Automatic Control Method of Resonance PLC for Permanent Magnet Brushless DC Motor
The permanent magnet brushless DC motor undergoes current distortion due to resonance during operation.The current control methods do not clearly distinguish between the non commutation time and the midpoint voltage of the commutation time of the permanent magnet brushless DC motor,resulting in significant deviation of its resonance characteristics under voltage fluctuations.Ex-cessive residual fluctuations lead to poor control performance in the later stage.A resonant PLC automatic control method for perma-nent magnet brushless DC motor is proposed.By calculating the non commutation time and the midpoint voltage at the commutation time of the permanent magnet brushless DC motor,the operating state of the permanent magnet brushless DC motor set at the midpoint voltage is controlled to control residual fluctuations.On this basis,the resonance characteristics of permanent magnet brushless DC motors are extracted through modal analysis,providing a basis for the resonance control of permanent magnet brushless DC motors.Control the modal impedance value of the motor,use PLC controller as the core control system of the permanent magnet brushless DC motor,and introduce PI controller to form a PI-PLC controller.Add z coefficient to improve the resonance control effect,and achieve resonance control of the permanent magnet brushless DC motor.The experimental results show that the method has fast convergence speed and high control performance.
permanent magnet brushless DC motorresonance controlresonance analysisPI controlPLC controller