Kollafjord Pelagic Ltd. Faroe Islands Case study Customer profile: Kollafjord Pelagic Ltd. Product: vacuum-packed, frozen fish Capacity: 1000 t/day, largest in the world Employees: 50 Landing dock, factory Factory, freezing towers Load profile: 6 units Cardner Denver screw compressors Each unit comprises: • transformer 800 kVA, 22 kV/690 V, Dd every second, others Dy • Vacon frequency converter, 3-ph, six-pulse diode bridge • Motor, continuous load 720 kW Units are switched on and off aiming at a Dy-Dd-Dy-Dd-Dy-Dd sequence because of Dy/Dd-balancing of loads and suppression of 5th and 7th harmonics. Local power utility, SEV, grid and requirements: • voltage 22 kV • connection to diesel power plant, length 10 km • total grid length ~200 km • distortion limits, THD(U), are set out by Danish “DEFU rekommandation 21” • the requirements of SEV for the 22 kV supply point of the factory: Harmonic number 5 7 11 13 Maximum current emission, A 7,1 4,2 2,4 1,7 Installation and commission of MaxSine shunt active filter • decision to install fast response active filters was made after load simulations • MaxSine 500A-3L-50Hz was selected • special CT connection was needed because of available space •Measurements were done in worst situation units 1, 3 and 5 (DyDy-Dy) running • Measurement point was on the feeder side, 22 kV, measuring total load of the factory Measurements without MaxSine Harmonic number Measured current emission, A THDr 1 43,2 97,2% 100% 5 9,6 21,6% 22,2% 7 3,2 7,2% 7,4% 11 2,1 4,7% 4,9% 13 1,3 2,9% 3,0% 17 0,6 1,3% 1,4% 19 0,5 1,1% 1,2% THDf Total values Conclusion: I RMS/A 44,4 THDr 23,5% THDf 24,1% Current is distorted and the 5th harmonic exceeds the limit set by local power utility, SEV. Measurements with MaxSine Harmonic number Measured current emission, A THDr THDf 1 36,3 99,7% 100% 5 0,6 1,6% 1,7% Total values Conclusion: 7 2,2 6,0% 6,1% 11 0,0 0,0% 0,0% 13 1,0 2,7% 2,8% 17 0,1 0,3% 0,3% 19 0,5 1,4% 1,4% I RMS/A 36,4 THDr 7% THDf 7% Current is still a little distorted but all the harmonics fulfill the requirements set by local power utility, SEV.