Negative sequence and harmonic mitigation of grid connected AC railway traction using PI and fuzzy controllers

Railway traction has become an important part of power system. It creates power quality issues in the grid. Negative sequence and harmonic currents have become the main issues in high speed train traction systems. Railway static power conditioner (RPC) has been developed to mitigate the power quality issues. A comprehensive technique for compensation of negative sequence and harmonic currents has been discussed. RPC is a back to back connected converter with a dc link. The controller also provides a constant dc link voltage and thus helps in the compensation of power quality problem. In this paper PI and FUZZY controllers are discussed and compared for their performance. These controllers are introduced for the current tracking control of RPC, thus the PQ issues are mitigated. Thus RPC improves the power quality in railway traction.