Research On Variable Frequency Speed Control System And Control Strategy For Interior Permanent Magnet Synchronous Motors

Due to its performance advantages and China's abundant reserves of permanent magnet materials,Permanent Magnet Synchronous Motor(PMSM)plays a more important role in daily life.The permanent magnet synchronous motor has no brush and slip ring,and the maintenance is simple,economical and safe;the magnetic field is generated by the permanent magnet,the motor is small in size,light in weight and high in efficiency.The embedded permanent magnet synchronous motor(IPMSM)is the mainstream motor driven by new energy vehicles.The drive system has the requirements of constant power and wide speed range.It is combined with power electronics technology and modern control theory to study the IPMSM control strategy.It has certain theoretical and engineering application value for the development of future new energy vehicle driven permanent magnet motor and its system.The common control chips in motor control are DSP,ARM,MCU,etc.These need to be manually programmed according to the designed algorithm,and the development cycle is long.The semi-physical simulation system dSPACE proposes a good solution to this kind of problem,which greatly shortens the development cycle;the effective and stable estimation of the initial position of the rotor under different control strategies is the key to ensure that the motor can start smoothly with maximum torque;This topic is based on the development of hardware system of dSPACE.The following research is carried out on the control strategy of the embedded variable frequency speed control system of the permanent magnet synchronous motor.1.Developed a dSPACE-based 2.2kW permanent magnet synchronous motor control system experimental platform.The hardware protection and software protection of the motor control system are introduced.The conflicts between the IPM dead zone protection and the dSPACE dead zone module are analyzed.The control system driver board is modified.The test results show that the proposed method can meet the requirements at the same time.Dead zone protection and hardware protection as well as the normal operation of the IPM.2.For the vector control system of permanent magnet synchronous motor i_d=0,the mathematical model of permanent magnet synchronous motor.The transfer function is obtained.According to the performance requirements of the system,the cutoff frequency and the minimum phase angle margin satisfying the performance are obtained.The PI parameters are adjusted and the influence of different PI parameters on the dynamic performance of the motor is analyzed.The experimental results verify the feasibility of the method.Improve the starting performance of the motor and expand the speed range of the motor.3.For the characteristics of different weak magnetic algorithms,choose MTPA with curve fitting below the base speed.The motor is regulated,and the base speed is selected based on the MTPA-based gradient descent method to control the motor.According to the torque of different weak magnetic regions,the direction of voltage change and the current regulator and voltage setting value.The difference determines the magnitude of the current correction value.Realize the speed regulation experiment in the full speed range of the motor.4.Using the saturated salient pole effect of the IPMSM armature winding inductance,using the stator winding pulse injection.The entry method determines the starting position of the d-axis of the rotor,and determines the position of the positive direction of the d-axis of the rotor according to the steering detection of the incremental encoder feedback motor under the action of a specific voltage vector.The experimental results show that the scheme can accurately and stably detect the initial position of the rotor.5.Improved vector in dSPACE-based 2.2kW IPMSM control system experimental platform.The control program and PI parameters improve the speed and stability of the motor's starting,speed regulation and anti-load disturbance.The IPMSM weak magnetic speed control based on the gradient descent method is realized,and the weak magnetic speed regulation area is expanded.