基于双DSP微处理器的大功率牵引逆变器

High Power Traction Inverter based on Dual DSP Controller

在大功率牵引逆变器研制中,通常采用矢量控制或直接转矩控制等复杂的控制算法,若仅使用一片通用微处理器作为控制芯片难以胜任。文中介绍了一种基于TI公司TM S320LF2407(简称LF2407)和TM S320VC33(简称VC33)微处理器的双机系统。应用该系统研制出一台1.7M VA 牵引逆变器。该双机系统充分发挥了两个微处理器各自的硬件特点,利用LF2407 的PW M 逻辑单元和丰富的外围接口功能完成了电机的控制和输入输出;利用VC33 的浮点运算优势完成了直接转矩控制运算。双机系统的程序工作周期由LF2407 定时器1 的中断决定,两个微处理器间依靠双端口RAM 共享数据和传递控制信息。当LF2407 向双端口RAM 中断地址写入一个数据时,双端口RAM 就会产生一个中断信号,触发VC33 进入中断子程序,反之亦然,它们通过中断完成交互式协同工作。试验中牵引电机功率为1.25M W ,电机输出转矩达到了10kN·m ,实现了恒转矩、恒功率和憜行再起动等运行工况。经试验验证,该系统具有很高的软、硬件控制性能,工作可靠,适合用于各种复杂的应用场合。

In high power traction inverter,those control algorithms such as vector control or direct torque control are generally applied,which results in CPU loading restriction for a single general microprocessor.In this paper,one dual CPU controller system based on TI DSP TMS320LF2407 and TMS320VC33 is introduced.An 1.7MVA traction Inverter was developed based on such a controller system.By fully taking advantage of the hardware features of the two CPUs,the motor control and I/O functions were implemented based on PWM unit and rich peripheral devices of LF2407,and the direct torque control algorithm was implemented based on powerful floating calculation capability of VC33.The control period of this dual CPU system was determined by timer 1 interruption of LF2407.The data sharing and control message transferring between the two CPUs were implemented with dual port RAM.The dual port RAM generates an interrupt signal to trig the VC33 interrupt service routine once LF2407 writes a datum into the interrupt address of the dual port RAM,and vice versa.An experimental system with 1.25MW traction motor was developed,and 10kN·m output torque was implemented.Those operation situations such as constant torque,constant power and restarting from free running were implemented.The experimental results show high control performance,reliability and adaptability are realized to all kinds of complicated application fields.