天然气发动机起动点火能量控制策略

通过测量点火线圈初级回路的电流,确定初级回路的最佳闭合时间。为了有效提高点火系统的可靠性,提高点火能量,在发动机转速低于600 r/min时,采用了压缩上止点前多次点火策略。参照SAE J973—1999标准,采用稳压管串作为模拟负载,实现了点火能量的量化测试。为了确保多次点火的能量在压缩上止点前充分释放,调整了多次点火时的脉冲信号间隔。试验结果表明,初级线圈闭合时间为6 ms时,初级断开电流不再继续增大,储能接近饱和;采用多次点火策略时,脉冲信号间隔为1.28 ms,可以保证多次点火的能量都在压缩上止点前充分释放。

Spark Energy Control Strategy of Natural Gas Engine in Starting Process

The energy stored in primary coil was calculated and the optimal charge time of primary coil was determined through measuring the current of primary circuit,In order to improve the reliability of ignition system effectively and increase the ignition energy,the multi-ignition strategy was adopted before the top dead center(TDC) in compression stroke when the engine speed was lower than 600 rpm.Referring to SAE J973—1999 standard,the quantitative measurement of ignition energy was realized by using Zener string as simulation load.To ensure the complete release of multi-ignition energy before TDC,the pulse interval of multi-ignition was adjusted.According to the experiment,the charge time of primary coil was 6ms and the energy stored in primary coil was nearly saturate.When the multi-spark energy strategy was adopted,the pulse interval became 1.28 ms and the multi-ignition energy was released completely before TDC.