Why DC Contactors Fit The EV Market

WHY DC CONTACTORS FIT THE EV MARKET

·        Ability to Handle High Currents & Voltages: DC contactors are built to switch very high currents and voltages. They can carry more than 500 Amps and are rated upwards of 2,000 Volts. In order to achieve this, there are several unique design features built into these DC contactors. For example, the housings are built out of resin or ceramic and hermetically sealed. Inert gasses, such as hydrogen, fill the inside arc chamber. This helps prevent oxidation, helps quench arc current, and keeps resistance low and stable. The IP67 sealed housings keep the gasses inside and prevent arc leakage, thus proving to be a great safety feature as well.

·        The Magnetic Arc Blow-Out Feature: Another feature is known as magnetic arc blow-out. Permanent magnets inside the arc chamber create a magnetic field across the contacts, driving and stretching the arc current outward, helping to extinguish it faster. Arc current is created when contacts are opened and not good for the contacts, so these magnets in combination with the gas help increase the life of the contactor. 

·        The Coil Economizer: The coil economizer is a feature that reduces coil power and heating after the contactor is energized. It takes a great deal of power to close the switch of these powerful contactors, but once closed there is not much needed to keep it closed. So electronics such as PWM (pulse width modulation) help reduce this power and heat as well.

EV APPLICATIONS FOR DC CONTACTORS

Contactors can find a home in a variety of areas in the EV world. Applications for high voltage DC contactors in the EV space include charge and pre-charge contactors, main and auxiliary power contactors, battery disconnect units, charging stations, battery packs, and energy storage systems.