Vibration Reduction Control Strategy Of Common Bus Open Winding Permanent Magnet Synchronous Motor Based On Harmonic Suppression

The open winding permanent magnet synchronous motor(OW-PMSM)has the advantages of traditional PMSM with simple structure,high power density and high operating efficiency,and has good application prospects in high-end agricultural equipment fields such as agricultural plant protection machines,electric tractors,and agricultural robots.In addition,the common bus OWPMSM only needs a single DC power supply under the premise of high bus voltage utilization,which is extremely suitable for high-voltage and high-power electric drive systems.Aiming at the common bus OW-PMSM drive system,this paper proposes a zero-sequence current closed-loop zero vector redistribution random switching frequency modulation control strategy.On the basis of ensuring the maximization of the utilization rate of the bus voltage,this strategy realizes the vibration reduction control of the common bus OW-PMSM drive system by suppressing the current harmonics in the high and low frequency bands of the OW-PMSM.The main contents are as follows:1.The topology and working principle of the common bus OW-PMSM are described.The mathematical model of the motor in different coordinate systems are researched and established,and the voltage,flux linkage,electromagnetic torque and other equations are obtained.2.The output voltage space vector distribution of the dual inverter system is analyzed.,the medium vector SVPWM strategy of the dual inverter is studied,and an improved large vector SVPWM strategy with high voltage utilization is proposed.Furthermore,the zero-sequence loop in the system is further analyzed,and the zero-sequence current closed-loop control is realized by using the common-mode voltage generated by the zero-voltage space vector,and the lowfrequency harmonic content in the phase current is suppressed.3.Aiming at the high-frequency harmonic amplitude at the switching frequency of the phase current,random modulation technology is introduced,and a zero-sequence current closed-loop zero vector redistribution random switching frequency modulation strategy is proposed.The simulation results show that the current harmonic amplitudes of the common bus OW-PMSM in the high and low frequency ranges are reduced by 12.63% and 25.18%,respectively.4.A common bus OW-PMSM drive control experimental platform is built,and the design method of key software and hardware in the platform were demonstrated.Finally,the corresponding experimental research on the control strategy proposed in this paper is carried out on this experimental platform,and the measured experimental current and vibration acceleration data are analyzed.