The Research On The Specific Integrated Circuit Of Phase Shifting PWM Control Used In Multilevel Inverter

Recently, multilevel inverter is used more and more widely in fields such as high-voltage& high-power frequency control, PWM invertible rectification, compensation of harmonicwave & reactive power in power system, power generation by solar power and wind poweretc. The topology, control method and theory related to multilevel inverter has become the hotpoint in the researching field of power electrical technology. However, the R&D ofapplication specific integrated circuit of PWM control in multilevel inverter is relativelylagged, which fails to adapt with the research on all kinds of topology, control and application.This current state hinders the development of multilevel inverting technology. In view of theresearching blank of application specific integrated circuit of PWM control of multilevelinverter in the world, the thesis develops a kind of application specific integrated circuit ofphase shifting PWM based on CPLD. From aspect of operating principle, control systemdesign, calculation simulation as well as sample machine experiment etc, the thesis carries outsystematic, comprehensive and detail research on the unit cascading type multilevel inverterand phase shifting PWM integrated control system. According to the requirement by the phaseshifting PWM control of unit cascading type multilevel inverter, the thesis stresses on thewhole-digital integrated design for a kind of digital-storage-type circuit generating the phaseshifting PWM control wave. The design includes the digital storage format of multi-pathphase shifting PWM pulse generation, model configuration method and the time sequencedesign of CPLD time sharing control. Through the design of CPLD and outside hardwarecircuit, the measure to increase frequency resolution is researched. Furthermore, theisochronous modulation of PWM wave in segment of multilevel inverter and the smoothswitching between different frequency range are researched.This thesis adapts C8051F series SCM and CPLD as the control core. The applicationspecific integrated circuit of shifting phase PWM control based on CPLD is designed, on basis of which, a sample machine of unit cascading type medium and high voltage multilevelinverter is developed. According to large amount of simulation and experiment testing, thesystem plan is proved to be reasonable and feasible.