Enhanced PLL based SRF control method for UPQC with fault protection under unbalanced load conditions
SRF, EPLL based SRF control strategy used in SAF, PAF for generating references. Sine PWM, modulated hysteresis current control technique is used for gate pulse generation for UPQC. A primary bypass breaker is placed in the primary side to give protection to primary windings. A protection circuit is connected across the series transformer to protect the secondary of series transformer. Experimental results obtained from a model of 1.5kVA, along with a theoretical analysis.
upqc epll modulated hysteresis current controller power quality