220 kV 80 MVA 100 MVA Power Transformer

This 80 MVA 100MVA transformer is designed for export to the Libyan market. It is a three-phase, three-winding, oil-immersed transformer equipped with an oil cushion protection system. The transformer features a high-voltage (H.V) winding rated at 220 kV, a low-voltage (L.V) winding rated at 30 kV, and a tertiary winding rated at 11 kV, with a frequency of 50 Hz. It includes a one-stage cooling system; with the fan activated, the transformer capacity can be increased to 100 MVA. The ONAF cooling system is equipped with a winding temperature relay, an auto-manual switch, and a control box containing the control devices.

The 220 kV 80 MVA 100 MVA transformer can be paralleled with other transformers of the same power rating and tap positions.

Ratings

Transformer Characteristics

• Short Circuit Impedance: 12.5%
• Temperature Rise:
  • The temperature rise of the 220 kV 80 MVA transformer is 50°C. The top oil temperature rise does not exceed 50°C, as measured by a thermometer, and the winding temperature rise does not exceed 55°C, as measured by resistance.
  • The transformer can continuously operate at 105% of the secondary rated voltage and 80% of the load factor without exceeding the specified temperature rise limits. It can also operate continuously at 110% of the secondary rated voltage at no load without exceeding the temperature rise limits.

Suppression of Harmonics

The transformer is designed to suppress harmonic voltages, specifically the 3rd and 5th harmonics, to eliminate waveform distortion and interference with communication circuits due to high-frequency disturbances.

Bushing

The electrical characteristics of the bushings meet the requirements of IEC 60137 and IEC 60507.

The insulation level of transformers and bushings

80MVA /100MVA Transformer No-load loss and load loss limit at 75°C

Sound Level

The transformer’s sound level meets the requirements of IEC 60076-10.

Insulation Oil

The 80 MVA transformer is filled with mineral insulation oil. The characteristics of the insulation oil meet the requirements of IEC 60296 and GES 6071101. The oil is free from contamination by Polychlorinated Biphenyls (PCBs).

Tests

The 80 MVA transformer has undergone type and routine tests and has passed all tests successfully.

• Type Tests:

  • Temperature-rise test according to IEC 60076-2 (including Dissolved Gas Analysis)
  • Lightning impulse test (IEC 60076-3)

• Routine Tests:

  • Visual inspection
  • Oil Leakage Tests: All tanks and oil-filled compartments are tested for oil tightness by being completely filled with air or oil of a viscosity not greater than that of insulating oil conforming to the latest edition of IS: 335, at an ambient temperature, and subjected to a pressure equal to the normal pressure plus 0.35 kg/cm² measured at the base for a period of not less than 12 hours for oil and 1 hour for air, during which time no leakage shall occur.
  • Measurement of winding resistance (IEC 60076-1, 10.2)
  • Measurement of voltage ratio and check of phase displacement (IEC 60076-1, 10.3)
  • Measurement of short-circuit impedance and load loss (IEC 60076-1, 10.4)
  • Measurement of no-load loss and current (IEC 60076-1, 10.5)
  • Separate source voltage withstand test (IEC 60076-3)
  • Induced overvoltage withstand test (IEC 60076-3)
  • Test on On-Load Tap Changer, if applicable (IEC 60214)
  • Noise level test
  • Partial discharge test

Spare Parts

• 1 set of all types of gaskets
• Buchholz relay
• Winding temperature indicator
• Oil temperature indicator
• Raise & lower relay for OLTC
• A complete set of current breaking contacts for OLTC
• Moving cylinder for OLTC
• Recommended spare parts for reliable operation

Warranty

Daelim Transformer provides a full three-year limited warranty on the transformer. Warranty coverage begins on the date the equipment is shipped.