Electromagnetic contactor

Abstract

The invention discloses an electromagnetic contactor. The electromagnetic contactor comprises an electromagnetic contactor main body, a contact assembly, an arc extinguishing assembly, a contact suction assembly and a coil suction control assembly, wherein the contact assembly is positioned in the electromagnetic contactor main body and includes a movable contact and a static contact; the contactsuction assembly includes a first coil, a second coil and a moving assembly; the moving assembly includes a movable iron core, a swing arm, a pressure spring and a contact fixing seat, the movable iron core is located above the first coil, a lower end of the movable iron core enters a middle portion of the first coil, an upper end is hinged to one end of the swing arm, the other end of the swing arm is hinged to the electromagnetic contactor main body, one end of the contact fixing seat is fixedly arranged on the swing arm, and the movable contact is fixedly arranged on the other end of the swing arm; when the first coil is powered on to enable the movable iron core to move downwards, the swing arm and the contact fixing seat can be driven to swing, and the movable contact is made to beatthe static contact; the coil suction control assembly includes a first travel switch; and a pressing block is fixedly arranged on the movable iron core, and after the movable iron core moves downwardsby a set distance, the pressing block extrudes a contact of the first travel switch to enable the second coil to be connected into a loop of the first coil in series.

Description

Technical field [0001] The invention belongs to the technical field of contactors, and specifically relates to an electromagnetic contactor. Background technique [0002] A converter installed in the main traction circuit on electric locomotives and other locomotives equipped with electric transmission devices. The function of the traction converter is to convert the electrical energy between the DC system and the AC system, and to control and regulate various traction motors, thereby controlling the operation of the locomotive. [0003] In order to realize the separation / closing of the auxiliary converter input terminal and the secondary auxiliary winding of the main transformer, it is necessary to install an electromagnetic contactor in the traction auxiliary converter of the power-concentrated train; although the existing electromagnetic contactor can realize the auxiliary transformer The input terminal of the current transformer and the secondary auxiliary winding of the main ...

AI Technical Summary

Problems solved by technology

[0003] In order to realize the opening / closing of the input terminal of the auxiliary converter and the secondary side auxiliary winding of the main transformer, it is necessary to install an electromagnetic contactor in the traction auxiliary converter of the centralized power train; although the existing electromagnetic contactor can realize auxiliary transformer However, due to the high voltage and large current between the input terminal of the converter and the secondary auxiliary winding of the main transformer, when the electromagnetic contactor has closing and opening switching A strong arc will be generated. In the prior art, the arc extinguishing cover is often used to extinguish the arc, but the arc extinguishing effect is not good, and the contacts and internal structures of the electromagnetic contactor are often burned by the arc, resulting in damage to the electromagnetic contactor; In addition, when the electromagnetic contactor is closed, it needs to use a coil with a larger current and a higher attractive force to start, and contact the moving contact with the static contact, but the requirements for the power and attractive force of the coil will be reduced after starting. Then only a low-power working coil is needed to maintain the continuous contact between the moving contact and the static contact under the long-term energized operation state. In order to solve this problem, the existing technology uses a starting coil to start, and after starting, it is controlled by an electronic module. Connect a resistor in series in the circuit of the starting coil to reduce the current of the starting coil to solve the above problems, but it has the problems of high resistance heat generation and low stability of the electronic module in a high-voltage environment; Finally, the arc extinguishing cover will be obviously damaged in the place where the arc is relatively concentrated, which will affect the arc extinguishing effect. The cost of replacement is too high, but there will be risks in continuing to use

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