The Electric Variable Transmission without slip ring for the Hybrid Electric Vehicle driving structure

In this paper, the Electric Variable Transmission (EVT) without slip ring for the Hybrid Electric Vehicle (HEV) structure is proposed. In the EVT structure, the motor with floating stator is applied instead of the planetary gear, and it enhances the reliability by removal of the mechanical friction. However, the slip ring used in the EVT for the electric connection between rotating windings and the fixed inverter circuit makes mechanical friction, which harms the merit of the EVT structure. Therefore, the EVT structure without mechanical contact is proposed in this paper, which is composed of two H-bridge circuits with inductive link, which are connected to the fixed battery and the rotating inverter, respectively. The bidirectional power transfer is realizable by phase shift control of two H-bridges, and simple data transmission is also realizable by phase perturbation. The operation of the proposed circuit is verified by the simulation result.