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RESONANT GROUNDING versus LOW IMPEDANCE GROUNDING. Neutral Point Treatment Application Survey. Neutral point treatment in Germany *. Resonant grounding is also applied in: Scandinavia numerous Central European countries Eastern Europe. * VDEW Störungsstatistik 1998. L 3. V 3N. L 2.
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RESONANT GROUNDING versus LOW IMPEDANCE GROUNDING
Neutral Point TreatmentApplication Survey Neutral point treatment in Germany * Resonant grounding is also applied in: • Scandinavia • numerous Central European countries • Eastern Europe * VDEW Störungsstatistik 1998
L3 V3N L2 N V2N L1 V1N CE CE CE IL IC V1E V2E V3E V0 I2 I3 Voltages during earth fault L3 L2 V2N V3N N V2E V3E V0 = V1N I3 L1=E IL IC L1 I2 Resonant GroundingBasics - Theory E Ires / IC d undercompensation overcompensation
EPSY - Earth fault Protection SYstemSystem Components Earth Fault Compensation Controller Earth Fault Detection Arc Suppression Coil(ASC)
Resonant GroundingComparison 100 % Earthfaults Resonant grounding • 70 ... 80 %transient faults • self-extinction by the ASC • no influence on power supply Low impedance grounding • 20 ... 30 % steady faults • low fault current - increased human safety - reduced damage - reduced interference - reduced earthing effort - high fault current (e.g. 2 kA) - immediate tripping high number of power interruptions quality of power supply increased