2009 VON ROLL TRANSFORMERS LTD TRANSFORMER 41.7MVA 115/44KV 136981

Technical Description

THIS 2009 VON ROLL TRANSFORMERS LTD. UNIT IS A THREE-PHASE POWER TRANSFORMER ENGINEERED FOR HIGH-VOLTAGE SUBSTATION APPLICATIONS. IT FEATURES A THREE-STAGE COOLING ARCHITECTURE CLASSIFIED AS ONAN/ONAF/ONAF (OIL NATURAL AIR NATURAL / FORCED), WHICH PROVIDES SCALABLE POWER RATINGS OF 25.0 MVA (PASSIVE COOLING), 33.3 MVA (STAGE 1 FANS), AND 41.7 MVA (STAGE 2 FANS). THE UNIT MAINTAINS A 65°C TEMPERATURE RISE LIMIT ACROSS ALL COOLING MODES, ENSURING THERMAL STABILITY UNDER PEAK LOADS. ELECTRICALLY, THE TRANSFORMER STEPS DOWN VOLTAGE FROM A PRIMARY HIGH VOLTAGE (HV) OF 115 KV (GROUNDED WYE) TO A SECONDARY LOW VOLTAGE (LV) OF 44 KV. CRITICAL TO ITS OPERATION IS THE 33-POSITION ON-LOAD TAP CHANGER (OLTC), WHICH PROVIDES DYNAMIC VOLTAGE REGULATION. THE OLTC ALLOWS FOR "LOW VOLTAGE VARIATION" RANGING FROM 52,800 V (TAP 1) DOWN TO 35,200 V (TAP 33), ACCOMMODATING SPECIFIC GRID REQUIREMENTS AND LOAD FLUCTUATIONS. THE SHORT-CIRCUIT IMPEDANCE IS APPROXIMATELY 7.42% AT THE NOMINAL TAP, OPTIMIZING THE BALANCE BETWEEN VOLTAGE REGULATION AND FAULT CURRENT LIMITATION.