The perfect and complex design and use of high-quality materials will result in expensive acsr cable costs. Experience shows that, for specific high voltage cables, it can be tailored by optimizing the cross section, temperature requirements, flexibility and shielding effect. Weight and cost savings can be highlighted, and over sized and over sized components can be avoided.
1. optimization of sectional area and temperature grade
The selection of cables is mostly based on the ambient temperature and the transmission current index. In this regard, the most important features are “cable section” and “heat resistance grade of materials used for cables”.
The voltage drop of the conductor is converted into the conductor of the high voltage cable heated by heat energy. This heat can be partially transferred to the environment, which reduces the operating temperature of the conductor. Lower temperature gradients can transfer less heat. Cables with continuous load current can cause the highest rated temperature to be borne. This temperature can cause the aging of the materials used.
The challenge for cable designers is to design the most suitable cable for application: excessive conductor specifications can lead to increased cost and weight, and larger outer diameter. In the worst case, only considering the highest possible load current and ambient temperature will result in the use of large section cables, high temperature resistant materials such as organic fluorine or silicon.
It is very meaningful to determine the relationship between current and load environment temperature from the technical and economic point of view. The real driver periodic dynamic current peak should be considered, allowing for a reasonable definition of the load current and peak current in the worst case.
A good design prerequisite is an understanding of the basic conditions, such as the need to determine the ambient temperature and cable load first.
Generally, the high-voltage cable manufacturer with large cross-section has a large inertia in terms of temperature change, so the peak current of acceleration or deceleration of vehicles will not cause the influence of a large conductor temperature.
The ability of high voltage cables to handle these peaks is usually defined by thermal overload performance, even if the short-term temperature peaks are allowed to exceed the cable temperature level defined above. Therefore, the cable does not need to be designed as a higher working temperature level, and it is unnecessary to use cables that exceed the specified working temperature.
The permanent load current and single pulse or series pulse can be considered comprehensively, together with various parameters, such as ambient temperature.
The combination of theoretical basis and practical experience can preliminarily determine, select and optimize the high voltage cable which meets the application.
2. flexibility optimization
The available space for the cable routing of the vehicle should be considered carefully. The bending radius of the vehicle in a specific area will lead to the improvement of the flexibility requirements of the whole cable. If small changes may be made in the overall design, it is very meaningful to avoid the problem of tight bending.
Cables do not have to be of the highest flexibility. The exact definition of bending force, combined with the structure and corresponding test equipment, enables the designer of the cable to create the most suitable application design. Especially for larger section cables, it is significant to reduce the cost by replacing the high flexibility design with flexible or conventional structural design.
3. optimization of shielding effect
The shielding effect defined in a certain frequency range is very necessary for the development of cables. Shielding effects without frequency information are not useful, which may lead to excessive size and expensive combination shielding for the solution, which is no longer necessary from a technical point of view.
Generally, the electric vehicle cable development and design stage can be considered by theoretical calculation. Then the shielding effect of high voltage cable is verified by means of test.
The high voltage harness of electric vehicle and traditional wiring system still have a long way to go. Specific specification requirements are usually not clearly defined, which can lead to technical complexity, and thus lead to expensive solutions.
All parties involved in the development stage must adopt system oriented method to optimize the technology and cost of high voltage cable reasonably.
These parties may include cable, connector and component suppliers, harness plants, and host plants.
The knowledge accumulation of the whole system and the specification of a high voltage cable which is oriented to the target requirements are the basis of the optimization design.
The R & D Department of cable manufacturing uses theoretical calculation and appropriate measuring equipment to verify that it is capable of developing more suitable cables for application.