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Research on Electric Shock Prevention and First
Aid for Electric Vehicles
Guo Hao
Tianjin University of Technology and Education
School of Automotive And Transportation
Tianjin, China
LingxiaoYang
Tianjin University of Technology and Education
School of Automotive And Transportation
Tianjin, China
Abstract—This paper analyzes the harm of electric current
to human body and the person electric shock hazard may occur
during the process of using electric vehicles, puts forward
measures to prevent people from electric shock, and introduces
the correct method of On-the-spot rescue in case of the electric
shock accidents.
Keywords—Electric vehicles; electrical safety; first aid
I. INTRODUCTION
The traction battery supplies power to the drive motor, and
the motor drives the wheels. The entire drive system, it
includes traction battery, the converter, the drive motor, the
transmission and the power cable. Additional auxiliary
equipment also includes electric air conditioning compressor.
These high-voltage components work at a voltage up to be
200-600v. AC voltage greater than 25V, DC voltage more
than 60V will pose a threat to human life. Therefore, once the
electric vehicle caused a person to electric shock; the person is
very dangerous. In the design of the electric vehicle, the direct
protection and indirect protection should be adopted to reduce
the probability of electric shock and the harm to the human
body. [1] However, some uncertainties (e.g. Aging and
corroded power cables, damaged power cable insulation, and
Incorrect Operation by Maintenance Staff, etc.) may pose a
threat to the lives of people during normal operating
conditions and maintenance. The paper is organized as
follows. Detailed theoretical analysis is reported for Electrical
safety of electric vehicles in the next section. Preventive
measures of the electric shock accidents from different aspects
in the subsequent section. This is followed by the First aid
method of the electric shock accidents. The conclusions are
given in the last section.
II. THE OCCURRENCE OF THE ELECTRIC SHOCK
ACCIDENTS
A. Electrical Hazards of High-voltage Systems in Electric
Vehicles
Electric currents through the human body can cause
electric shocks, breath and heartbeat interruptions, burns and
permanent bodily injury and even death. In the IEC 60479-1,
The relationship between the current flowing through the
human body and the duration of the current on human
physiological effects is given, as shown in Figure 1.
In the AC-1 area, the flow of current through the human
body is 0-0.5mA and does not adversely affect the human
body. The AC-2 area, 0.5-2mA, you can feel the current; 3-5
mA, the body feels pain, but can still get rid of the electric
shock conductor at this time; 10-20 mA, the current will
trigger muscle spasms. The human body cannot actively
control the muscle, resulting in a prolonged electric shock
time; in the AC-3 area, electric currents can cause shock
personnel to breathe difficult and arrhythmia; in the AC-4
area, electrical currents can cause cardiac fibrillation, cardiac
arrest and stop breathing, risking life during this time. [2]. The
different consequences depend on the voltage of the contact
position of the electric shock, the flow of current through the
human body and the current frequency. Usually, the most
dangerous is that the current path is from hand through the
heart to foot.
AC power flow through the body will ca`use the risk of
arrhythmia. Lower frequency of AC, the more damage to the
human body. Direct current mainly causes chemical reaction
inside a human body in the electric shock accident.
Fig. 1. The relationship between current and current duration of the human
body
The human body resistance will be different because of
sex, individual difference or skin's wet and dry degree and so
on, in which the skin is dry, the human body resistance can be
as high as 100,000Ω, but in the case of sweat or wet skin, the
body resistance has about 1,000 Ω. In theoretical studies, the
selection of the human body resistance is approximately
1,000. Assuming that the high-voltage direct current on the
electric vehicle is 300V, according to the Ohm's law, the
current flow through the human body is 300mA, according to
the figure 1, if the current cannot be cut in a short period of
time, Electric shockers may have a life threat.
International Journal of Engineering Research & Technology (IJERT)
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B. Common Electric Shock Forms for Electric Vehicles
The Electric shock means that there is an electric potential
difference at both ends of the person's contact and the current
flows through the body.In order to protect the safety of the
electric vehicle users and maintenance personnel, the electric
shock protection mainly includes direct and indirect contacts,
in which direct contact refers to contact with parts normally
operation, for example, the personnel directly contact with the
high-voltage terminals. Indirect contact refers to a contact
with an electrically charged device that is not electrically
charged under normal conditions, but because of an insulating
fault, such as a person with a shell of a leakage device. Direct
contact protection can be regarded as the basic protection,
which is the protection before the failure, for example, the
insulating layer outside the high-voltage cable. Indirect
contact protection is to minimize the damage to the human
body caused by the failure of the basic protection, which
belongs to the protection after the failure, such as the
equipotential connection between each high-voltage
component.
If the poles of the electric vehicle battery are isolated from
the chassis, the failure of the basic insulation of exposed
conductive components (i.e. metal enclosure of equipment)
does not pose a threat to the safety of personnel in contact
with the electric vehicle.
In the design of the electric vehicle, the traction battery
and the high-voltage components adopt the IT topology as
shown in the Figure 2, When the electric energy is
transmitted, the high-voltage passes through the positive pole
of the high-voltage power battery to each high-voltage
element, and then goes back to the negative pole of the
traction battery. During the whole transmission process, the
current does not flow into the chassis, with the supply circuit
isolated from the chassis. The equipotential bonding wire
connects the metal enclosure of each high-voltage component
to the chassis by welding or bolting [3].
When the metal enclosure of high-voltage component is
charged, the current flows through the equipotential bonding
wire to the chassis, thus ensuring that current do not flow
through the body when the person touches both the charged
enclosure and the chassis. At this time, the system can still
work. As shown in picture 2.
Fig. 2. The first failure occurs and the person is not electrocuted
When two high-voltage components of the enclosure at the
same time charged, even if the human body at the same time
contact with the two charged enclosure, electric current forms
current circuit in the equipotential bonding line, and will not
flow through the human body, at this time, the entire system
short-circuit, fuse blows in the high-voltage system, and the
electric current is cut off. As shown in Figure 3.
Fig. 3. The person does not get an electric shock when the second fault
occurs and the equipotential bonding line is well connected.
During the use of electric vehicles, the equipotential
bonding wire aging, wear, insulating layer rupture or cable
rupture, and equipotential bonding point damp rust or
connecting bolts loose or falling off by the body vibration and
other uncertainties caused by poor insulation or failure, at the
same time, high voltage components of internal damage or
humidity will make the enclosure of High-voltage components
charged, If the human body contact with two charged high-
voltage component enclosure, the current cannot normally
through the equipotential bonding wire to the chassis. There is
a potential difference at both ends of the contact, the current
flow through the human body, causing an electric shock
accident. As shown in Figure 4.
Fig. 4. When the equipotential bonding line fails, the person is at risk of
electric shock
International Journal of Engineering Research & Technology (IJERT)
ISSN: 2278-0181http://www.ijert.org
IJERTV8IS010003 (This work is licensed under a Creative Commons Attribution 4.0 International License.)
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III. THE PREVENTION OF THE ELECTRIC SHOCK
ACCIDENTS
Through the above analysis, once the electric shock
accident, the life safety of electric shock personnel poses a
serious threat, in the normal use of electric vehicles and
maintenance process, should be as far as possible to reduce the
probability of accidents, in addition to the electric vehicle
high-voltage components to the personnel shock protection
design, here are some measures to prevent electric shock
accidents.
A. Remote Monitoring Platforms
In accordance with the provisions of Article 17 of the
regulations regarding the admission of New Energy
Automobile Manufacturers and products issued by the
Ministry of Industry and Information Technology of the
people's Republic of China in January 2017, the New Energy
Automobile Manufacturers should establish a monitoring
platform for the running safety condition of new energy
automobile products. According to the agreement with new
energy automobile product users, the running safety status of
all new energy vehicle products that have been sold is
monitored. Enterprise monitoring platform should be
connected with local and national new energy vehicle
monitoring platform docking [4]. The existing monitoring
platform is mainly composed of electric vehicle terminal,
enterprise Monitoring Platform server, enterprise monitoring
Platform data processing platform, national or local
monitoring platform, the main structure as shown in Figure 5.
The remote monitoring platform analyzes the operating
parameters of the high-voltage components uploaded by the
vehicle terminal. Judges its working status, predicts the
possible faults, and sends warning messages to the vehicle
terminal to remind the driver.
Fig. 5. Remote monitoring platform architecture for electric vehicles.
B. System of Monitor the Insulation Fault
The insulation resistance between the high-voltage
components and the chassis is too small due to the bad
operating environment during the use of electric vehicles,
which will threaten the lives of drivers and passengers.
However, not all high-voltage systems of electric vehicles
include insulation monitoring systems. The high-voltage
insulation monitoring systems of electric vehicles should
continuously or intermittently monitor the insulation
resistance of the entire high-voltage system, if a decrease as
the insulation resistance is found, a warning should be issued,
then disconnect the high-voltage system according to the
running state of the vehicle or restrict the activation of the
high-voltage system.
C. High-voltage Operation Training
In the maintenance of electric vehicles, the maintenance
personnel must undergo complete high-voltage operation
training and obtain the qualification certification of high-
voltage maintenance personnel. At the same time, in the
maintenance operation, maintenance personnel shall wear
protective equipment and work strictly in accordance with the
operational specifications. Professional maintenance personnel
should remind drivers and passengers not to blindly touch the
orange high-voltage power line or the high-voltage
components connected to it on the electric car during use.
IV. ON-THE-SPOT RESCUE OF THE ELECTRIC
SHOCK ACCIDENTS
After When an electric shock happens, first of all, keep
calm, and when you are in direct contact to a person who is
not separated from the conductor, you will also be
electrocuted. Therefore, according to the correct rescue
process, the electroshock personnel can be rescued in the
shortest time, and the safety of the rescuers can be guaranteed.
The correct On-the-spot rescue process is shown in figure 6.
Fig. 6. On-the-spot rescue process of the electric shock accidents
International Journal of Engineering Research & Technology (IJERT)
ISSN: 2278-0181http://www.ijert.org
IJERTV8IS010003 (This work is licensed under a Creative Commons Attribution 4.0 International License.)
Published by :
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V. CONCLUSION
This paper introduces the possible electrical hazards and
the form of electric shock that may exist in the use of electric
vehicles and expounds how to prevent electric shock
accidents in the design of electric vehicles and use of electric
vehicles. If people are electrocuted and how to correctly
rescue, this paper puts forward some guidance.
REFERENCES
[1] Freschi, Fabio , M. Mitolo , and R. Tommasini . “Electrical safety of
electric vehicles. ” Industrial & Commercial Power Systems Technical
Conference IEEE, 2017.
[2] IEC TS 60479-1: “Effects of current on human beings and livestock.
Part 1: General aspects. ” 4th Ed., 2005.
[3] Zhao Jiawang, Liu Guibin, Zhou Rong. “Research on the protection of
electric shock for electric vehicles, ”Automotive Applied Technology,
pp. 22-24,2016
[4] Ministry of Industry and Information Technology of the People's
Republic of China, “New energy vehicle production enterprises and
product access management regulations. ” 2017: 1-17.
[5] ISO 6469-2:2009, “Electric road vehicles - Safety specifications - Part
2: Vehicle operational safety means and protection against failures”
[6] ISO 6469-3:2011, “Electrically propelled road vehicles. Safety
specifications -Part 3: Protection of persons against electric shock.”
International Journal of Engineering Research & Technology (IJERT)
ISSN: 2278-0181http://www.ijert.org
IJERTV8IS010003 (This work is licensed under a Creative Commons Attribution 4.0 International License.)
Published by :
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Vol. 8 Issue 01, January-2019
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