The Test Centre for Rolling Stock at TÜV SÜD Rail is accredited according to EN ISO/IEC 17025 and approved by the German Federal Railway Authority (Eisenbahn-Bundesamt, EBA) as an inspection body for railway-specific inspections.
One of its most recent areas of expertise deals with the dynamic interaction between pantographs and overhead contact lines. According to the EN 50317 standard, measurement of the contact force is one method for carrying out approval-relevant measurements on the pantographs of rail vehicles. This method, which was developed five years ago, measures the forces between the pantograph carbon strip and the contact wire during an on-track test. The arrangement of the sensors at high-voltage potential and the specific setup of the measurement instruments require relatively complex measuring equipment. In addition to this method, applied and continuously further improved by TÜV SÜD Rail, the company has now developed a second test method in conformity with the standard. By applying electric arc measurement, the inspection body now aims to measure the duration of electric arcs with defined wavelength and intensity of light on the roof of the locomotive up to the vehicle's maximum speed.
The measurement instruments needed had to be in compliance with the requirements of the standard, as well as rail- and weather proof. Extensive research showed that no such special sensor was available on the market. Given this, the department for track tests had to design the measurement instrument in-house. Parallel to contact force measurement at the customer's premises, the department continually changed the sensor setups and tested them in realistic test environment. Proceeding in this manner, the experts were able to identify and constructively exclude factors that interfered with measurement, such as electromagnetic fields or solar radiation. In addition, this approach allowed the experts to gain important know-how in a field of testing as yet undeveloped. The measurement solution, which is now available, fulfils all requirements of the standard. A single sensor can now be used to test rail vehicles for all relevant rail energy systems (1.5 and 3 kV direct current and 15 and 5 kV alternating current).