A case study on Power Quality issues in the Indian Railway traction sub-station

The railway traction loads has more effect on power quality. Its effects on power quality cannot be ignored. The relevance of Power Quality (PQ) issue has recently augmented because of the increased use of power electronic equipments, which results in a voltage deviation and current waveforms. The performance and life expectancy of industrial electronics and electrical equipments is significantly affected by power supply anomalies caused by polluting loads at an industrial site and by utility normal operational activities. Hence railway traction loads have been taken as case study. Power quality issues have been studied by installing power quality monitoring system in traction sub-station1 and in traction sub-station2. In traction substation1, 2400 kVar rated capacitor alone is installed and where as in traction sub-station2, IGBT based DRPC (Dynamic Reactive Power Controller) with 1800 kVar is connected along with fixed 2400 kVar capacitor. The actual power quality issues of these traction sub stations were measured. The harmonics due to load currents, voltage and current unbalance measured are compared based on IEEE Standards 519-1992.