Sintering detection device and method for contactor

Abstract

The invention provides a contactor-used sintering detection device and a method. The device comprises a first detection end and a second detection end arranged at two contact points of the motor contactor, a transformer, a control module, and an operational amplifying module, wherein two ports of the secondary side of the transformer are respectively connected with the first detection end and the second detection end for acquiring on and off states of the first detection end and the second detection end; the control module is used for generating test signals and sending the test signals to the primary side of the transformer; the operational amplifying module is used for acquiring signals at two ends of the primary side, amplifying the signals and generating extraction signals; the control module controls the contactor to be cutoff when the difference value between the extraction signals and the testing signals is judged to be larger than a preset threshold, if the difference value between the extraction signals and the testing signals later is still larger than the preset threshold, the contactor is judged to be sintered. According to the device of the embodiment of the invention, whether the contactor is sintered can be detected, and when the contactor is sintered, measures are adopted to protect a driving module, and safety of an electrical vehicle is improved.

Description

technical field [0001] The invention relates to the field of electric vehicles, in particular to a sintering detection device and method for a contactor. Background technique [0002] A current loop is required in the motor driving process, and single-phase contactors cannot be connected to form a loop. Therefore, in the three-phase line of the motor of an electric vehicle, two contactors are used to control the V-phase and W-phase of the motor respectively, and the U-phase is connected with The drive module IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) of the controller is directly connected, and no contactor is used for disconnection. [0003] For most electric vehicles, the driving power is small, and increasing the number of battery packs can increase the voltage, so the required driving current will be relatively small. Therefore, there are many types of AC contactors that can be selected. However, in the design of high-power VTOG (two-wa...

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Problems solved by technology

However, in the design of high-power VTOG (two-way inverter charging and discharging technology) of electric vehicles, the driving power is relatively large, and the number of battery packs cannot increase infinitely, that is, the voltage of the battery pack will not increase infinitely, so the driving current cannot to avoid increasing

[0004] At present, there are mainly the following problems: (1) There are few types of high-current AC contactors. Most high-current AC contactors are customized with non-standard parts, or replaced by DC contactors. Therefore, the failure rate of contactors is greatly increased. (2) The contactor is a mechanical device with a short service life, so it is prone to damage during use; (3) The contactor is in the high-voltage distribution box, and the state of the contactor cannot be detected. During sintering, if measures cannot be taken in time to protect the electric vehicle, it is easy to cause serious damage to the electric vehicle

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