Ignition Circuit for Natural Gas Ignition System

This paper presents the development of the high- voltage ignition circuit for coil-on plug ignition system of the natural gas engine. The main specification of the circuit is the modelling and optimization of the ignition power-switching device at the primary side of the circuit, which is important to provide high switching speed to turn-on and off the device. The selected power-switching device is Insulated Gate Bipolar Transistor or IGBT. The other specification of the circuit design is the snubber circuit that can provide over-voltage protection at the primary circuit. Finally, the testing of the circuit is done by applying a control signal at the input source terminal or at the gate terminal of the ignition IGBT. The complete circuit design is integrated with the high-voltage ignition coil and special designed long neck spark plug. The results of the circuit performance are discussed as a comparison with the conventional ignition system of the gasoline engine.