There are some differences between the high voltage cables of new energy automobiles and those of ordinary automobiles, mainly due to the great changes in the usage environment.
1. High Voltage and High Current (Car)
It can reach 600/300A, but the battery voltage of conventional fuel vehicles is usually 12V, and the corresponding conductor resistance level is less than 60V.
2. Large diameter and large number of cables (in vehicle)
High Voltage Battery Frequency Converter/Low Voltage Battery/Air Conditioning Compressor/Electric Heating/Power Supply Allocation Sheet, many electrical structures are connected by cables, and large cables are configured in limited space.
3. Exposure space (outside vehicle)
The cables of the charging gun part are exposed for a long time, and they are weatherproof, wear resistant, bend resistant, tear resistant...There are strict requirements.
Because the high voltage harness in the car has the characteristics of high voltage/current and large number of wire diameter, the harness design is facing challenges such as wiring, safety, shielding, weight and cost.
The layout requirements of the new energy automobile high voltage cable car are as follows:
(1) Traverse outer diameter 4 times the minimum turning radius under static load
(2) Under dynamic load, the outer diameter of the traverse is 8 times the minimum turning radius
(3) The minimum spacing between high and low voltage wires is more than 100mm
(4) The distance from the end of the high voltage connection to the initial fixed point is less than 100 mm.
The distance between adjacent fixed points is generally less than 150~200mm
(5) Place the high voltage Harness under the car as far as possible
(6) Wire selection of flexible wires such as silicone rubber wires and flexible crosslinked polyolefin wires
High voltage and high current, in addition to its own high voltage has strict requirements on insulation performance, the high temperature caused by high current is also an inevitable point to consider.
(1) Traverse selection
600V900V (AC) with high voltage conductor
Use wall thickness high line, wall thickness 0.6mm-1.1mm
Heat resistant cord, heat resistant more than 150 degrees: Silicone rubber cord, cross-linked polyethylene cross-linked polyolefin material, with excellent flame retardant effect.
In order to cooperate with high-pressure connectors, the seals are waterproof and dust-proof (IP67, IP69K), and the wires require dimension stability, good roundness and aging performance.
The reason why high voltage harness needs electromagnetic shielding is
Electric and Magnetic Field Noise Caused by High Voltage and Large AC Current
Electromagnetic interference caused by fast power-on and cut-off of electrical components