To perk up the cruising range of FCHV per charge to 500km, which is on par with that of the gasoline vehicles, Toyota Motor Corp held a lecture titled ‘Development of Fuel Cell Hybrid Vehicle-Cruising Range’ at EVS23. The company focused on enhancing the fuel tank pressure and improving its fuel efficiency. The pressure in the fuel tank was increased from 35 to 70MPa so that the tank can store about 6kg of fuel, which is 1.9 times that in the existing tank.
In addition, loss at the compressor, which supplies the fuel cell stack with air and losses in the boost converter and motor inverter were consuming fuel, Toyota focused on the reduction of energy loss in the fuel cell system and the converter of the hybrid system, both of which consume a large amount of energy. In the fuel cell system, the air supply pressure to the air electrode side was reduced for all engine loads. As a result, the efficiency of the fuel cell system as a whole improved although the output voltage from the fuel cell was reduced by about 1%.The heat loss in the fuel cell stack and the loss in the compressor to supply the stack with air were both reduced by 12%, thereby improving the fuel efficiency of FCHV by 5%, the company added.
The company has improved the efficiency of the converter in the low load region by using only one bridge. This will result in a 3% increase in the fuel efficiency of the fuel cell vehicle, the company said. With these improvements, the energy consumption of the remodeled FCHV during driving was reduced by 15% compared to the 2005 model, while the regeneration energy was increased by 25%. The company also said that the fuel efficiency based on the US LA-4 test cycle was improved by 25%, and the fuel efficiency during the actual driving exceeded 85km/kg, resulting in a cruising range of 500km or longer.
Via: Techon
