The Clean Energy Patent Growth Index tracks the granting of US patents in solar, wind, hybrid/electric vehicles, fuel cells, hydroelectric, tidal/wave, geothermal, biomass/biofuels and clean, renewable energy. GM’s 135 patents represent nearly 14% of the total 1,881 received by 700 entities.
GM’s patents covered hybrid electric vehicles, fuel cells and solar energy, and focused on improvements to current and future technologies. Here are a few of last year’s inventions:
Multi-injection combustion cycle systems for spark ignition direct injection engines: Improves fuel and air mixing, and reduces hydrocarbon emissions during engine startup and cranking.
Dynamically adaptive method for determining a battery’s state of charge: Improves fuel economy with a new algorithm that estimates a lithium-ion battery’s internal parameters in real time.
Electrically variable transmission having three planetary gear sets with two fixed interconnections: Ultra-efficient hybrid electric vehicle transmission design that features low electrical losses, high torque capacity and city and highway modes.
Variable active fuel management delay with hybrid start-stop: Control system that seamlessly integrates active fuel management with start-stop for additional fuel savings.
Control of hybrid power regeneration during cruise control: Uses regenerative braking so the onboard battery can be charged during vehicle operation, saving fuel.
Method of operating a plug-in hybrid electric vehicle: Involves operating a heater when the vehicle is cold to preheat the battery, improving electric driving range.
GM received 940 US patents in 2010, placing it in the top 25 of all companies. This includes sectors such as information technology and consumer electronics.