天然气发动机宽域氧传感器控制系统

Universal Exhaust Gas Oxygen Sensor Control System for CNG Engine

摘要:

研究了基于电控调压器的增压单燃料CNG发动机电控系统，在分析宽域氧传感器的结构和工作原理的基础上，设计了以MPC561为主芯片的宽域氧传感器控制系统，采用CJ125芯片设计了宽域氧驱动电路以及加热电路。设计了基于自适应算法的空燃比闭环控制器，对氧传感器加热温度进行闭环控制和对空燃比进行闭环控制。通过在天然气发动机试验台架上的空燃比闭环试验，验证了所设计的空燃比自适应闭环控制算法可以实现对空燃比的快速、精确瞬态控制，为发动机空燃比智能控制、提高发动机的经济性和改善排放提供了条件。

Abstract:

The control system of boost CNG Engine based on electronic pressure regulator was studied. The structure and working principle of universal exhaust gas oxygen sensor were analyzed. Based on the main chip MPC561 and integrated CJ125, universal exhaust oxygen sensor control circuit and heater circuit were designed. Based on adaptive algorithm, the A/F ratio closed controller was designed and its control strategy of air-fuel closed loop was discussed. The CNG engine experiments of air-fuel ratio closed loop on bench test showed that the dynamic response of UEGO control system was rapid and accurate. Based on UEGO control system, the intelligent control of engine’s air-fuel ratio could be achieved, and the performance of economy and emission could be improved.