Technical Library

Latest Technology Trends for EVs


1. Introduction

Countries around the world are taking on environmental problems in hopes of creating a low-carbon society. One key area involves steps to increase the usage of EVs (electric vehicles) and HVs (hybrid vehicles), and this is where Japan has taken a leading role. Under an economic growth strategy which will be culminating in 2020, Japan's METI (Ministry of Economy, Trade and Industry) has set a target of increasing the number of Eco Cars in Japan to 20-50% of all vehicles (610,000 worldwide in 2015) and the number worldwide to 3.9 million (1.75 million EVs, 2.15 million PHVs [plug-in hybrid vehicles]).
Meanwhile, the earthquake and tsunami that struck Japan in March 2011 have prompted the country to move away from its basic energy policy of depending on fossil fuels and nuclear power. Instead we are working to increase the use of solar power and other renewable energy sources. Cutting back on nuclear power has prompted fears of energy shortages and the country has had to consider rolling blackouts to ensure energy needs are met during the high-demand Summer months. As an initial measure for the near future, all of Japan has been required to use energy more efficiently by whenever means possible by saving, storing, and creating the limited amount of energy supplies that are available. Particularly important has been the use of lithium-ion batteries to store energy for more overall effective use: this is done by implementing peak-time shifts in which plentiful night-time energy is stored for use during the daytime. Helping meet the need for such peak-time shift is Nichicon's Vehicle to Home (V2H) system EV Power Station, the first product in the world to use an EV lithium-ion battery to provide the home with electricity. Here are the state-of-the-art technologies behind EVs: V2H, EV on board chargers, EV quick chargers, and on board capacitors.


2. On Board Capacitors

Capacitors constitute Nichicon's core business, and the company has a capacitor lineup designed for applications from gasoline vehicles to EVs and HVs. For capacitors mounted on microprocessors and other circuit boards in under-the-hood applications, Nichicon's chip-type CX Series is used by numerous car companies: it has a vibration-resistant construction and offers low-temperature ESR (equivalent series resistance) throughout a wide range of temperatures (-40°C to 135°C).
Recent years have seen film capacitors gradually replace the large aluminum electrolytic capacitors conventionally used in EV/HV motor drives. Nichicon's EM Series of plastic film capacitors can be customized with specific sizes and performances depending on the model of car.

CX Series aluminum electrolytic capacitors
EM Series plastic film capacitor

CX Series aluminum electrolytic capacitors

EM Series plastic film capacitor

3. Quick Charging System for EVs

Ultra-compact charger for EVs

Ultra-compact charger for EVs


1) Ultra-Compact Quick Chargers for EVs
Toward its goal of realizing a low-carbon society, Japan was the first country to develop EVs (electric vehicles) and install an EV charging infrastructure. In addition, an industry group led by Tokyo Electric Power Company has proposed an international standard for quick chargers called CHAdeMO. A number of manufacturers in Japan and other countries are already offering products that use this standard, and over 1,600 CHAdeMO-compatible quick chargers have been installed worldwide. Nichicon was the first company in the world to develop and manufacture OBCs (On Board Chargers) which are the devices that charge the lithium-ion batteries inside EVs. Most of today's mass-produced EVs are equipped with Nichicon OBCs. Nichicon is also contributing to the spread of the charging infrastructure: it has applied its technology to a four-product lineup (10-, 20-, 30-, and 50-kW) of the world's smallest and lightest quick chargers for EVs. The company is contributing to the spread of the EV charging infrastructure by providing these chargers to car dealers of Mitsubishi Motors Corporation, as well as to service areas alongside Japanese freeways and other public facilities.

2) Quick Charging System Combining Solar Power and Energy Storage
50-kW-class quick charging systems often require high-voltage electrical equipment, but Nichicon has developed a quick-charging system that can run on a low-voltage commercial power source. This system has been installed at the Suita Service Area on the Meishin Expressway in West Japan. This quick charging system combines solar power and a lithium-ion storage battery and it therefore has the advantage of being able to operate on its own as an emergency power source.

On board DC-DC converter with built-in charger

On board DC-DC converter with built-in charger


4. EV Power Station for 2-Way Charging and Power Supply (V2H System)

Nichicon has developed the EV Power Station, the world's first two-way charging and power supply system allowing owners to use the large-capacity storage battery in their EV to send electricity into their home. It is known as a V2H (vehicle to home) system since it can power a home using your car's battery. The EV Power Station can store inexpensive night-time electricity and shift it to the daytime for use in the home, thus contributing both to peak-time shifts and lower electricity costs.

Features of the EV Power Station

  1. Stores electricity at night for use in the daytime to contribute to peak-time shifts and lower electricity costs.
  2. The lithium-ion battery in the Nissan Leaf EV can be used as a backup power source.
  3. Can fully charge the battery in as little as four hours, which is about twice as fast as a conventional 200V household power source.
  4. Compliant with the CHAdeMO standard for electrical charging and discharging.
  5. Designed to prevent reverse power flow to the grid.

EV Power Station

EV Power Station


5. Household Power Storage Systems

There is a complementary relationship between fixed power storage systems and mobile storage systems such as the V2H system using EV storage-capable batteries. Whether a household owns an EV, there must be a way for customers to automatically choose the most economical energy method by making optimal use of the fixed storage system. It is up to private companies to explore ways to make the most effective use of things like HEMS (home energy management systems).


6. Conclusion

The first generation of power supply systems is represented by distributed systems: these include grid-connected solar power generation systems, storage-battery power generation systems, and fuel cells.
To proliferate such distributed power systems, we have to solve the problems faced by all concerned parties-utilities companies and providers of renewable energy and energy storage systems-and work towards the realization of a society in which smart grids provide a stable supply of power.


Nichicon Corporation
From the Dempa Shinbun, January 9, 2013

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