Electric vehicle and its on-board charger and control method for the on-board charger

Abstract

An electric automobile, an on-board charger thereof, and an on-board charger control method. The control method comprises: when a power battery is charging, obtaining a first total charging time TA for controlling an H bridge via a first mode and a second total charging time TB for controlling the H bridge via a second mode; according to a relationship between TA and TB, selecting a mode to control the H bridge in order to perform temperature equalisation control on first to fourth switches (T1-T4); when the power battery is discharging externally, obtaining a first total discharging time TC for controlling the H bridge via the first mode and a second total discharging time TD for controlling the H bridge via the second mode, and obtaining a first discharging setting time Tm and a second discharging setting time Tn within each discharging cycle; according to a relationship between TC and TD, selecting a mode to control the H bridge when the external discharging starts, and performing alternating control on the H bridge according to Tm and Tn in order to perform temperature equalisation control on the first to fourth switches.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a control method of an electric vehicle on-board charger, an electric vehicle on-board charger and an electric vehicle. Background technique [0002] With the commercialization of electric vehicles, the electric vehicle on-board charger has become one of the important components of electric vehicles. [0003] Among them, there are many methods of charging and discharging the vehicle by controlling the on-board charger, and most of the related technologies adopt the control method of single-phase H-bridge, and the control method of using single-phase H-bridge generally includes bipolar polarity control method and unipolar control method. [0004] However, when the bipolar control method is adopted, the four switching tubes in the H bridge are in a high-frequency switching state, the switching loss is high, and the heat loss generated is relatively large; when the unipol...

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Problems solved by technology

[0004] However, when the bipolar control method is adopted, the four switching tubes in the H bridge are in a high-frequency switching state, the switching loss is high, and the heat loss generated is relatively large; when the unipolar control method is adopted, although it can be Solve the heat loss of the switching tubes when the bipolar control method is adopted, but the four switching tubes in the H bridge are always controlled in a fixed way during the charging or discharging process of the vehicle, and some switching tubes in the H bridge need to be turned off with current. The overheating problem of the switching tube with current shutdown cannot be effectively solved

[0005] Therefore, regardless of the bipolar control method or the unipolar control method, the heating problem of the switch tube in the H bridge cannot be effectively solved, and the working life of the switch tube is affected.

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