基于PID的柴油机闭环EGR控制策略研究

摘要

介绍了基于PID控制原理的柴油机闭环EGR控制策略；探讨比例系数P、积分系数I对EGR系统稳定性和响应性的影响，提出不同工况下PI参数的整定原则；在欧洲稳态试验循环NOx排放水平一致的前提下，对比分别采用开环、闭环控制策略控制EGR开度时，不同转速加速工况下发动机烟度排放、加速性能的区别。结果表明，采用闭环控制EGR系统时，发动机的瞬态工况烟度排放和加速性能都明显优于开环控制系统。%The closed-loop control strategies of diesel EGR system based on PID control principle are introduced in this paper. Researches are carried out to find out the effect of proportional factor (P)and integral factor (I) on stability and responsiveness of EGR system, and the setting principle of PI parameters in different cycles is proposed; under the precondition of consistent NOx emission level in European steady state test cycle, the difference of smoke emission and acceleration performance is compared in different acceleration conditions with open and closed-loop control strategy to control EGR opening. The results show that the smoke emission and acceleration performance in engine transient conditions is better that that of open-loop control system remarkably.