The Research On Three-level PWM Rectifier And The Elimination Of High Frequency Harmonics In Grid Side

Today, Power electronic devices are main homarnic sources of public power grid. Following the using of power electrionic devices widely, the harmonic pollution in power grid become serious gradually.Because more power electrionic devices have low power factor,they will bring extra load to power grid and affect the quality of power energy.Eliminating harmonic and improving power factor were focused more and more.New type high power factor rectifier can satisfy all performance needed by load with high power factor and no harmonic.Firstly, The article introduces the method of SVP WM modulation in detail, gives the procedure of mathematical derivation, makes a comparision with SPWM modulation and test the relative theory basing the model of simulink. Second, introduce the control theory of three-level PWM rectifier,deduce the mathematical model basing d-q axis,introduce the decoupling of current loop and two close loops control method and verify it using simulation model.In addition, discuss the method of eliminating harmonic in AC side of three-level PWM rectifier.Respectively using L type filter and LCR type filter, analyze the filter effect. Finally, make the hardware platform of two-level PWM rectifier.Control unit is the TI's MCU DSP320F28335.The filters in AC side are LCR type.Perfectly realize the synchronization of voltage and current in AC side through experiment.