The traditional car is powered by a gasoline engine. The role of the traditional car cable is to transmit control signals. The current and voltage bears are very small, so the diameter of the cable is small, and the structure is only external insulation of the conductor. But according to the use requirements of electric passenger car high voltage cable, electric passenger car high voltage cable mainly plays the role of energy transmission, need to transfer the energy of the battery to each subsystem, so the design of electric passenger car high voltage wiring harness must meet the high voltage and large current transmission. Electric passenger cars of high voltage cable under high voltage (the highest rated voltage 600 v), the current is larger (600 a) the highest-rated current, electromagnetic radiation is stronger, so the diameter of the cable is increased, at the same time to avoid electromagnetic radiation with a strong electromagnetic interference on the surrounding electronic equipment, affect the normal operation of other electronic devices, cable resistance to electromagnetic interference shielding structure was designed, which adopts coaxial structure, the use of inner conductor and outer conductor (block), cable into concentric circles within the magnetic field distribution, and the electric field from the inner conductor pointing and check in the outer conductor, make external electromagnetic field around the cable is zero, shielding of electromagnetic radiation, And make sure the electric car runs normally.

Usually, the connector (mainly refers to the contact parts) has the use of temperature limit, once the use of temperature exceeds the specified limit, the connector will be due to heat and reduce safety, or even failure damage. There are two main reasons for the increased use temperature of the connector:

• A. The car itself. The hottest part of a car is around the engine. For example, the temperature around a traditional car engine can reach more than 125℃.
• B. Connector itself. The connector will heat up during use, and the contact parts inserted in the connector have contact resistance. The greater the contact resistance, the greater the power loss, and the higher the temperature of the contact parts, the lower the reliability. In this regard, in the design of electric passenger cars, high voltage high current connectors need to pay special attention. To avoid the use of high temperature damaged insulation material of connector, reduce its insulation performance, even burning failure, and to make contact with a heated elastic decline, or on the contact area to form the insulating film, reduce the contact reliability, increased contact resistance, thereby deepening the use of temperature, a vicious cycle eventually leads to connect contact failure, must the reasonable design of electric passenger car large current of high voltage large current connector contact. In the design of reflecting current contact parts, the choice of contact forms will directly determine the quality and cost of the connector. Generally, the contact forms of the contact parts are mainly chip type, leaf spring type, and wire spring type. The jacks of the chip contact parts are slotted and buckled for cylindrical cylinders, and the jacks are processed by beryllium copper wire (rod).