In recent years, new energy vehicles and charging facilities have developed rapidly, and the market capacity of key electronic components has also expanded. In response to the special needs of this emerging industry, how do DC electrical equipment design engineers such as automotive design and charging piles design the right electronic components for their design? What are the main key points to focus on? This article is based on product application and product adaptability, the following is introduced by the electrolytic capacitor manufacturers.
First, the provisions of electric vehicle charging equipment [GB/T 18487.1 4.4]:
Electric vehicle power supply equipment is classified according to output voltage:
AC: single phase 220V, three phase 380V;
DC: 200V‐500V, 350V‐700V, 500V‐950V.
DC charging current preferred values: 80A, 100A, 125A, 160A, 200A, 250A.
Note: Power supply equipment above 950V is determined by the vehicle manufacturer and the power supply equipment manufacturer.
It can be seen from the above standards that the commercial and passenger electric vehicles have the basic characteristics of high voltage and high current, so high reliability and high insulation voltage are required. Different from ordinary industrial products, it also requires professional manufacturing processes such as vacuuming, gas filling, pressure sealing and intelligent control in manufacturing. It has high requirements on design technology and manufacturing technology.
Second, the application in new energy vehicles, charging piles (machines)
1. Application in charging pile (machine): for DC charging pile, DC output side of charging station or output side for vehicle charger. When the contactor is closed, the charging pile and the automobile are connected; when disconnected, the connection between the charging pile and the outside is isolated to provide a safety protection function.
2. Application in electric vehicles: DC contactors are arranged between the battery system of the electric vehicle and the inverter. When the system stops running, it acts as an isolation function. When the system is running, it acts as a connection. When the vehicle is shut down or fails, the energy storage system can be safely separated from the vehicle electrical system and function as a breaking circuit. Used as a power control device in other auxiliary circuits.
Important technical indicators:
a) The isolated power supply end and the load end function after the system stops running; (Important technical specifications: rated insulation voltage Ui)
b) Connect the power supply end and the load end when the system is running; (Important technical indicators: agreed heating current Ith)
c) The function of the breaking circuit at the time of the fault. (Important technical indicators: maximum operating voltage U)
Third, the product's adaptive design
1. Environmental adaptability design: Different from general industrial component products, the environmental conditions are more demanding for the adaptor of electric vehicle contactors, and must meet the basic conditions of wide temperature range, high protection level and high vibration resistance. .
1) High and low temperature design: It is required to meet the temperature requirements of electric vehicles and charging piles (machines) for normal use in extreme weather. Product storage ambient temperature: -55~+125°C, normal working environment temperature is -25~+40°C, and the ambient temperature is -40~+85°C under extreme conditions.
2) Protection level design: It needs to meet the normal work under harsh environmental conditions, and it can be used normally under rain and dust environment. The product completely prevents dust from entering, meets the requirements of short-term water immersion, and the protection grade reaches IP67.
3) Anti-vibration performance design: The product needs to have strong vibration resistance and impact resistance. Meet the special needs of cars used in bumpy vibrations of various road conditions.