Study On AC Servo Driver Of Real-time EtherCAT Communication

Servo driver is the core of servo control system. Its performance determines whetherservo system can quickly and accurately respond to the requirements of the control commands.So servo driver has a crucial effect on the whole manufacturing system. With the rapiddevelopment of industrial Ethernet and field bus technology, application of industrial Ethernetto servo system has become one of the important developing trends of modern servo driver.High-speed Ethernet field bus EtherCAT is widely used increasingly for its short refresh cycle,high real time capability and synchronicity.This paper based on the research of real-time industrial Ethernet, applies EtherCAT tothe servo system, take PMSM as object, using the TI dedicated to the motor control DSPTMS320F28335as control chip, designs a set of EtherCAT communications digital AC servodriver, this paper includes the following contents:First, this paper introduces EtherCAT technology and the development of PMSM ACservo system, by analyzing the mathematical model and control strategy of PMSM, adoptsvector control and SVPWM algorithm, uses Matlab for modeling and simulating speed andcurrent double closed-loop servo system, results verifies the correctness of the algorithm.Secondly, this paper designs the main control circuit of system using DSPF28335chip,combines with the IPM module, designs power driver circuit, uses Beckhoff’s ESC chipET1100to set up a servo system hardware platform, uses CCS software program system codeusing C language based on hardware, including system initialization program, interruptprogram and ET100communication program. Interrupt program mainly includes the PWMinterrupt, timer T0interrupts, AD sampling interrupt, ESC interrupt, etc. In the interruptroutine, designs current loop, speed loop and position loop control algorithm, motor speedcalculation, AD sampling calculation and ET1100communication program, etc.Finally, on the basis of the hardware and software, sets up the EtherCAT communicationservo system experiment platform, uses the Microsoft VS2010design human-machineinterface in the PC and experiments on PMSM, the results verify the validity of the servosystem software and hardware, lay a good foundation for further study.