As electric vehicles (EVs) continue to gain popularity, the importance of selecting the right high-voltage cable cannot be overstated. These cables are responsible for transmitting power between the battery pack and various electric systems, and their proper selection is crucial for ensuring the safety, performance, and reliability of the vehicle. This article will provide some useful tips on choosing high-voltage cables for electric vehicles.

1. Cable Size Selection

1.1 Factors to Consider

The cable size selection mainly refers to the following factors:

• Conductor design standards: Such as LV216 – 1/2, ISO19642 and other standards. These standards ensure the quality and performance of the conductor.
• Working voltage platforms and voltage ranges: The working voltage platform of the high – voltage conductor needs to be verified. Currently, the general voltage platform is below 1000V DC, so high – voltage conductors with a resistance of 1000V DC are often used.
• Effective working current of the loop: It is necessary to determine the effective working current of the loop to ensure that the cable can handle the current without overheating.
• Working environment temperature: The working environment temperature of high – voltage conductors has a significant impact on cable performance. High current transmission leads to high power consumption and increased temperature rise of related components. If the cable layout environment exceeds the allowable operating temperature of the cable, a cable with a larger cross – sectional area must be selected. For example, when Tmax reaches 180°C, the cross – sectional area of the conductor needs to be raised to one gear, and when Tmax reaches 250°C, the cross – sectional area of the conductor needs to be raised to the second gear.
• Circuit peak current and peak duration: Compare the peak current, peak duration and conductor smoke curve. The peak duration should be less than the conductor smoke time.
• Circuit fuse capacity: The fuse capacity should be considered to ensure that in case of an over – current situation, the fuse can blow in time to protect the cable and the entire circuit.
• Allowable crimping diameter of high – voltage harness plug – ins: The cable size should match the allowable crimping diameter of the high – voltage harness plug – ins.

1.2 Selection Steps

The basic steps for high – voltage conductor selection are as follows:

1. Verify the working voltage platform: As mentioned above, ensure that the cable can withstand the system’s voltage.
2. Select the conductor diameter based on temperature rise curve: Combine the conductor current – carrying capacity and the working environment temperature to select the appropriate conductor diameter.
3. Compare peak current and duration with smoke curve: Ensure that the cable can handle the peak current within a safe time limit.
4. Compare fuse blowing time and conductor smoke time: The conductor smoke time should be greater than the fuse blowing time to ensure safety.
5. Confirm with plug – ins: After preliminarily determining the conductor diameter, combine the high – voltage plug – in model and specification to confirm whether the conductor can be used, especially verify that the high – voltage plug – ins on both sides of the conductor meet the requirements.

2. Jacket Material Selection

2.1 Silicone Cable

Silicone cable is soft and has good temperature resistance, but poor tear and oil resistance. It is recommended in the following environments:

• High – temperature areas: Areas where the working environment temperature is greater than 150°C.
• Small layout space: Areas where the wiring harness layout space is small and the complete radius does not meet 5D, or areas where the softness of the wiring harness is strictly required due to assembly requirements.
• Good protection areas: Areas with better protection of high – voltage harnesses, no oil and no wear.
• Specific plug – in requirements: Areas with clear use requirements for high – voltage plug – ins.

2.2 Cross – linked Polyolefin (XLPO) Cable

Cross – linked polyolefin (XLPO) cable is harder in material, has good wear and tear resistance, and is of low cost, but has poor softness and temperature resistance. It is suitable for the following environments:

• Moderate – temperature areas: The working environment temperature is not greater than 150°C.
• Large layout space: The wiring harness layout space is large, the complete radius≥5D, or there is no difficulty in wiring harness assembly.
• Harsh environments: The wiring harness may come into contact with oil, or the wear and vibration amplitude is large.
• Specific plug – in requirements: There are clear usage requirements for high – voltage plug – ins.

3. Other Considerations

3.1 Flame Retardancy

If there is a flame retardant requirement for the cable, you can choose HB or V0 grade cable. This is important for ensuring the safety of the vehicle in case of a fire.

3.2 Shielding

If there are requirements for shielding, you can choose unshielded cable, single – layer shielded cable, double – layer shielded cable, and the shielding density of the cable can be defined according to the shielding requirements. Generally, the shielding density is above 85%. High – voltage screened EV cables are equipped with shielding to protect against electromagnetic interference (EMI), which can arise from various sources, including other electrical components within the vehicle or external sources. The shielding consists of a conductive layer surrounding the high – voltage cable, which helps contain and dissipate EMI, preventing its interference with other electronic systems and ensuring reliable operation.

3.3 Cable Length and Connection

When selecting high – voltage cables, it is important to choose the appropriate length of high – voltage cable according to the design and layout of the vehicle. Suitable lengths simplify the installation process and increase the reliability of the cable. Also, ensure that the connection method and connectors meet the requirements of the vehicle system. For example, the high – voltage connectors should consider electrical performance (rated operating voltage, rated operating current, insulation resistance, withstand voltage level, shielding and interlocking), environmental performance (working temperature, ambient temperature, salt spray level, flame retardant level, resistance to solution reagents, and prohibited substances), mechanical properties (vibration resistance and mechanical life), and safety performance (high – voltage interlock).

3.4 Compliance with Standards

It is important to ensure that the cables comply with relevant safety certification standards and regulations, such as national or regional product certifications, International Electrotechnical Commission (IEC) standards, ISO 6469, IEC 62955, SAE J1772, etc. These certifications guarantee the quality and safety performance of high – voltage cables.

In conclusion, choosing the right high – voltage cable for an electric vehicle requires a comprehensive consideration of various factors. By following these tips, you can select a cable that meets the vehicle’s requirements, ensuring its safety, performance, and reliability.