商用车48 V混动发动机减压技术研究

Research on Decompression Technology of a Commercial Vehicle 48 V Hybrid Engine

混合动力是促进传统内燃机实现节能减排的主要技术手段之一,但混合动力发动机频繁起停会造成零部件摩损大、能耗高、振动剧烈、发动机转速波动大等问题,并会引起起动系统或起动电机可靠性问题。针对某商用车48 V混合动力系统开发了一套减压系统,设计了控制策略,完成了在混合动力系统台架上的试验验证。试验结果表明:该减压系统可以明显降低起停过程发动机振动,停机过程最大降幅约88%,起动过程最大降幅约53%;另外,该系统可明显改善发动机停机过程的转速波动,减小带传动一体化起动/发电机(BSG)起动时的电流波动,并能消除停机时反转现象。

Hybrid power system is one of the main technical means to achieve energy saving and emission reduction. However,frequent start and stop of hybrid engine will cause the problems of large parts friction,high energy consumption,severe vibration and large fluctuation of engine speed,and will cause the reliability of starting system or starting motor. A set of decompression system is developed for a 48 V hybrid power system of a commercial vehicle,and the control system is designed. The results of tests show that the system can significantly reduce the engine vibration during start-up and shutdown,with a maximum reduction of about 88% during shutdown and 53% during start-up. In addition,the system can significantly improve the speed fluctuation during engine shutdown,reduce the current fluctuation during BSG starting,and eliminate the reversal phenomenon during shutdown.