Study of the injector drive circuit for a high pressure GDI injector

In order to meet future emission regulations, increase the power production and reduce the fuel consumption the modern SI engines uses the electronic actuators such as solenoid injector, idle air control actuator, valve timing actuator etc. Engine performance and emissions are mainly depending on the accurate control of both the injection timing and fuel injection quantity of the injector. In order to fully exploit the advantages of modern GDI injector, the electronic system should be capable of driving a high speed solenoid injector at a very fast switching frequency efficiently and with less power consumption. The electric driving circuit is required to be designed with a fast response and precise control. The most serious problem which decreases the injector performance is the response time delay of the injector. There are many reasons for the delay in opening and closing of electromechanical injector such as voltage drop, limitation of injector driving circuit, electromagnetic interference, etc. In this paper, an injector drive circuit has been designed and analyzed for driving a high pressure injector. Also, PWM control using NE 555 timer has been introduced for quickening the cut-off response time. In the process of designing an injector drive circuit high frequency switching component like MOSFET, IGBT and power transistor has been used. Comparison of response time between these three injector driving circuit has been given using NI Multisim. Analysis of switching characteristic among the three injector driving circuit was carried out. In the end, switching characteristic and temperature sweep of all the three IDC have been plotted.