Energy and Power Engineering, 2013, 5, 1362-1366
doi:10.4236/epe.2013.54B258 Published Online July 2013 (http://www.scirp.org/journal/epe)
Design of New-generation Electric Vehicle Terminal
Lei Li1, Xin Lu1, Jiasheng He2, Zhe Sun1, Guang Yang1
1Electric Power Science & Research Institute of Tianjin Electric Power Company, Tianjin, China
2Beijing China Power Information Technology Co., Ltd., Beijing, China
Received January, 2013
ABSTRACT
EVT (electric vehicle terminal) has played an important role in EV (electric vehicle) operation. Based on research status
of vehicle terminal, EVT brought about in the future should have the following functions: (1) fundamental functions,
including real-time monitoring of batteries, guidance in station, position guidance of charging/battery-swap infrastruc-
tures, communication with OMS (operation and management system), and so on; (2) advanced functions, including but
not limited to multi-media entertainment, subscribing and payment for charging/battery-swap, iden tification, and safety
control during driving. Complete design of new-generation EVT in software structure and hardware architecture is pro-
posed; a new idea of the application of EVT in EV industry is put forward.
Keywords: EV (electric vehicle); Power Battery; EVT (electric vehicle terminal)
1. Introduction
In recent years, with the development of EVs (electric
vehicles) industry, OMS (operation and management
system) for EVs has been gradually constructed, in order
to support th e operation of EVs. A number of cities, su ch
as Beijing, Tianjin, Qingdao, Hangzhou, have being
launching pilot projects to construct OMS for EVs. All
branch companies of SGCC (State Grid Corporation of
China) are going to accomplish construction of OMS for
EVs in the next two years [1].
In order to realize the functions of revealing real-time
information of power batteries as well as location infor-
mation of EVs in OMS for EVs, real-time information
acquisition of power batteries is needed. At the same
time, it is necessary for charging/battery-swap infra-
structures to take rational and orderly management to
coming EVs, which is known as charging guidance. All
of these functions demand the EVT (electric vehicle ter-
minal) to acquire real-time information of power batter-
ies, as well as to communicate with OMS and facilities in
station.
To EV consumers, the EVT must reveal the real-time
SOC (state of capacity) of batteries, like other products
whose energy are supplied by battery, such as mobile
phones and laptops, and give an alarm under the circum-
stance of low SOC. At the same time, the construction of
charging/battery-swap infrastructures is now in progress,
which is small area covered, bringing about inconven-
ience to consumers to charge or swap batteries. Therefore,
the EVT must have the function of navigating to the
nearest charging/battery-swap infrastructure.
According to the requirement analysis of EVT, a kind
of EVT meeting the needs from OMS, charging/battery-
swap infrastructures, as well as consumers is designed.
2. Research Status of Vehicle Terminal
The original design of EVT roots in traditional vehicle
terminal [2], 15 member states of EU (European Union)
enacted relevant laws and regulations in 1980s, that is,
vehicle terminals must be installed and applied on trans-
port vehicles for passengers and goods. Vehicle terminals
are applied on 70 million vehicles in Japan; as a result,
the death toll due to traffic accident is under 10 thousand
per year.
Vehicle terminals are divided into two kinds; one is
applying navigation technology recommended and de-
veloped by Japan, the other is applying remote informa-
tion technology widely popularized in Europe and
America. In Japan, electronic map navigation function
has been standard configuration, and is being developed
to austere version navigation along with the reinforce-
ment of graphic function. In Europe and America, sight
is focused on value-added services as emergency rescue;
in such a system, speech guidance and recognition, indi-
vidual assistant function is necessary.
For domestic consumers, vehicle navigation and re-
mote information are both urgently needed; therefore,
EVT is neither simply following vehicle navigation, nor
blindly absorbing remote information technology, but
assembling their advantages and referring to develop-

L. LI ET AL. 1363
ment level of domestic EV and individual desire of con-
sumers. On vehicle navigation, in consideration of the
status that charging/battery infrastructures are small area
covered mentioned above, charging/battery infrastructure
navigation function is pressing; on remote information
technology, the EVT must provide sufficient data for
OMS and receive useful information relative to EV fro m
OMS.
3. Function Summary of New-generation
EVT
In OMS for EVs, thermal model for batteries, real-time
information, as well as battery v oltage model reveal need
real-time data of batteries. Power battery has three oper-
ating states: in stock, on rack and at work. In stock indi-
cates that the battery is kept in stock; on rack means the
power battery is charging on charging rack; at work
means the power battery is placed in EV to operate.
When the battery is in stock or on rack, information ac-
quisition can be realized by means of wireless network
through reconstruction of stocks and charging plants.
Nevertheless, when the battery is at work, the EVT is
needed as terminal for information acquisition and com-
munication.
When EVs enter charging/battery-swap station to
charge or swap battery, workers in station should take
rational guidance to them. Its realization needs the sta-
tions and EVs to install corresponding wireless sensor
modules. Only direction and position information of EVs
is acquired and uploaded to management terminals in
station, can workers take charging guidance to EVs.
At the same time, the EVT should show the current
SOC to consumers and give an alarm under the circum-
stance of low SOC or abnormity. When charging or bat-
tery-swap is needed, the EVT should point out the loca-
tion of the nearest infrastructure.
As the EV s are ridd en instead of walking, EV T should
have advanced functions. Comprehensively considering
various aspects for EVT and progressiveness, their func-
tions can be divided into fundamental ones and advanced
ones.
3.1. Fundamental Functions
The fundamental functions of EVT are composed by the
four aspects bellow: real-time monitoring of batteries,
guidance in station, position guidance of charging/bat-
tery-swap infrastructures, communication with OMS, as
is show in Figure 1.
1) Real-time monitoring of batteries
Real-time monitoring of batteries is mainly meeting
requirement from two aspects: one is remote data acqui-
sition from relative applications of OMS to batteries; the
other is basis of real-time show of SOC, low SOC alarm
and abnormity alarm to consumers. Real-time data of
batteries are acquired through the CAN transceiver from
BMS (battery management system), uploaded through
GPRS (general packet radio service) to the front end
server of the OMS, and displayed on terminal screen.
When abnormity or low SOC occurs, the EVT can carry
out audible and visual alarms [3].
Figure 1. Fundamental function of EVT.

L. LI ET AL.
1364
2) Guidance in station
Guidance in station is mainly for the convenience of
the workers to manage EVs, bringing about effective
charging or battery-swap. The EVT communicates with
the infrastructures in station and PDA (personal digital
assistant) through ZigBee, computers in station show the
azimuth information and sequence information. The
drivers only need to cooperate with the workers and
screen in station to easily find out free charger or battery-
swap equipment. Disputes from jumping a queue can be
avoided due to the sequence information [4].
3) Position guidance of charging/battery-swap infra-
structures
As the construction of charging/battery-swap station
isn’t completed at present, compared with petrol filling
stations for traditional vehicles, coverage area of charg-
ing/battery-swap stations is badly limited; all of this
brings about inconvenience to charging and battery-swap.
In addition, as a result of bottleneck effect from battery
technology, the range of EV is short; consumers must
charge or swap batteries frequently. Consequently, for
the convenience of usage, the EVT should have the func-
tion of position guidance of charging/battery-swap infra-
structures, with the help of which value-added services,
such as long-distance rescue, can also be launched.
4) Comm uni cat i on wi t h OM S
Compared to traditional vehicles, the greatest advan-
tage of EV is their energy supply depends on compre-
hensively constructed smart grid. In recent years, all
branch companies of SGCC are constructing OMS for
EVs as well as information management towards EVs.
Through OMS for EVs, batteries and charging/battery-
swap equipments are managed, operating state of batter-
ies is monitored, trajectory of EVs is reappeared, relative
services are provided and short messages about tariff are
sent. The EVT is essential to information management
for EVs, which is not only supplier of real-time data for
OMS, but also service window between OMS and con-
sumers. Through EVT consumers can obtain the latest
tariff information about charging and battery-swap, ask
for long-distance rescue and remind subscribe of charg-
ing and battery-swap. Providing comprehensive services
through communication between EVT and OMS is one
of the most fundamental and important functions.
3.2. Advanced Functions
Compared to traditional vehicles, EV is in its elementary
period, not only for production scale, but also for the
functions and types of its auxiliaries. However, the ap-
pearance of vehicle comprehensive service platforms,
such as iDrive of BMW and G-Star of GM, offers valu-
able experiences to the EVT’s development. Besides
fundamental functions mentioned above, future EVT
should provide more comprehensive and abundant ad-
vanced functions for consumers. Taking consumers,
electric power corporations and charging/battery-swap
infrastructures into consideration, EVT should have the
following four advanced functions: multi-media enter-
tainment, subscribing and payment for charging and bat-
tery-swap, identification and safety control during driv-
ing.
1) Multi-media entertainment
Multi-media entertainment has b een indispensable pa rt
for traditional vehicle. From inchoate radio to cassette,
till multi-media player nowadays, consumers are enjoy-
ing the driving pleasure as well as multi-media enter-
tainment inside the car as the result of the development
of vehicle terminal. Future EVT should not only play
audio and video, but also bring about VOD (video on
demand) and surf the Internet with the help of wireless
communication networks. By self-organizing wireless
networks, mobile office and mobile meeting in car can
easily accomplished.
2) Subscribing and payment for charging and battery-
swap
In the near future, disperse AC (alternating current)
charging spots will be important infrastructures in com-
munities, rest areas on super highway, and parking areas.
Taking convenience of customers into consideration, the
EVT should have the function of subscribing and pay-
ment for charging and battery-swap. By the EVT, con-
sumers can find out the nearest disperse AC charging
spot available, subscribe the spot through OMS, write
their own ticket to determine the time to proceed to the
spot after they are informed the subscribed time. When
the consumer is to charge after arriving at the spot, it will
confirm the subscribing information through communi-
cation with the EVT. As long as the subscribing informa-
tion is confirmed, the spot starts charging according to
consumer’s operation. When charging is finished, the
spot will confirm the charging information through the
communication with the EVT, as long as the charging
information is confirmed, the consu mer can pay not only
by swing card, but also by account presorted in the EVT.
After payment, the EVT will communicate with OMS,
updating account information and uploading charging
information.
3) Identification
Identification is the extending of the existing intelli-
gent electricity card. The EVT will identify the card and
upload the consumer’s essential information to OMS,
displaying consumer’s information after confirmation.
After that, using information of batteries, charging/bat-
tery-swap information and payment information will be
uploaded and updated to OMS by EVT. Moreover, iden-
tification can take precautions against theft, that is, the
card is corresponding to EV and EVT, any inconformity
will trigger alarm, OMS will send message to cell-phone

L. LI ET AL. 1365
obligated by the consumer.
4) Safety control during driving
Guaranteeing driver’s safety is one of research areas in
traditional vehicle fields, which is equal problem to EV.
The future EVT will be redesigned on safety control
during driving. The EVT will play two main roles on
safety control: one is taking precautions against potential
safety hazard, the other is giving an alarm and control-
ling in case of accident. Locations where potential safety
hazard probably appears, such as the tire pressure and
environmental conditions of battery boxes will be moni-
tored, magnanimous sensors of varied function are in-
stalled, monitoring results ar e transmitted to the driver to
check the corresponding location. In case of malfunction
or accident, the EVT will transmit the alarm information
to OMS, cut off power supply and open the door. The
consumer can escape, avoiding misoperation from nerv-
ousness.
4. Architecture Design of EVT
In EVT design, fundamental functions are nucleus; de-
sign and lecto type of corresponding functional units
meet the requirement of fundamental functions at least.
Inconsideration of advanced functions, bus interfaces are
reserved for corresponding modules [5]. As designs of
main control unit an d memory cell needs con tinu ity, their
lectotype depends on performance indices for prospec-
tive advanced functions.
Application programs for fundamental functions are
designed to realize the fundamental functions mentioned
above. Hardware architecture is shown in Figure 2; the
EVT consists of the following main units: main control
unit, power supply unit, vehicle interface unit, memory
cell, communication unit, human computer interaction
unit.
4.1. Main Control Unit
Main control unit is the processing core of EVT, which
integrates various per i pheral cont ro l units and bus con t rol
units, assembling the EVT into an entirety. ARM9 cored
SoC control chip is selected.
4.2. Power Supply Unit
Compared with other hand-held flush-type products, the
power supply unit of EVT should allow wider input
Figure 2. Hardware architecture of EVT.

L. LI ET AL.
1366
voltage scale and better stability. Power supply of EVT is
from 12 V lead-acid cells on board. Output voltage of
lead- acid cell ties up with driving status: when the vehi-
cle is running, it is 10 to 12 volts; when the vehicle is
pulsing on, it is 14 to 16 volts. In order to prevent ab-
normality from sudden change of input voltage, the
power supply unit is designed according to standards in
automotive industry.
4.3. Vehicle Interface Unit
Vehicle interface unit is communication interface be-
tween EVT and EV. In automotive industry, CAN (con-
troller area network) bus have been used proverbially as
another appellation of interior bus? EVT needs to acquire
the batteries’ status information and condition informa-
tion on the interior bus, which makes this unit one of the
most important fundamental units, as well as main source
of communication data.
4.4. Memory Cell
Memory cell consists of two parts: internal storage and
external storage. The former drives at storage compo-
nents integrated in EVT, such as SDRAM and FLASH;
the latter indicates external extended storage components,
such as SD cards and TF cards. Memory cell mainly
stores Bootloader, embedded system, user parameter,
application program, user data, etc. At the same time, in
order to prevent valuable experimental data from missing,
historical information can also be stored in external ex-
tended storage.
4.5. Communication Unit
Communication unit includes GPRS, GPS (global posi-
tioning system) and ZigBee. Through GPRS module,
EVT uploads battery information to OMS at regular time,
and receives relative service information from OMS.
Through GPS module, location information of vehicle is
positioned, which will help navigation software to com-
pute the shortest path to charging/battery-swap infra-
structure. ZigBee module is designed to realize guidance
in station. Through communication with short distance
wireless devices in station, EVs are guided to the target
spot. Besides, out of communication security, security
chip is integrated to encrypt sensitivity data.
4.6. Human Computer Interaction Unit
Human computer interaction unit cons ists of display, I/O
and audio, by means of which EVT communicate with
consumer. Moreover, this unit makes control to EVT
come true.
5. Conclusions
EVT is significant device for OMS to lay on correlative
services. Through EVT can consumers enjoy convenient
value-added services? Besides, EVT provides valuable
experimental data for research on EV and power battery.
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