New energy electric vehicle driving system current sensor tiny fault diagnosis method

Abstract

The invention discloses a new energy electric vehicle driving system current sensor tiny fault diagnosis method, and belongs to the technical field of fault diagnosis. The method comprises the following steps of establishing a hybrid logic dynamic model, establishing a state equation, establishing an augmentation system and carrying out coordinate transformation, establishing a novel adaptive sliding mode observer, making residual errors, giving an adaptive threshold value and carrying out fault diagnosis. The state augmentation method is adopted to reconstruct the fault so that the tiny fault is easier to detect. Compared with a traditional sliding mode observer, the novel self-adaptive sliding mode observer adopted by the method has the advantages that the sliding mode motion time and buffeting are reduced; according to the method, the accuracy, the robustness and the anti-interference performance of fault diagnosis are improved by adopting a self-adaptive threshold value; and according to the method, a fault detection characteristic quantity is defined by comparing a relation between a residual error and a self-adaptive threshold value to carry out fault diagnosis on a current sensor of a three-phase two-level inverter.

Description

technical field [0001] The invention relates to the field of fault diagnosis, in particular to a small fault diagnosis method for a current sensor of a drive system of a new energy electric vehicle. Background technique [0002] The drive system of permanent magnet synchronous motor is an important part of new energy electric vehicles, and its safety and reliability directly affect the normal use of electric vehicles. The current sensor is one of the important components of the drive system, which is prone to failure, which will lead to the failure of the entire drive system, resulting in serious traffic accidents, casualties and property losses. [0003] Sensor failures fall into two main categories: critical failures and precision failures. Serious faults mainly include: current sensor short circuit, open circuit, stuck fault, etc.; and precision faults include current sensor tiny, drift, proportional fault, etc. At present, there are mainly two kinds of fault diagnosis ...

AI Technical Summary

Problems solved by technology

[0009] 2. Minor faults are not easy to detect;

[0010] 3. When the sliding mode movement occurs, the approach speed is slow and the vibration is large;

[0011] 4. The adaptive threshold is not strong in anti-interference

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