Control method of vehicle-mounted solid-state relay

Abstract

The invention discloses a control method of a vehicle-mounted solid-state relay. The method comprises the steps of controlling a field effect transistor to be closed after a driving chip receives a closing control instruction sent by a single-chip microcomputer, performing overcurrent judgment according to a relative relation between a first signal value and a first preset value, and then switching on the field effect transistor at a first preset time after the closing control instruction is received, the first preset value is modified from being equal to the first threshold value to being equal to a second threshold value, overcurrent judgment is continued until a disconnection control instruction is received, and if it is determined that an overcurrent fault occurs, overcurrent protection is triggered; and after the driving chip receives a disconnection control instruction sent by the single-chip microcomputer, the field effect transistor is controlled to be disconnected, open and short circuit judgment is carried out after second preset time, and open and short circuit protection is triggered if it is determined that an open circuit or short circuit fault occurs. According to the invention, diagnosis misjudgment caused by a capacitive device in the vehicle-mounted solid-state relay is avoided, and the control precision of the controller on the vehicle-mounted solid-state relay and the reliability of the vehicle-mounted solid-state relay are improved.

Description

technical field [0001] The embodiments of the present invention relate to a relay control technology, and in particular, to a control method of a vehicle-mounted solid-state relay. Background technique [0002] In the automotive electronic system, the controller can control the pull-in and disconnection of the relay to realize the conduction or closure of the high-voltage power output line, and then provide energy to the power load through the high-voltage bus. Due to the large power output current and the need for isolation between high-voltage lines and low-voltage lines, vehicle-mounted relays are generally implemented by solid-state relays with isolation functions and no contacts. [0003] The low-voltage control signal terminal of the solid-state relay generally exhibits capacitive characteristics. When the controller controls the switching state of the solid-state relay, the controller is prone to falsely triggering fault judgment, so that the controller cannot continu...

AI Technical Summary

Problems solved by technology

[0003] The low-voltage control signal terminal of the solid-state relay generally exhibits capacitive characteristics. When the controller controls the switching state of the solid-state relay, the controller is easy to trigger a fault judgment by mistake, so that the controller cannot continue to work normally, and the reliability of the solid-state relay controller is poor.

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