Power Quality at Railway Traction Substations in Ukraine and Its Role in Power System Stability

This study analyzes power quality indicators in both direct current and alternating current traction systems, highlighting their impact on system performance and stability. The findings reveal that voltage level is a key determinant of system stability, with alternating current systems contributing to a more stable power supply due to their higher voltage capabilities. However, harmonic distortions in both alternating current and direct current systems present significant challenges, affecting metering accuracy, increasing energy losses, and interfering with protective mechanisms. While direct current systems provide superior voltage stability, alternating current systems offer greater flexibility and higher power capacity, albeit with inefficiencies caused by phase shifts and harmonic distortions. A comparative analysis of power quality indicators shows that direct current traction substations exhibit lower total harmonic distortion, better voltage balance, and a higher power factor compared to alternating current substations. However, alternating current systems demonstrate lower voltage deviation, making them more resilient in maintaining grid stability.