基于SHEPWM的轨道交通直线电机脉宽控制系统

SHEPWM⁃based pulse width control system of rail transit linear motor

为了解决脉宽控制效果差的问题,提出了基于SHEPWM的轨道交通直线电机脉宽控制系统设计。以AT89C51单片机为主要芯片,设计硬件结构。将AT89C51调整到0 Hz静态逻辑操作模式,在该模式下保证系统工作节能。设计集成电路驱动模块L298,接收标准的TTL逻辑电平信号,驱动直流电机。构造脉宽测量装置,通过PCI总线协调模块间通信。设计电机脉宽控制系统主CPU程序,在SHEPWM模式下,推导电压矢量角,设置中断间隔来实现脉宽控制,有效抑制谐波。由实验结果可知,该系统比原始电流仿真波形平滑,脉动转矩基频变化具有规律性,能够有效抑制谐波,具有良好的控制效果。

In order to solve the problem of poor pulse width control,the design of a pulse width control system for rail transit linear motors based on SHEPWM is proposed.With AT89C51 microcontroller as the main chip,the hardware structure is designed.Adjust AT89C51 to 0 Hz static logic operation mode,in this mode,ensure that the system works and save energy.The integrated circuit driver module L298 is designed to receive standard TTL logic level signals to drive DC motors.Construct a pulse width measuring device to coordinate the communication between modules through the PCI bus.Design the main CPU program of the motor pulse width control system.In the SHEPWM mode,the voltage vector angle is derived,and the interrupt interval is set to realize the pulse width control and effectively suppress the harmonics.It can be seen from the experimental results that the system is smoother than the original current simulation waveform,and the fundamental frequency of the pulsating torque changes regularly,which can effectively suppress harmonics and has a good control effect.