A Fault Diagnosis Method for Fan Drive Stage

Abstract

The invention discloses a fault diagnosis method for a fan drive stage. The fan drive stage is provided with a low-side MOS tube and a high-side MOS tube. The low-side MOS tube is used for switch control of the inductive load freewheeling circuit, and the high-side MOS tube is used for the drive circuit. The switch control method includes the following steps: the fan is short-circuited to the power supply fault diagnosis step: open the low-side MOS tube and close the high-side MOS tube to connect the freewheeling circuit of the fan, and detect the source-drain voltage of the low-side MOS tube: If the source-drain voltage is greater than the threshold, the fan is short-circuited to the power supply, otherwise, the fan is not faulty; and / or the fan is short-circuited to the ground. Diagnosis steps: open the high-side MOS tube and close the low-side MOS tube to connect the fan The drive circuit detects the source-drain voltage of the high-side MOS tube: if the source-drain voltage is greater than the threshold, the fan is short-circuited to ground; otherwise, the fan is not faulty. The invention has the technical characteristics of convenient, efficient and accurate diagnosis, small duty ratio fault detection, prolonging the service life of the fan, and improving the use safety of the fan.

Description

technical field [0001] The invention belongs to the technical field of fan fault diagnosis, and in particular relates to a fault diagnosis method of a fan driving stage. Background technique [0002] The fan controller generally has to bear a large fan power, and the heat generated by the controller device is very large. Especially in failure modes such as short circuit, the heat generation is greater. Excessive heat generation will reduce the service life of the controller, and in severe cases, the controller will be damaged within tens of milliseconds at most. [0003] The driver stage diagnosis of the fan controller includes three fault modes: short circuit to power supply, short circuit to ground, and open circuit at the drive end. The current general diagnosis method is to directly drive the motor when there is a drive request. In the drive state, the hardware chip will report a response fault message. [0004] This conventional diagnostic method has the following di...

AI Technical Summary

Problems solved by technology

Since the duty cycle driving has a certain period, in the small duty cycle driving process, the effective driving time of a duty cycle driving waveform is very short, and it is difficult to reach the time threshold required for hardware chip diagnosis. In this case, even There is a driver-level fault problem, and the fault status cannot be obtained

In this way, in the process of driving with a small duty cycle, a large amount of heat will be accumulated instantaneously, reducing the life span or risking damage to the device

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