Copper and silver alloyed copper magnet wireor continuously transposed copper cableis used for the winding conductors on all Waukesha® power transformers. Continuously transposed copper cable is used to minimize losses and hot-spot temperatures and to produce a more compact winding with improved short-circuit performance.
All windings are circular, concentric type and provide maximum through-fault withstand capability. High voltage, low voltage and tertiary windings use a continuous-disc or helical winding design exclusively. This construction provides maximum strength and short-circuit withstand capability, increased predictability and lower hot-spot temperatures for loading and overloading.
Multiple conductor continuous disc and helical windings are transposed throughout the winding to minimize circulating current losses. State-of-the-art design techniques are used to provide maximum impulse strength in the windings and to minimize voltage stresses. Special design consideration is also given to the line end discs to control voltage stress distribution.
Ampere-Turn balancing techniques are used to minimize radial leakage flux and to minimize axial short-circuit forces. The conductor insulation allows continuous operation at 65°C average winding temperature rise and 80°C hot-spot temperature rise without abnormal reduction of insulation life.
Cooling ducts are formed between discs in the windings by keyed radial spacers made of special high-density pressboard insulation. These spacers are aligned in column to provide axial support for the windings and high short-circuit strength.