FPGA-based Development Of Predictive Current Control Of Permanent Magnet Synchronous Motor

In recent years,permanent magnet synchronous motors(PMSM)have been widely used in industries such as new energy vehicles,household appliances and modern industry.At the same time,model predictive control(MPC),which is considered as a new generation of high-performance PMSM control strategy,has become a research hotspot in industry and academia because of its simple structure,multi-objective optimization,nonlinear system and fast dynamic response.However,MPC has the disadvantages of large amount of computation and complex algorithm.In this paper,how to reduce the amount of MPC calculation and improve the control performance are studied,and the corresponding solutions are proposed.Firstly,PMSM in three different coordinate systems are obtained by using Clark and park coordinate transformation.The advantages and disadvantages of three highperformance PMSM control strategies are summarized,and the basic theory of MPC is described in detail from the three elements of prediction model,cost function and rolling optimization.Secondly,two optimization strategies of dual vector MPCC are proposed to reduce the calculation of traditional model predictive current control(MPCC)and improve the control performance.1)When the first voltage vector is selected,the number of switch is limited to 1,but zero vector is not considered,so the number of candidate voltage vectors is only 3.The alternative vectors for selecting the second voltage vector are the two voltage vectors adjacent to the first voltage vector and the zero vector.the optimal voltage vector combination is selected by cost function 2)According to the inverse Park transform,the q-axis value of the reference voltage in the two-phase static coordinate system is expressed as a straight line.Firstly,the abscissa of the intersection point between the straight line and the basic voltage vector and the hexagon boundary of the vector space is obtained,and then the abscissa value is transformed into the duty cycle of the corresponding voltage vector using the corresponding geometric relationship.Using Modelsim simulation software to simulate the designed modules,the results verify the correctness of each part of the microcontroller based on FPGA.Then,compared with microcontrollers such as DSP and STM32,FPGA has the advantages of parallel operation and good real-time performance.When implementing the MPCC control strategy,the parallel structure of MPCC can be better utilized to reduce the calculation time in hardware implementation.In order to improve the solution speed as much as possible and use as few resources as possible,the singlecore FPGA and hardware description language are adopted to design the scheme.In the implementation of each module,according to the basic principles involved,the parallel structure of each module structure is used as far as possible,and the use of resources is optimized.Using modelsim simulation software,the designed modules are simulated and verified,and the simulation results show the correctness of the designed modules.Finally,Simulink software is used to simulate and verify the proposed MPCC optimization scheme.Simulation results show that the proposed optimization scheme reduces the amount of calculation and improves the control performance.A PMSM experimental platform based on FPGA is built,and some contents are verified on FPGA board.