基于TMS320F28035 CLA的IIR低通滤波器设计

摘要

在基于TI公司Piccolo系列DSP芯片的变频控制中,ADC采样的信号不可避免的要受到开关电源高频开关信号或者IGBT高频开关信号的影响,使采样得到的信号夹带有高频信号干扰,从而导致控制算法得到错误的信号,产生误动作,使控制效果下降甚至失效.在DSP芯片CPU中虽然可以设计滤波器,但是滤波器的运行会增加CPU开销,使CPU无暇处理其他诸如通信、诊断之类的系统任务.正是基于上述原因,在TMS320F28035芯片CLA硬件平台上设计出IIR低通滤波器,它能有效的滤除高频信号的干扰,解决三相变频控制信号受高频信号干扰的难题,提高控制系统的控制精度,同时减少CPU的开销.给出IIR低通滤波器的Matlab/Simulink仿真设计和在TMS320F28035芯片CLA上的软件设计.最后通过实验验证IIR低通滤波器设计的正确性.%In the variable frequency control based on TI company Piccolo series DSP chips, the signals input to the analog to digital converter(ADC) are inevitably impacted by the switching power supply high switching frequency signals or insulated gate bipolar transistor(IGBT) high switching frequency signals , this impact will make the control algorithm get the wrong signal and will lead to a fault control effect. Though infinite impulse response(IIR) filters could be designed in the CPU of the DSP chips.it will take CPU much time to run the IIR filters and thus the CPU will have no time to perform other system tasks such as communications and diagnostics. Based on these, a design of IIR low pass filter based on the control law accelerator (CLA) of TMS320F28035 was given. It can effectively filter out the high switching frequency signals to make sure the accuracy of the control system and to mitigate the CPU overhead. The Matlab/Simulink design and the software design on the CLA were given. Finally,the validity of the IIR low pass filter is demonstrated by the experimental results.