Design and Control of Active Front End Converters for Traction Application

Supply Line disturbances, harmonics in line current, low power factor to electric power system are some of the common problems in traction power supply system. In order to overcome these problems a control structure is proposed which consists of dc link voltage controller and proportional resonant (PR) current controller using phase angle estimator. Current controllers are designed using PR controller to overcome the limitations of PI controller such as steady state errors, limited disturbance rejection capability and unsatisfactorily performance under parameters variations, nonlinearities etc. The simulations are carried out with both PR and DQ model-based controllers and comparative results have been presented. The simulation is carried out in PSIM environment and the results demonstrate fast response and improved power quality in terms of reduced harmonics in AC mains current, high power factor and well-regulated DC output voltage. This model can easily be adopted in the actual system while reducing the overall complexity in design and control of the existing system.