Study of Novel Dog Brake System for Changing EV Drive Mode

Abstract

This paper proposes a novel dog brake for an electric vehicle (EV) drive system that combines a dual motor and a planetary gear set. This brake can be in one of the following three states: 1. An engaged state for single-motor drive, 2. A disengaged state for dual-motor drive, 3. A stand-by state for changing the drive mode from single- to dual-motor drive. The dual-motor EV drive system with the proposed dog brake can expand the operating region compared to the previous drive system. Moreover, the proposed dog brake absorbs the energy of the rotating parts, because the timing of brake engagement is controlled when the EV drive mode changes. The results of these study indicated that when the drive mode was changed, the driving torque gap was reduced by up to 62% by control of the engagement timing.