Self-generating limp system and method for hybrid electric vehicle

Abstract

The invention discloses a self-generating limp system and method for a hybrid electric vehicle. The method comprises: setting electric appliance loads with the current fluctuation value larger than aset current fluctuation threshold value during opening / closing in whole vehicle loads to be R1, R2,..., Rn; when the 48V lithium battery has a fault, the lithium battery is charged, firstly, requesting an IBSG motor to enter an idle mode; then pre-charging and adjusting the idling speed of the engine are carried out; and after the voltage in the IBSG motor loop and the rotating speed of the IBSG motor meet the requirements, requesting the IBSG motor to enter a power generation mode to generate power, forbidding R1, R2,..., Rn to be switched on / off, and then converting the output voltage of theIBSG motor to charge the storage battery. According to the invention, after the 48V lithium battery breaks down and is disconnected, the IBSG motor can continue to generate power, and the situation that half-way feeding crouches down is avoided.

Description

technical field [0001] The invention relates to the field of hybrid electric vehicle control, in particular to a hybrid electric vehicle self-generating limp system and method. Background technique [0002] With the average fuel consumption requirements of national four-stage vehicle companies, major car companies are in urgent need of low-cost fuel-saving new technology solutions that are easy to integrate into existing models to achieve the purpose of reducing fuel consumption. At this time, the emergence of 48V power supply systems just caters this need. Compared with the power system of traditional fuel vehicles, the 48V power system of hybrid electric vehicles mainly adds three core components: IBSG motor (ie 48V power recovery motor), DC converter DCDC and 48V lithium battery (BMS, Battery Management System), With functions such as start-stop, braking energy recovery, and acceleration assist, it will save 8% to 15% of fuel consumption (under NEDC conditions) for passe...

AI Technical Summary

Problems solved by technology

[0003] Although since 2016, domestic mainstream automakers have launched a number of models equipped with 48V systems; however, due to the short development time, the technology is not fully mature, especially the matching between the entire 48V components, and the connection between the 48V system and the entire vehicle. There are still some imperfections in the matching, and the system functions have not been fully developed.

At present, based on the whole vehicle architecture, most of the major OEMs use the Hybrid-CAN composed of IBSG motor, DC converter DCDC and 48V lithium battery to realize the system communication function. In the case of 48V lithium battery failure, the IBSG motor It cannot work normally to generate electricity, and the vehicle will lie down halfway during driving, causing customers to complain

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