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Transformer PROTECTION. 7.4. Differential Relays . Figure 10: Differential protection for a generator phase winding. Transformer Protection. Problem 1: For a 45 MVA, 11 kV/66 kV, Y-∆ transformer design a percentage differential scheme. Use 125% overloading to find CT ratios. - PowerPoint PPT Presentation
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TRANSFORMER PROTECTION
7.4. Differential Relays
Figure 10: Differential protection for a generator phase winding.
Transformer Protection
• Problem 1: For a 45 MVA, 11 kV/66 kV, Y-∆ transformer design a percentage differential scheme. Use 125% overloading to find CT ratios.
• What is the minmum recommended percentage bias?
Transformer Protection Example
Magnetizing Inrush
Harmonic Restraint • Flow Chart
Percentage Bias Differential Relay with Harmonic Restraint
Inter-turn Faults in Transformers
Volts/Hertz Relay Characteristics
Protection During an Earth Fault
•
Condition for a fault in middle of phase C on 13.2 kV Side
Problem 2: Connection Diagram
•
Differential Protection for a Generator Connected in Star with four terminals
•
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