Toyota City Low-Carbon Society System Verification Project (Smart Melit)

Restraining electrical power peaks when simultaneously recharging multiple PHVs and EVs


Controlling contracted power volumes and reducing the running costs of recharging facilities

Release:2013/02/08Click here for news items >>
Toyota Industries Corporation is currently working on a verification experiment for a Smart Recharge System as part of Toyota City Low-carbon Society System Verification Project (Smart Melit). This verification experiment targets seven recharging stations located within Toyota City, and involves a system in which multiple plug-in hybrid vehicles (PHVs) and electric vehicles (EVs) can be efficiently recharged at the same time. The adjustment of the amount of electrical power used to recharge each of these vehicles is carried out in order to restrain electrical power peaks and thereby cut down on energy costs. This system also includes the combined use of storage batteries, and is linked up to the community's EMS (Energy Management System), etc.

One of the most important themes of Toyota City's Smart Melit (Smart Mobility & Energy Life in Toyota City) Low-carbon Society System Verification Project is establishing next-generation mobility. (Related article: Instant Searches on Connections between Automobiles and Public Transport.) This envisages a time when plug-in hybrid vehicles (PHVs) and electric vehicles (EVs) become the "wheels" of local residents.

The main issue with achieving the wide-spread use of PHV/EVs is making sure that recharging stations are available. In addition to recharging at individual households, it is thought that multiple recharging stands need to be installed in commercial facilities, etc. to which many vehicles gather as a part of the customer services.

The problem is, however, that recharging multiple PHVs and EVs simultaneously exceeds the power capacities available at facilities, as well as the volume of electricity they are contracted to receive from power companies, which means that they have no choice other than to revise their contracts. Increasing facility capacities in alignment with peaks in power usage and increasing the amount of power they are contracted to receive leads to cost increases. The result of this is that it is difficult to move ahead with the installation of recharging facilities, which puts a damper on the distribution of PHV/EVs. The key to avoiding this situation is the Smart Recharge System, developed by Toyota Industries Corporation and for which testing is continuing to be carried out.

The Smart Recharge System verification experiment is scheduled to be implemented in four phases from fiscal 2011 through fiscal 2014. Phase #1 involved installing recharging stands capable of handling multiple PHV/EVs in seven locations throughout Toyota City in fiscal 2011. (Photo #1)

Photo #1. External view of a recharging station

Photo #1. External view of a recharging station
    The station in the photograph is located in front of the west building of Toyota City Hall. It contains six
    recharging stands and two smart recharge systems, each of which controls three stands respectively.
    (Photograph by: Hidekazu Ueno)

Phase #2 was implemented in fiscal 2012 and consisted of a plan to incorporate storage batteries in the Smart Recharge System, and tests are currently being repeatedly carried out on the performance of lithium ion storage batteries manufactured by Toshiba Corporation. The combined use of storage batteries aims at both maintaining sufficient recharging power for PHV/EVs during peak demand periods, and reducing reliance on the power grid. In addition, concentrating functions such as consolidating communication function in each recharging stand, etc., will bring down the cost of each stand, which is expected to result in the promotion of a wide-spread recharging infrastructure.

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