Simulation of delta connected current transformers in a differential protection scheme

This paper describes the development of a mathematical model of three current transformers which are connected in a delta configuration as part of a differential protection scheme. The delta connected configuration is typically found in transformer differential protection schemes for star-delta transformers. This model can be used in real time algorithms for testing of relays and can also be used to study differential protection schemes off-line. The accuracy of the model is validated by comparing the simulations with waveforms recorded at a synthetic test plant.