High Frequency Corona Discharge Ignition System Demonstration

Advanced ignition systems for heavy-duty natural gas vehicles improve combustion efficiency and reduce emissions

Institute of Gas Technology dba Gas Technology Institute


Des Plaines, IL

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Result

Research was completed on the advanced high-efficiency spark-ignited engine (HESI) with a traditional transistor coil ignition (TCI) and the advanced high-frequency EcoFlash ignition system. The high frequency ignition corona discharge technology is transitioning from alpha-level prototypes, on test benches and in engine cells, to beta-level prototypes. Newer prototypes are expected to improve the energy efficiency in the DC to high frequency circuitry. The newer design will also have more advanced communication interface features. The technology has demonstrated faster initial burn rates from the start of ignition and better EGR tolerance in gasoline engines. For these reasons, the project team believes this to be a most promising technology for future ignition work with advanced natural gas engines. [br /]
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The Issue

Conventional ignition systems, which use a transistor coil ignition (TCI) architecture and are widely used in spark-ignited engines, are limited in their ability to operate at very high dilution levels driven by high levels of exhaust gas recirculation, which is commonly used as a strategy to reduce high levels of NOx. Modern commercial medium-duty natural gas engines with TCI typically require spark plug replacement at 1,500 hour intervals to avoid instances of misfire and/or damage to the exhaust aftertreatment system. Longer service intervals for ignition components would be very desirable for end-users, as it reduces cost of maintenance and reduces time when vehicles are not in service.

Project Innovation

This project developed ways to improve efficiency using an advanced ignition method based on the corona discharge principal for use in medium-duty natural gas engines. The emerging ignition technology improved the robustness of the ignition and combustion performance in engines with high dilution or at high boost pressures. Benefits include reduction in fuel consumption, GHG emissions, and NOx emissions. The project also developed a better understanding of the potential for long ignition service life relative to the conventional technology (i.e. conventional spark plugs).[br/][br/]The project team of Gas Technology Institute (GTI), Westport Fuel Systems, Inc. (Westport), and BorgWarner Beru (BorgWarner) demonstrated an advanced engine and ignition technology to test for emissions, performance, and fuel economy improvements over traditional architectures. High Frequency Corona Discharge Ignition technology has a large corona ignition region that is almost 1,000 times that of a tradition spark plug and has been shown to reduce ignition delay and enhance the early ignition process, stabilize main combustion, and reduce some throttling/pumping losses.

Project Benefits

Advanced ignition systems for heavy-duty natural gas engines can lead to improved performance and efficiency while reducing tailpipe emissions. The corona ignition system developed by this project demonstrated increased exhaust gas recirculation tolerance by up to 40 percent, thereby reducing pumping losses due to higher work cycles during the intake and exhaust stroke.

Lower Costs


The corona ignition system itself is a non-thermal plasma and the gas temperature is much lower than the thermal plasma that forms in a traditional spark plug using transistor coil ignition. Preliminary experience with light-duty gasoline engines has so far lead researchers to expect electrode life expectancy greater than 60,000 miles, or greater than 150 million ignition event, which can reduce maintenance costs.

Environmental & Public Health

Environmental Sustainability

CO2 emission results show 75% of the brake specific CO2 data maps are below 425 g/hp-hr. With the pretest target being 424 g/hp-hr on the SET cycle, there is adequate room to further trade off CO2 for fuel economy while still meeting the target, which is based on expected EPA regulations through model year 2027.

Meet the Team

Connect with the project team members that are helping California lead clean energy innovation.

Key Project Members

Project Member

Ted Barnes

Project Manager



Westport Innovations


Match Partners


Gas Technology Institute


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