Calculation and measurements of electromagnetic emissions from IGCT-based chopper

Implementation of new IGCT elements into the chopper circuitry requires great attention that has to be paid to the level of electromagnetic emission (EMI) noise. In order to estimate these levels, relatively simple procedures have been used, based on an approximation of typical waveforms of current pulses flowing through the cables connecting a filter capacitance and the chopper. These current pulses represent the main source of the EMI noise radiated by the chopper. The predicted results were compared with measured values with a quite good agreement. The magnetic field produced by the prototype of the trolley-bus was also measured and tested. The preliminary measurements performed on the prototype of the innovated trolley-bus have indicated that the EMI produced by the vehicle comply with the current standards.