| In all walks of life in today’s society,power supply as the fundamental source of power plays an irreplaceable role,and with the rapid development of society and power electronics technology,the demand for power supply is also higher and higher,which not only requires the quality and efficiency of power supply,but also has higher requirements for the capacity of power supply.Therefore,how to improve the power and efficiency of power supply has become the current scholars and scientific research the focus of personnel research.As an important part of high-power power supply,low-voltage and high-voltage DC power supply has a very wide application prospect in the fields of electrochemistry,aerospace,new energy vehicles and other industrial fields.The elimination and suppression of the harmonic components contained in the generator is a common means to improve the power generation efficiency,but there are few industrial examples using harmonics.This paper presents a new type of high current DC power generation system of multi-phase permanent magnet synchronous generator with only half turn coil in each phase.It is mainly composed of generator and two collector disks.The heat dissipation guide bar is installed on the surface of the bus plate,and the rectifier module is installed in parallel on each heat dissipation guide bar,which has high integration degree.The nine slot half turn coil,rectifier bridge arm and drive control are taken as an independent module.Each module is driven independently,which has the characteristics of high reliability and flexible control.Secondly,the mathematical model of the nine phase permanent magnet synchronous generator is analyzed,and the decoupling transformation matrix of the nine phase motor is derived.The voltage,flux,torque and motion equations in the dq coordinate of the orthogonal coordinate system are obtained.Through the decoupling transformation,the decoupling mathematical model of the motor is obtained.Finally,the vector control system is introduced.In view of the utilization of harmonics,modular nine phase vector control proposed a solution to rectify the current containing tooth harmonics from the aspect of space vector selection.On the basis of multi-phase space vector theory,the key control parameters of space vector pulse width modulation of high degree of freedom nine phase rectifier module were deduced,and the rectifier control model was built by using 72 vector/18 sector.The space is divided into fundamental wave and harmonic subspace.The fundamental and two harmonic vectors are in one sector at each time.The complex space vector control is realized by using the characteristic of uniform velocity difference.Through simulation,the rectifier output capability and harmonic control effect of symmetrical nine phase and asymmetric three phase winding connection are verified and compared.Finally,a 54 slot half turn synchronous generator is designed and developed.The modular experiment shows that the system can achieve the output of 5V/1000 A low voltage and high current,and has low harmonic distortion and high robust control ability. |
