公开(公告)号：EP3550709A1

公开(公告)日：2019-10-09

申请号：EP17875909.8

申请日：2017-12-01

Applicant: BYD Company Limited

Inventor： ZHANG, Ni ,  WANG, Xinghui ,  WANG, Chao ,  SHEN, Xiaofeng ,  WU, Baihe

IPC: H02M3/335

Abstract: This application discloses an electric vehicle, a DC-DC converter thereof and a control method of the DC-DC converter. The control method includes the following steps: when the DC-DC converter works every time, acquiring total time TC for controlling an H-bridge in a third mode and total time TD for controlling the H-bridge in a fourth mode, and acquiring set time Ti for controlling the H-bridge in the third mode and set time Tm for controlling the H-bridge in the fourth mode in each working cycle during a working process of the DC-DC converter; judging a relation between the TC and the TD; and selecting the mode for controlling the H-bridge when the DC-DC converter is started according to the relation between the total time TC and the total time TD, and alternately controlling the H-bridge according to the Ti and the Tm, so as to perform temperature equalization control on a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, thereby enabling heat generation of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube in the H-bridge to be relatively balanced, so as to prolong the working life of the switch tubes in the H-bridge.