How does the electric vehicle DC contactor work? How to connect?

Electric vehicle DC contactor is mainly used to control DC circuits (main circuit, control circuit, excitation circuit, etc.). Unlike AC contactors, the iron core of DC contactors has no eddy currents, so it is generally made of low carbon steel or industrial pure iron.

Since the attracting coil of the electric vehicle DC contactor is energized by DC, there is no impact starting current and severe impact of the iron core, so the service life is long and it is suitable for frequent start and stop occasions. The selection of AC and DC contactors can be checked according to the working voltage and current of the line.

When the coil of the electric vehicle DC contactor is energized (generally 12V or 24V voltage), the coil current will generate a magnetic field, which will cause the static iron core to generate electromagnetic attraction to attract the moving iron core, thereby driving the contact action: open the normally closed contact, Close the normally open contacts and link with each other. When the coil is de-energized, the electromagnetic attraction disappears, and the moving iron core is released under the action of the "compression spring", so that the contact is reset: the normally open contact is opened, and the normally closed contact is closed.

When the contactor coil is energized, the coil current will generate a magnetic field, which causes the static iron core to generate electromagnetic attraction to attract the moving iron core, thereby driving the contact: movement. The normally closed contact is disconnected and the normally open contact is closed, and the two are linked. When the coil is de-energized, the electromagnetic attraction disappears, and the armature is released under the action of the release spring, so that the contact returns: the normally open contact is opened, and the normally closed contact is closed.

Electric vehicle DC contactor is often used in DC circuits that require remote control switches, and in motors that require frequent start, stop, commutation and reverse braking DC. They mainly play the role of frequent switch lifting electromagnet, solenoid valve and clutch solenoid.

When the coil of the DC contactor of the electric vehicle is turned on, the current of the coil will generate an electromagnetic field, which will cause the stationary transformer core to attract the moving transformer core through electromagnetic induction adsorption force, push the contact posture of the DC contactor, and open The normally closed contact closes the delay relay, and the two are linked.

How to connect the DC contactor of the electric vehicle?

T1 and T2 are separately excited windings; H1 and H2 are speed control windings. Separate excitation connection mode: T1 and T2 are respectively connected to the positive and negative poles of the power supply system; H1 and H2 are respectively connected to the positive and negative poles of the power supply system, and parallel mode: T1 and H1 are connected to the anode stage; T2 and H2 are connected to the negative phase. Swap positive and negative.

When energized, the current of the coil will generate an electromagnetic field, so that the stationary transformer core attracts the moving transformer core through electromagnetic induction adsorption force, pushes the contact posture of the DC contactor, opens the normally closed contact, and closes the delay relay.

In the whole process, the coil itself has a resistance, which continuously consumes electromagnetic energy. This is one of the key application costs of DC contactors for electric vehicles, wasting a lot of power and assets. Therefore, how to reduce the energy consumption of DC contactor for electric vehicles is the key link and key difficulty of DC contactor research.

The permanent magnet operating structure of the electric vehicle DC contactor is a composite operating structure, which is basically developed from the electromagnetic induction operating structure of the traditional DC contactor. It combines the electromagnetic induction operation structure closely with the permanent magnet. It not only uses the original electromagnetic induction adsorption force and elastic yellow axis force as the driving force for the iron core to attract and separate, but also increases the attraction of the permanent magnet to the iron core. Energy storage technology is used to charge capacitors and batteries to display reclosing and attract electricity, commonly known as "electromagnetic induction operation, permanent magnet maintenance and electronic device operation".