Digital Control and Simulation for Power Electronic Apparatus in Dual Voltage Railway Locomotive

An object-oriented simulation-in-the-loop C-written tool for power electronic apparatus in a dual (ac and dc) voltage prototype railway locomotive is proposed. By considering also the hardware elements of the control board, the simulator structure ensures the straightforward portability of the control codes from simulation to implementation, thus allowing to check the control algorithms and codes via realistic numerical tests. Each component of the locomotive is modeled as an object, by using state space dynamic models for the dynamic subsystems. The two line-side converter configurations, the field oriented controlled induction motors with Kalman filter as flux estimator and the space-vector modulated voltage source inverters are considered as examples. A new control strategy for the line-side converter ensuring voltage regulation and harmonic active filtering is also proposed and simulations show the effectiveness of the controller. The digital implementation of the control algorithms on an electronic control unit equipped with a DSP and a microcontroller is detailed, showing the time relationship between the control board tasks and the converters switching functions.