|Toyota’s view of E-Flex (the EV-based PHV) series-hybrid approach versus Toyota’s PHEV approach. Click to enlarge. Source: Toyota|
Toyota Motor Corporation (TMC) is positioning its emerging approach to plug-in hybrid vehicles—based on augmenting the battery pack of a conventional hybrid and altering the operating strategy (earlier post)—as an approach superior to that of the series-hybrid architecture of GM’s E-Flex systems (earlier post), as represented by the different versions of the Chevy Volt.
The rationale, outlined by Toyota Executive Vice President Kazuo Okamoto in a presentation about the company’s technology strategies to investors in Tokyo on 3 Sep, is that once current parameters such as driving range, required battery size and charge time are factored in, the augmentation of the existing parallel-hybrid platform makes the most sense.
|Toyota’s view of the plug-in. Click to enlarge.|
The prototype Toyota plug-in is based on a Prius with a 2.6kWh NiMH battery pack supporting an all-electric range of 13 km (8 miles). The gasoline (flex-fuel) version of the Chevy Volt, targeted for production in 2010, is spec’d to have a 16kWh li-ion battery pack that supports a 40-mile all-electric range.
The presentation, Challenges for Sustainable Mobility, outlined a number of Toyota technology efforts including advanced gasoline and diesel engine work and alternative fuels (biofuels, hydrogen and electricity).
The investor presentation followed Toyota’s announcement in July that it has developed a plug-in hybrid vehicle and had become the first manufacturer to have such a vehicle certified for use on public roads in Japan.
Toyota will conduct public-road tests in Japan with eight units of the Plug-in HV to verify electric-motor-only cruising ranges and optimal battery capacity. While doing so, it plans to provide the government with data for formulating testing methods for emissions and fuel efficiency and to consider TMC’s measures for promoting plug-in hybrids and the use of electricity.
In addition, Toyota is also providing plug-in hybrid prototypes to the Advanced Power and Energy Program at the University of California, Irvine (UCI) and the Institute of Transportation Studies at the University of California, Berkeley (UCB), as part of its on-going sustainable mobility development program with the two UC campuses. (Earlier post.)
Toyota and French utility EDF reportedly will announce an agreement this week to develop recharging points to serve the plug-in hybrid cars Toyota plans to roll out in a few years’ time. (Earlier post.)
|Specifications of Toyota Plug-in HV|
|Seating capacity||5 persons|
|All-electric performance||Cruising range||13 km in 10-15 cycle|
|Max. speed||100 km/h|
|Max. output||56 kW (75 hp) @ 5,000rpm|
|Max. torque||110 Nm (81 lb-ft) @ 4,000 rpm|
|Max. output||50 kW (67 hp) @ 1,200 - 1,540rpm|
|Max. torque||400 Nm (295 lb-ft) @ 0-1,200 rpm|
|Capacity||13 Ah (6.5 Ah x 2)|
|Overall System||Maximum Output||100 kW (134 hp)|
|Voltage||202 - 500V|
|Battery charging||Power source||Household electrical power|
|Charging time||1 - 1.5 hrs (200V); 3 - 4 hrs (100V)|
Toyota has already expressed concerns on the record about after-market conversions of existing hybrids to plug-in hybrids. (Earlier post.)
Also, at the recent 2007 Management Briefing Seminars in Traverse City, Michigan, Toyota told the audience that a number of serious hurdles stand in the way of getting plug-in hybrids on the road, and that even if the vehicles do make it to market, a battery-powered plug-in may be no more efficient in reducing carbon dioxide emissions than the current charge-sustaining gas-electric hybrids on the road today. (Earlier post.)
In August, reports contended that Toyota was going to delay its deployment of lithium-ion batteries in high electric-mileage hybrids because of safety concerns with its batteries, which use cobalt oxide cathode materials. (Earlier post.)