LCL-filter design and analysis for PWM recuperating system used in DC traction power substation

Voltage source inverter (VSI) had been used in dc traction power substation to deliver the trains braking energy back utility grid. To mitigate low order harmonics components, pulse-width-modulation (PWM) technique is commonly VSI controlled. As a result, ac voltage and current waveforms may contain high frequency ripples. This paper proposes using LCL-filter with series <em>R</em>-damper. filter offers good attenuation on smaller size compare other passive topologies. Theoretical analysis simulation verification are conducted designing proposed filter. System level also carried out. Sinusoidal grid recorded (THD<2%). includes damping losses conjunction resonance peak suppression