| With development of science and technology,the permanent magnet synchronous motor has promoted the process of industrial automation.As a highly efficient actuator,it has many advantages,for example,it has an irreplaceable position in the field of industrial control and electric drive.The rotor of the permanent magnet synchronous motor is made of rare earth material.This kind of material reserves is very abundant in our country.This is also one of the factors that can be strongly promoted by permanent magnet motors.Therefore,it is also given a huge opportunity to develop the permanent magnet synchronous motor control system.The principle of multilevel inverter is to increase the number of output levels at the inverter.In this way,the output voltage harmonics and voltage change rate are reduced,and the actual withstand voltage of the power switch tube is lowered,making it more suitable for use in high voltage and high current engineering applications.Therefore,this paper constructs a three-level vector control system to realize the control of permanent magnet synchronous motor.Firstly,the article introduces the types of permanent magnet synchronous motors and establishs PMSM mathematical models.Expounded the basic principle and mathematical model of vector control are discussed.The magnetic field oriented vector control method is used as the strategy.It uses the control method of id=0 built the control system,and it is realized to control about synchronous machine of current closed-loop control and speed closed-loop control.Secondly,the traditional three-level SVPWM modulation technique is expounded.On this basis,a simplified three-level SVPWM modulation method is proposed,and algebraic method is used to judge small sectors.Harmonic current is suppressed by a quasi-PR regulator.Use a hardware grading circuit to achieve midpoint potential balance.The simulation is carried out with MATLAB/Simulink,and the effectiveness of the proposed scheme is verified.Finally,the software and hardware experimental platform of the three-level permanent magnet synchronous motor speed control system is built.The hardware includes the control circuit,drive circuit and main circuit of the diode clamp type three-level inverter system.At the same time,software programming is performed.Experimental research is carried out on the basis of this platform.The results verify the feasibility of the proposed control scheme. |
