Research On Fault Diagnosis Of Inverter And Fault-tolerant Technology In The Brushless DC Motor(BLDCM)

With the wide application of brashless DC motor in the high security fields,such as military,traffic and aerospace,it becomes more and more important to improve the reliability of the brushless DC m,otor in the system.But the power converter is the most vulnerable unit in BLDC motor,it greatly affects the security of the system.Therefore,it was studied that fault diagnostic method and fault-tolerant control strategy of open-circuit fault of the BLDC motor single power inverter in this paper.Firstly,the fault diagnosis method of power converter is studied in this paper.The shortcomings of the traditional error voltage method are com,plex design and high cost,this paper adopts the voltage detection error method based on terminal voltage,the fault location is diagnosed quickly and simply by measuring the terminal voltage of the motor.The logic expression of the terminal voltage forjudging the fault is given by combining the commutation signal and the PWM control signal.By comparing the difference between the calculation value and the actual measured value of the terminal voltage in the motor operation,the diagnosis and location of the fault are realized.Secondly,after diagnosing the fault location,the motor should be fault-tolerant to ensure the safe operation of the motor.In this paper,the fault-tolerant technology is the combination of hardware fault-tolerant topology and software control strategy.The fault tolerant operation of the motor is realized,and the output performance and control mode of the motor are not changed.Finally,the fault diagnosis method and its fault-tolerant control strategy are modeled under the MATLAB/SIMALINK simulation system.Meanwhile,the hardware platform of BLDCM fault-tolerant system is built,with the core of ARM STM32F103ZET6 controller,and the realization and debugging of hardware circuit and software program are completed.By comparing the experimental waveforms with the simulation results,it is verified that the system can achieve fault diagnosis and fault tolerant operation for single switch has open-circuit or short-circuit and two switches in the same bridge has open circuit or short circuit.