船用低速柴油机电控系统控制策略试验研究

Control strategy research on the electronic control system of the marine low-speed diesel engine

为研究电控系统主要控制参数随柴油机负荷变化规律及各参数间的相互关联,利用船用低速柴油机高压共轨电控系统硬件在环仿真试验平台,同步采集试验平台重要控制参数,对电控系统燃油轨压调节、伺服油轨压调节、低负荷喷油器轮换工作、燃油喷射定时和排气阀启闭定时等控制策略进行了研究.研究表明:燃油轨压调节采用闭环和前馈修正的控制算法,喷射定时控制与柴油机转速、扫气压力和燃油轨压相关联,柴油机低负荷时3个喷油器按一定间隔时间轮换工作;随柴油机负荷增加,伺服油轨压和排气阀开启持续角度亦增加;排气阀开启与柴油机转速和排气关闭角度相关,而排气阀关闭则仅与柴油机转速相关.

In order to research the law of the main control parameters of the electronic control system changing with diesel engine loads, as well as correlation of parameters, the control strategy of the high-pressure common-rail elec- tronic control system for a marine low-speed diesel engine is presented in this paper. Based on a hardware-in-loop simulation test bench, the important control parameters of the test bench were collected synchronically to research the fuel rail pressure control of the electronic control system, servo oil rail pressure control, low load injector rotation law, the injection timing and the exhaust valve start and stop timing, etc. The research results show that the common- rail fuel pressure is regulated by using a closed-loop and a correction of a feed-forward control algorithm. The injection timing control is affected by the rotation speed of the marine low-speed diesel engine, the scavenging pressure and the fuel common-rail pressure. Three injectors in a cylinder work alternately with a certain interval time at low loads of the marine low-speed diesel engine. With the increase of the load of the marine diesel engine, the servo oil pressure and the exhaust valve opening duration increase respectively. The exhaust valve opening angle is related to the rotation speed of the marine diesel engine and the exhaust valve closing angle of the former cycle, and the exhaust valve clos- ing angle is solely associated with the revolving speed of the marine low-speed diesel engine.