscopic third ventriculostomy (ETV) and shunting on craniometric measurements during the follow-up of a cohort of infants with symptomatic triventricular hydrocephalus secondary to aqueductal stenosis. Methods We performed a post hoc analysis of data from the International Infant Hydrocephalus Study (IIHS)-a prospective, multicenter study of infants (< 24 months old) with hydrocephalus from aqueductal stenosis who were treated with either an ETV or shunt. During various stages of a 5-year follow-up period, the following craniometrics were measured: HC, HC centile, HCz-score, and frontal-occipital horn ratio (FOR). Data were compared in an analysis of covariance, adjusting for baseline variables including age at surgery and sex. Results Of 158 enrolled patients, 115 underwent an ETV, while 43 received a shunt. Both procedures led to improvements in the mean HC centile position andz-score, a trend which continued until the 5-year assessment point. A similar trend was noted for FOR which was measured at 12 months and 3 years following initial treatment. Although the values were consistently higher for ETV compared with shunt, the differences in HC value, centile, andz-score were not significant. ETV was associated with a significantly higher FOR compared with shunting at 12 months (0.52 vs 0.44;p = 0.002) and 3 years (0.46 vs 0.38;p = 0.03) of follow-up. Conclusion ETV and shunting led to improvements in HC centile,z-score, and FOR measurements during long-term follow-up of infants with hydrocephalus secondary to aqueductal stenosis. Head size did not significantly differ between the treatment groups during follow-up, however ventricle size was greater in those undergoing ETV when measured at 1 and 3 years following treatment