A Fault Detection and Protection Circuit for Brushless DC Motor

Abstract

The invention discloses a fault detecting and protective circuit of a brushless direct current motor, which comprises a three-phase current signal detecting module, a stator winding open-phase fault switching module, a Hall sensor signal detecting module, a stator winding overcurrent detecting module, a CPLD (Complex Programmable Logic Device) fault processing module and a winding current cutting module, wherein the three-phase current signal detecting module is used for detecting a three-phase signal of a direct-current motor; the Hall sensor signal detecting module is used for detecting and reshaping an output signal of the Hall sensor; the stator winding overcurrent detecting module is used for collecting winding currents and comparing the winding currents with a set value; and the CPLD (Complex Programmable Logic Device) fault processing module is used for logically processing the three-phase signal, a Hall reshaping signal and a overcurrent fault signal and respectively sending signals to the stator winding open-phase fault switching module and the winding current cutting module. The circuit can increase the reliability of a controller of the brushless direct current motor, can protect a stator winding, a Hall sensor and a stator winding after open-phase faults of the stator winding, the Hall sensor and the stator winding and prevents the stator winding, the Hall sensor and the stator winding from being damaged due to the faults.

Description

technical field [0001] The invention belongs to the technical field of brushless direct current motor controllers, and in particular relates to a circuit for detecting and protecting phase loss of a stator winding of a brushless direct current motor, phase loss of a Hall sensor, and winding overcurrent. Background technique [0002] With the rapid development of science and technology and power electronics industry, the motor, as an electromechanical energy conversion device, has been used in various fields of the national economy and people's daily life. Because traditional DC motors use brushes to commutate mechanically, there is relative mechanical friction, which brings fatal shortcomings such as noise, sparks, radio interference and lifespan, which limits its application range. Brushless DC motor not only has the advantages of simple structure, reliable operation and convenient maintenance of AC servo motor, but also has good speed regulation characteristics like DC s...

AI Technical Summary

Problems solved by technology

[0004] When the drive circuit of the motor fails, the phase current output of the motor will be abnormal or missing, and the stator winding phase failure will occur, resulting in the motor not working normally. The controller is easy to burn out when it works in the state of winding phase loss; Hall sensor failure will cause Hall sensor phase loss. In this case, the controller cannot detect the correct sensor output and cannot achieve motor commutation; Stator winding overcurrent is prone to occur when starting or reversing. If the overcurrent protection is not carried out in time, the motor winding will be burned; therefore, in practical applications, the motor should be protected against faults to ensure the safe operation of the motor

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