Abstract
The performance and advancement of ignition systems become more important than ever to further improve the fuel efficiency and exhaust emissions of modern engines. The ignition processes of modern engines are often subjected to a fuel-lean or inert-gas-diluted mixture of considerably high density and strong air motion. Bulk gas movements in the vicinity of the spark gap, such as crossflows, can stretch the plasma channel across the spark gap, which enhances the total discharge energy compared with quiescent conditions. A higher discharge current has been proven to be an effective way to prolong the spark plasma stretching. However, high discharge current (boosted up to 3A) increases the power consumption of the ignition systems, affecting system durability and energy efficiency. Besides, the continuous high current cause rapid spark electrode erosion, which affects the durability of the spark plug. In this work, a novel high-frequency pulsed current management strategy is proposed to improve plasma stretching and energy release, while decreasing the total energy consumption of the ignition system. Within precise control of discharge duration, a high-frequency pulsed discharge strategy is achieved without interfering with the plasma stretching process. The characteristics of the plasma channel are recorded via both electrical and optical measurements.
