Measurement of λ-i characteristics of asymmetric three-phase transformers and their applications

Modeling of three-phase transformers with three-limb cores is important, such units are very ubiquitous and are asymmetric due to the different lengths of the three limbs of the core. It is, therefore, important to devise a measuring procedure, where the (λ-i) characteristics of the three limbs and the zero-sequence (λ₀-i₀) characteristic due to the tank can be determined. A simulation program is developed so that currents at no-load and symmetric or asymmetric loads can be computed. Measured currents are compared with computed results for 2.3-kVA and 45-kVA units.