The Application Of DSP In The Variable Voltage Variable Frequency System

In the field of electric driving , the adjustable speed control of AC asynchronous motor by inverter was a hot spot because of its energy saving function. A new DSP chip TMS320F240 used in the digital motor control (DMC) was presented, and its application in the VVVF system was discussed.The thesis introduced the actuality in the field of frequency conversion and its principle,and the mostly characteristic of DSP. A DSP based digital motor control system using V/F control and Space Vector PWM technique was developed. The space vector graphs of voltage were presented better.We adopted DSP to realize the complicated vector control algorithm, the IPM PM15RSH120 was used to enhance reliability and it also made hardware circuit simple.The system had auto startup and stop function by software .The DSP based motor control system had lower current harmonic,more efficient use of supply voltage than SPWM, less switch loss. On the other hand, this system make a lower noise for the PWM modulation. Frequency is up to 20KHZ. The system had the advantages of simple control, few peripheral, high performance and low price, which would meet the demands of general purpose inverter, and the inverters using in HVAC(Heating Ventilating Air Conditioning)sysytem..