Abstract :
The first commercial demonstration of six-phase transmission, the Goudey-Oakdale three-phase/six-phase project, used two delta wye-grounded three-phase transformers to realize the required phase/voltage conversion. This paper proposes the usage of autotransformers for phase/voltage conversion for the actual three-phase/six-phase systems to be built in the future. The design considerations of the three-phase/six-phase conversion autotransformers are described. Topology-based, nonlinear, core-type conversion autotransformer EMTP models are developed. The behavior of the conversion autotransformers in a practical three-phase/six-phase system is simulated. These include transformer energization, short circuits, voltage regulation, open conductor, and ferroresonance. The simulation results show that the autotransformer is a viable choice for the conversion transformer. Since the cost ratio of the proposed conversion autotransformers with respect to the three-winding conversion transformers is approximately 64%, the new design is superior economically to other transformer designs, and will help push the HPO technology.
Keywords :
EMTP; autotransformers; conductors (electric); ferroresonance; phase convertors; short-circuit currents; voltage control; EMTP models; Goudey-Oakdale three-phase/six-phase project; delta wye-grounded three-phase transformers; ferroresonance; nonlinear core-type conversion autotransformer model; open conductor; phase/voltage conversion; short circuits; three-phase/six-phase conversion autotransformers; three-winding conversion transformers; topology-based autotransformer models; transformer energization; voltage regulation; Circuit simulation; Conductors; Costs; EMTP; Ferroresonance; Phase transformers; Power generation economics; Power transmission; Transformer cores; Voltage control;
