Do you need to do radiation protection when using an electric car?

Does the electric car battery pack have radiation is it harmful to the human body? What is more to say that children and pregnant women are not suitable for electric vehicles? As more and more electric cars enter the homes of ordinary people, how can we know if the batteries that we buy for electric vehicles have radiation? What is the standard value of radiation, and do you need to do radiation protection for daily use of electric vehicles? In response to these questions, let us hear how the experts answer.

1. The electromagnetic level of electric vehicles is much lower than that of common electric appliances.

First of all, we have to understand a concept, what is radiation, what kind of it, and what kind of radiation value is harmful to the human body? Radiation includes both ionizing radiation and non-ionizing radiation, which isspecial radiation that people often hear, such as X-rays. In addition, non-ionizing equipment includes part ofspecial power, infrared, broadcast television, household appliances, and the like.

The effect of radiation on the human body mainly consists of two parts. The first part is that when the frequency is lower than 100 Hz, it mainly affects the human body through the induced electric field and the induced magnetic field. The second part is the thermal effect on the human body when the frequency is higher. , such as infrared rays, it can cause heat to form a thermal effect on the body.

As for the induced electric field and the induced magnetic field, such as the induced current, it is the same as the high-voltage current, which affects the electrical signal of the human body. The World Health Organization (WHO) pointed out that for the role of living organisms, electromagnetic sources of different frequencies have different effects on the human body, andspecial radiation and non-ionizing radiation cannot be mixed together. How much impact on the organism depends on the wavelength (frequency) and its energy, and it only has a detrimental effect on health when it exceeds the biological action of the body's compensation mechanism.

Huang Wei, manager of the high-voltage electronic and electrical department of Tengshi R&D Department, said that the concept of electromagnetic radiation is very extensive, from radio tospecial radiation, and even visible light is also a range of radiation. The influence of electromagnetic environment exposure on living organisms depends on the wavelength (frequency) of the electromagnetic source and the magnitude of its energy. Only biological effects that exceed the human compensation mechanism will have a harmful effect on health.

In daily life, it is difficult for ordinary people to have access to “nuclear radiation”, and “medical radiation” is also operated under a specific process, and the impact is not severe, but as for “radiation” such as mobile phones, microwave ovens, and hair dryers. Not in the category of "ionizing radiation", they belong to "electromagnetic radiation" or "non-ionizing radiation", and the damage to the human body is minimal.

According to the UN International Health Organization safety standards for electromagnetic radiation electromagnetic fields, the electric field radiation safety standard is 5000V/m, and the magnetic field radiation safety standard is 100μT. That is to say, as long as ordinary household appliances have data below 5000V/m and 100μT, the radiation value is within the safe range.

According to the data, electronic products, including mobile phones, chargers, and computers, all have magnetic fields, which are about 4μT. According to the previous professional test results, the highest magnetic field level in the Tengshi car is only 0.39μT, which is less than one tenth of most home appliances and electronic products, only 4% of the safety limit. The electromagnetic level in Tengshi pure electric vehicles is much lower than that of common electrical appliances and is lower than the EU standards and Chinese national standard limits.

2, power battery safety

Electricity is the main driving force of electric vehicles. The battery is also one of its core components. Battery safety involves the overall safety of electric vehicles. According to Huang Wei, manager of the high-voltage electronic and electrical department of R&D Department, the battery safety of Tengshi Pure Electric Vehicle is divided into three parts: battery safety, battery module safety and battery system safety. They are designed with the highest safety standards, manufactured to ensure the chemical safety and structural safety of the battery.

Unlike some electric vehicles, Tengshi's battery cells are specially developed for electric vehicles. For maximum safety, each battery cell is tested separately and then tested throughout the system and is “naked” without a protection frame. In the test process, Tengshi battery has to pass a variety of battery acupuncture, extrusion and even fire test items to ensure the safety of the battery pack in the event of a short circuit caused by an accident. In addition, the aluminum alloy frame structure that the Tengshi R&D team provides for battery protection has undergone several rounds of optimization, including collision, simulation, and structural design. Supported by Daimler simulation and cutting-edge safety technology, Tengshi has achieved five-star results in accordance with C-NCAP's collision criteria.

While meeting safety requirements, BYD's leading battery technology allows the battery to provide up to 400 kilometers of long-range cruising range, fully meeting the needs of the owner's daily use. The design life of the Tengshi battery is the same as the life of the vehicle, and it can carry out at least 2000 full-filled electrical cycles and still have more than 80% of the battery capacity. According to a full charge, you can run for 400 kilometers. The normal life of Tengshi Battery can be at least 800,000 kilometers. "Until the car is scrapped, there is no need to worry about the battery life of Tengshi," Huang said.

3, high pressure system security

Eric Hartmann, senior engineer of Tengshi Defang, believes that in addition to battery safety design, the safety design of high-voltage components such as batteries, motors, electric controls and electric compressors used in electric vehicles is also an important part of the safety design of electric vehicles. Design is also an important factor affecting the safety of electric vehicles. Therefore, the high-pressure design of Tengshi pure electric vehicle completely adopts the Daimler high-pressure safety design requirements. The Daimler high-pressure safety design requirements are based on the recognition of the five auto companies of Mercedes-Benz, Porsche, BMW, Audi and Volkswagen set up.

At the beginning of the design, Tengshi pure electric vehicles avoid the user's touch of the high-voltage system through the structural layout. At the same time, in extreme cases, the Tengshi high-voltage system has passive and active safety measures to ensure the safety of users through functions such as monitoring, isolation and rapid discharge.

If the vehicle collides, the electric car will set up a lot of discharge mechanism. After the collision, all the electricity will be released within 2-5 seconds. Taking Tengshi as an example, it is equipped with a collision power-off mechanism, with a PW signal and a power-on signal. When two channels are simultaneously cut off, the high-voltage power can be disconnected immediately.

The reporter interviewed Huang Wei, the manager of the high-voltage electronic and electrical department of Tengshi R&D, and Eric Hartmann, senior engineer of Tengshi Defang. Regarding the battery radiation and high-voltage battery problems that everyone care about, they answered them one by one from a professional perspective.

Question 1: The battery safety just mentioned, the battery tray protects the battery. When the vehicle is hit, it does not hit the battery. If something special happens, such as rollover, tipping, bumping into the battery from below, how is the safety? kind?

Huang Wei: The tray is an important part of the whole system to protect the battery. Secondly, it also considers why the monomer is squeezed, needled and the system modules and modules. In that case, there is no battery tray protection. In this case, flat pressure, needling or different types of extrusion and acupuncture of the module are used to simulate how our battery behaves once the tray fails.

Question 2: The lithium iron phosphate battery used by Tengshi knows some of the owners of the Tengshi. They said that the vehicle's battery life will be attenuated in a low temperature environment. You write without the need to actively heat this piece. Why?

Huang Wei: There are many kinds of lithium iron phosphate batteries, each with a small difference. BYD is in this leading position, charging and discharging below minus 20 degrees, there are many lithium iron phosphate batteries cannot charge and discharge under 5, 6 degrees Celsius. In November last year, we invited the media and car owners to experience the performance of Tengshi electric vehicles in an environment of minus 20 degrees Celsius. Under such circumstances, our vehicle battery performance can still be used normally.

In addition, the reduction of the cruising range in winter depends on three aspects: 1. the battery of the current battery is not limited in any system. Under low temperature, the activity will be limited, and the charging and discharging will be less than the normal temperature. 2, winter An important aspect of the reduction in cruising range is that it consumes a lot of power for air conditioning heating. It is conceivable that, for example, our car, which runs normally for 400 kilometers, stopped for one hour on the road in the case of air conditioning in the winter, and blocked for one hour in Beijing or the North Third Ring Road and the second ring. The electricity was 5-6. Kilometers, 30 kilometers is gone. A lot of it is spent on the architecture of the PDC. 3, is to reflect people's driving habits, like the gasoline engine, rapid acceleration and rapid deceleration will lead to a large loss of electricity, we will see that in the rapid acceleration, the power will rise instantaneously, requiring a lot of power.

Based on these three points, to the customer's feeling, in winter, the cruising range will be reduced to a certain extent than normal temperature.

Question 3: In the case of rain and water accumulation, many people say that it is better to buy an SUV. For a gasoline or diesel vehicle, it is generally avoided that the steam inlet and the ignition hit the water. What is the situation regarding the wading of the electric vehicle? If this aspect is well protected, taking the city as an example, how much height does the wading reach? Is there any suggestion?

Huang Wei: We have a test for wading. The deepest depth is 70 cm. What is the concept of 70 cm water? Just in the past, the water was already on the windshield.

EricHartmann: Because the battery is waterproof, this problem is not a problem with high voltage electricity more is low pressure, which is similar to fuel vehicles.

Question 4: Is the battery of a pure electric vehicle the same as the battery of a hybrid vehicle? Is the lithium battery or nickel battery or iron phosphate battery radiation the same?

Huang Wei: The battery has nothing to do with radiation. Only current will generate radiation. No matter what battery, it is DC or AC, the frequency of AC is different, the electronic control of the car is different, plus the battery radiation, the design position and frequency of the whole vehicle, as well as the shielded wire that is started, the shielding wire is many. The succession, magnitude, etc. will have an impact.

Question 5: I have a question about voltage. In fact, we know that because electric vehicles use a lot of battery resistance, such as when it is raining or bad weather, there is lightning, there will be voltage problems. In the extreme weather, did you consider this issue?

Huang Wei: This is a very important point. The safety of high-voltage electricity is equal potential. We have active safety and will start insulation resistance, insulation withstand voltage, and other potentials. Insulation withstand voltage is to prevent the dam from being destroyed like water. The equipotentiality is to divert it, not only the water does not damage the dam, but also to divert it into a vast ocean, let it go in the way you want, and wait for the electric potential to put every voltage into a flat, when the big voltage comes together Sharing.

The page contains the contents of the machine translation.