Research On Low-Harmonic Multi-Channel Converter Based On Phase-Shifted SVPWM

With the increasingly serious problem of traditional energy,new renewable energy wins more andmore widespread concern.Many countries have or are being started on the new renewable energyresearch,development and utilization.For its own advantage,wind and solar power occupy a primaryposition in power generation of new renewable energy.Construction of large-scale wind power andphotovoltaic power station is helpful for making use of them better and more effective.This willresearch one of the key components of new renewable energy generation system——high-powergrid-connected converter’s topology and switching modulation.With the number of channels increases,the traditional stair-cascaded converter could achieveoutput wave of high quality,but it also make it different to manfacture the phase-shifting transformersand the phase-shiftted could not be guaranteed accurate. This paper presents a novel multi-channelPWM converter controlled by phase-shift and researchs a type of switching modulation whoseswithcing frequency is3times the fundamental frequency and it’s application in multi-channelconverter.Firstly,this paper describes the structure of phase-shift control converter,phase-shiftingtransformer and the drive signals in detail， and analysis the space vector pulse widthmodulation(SVPWM) technology,including harmonic features,the fundamental phase delay caused bySVPWM and modulation linearity of SVPWM.To8-channel converter,for example,phase shiftcontrolled and the general8-channel converter were compared.Then,this paper established themathematical model of phase shift control converter at two-phase rotating coordinate system.Based onthe mathmatical model,a closed-loop control scheme of PWM converter was designed and the specificdesign parameters was given. A experimental system for phase-shift control multi-channel PWMrectifier was established,including some of the power circuit and controller.Design the overallscheme,selection of hardware and software design.Experiments of phase-shift multi-channel invertershows that it could achieve a good sinusoidal output wave at switching frequency of3times thefundamental frequency.The current-closed-loop control experiment of PWM rectifier verified thecontrol scheme.