NZ585483A - Inductive power transfer system with a primary track arrangement with first and second phase conductors with balanced mutal coupling between the conductors - Google Patents

Abstract

585483 Disclosed is a multiphase Inductive Power Transfer primary track conductor arrangement suitable for powering EVs through the road. The IPT primary track conductor arrangement has a first phase conductor (14) and a second phase conductor (15), the conductors (14, 15) being arranged substantially in a plane and so as to overlap each other and being arranged such that there is substantially balanced mutual coupling between the phase conductors (14, 15). The power supplies (16) and (17) will be each be synchronised and energised 90 degree out of phase with each other. Preferably they share a common DC bus to ensure any mistuning or VAR loading from the receiver (i.e. the pick-up) is managed. The pitch of the track, p, is the distance between the transverse conductor sections, and this should be fixed to achieve the substantially balanced mutual coupling. As a means to further improve horizontal tolerance, a three phase track topology is also disclosed. An advantage of the proposed unipolar topology, shown in Figures 10(b) and 13(b), is that the pattern can be easily continued at either end by adding additional tracks either side. Provided the power supplies are synchronised, this interleaving enables a long portion of road to be continuously powered. Such a track system can be completely modular with power supplies powering fixed lengths of track in the order of 10's of metres. This creates redundancy in the system, if one section gets damaged or one power supply fails, the powered roadway will still function at close to full capacity. This approach also makes installation simpler. The three phase unipolar track allows significantly better horizontal tolerance with a small increase in cost and copper losses.