Analysis of the losses in the electric drive train depending on switching frequency and modulation strategy of the converter

Abstract:
Increasing the overall efficiency of a traction system consisting of voltage source converter and induction motor requires exact knowledge of the loss components in the drive and of dependencies between traction motor and traction converter. Various system parameters, the modulation strategy of the converter and the operating conditions are affecting the fun-damental and harmonic losses of the traction motor and the losses of the traction converter. The investigations carried out are based on analytical modelling. In this paper, the model used is presented in an overview. The voltage source converter is represented by a transient simulation. However, the harmonic behavior of the induction machine is calculated in the frequency domain. Using the simulation model of the drive, all major loss components can be identified and analyzed depending on the actual parameters of the system. Based on a reference scenario, variations of the modulation strategy of the converter are investigated and optimization strategies are presented.