Design Of A Permanent Magnet Synchronous Motor Servo Driver Based On FPGA

In the procession of The Chinese Industry Automation, high precision AC servo system is used more and more widely in various industrial fields. And new types of permanent magnetic material and new proposed motor control strategies of good performance make the AC servo system of permanent magnet synchronous motor as a representative, which can be directly comparable to DC servo system in the performance. Also New power electronic devices、new high performance micro controllers and new programmable logic devices have being accelerating the development of the permanent magnet synchronous motor AC servo system from, such as analog to digitization, low frequency to high frequency, discretization to integration.In the past, DSP was always selected as the main controller in a permanent magnet synchronous motor servo system, which can only control one motor in most situations. As the introduction of FPGA that owns high performance and low cost, the method of using FPGA as the central controller to device a plurality of servo motors are adopted in an increasing number of industrial robots and the four axle vehicle.This paper first introduced the evolution process of the permanent magnet synchronous motor AC servo system, the basic system structure and the basic system performance index. Based on the analysis of permanent magnet synchronous motor physical model, the paper describes the process that how the motor electromagnetic torque generates. Through the analysis of the mathematical model of permanent magnet synchronous motor, the paper compared several kinds of vector control method and analyzed their advantages and disadvantages.Then this paper thoroughly demonstrated the control strategy of permanent magnet synchronous motor id=0, and derived Clark transform、Park transform、Ipark transform according to the principles of power equality and magneticmotive force equality. the principle of SVPWM was studied and described in this paper, and on this basis, the control strategy of permanent magnet synchronous motor id=0 was simulated by SIMULINK simulation tools.What’s more,based on the theory and Simulation, the hardware circuit design and software program design of this system had been proposed. the hardware circuit design includes the full bridge rectifier circuit、anti surge circuit、IPM power circuit、auxiliary switch power circuit based on LNK306、comparative hysteresis brake circuit、SVPWM signal transmission circuit、motor phase current sampling circuit and so on. And the software program design includes vector coordinate conversion program、cordic algorithm for computing the cosine、motor phase current sampling algorithm and SVPWM signal generation algorithm.At the last, the permanent magnet synchronous motor servo driver was detailed debugged. The key voltage and current waveform in the system were recorded. And analysis about the system error causes and the corresponding improvement measures were proposed.