ISG电机转矩补偿的低温预混柴油机瞬态控制  

Transient Control of PCCI Diesel Engine with ISG Motor Torque Compensation

作　　者：方成[1] 杨福源[1] 欧阳明高[1] 高国景[1] 陈林[2] 

机构地区：[1]清华大学汽车安全与节能国家重点实验室,北京100084 [2]上海汽车集团股份有限公司技术中心,上海201206

出　　处：《内燃机工程》2015年第1期112-118,共7页Chinese Internal Combustion Engine Engineering

基　　金：国家"八六三"高技术研究发展计划项目(2012AA111714;2012AA111705;2011AA11A207);科技部国际科技合作计划专项基金项目(2010DFA72760)

摘　　要：采用ISG电机进行动态转矩补偿,解决低温预混柴油机瞬态过程动力不足的问题。使用自主的燃烧状态分析单元,采集各缸缸压信号,计算燃烧状态指标,并发送给发动机控制单元。通过控制主喷油量和主喷定时,实现基于平均指示压力和放热中点的双闭环反馈的燃烧闭环控制。利用摩擦转矩增量与最大缸压增量之间的线性关系,进行摩擦转矩预估。利用反馈的平均指示压力、平均泵气压力和预估的平均摩擦压力,预估发动机输出的有效转矩。在转矩预估和燃烧闭环的基础上,进行转矩闭环控制。在发动机和ISG电机间进行转矩分配,在瞬态工况下,由于油量限制导致的转矩不足由ISG电机补偿。试验表明:在低温预混燃烧的瞬态加载工况和燃烧模式切换的瞬态工况下,利用ISG电机进行动态转矩补偿,无碳烟排放恶化状况,系统的转矩跟随效果好。Research on application of ISG motor to improve diesel engine transient torque response, especially in PCCI mode or combustion mode switching from PCCI to CI was conducted. Combustion indicators were calculated out from cylinder pressure data acquired by the self-developed in-cylinder combustion analysis tool and sent to engine control unit. By adjusting main injection delivery and timing according to indicated mean effective pressure and point of 50% of the total fuel burnt （CAS0）, double closed-loop feedback control was realized. Friction torque was estimated from the linear relationship between increments of friction torque and maximum pressure compared to the values in engine motoring operation. Engine effective output torque was determined by indicated mean effective pressure and mean pumping pressure feedbacks received from the in-cylinder combustion analysis tool and estimated mean friction pressure. A closed-loop torque control algorithm based on engine torque estimation and closed-loop combustion control was proposed. Engine output torque deficiency in transient condition due to fuel delivery limitation was compensated by ISG motor. Test in a 2.5 L diesel engine demonstrates that the system has good transient torque response characteristics in PCCI mode loading condition and combustion mode switching condition without smoke emission deterioration.

关 键 词：内燃机 低温预混燃烧 ISG电机 燃烧闭环控制 转矩预估 转矩补偿 

分 类 号：U461.1[机械工程—车辆工程]