Some differences between new energy vehicle cables and ordinary vehicle cables

2022-01-23
Some differences between new energy vehicle cables and ordinary vehicle cables
The differences between new energy vehicle cables and ordinary vehicle cables,  
 
new energy vehicle cables manufacturer

What is the new new energy vehicle cables? 
The new engy cable has 2 definitions,
1: it is made of one or more insulated conductors and wrapped with insulating protective layer, and power or information is transmitted from one place to another. 
2: rope like new energy cables are usually twisted by several wires or groups of wires (at least two in each group). Each set of wires is insulated from each other and often twisted around a center. The entire exterior is covered with a highly insulating covering. New energy cables have the characteristics of internal and external insulation.



1, high voltage and high current (vehicle)  
 
Up to 600/300A, while the traditional fuel car battery voltage is generally 12V, the corresponding wire voltage grade is less than 60V.  
 
2. Large wire diameter and large number of cables (vehicle-mounted)  
 
High voltage battery inverter transformer/low voltage battery/air conditioner compressor/electric heating/power distribution unit...  A large number of electrical structures are connected by cables, resulting in a large number of cables in a limited space.  
 
3. Exposed space (not vehicle-mounted)  
 
The cables of the charging gun are exposed in an exposed space for a long time, and have weather resistance, wear resistance, bending resistance, tear resistance...  There are strict requirements.  
 
Due to the characteristics of large voltage/current, large wire diameter and large number of wires, the design of the high-voltage wire harness in the car faces challenges such as wiring, safety, shielding, weight and cost.  
 
1, wiring 
 
The layout of the high-voltage wiring harness in the car has the following requirements  
 
(1) Under static load, the minimum turning radius is 4 times the outer diameter of the wire  
 
(2) Under dynamic load, the minimum turning radius is 8 times the outer diameter of the wire  
 
(3) The distance between high and low voltage conductors shall not be less than 100mm  
 
(4) The distance between the outlet end of the high voltage connector and the first fixed point is not more than 100mm  
 
The distance between adjacent fixed points should not exceed 150 mm to 200mm  
 
(5) High-voltage wiring harness should be arranged under the car as far as possible  
 
(6) Choose ductile wires such as silicone rubber wires and flexible crosslinked polyolefin wires  

2, security,  
 
High voltage and high current, in addition to its high voltage has strict requirements on insulation performance, high temperature caused by high current is also inevitable to consider a point.  
 
(1) Wire selection  
 
Adopts high voltage wire 600 v900v (AC) (see | SO19  
 
Adopt wall thickness high line, wall thickness 0.6mm-1.1mm  
 
Heat resistant wire, heat resistant 150 degrees or above: silicone rubber wire, crosslinked polyethylene crosslinked polyolefin material, excellent flame retardant effect.  
 
(2) sealing  
 
Matching with high pressure connector, sealing to achieve waterproof and dustproof (IP67,IP69K) wire requirements have good roundness, size stability, aging performance  
 
3, block  
 
The reason high voltage harness requires electromagnetic shielding is that  
 
● High voltage and large AC current produce electromagnetic interference  
 
● The rapid on-off of electrical components produces electromagnetic interference  
 
High voltage wiring harness shielding electromagnetic interference measures include:  
 
(1) Through the selection of shielded wire  
 
The ultra-high current and voltage of electric vehicles will produce a great electromagnetic induction phenomenon during operation. If the electromagnetic shielding problem is not well solved, it is bound to affect the performance of automotive electronic equipment. Therefore, it is a good choice to choose shielded wire as the high voltage line of electric vehicles for electromagnetic shielding.  
 
The shielded wire is braided by multiple strands of tin-plated annealed copper wire. The fine copper wire can keep the flexibility of the design and has a coverage rate of more than 90%. Reasonable insulation and sheath peeling force should be controlled to meet the requirements of wire stripping.  
 
(2) Bundle Shielding as a whole  
 
It is used to protect the wire bundle from electromagnetic interference when a light braided metal shield is fixed on the outside of the wire bundle as a shielding member.  At present, it is mostly used by Japanese OEM.  
 
(3) Aluminum tube shielding one wire directly into the aluminum tube, currently mostly used by Japanese and American OEM.  
 
4. Weight and cost  
 
(1) For new energy vehicles, lightweight is very important for the improvement of mileage, so the weight of wire harness can be started with the selection of materials. New conductor materials can be used as conductor, such as new aluminum conductor: insulation materials can be used as low-density materials, while thin-walled processing.  
 
(2) The current in-car high-voltage wires are mainly imported, and the threshold of wires is high. The production of early-stage mass production models is less, and new energy vehicles are facing greater cost pressure, so more domestic resources need to be developed.  
 
5, environmental protection  
 
Low volatile, low VOC and low odor materials are needed for the high voltage wiring harness in the car.  
 
Material selection and requirements of new energy cables  
 
Because of the high voltage and large current in the vehicle of new energy and the limited space, the charging pile cable is exposed outdoors for a long time, and the particularity of the use environment puts forward very strict requirements on the performance of the cable material.  New energy vehicle cables need to have high and low temperature resistance, oil resistance, water resistance, flame retardant, tear resistance, insulation, UV aging resistance and other properties.  Commonly used materials are TPE, TPU, XLPO, NBR+PVC, neoprene rubber, silicone rubber and so on.  
 
1, TPE  
 
TPE thermoplastic elastomer, also known as thermoplastic rubber TPR.  
 
The categories of TPE include: styrene, olefin, diene, vinyl chloride, polyester, ester, amide, organic fluorine, organic silicon and ethylene (TPS, TPU, TPO, TPV, etc.).  Most of the elastomers used at present refer to SEBS as the base material.  TPE is used for charging gun cables  
 
Advantages: simple processing technology, low density, moderate price, the whole cable is very soft, can meet the existing requirements of various standards.  
 
Disadvantages: mostly contains unsaturated keys, temperature qualitative difference;  Low oil resistance, especially gasoline;  Poor weather resistance, poor thermal stability of materials for long-term use, mechanical properties of materials under high temperature conditions decline a lot, outdoor use of cracking risk;  Not able to dirty, sticky hands.  
 
Working temperature: cold-resistant -50 degrees;  Temperature less than 120 degrees.  
 
2, TPU  
 
TPU, namely thermoplastic polyurethane elastomer, molecular structure is divided into polyester type and polyether type, composed of rigid block and flexible chain segment, in the processing process of injection molding accounted for more than 40%, extrusion molding about 35%;  The spring stretch length can reach the original spring length 2-6 times.  
 
The polyurethane sheath material of charging pile cable is made of TPU tree ester as the main material, adding environmental protection or halogen-free flame retardant, antioxidant and other additives through mixing, plasticizing and granulation. It has the characteristics of flexibility, rolling resistance, voltage resistance, high temperature pressure resistance, aging resistance, acid and alkali resistance, salt spray resistance and water resistance.  
 
Advantages: excellent high tension, high tension, toughness and aging resistance, environmental protection material.  
 
Disadvantages: at present, domestic processing is difficult, raw material enterprises are less, the cost is higher.  
 
Working temperature: cold-resistant -40 degrees;  Temperature up to 150 degrees.  
 
3. Polyvinyl chloride elastomer  
 
PVC PVC cable, based on PVC resin, by adding different amounts of plasticizer to adjust its softness, reduce its "glass" temperature, so as to have good softness, but also increase plasticity, make it easy to process molding.  
 
After crosslinking, the chain segment forms a network structure, and the elastic stretch length can reach 2-4 times the length of the original spring.  
 
Advantages: flame retardant and insulation, acid resistance, oil resistance, easy processing and modification, cheap.  
 
Disadvantages: Black smoke and HCl gas when burning.  
 
Working temperature: cold-resistant -40 degrees;  Temperature within 105 degrees (according to customer requirements).  
 
4, silicone rubber  
 
AGR silicone rubber cable processed by silica gel material, good elasticity, suitable temperature range of -60℃-200℃ voltage :300/500V Conductor material: the process principle is similar to rubber, through mixing, high pressure molding and other processes.  
 
Advantages: heat resistance, cold resistance and weather resistance, waterproof, flexible, easy to install.  
 
Disadvantages: oil resistance, poor tear resistance, more expensive price.  
 
Working temperature: cold-resistant -40 degrees;  Temperature within 200 degrees.  
 
5 described.properties,  
 
XLPE crosslinked polyethylene is a kind of physical or chemical method to change the molecular structure of XLPE insulating material from linear molecular structure to linear mesh structure.  PE is the base resin and silane is the bridge material.  
 
Advantages: high crosslinking, good flexibility, good insulation, light structure, easy installation, cheap.  
 
Disadvantages: poor heat resistance, color difference between batches difficult to control.  
 
Working temperature: cold-resistant -50 degrees;  Temperature less than 100 degrees.