DSP+CPLD实现CPS-SPWM下的单相多电平脉冲

Single Phase Multi-level Pulse Realization Under CPS-SPWM Technique Based on DSP+CPLD

载波相移调制SPWM(CPS-SPWM)技术是多重化和正弦波脉宽调制(SPWM)技术的有机结合。针对在CPS-SPWM调制下,单片DSP计数器和PWM输出口的局限,设计了一种DSP+CPLD的系统,实现了单相7电平和9电平脉冲输出。实验表明:用DSP+CPLD构成的系统突破了目前单片MCU的限制,使得CPS-SPWM技术在大功率装置上应用更加灵活、实用。

Together with the continual development of high power self-turn-off devices and intelligent high-speed microcontroller, high power electronic equipment is increasingly deeply studied and is more and more widely applied in large capacitance motor drive, power transmission and so on. In these power equipments, there is a sharp problem, which is the increase of the power level and the improvement of the switching apparatus frequency. Carrier phaseshifted SPWM（CPS-SPWM） technique is the novel technique to solve this problem. Besides, it has many advantages such as easy algorithm, and can reach an effect of higher equivalent switching frequency under much low real device switching frequency. This technique improves the equivalent switching frequency through the counteract of lower order harmonics but not simply through processing the harmonic from lower order to higher order, so that it has a perfect performance on harmonic feature. In this paper, some researches have been done to the digital control cascaded multilevel converter based on CPS-SPWM technique, and one phase seven-level, nine-level power magnify has been realized through CPS-SPWM technique based on DSP＋CPLD hardware platform. By exploring to introduce microcontroller to the control system of power electronics, the digital control of power converter is being improved. Experiment result shows that DSP＋CPLD system can break through the limit of one piece of MCU and make CPS-SPWM technique flexible and useful.