| At present,270 V high-voltage DC start/generation technology has become an important research technology for the development of a new generation of fighter aircraft in China.Due to its high reliability,simple structure,and large power-to-volume ratio,permanent magnet synchronous motors have rapidly become a hot research topic for scholars at home and abroad.The aero-engine itself cannot start itself.The permanent-magnet synchronous motor is used as a motor to drive the aero-engine.When the aero-engine is successfully ignited and started,the prime mover is used to drive the permanent-magnet synchronous motor to generate power,which provides power for the equipment on the aircraft.The shortcoming is that the magnetic field adjustment of the permanent magnet synchronous motor is difficult,and the output voltage cannot be changed by adjusting the excitation,which greatly limits its range.The output voltage of the motor can only be realized by changing the motor speed.When the engine drives the speed of the permanent magnet synchronous motor,the output voltage and frequency are changing at a time,and the stable DC bus voltage can only be output through the rectifier voltage regulator of the latter stage.Firstly,the working process,performance indicators and sub-modules of each component of the aeronautical permanent magnet starting power generation voltage regulation system are described in detail.The mathematical model of the built-in permanent magnet synchronous motor and the vector control principle under the electric motor state are analyzed,and the constraint equation of the vector control operation under the power generation state is proposed.For the permanent magnet synchronous motor,the back electromotive force is too large under the high-speed power generation state,resulting in DC.The problem of excessive bus voltage is proposed.Two kinds of weak magnetic methods,voltage feedback method and single current regulator,are proposed,and their advantages and disadvantages are listed.Finally,the commonly used uncontrolled rectifier circuit and buck-boost chopper circuit are analyzed.Secondly,the mathematical model of three-phase PWM rectifier is analyzed,and the decoupling control calculation of d and q-axis current regulator is carried out.The simulation of weak magnetic stabilized aerospace permanent magnet synchronous motor power generation system based on voltage feedback method and single current regulator is built.Model,simulation verified the output of the high-speed power generation system stable DC 270V;simulation analysis of the uncontrolled rectifier + buck-boost chopper circuit,the output voltage is unstable in a wide range of speed;for the motor at low speed The output voltage is low.Comparing the advantages and disadvantages of each rectifier voltage regulation method,a twostage voltage regulation control strategy of the primary PWM rectifier secondary buck-boost chopper circuit is proposed to build the Simulink simulation model.The simulation results show that the DC output voltage of the system output is stable and the dynamic response is fast in the wide speed range,which meets the aviation power standard.Finally,this conclusion is verified by experiments.Finally,the hazard of motor current harmonics is analyzed.It is proposed to replace the PI controller with the proportional resonance controller and the repetitive controller.The main 5th and 7th harmonics are compensated.After the model simulation analysis,the PI controller is separately constructed.The four-phase current is compared by Fourier decomposition,and the harmonic content is reduced from 2.57% to 2.02% and 1.47%,which is more than the uncontrolled harmonic content. |
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