The Application Of Field Oriented Control In The Micro Fan Of Three Phase PMSM

In recent years,the modern variable frequency control technology has been developed rapidly.As an important control method of the modern variable frequency control,the Field Oriented Control has a lot of applications and research in the asynchronous motor and synchronous motor control and obtained successful control results.Base on the analysis and research of relative literatures,this paper analyses the control method of Field Oriented Control in micro fan motor control and application of the refrigerators field.The motor structure of classical refrigerator micro fan is single-phase asynchronous.Because of national energy saving policies,we found classical micro fan motor has a lot of drawbacks such as low efficiency,uncontrollability,unacceptable noise and torque ripple.So the classical single-phase asynchronous motor has been replaced by three-phase Permanent Magnet Synchronous Motor and trapezoidal waveform control technology in recent years.After using the new motor structure and control method,it has obtained the good effect in increase efficiency and reducing torque ripple.But the trapezoidal waveform control method still on a rather simplistic level in the control of PMSM.According the feedback signals of rotor position sensor,the trapezoidal waveform control method generated six states in whole 360°commutating cycle.This makes the phase current turn into the trapezoidal waveform.The trapezoidal wave current still has a lot of torque ripple because of sudden change of phase current and zero current states.It's still far from perfect in motor efficiency and torque ripple.This paper mainly discusses the control theory and application of Field Oriented Control and Space Vector PWM by using the same three-phase PMSM.First,this paper introduces the realistic meaning of the application and introduction of the controlled objects.Then,it analyzed the technological principles and realizing methods of the Field Oriented Control and Space Vector PWM.At last this paper describes the C code in DSP and comparing the test results.Through the applied research of this paper,the trapezoidal waveform control method was replaced by the Field Oriented Control method,and the motor efficiency and torque ripple has been greatly improved.