基于模型的DPF主动再生排气温度控制

A Model-based Research on Exhaust Temperature Control for DPF Active Regeneration

颗粒物捕集器(DPF)主动再生发生时需要将柴油发动机排气温度提升到500℃以上并维持在较长一段时间内。为减少由于控制对象纯滞后特性、强扰动因素引起的不确定性,降低高排气温度带来的主动再生风险,结合基于模型的控制策略提出了一种优化的再生温度控制算法和控制器结构,并展开了仿真分析、参数优化等研究工作。设计的控制结构考虑实际工程应用需求,采用基于发动机排气温度和排气流量的增益补偿和前馈加反馈控制方案,可兼顾性能和成本因素,并具有较强的适应性和可操作性。仿真和台架试验、车辆道路试验结果均表明,主动再生过程中对实际排温控制的超调量小于3%,在发动机瞬态工况和车辆运行等强扰动工作工况下的稳态控制误差小于25℃。

Initiation of active regeneration of diesel particulate filter(DPF) requires that the diesel engine exhaust gas temperature be raised to 500℃ or above and maintained at the operating temperature for a moderately long period of time. To reduce the uncertainties by time-delays and strong disturbances of the control object and risks of active regeneration caused by high exhaust temperature, an optimized regeneration temperature control algorithm and controller structure are proposed based on model-based control strategy development, and simulation analysis and parameter optimization are carried out. Considering practical application requirements, the designed control structure adopts the scheme of gain compensation, feedforward solution and feedback control based on engine exhaust temperature and exhaust flow, which takes account of both cost and performance and has strong adaptability and operability. The results of simulation, bench test and vehicle road test show that the overshoot of actual exhaust temperature control in active regeneration process is less than 3% and the steady-state control error remains less than 25℃ even under aggressive disturbances during transient vehicle operation.