Research On VSM Control Of VIENNA Rectifier Used In High Power Charging Pile

With the deterioration of ecological environment caused by the rapid development of world economy,new energy industry emerges as the times require.In order to further meet the requirements of function and performance of electric vehicles in the process of production and life,rapid charging has become an important index in the development of electric vehicles.In order to complete the rapid charging,the electric vehicle charging pile should be suitable for high voltage and high power converters.Therefore,the VIENNA rectifier is used in the AC/DC part in this paper.In this paper,first,the working principle of VIENNA rectifier is analyzed,the SVPWM modulation method suitable for the rectifier and the midpoint voltage balance control method for DC output capacitance are studied.Then,in order to reduce the harmonic injection of charging pile power electronic interface to large power grid and provide voltage support to the latter,this paper studies the control technology of virtual synchronous machine suitable for VIENNA rectifier and its modulation method.In addition,in this paper,the main ideas and mathematical models of virtual synchronous machine technology are analyzed,the stator voltage equation and rotor motion equation of synchronous motor are introduced into the control strategy,and the active power frequency control and reactive power voltage control,as well as the double closed loop control method in dq0 coordinate system,are studied.In order to reduce the rectifier voltage to the applicable voltage level of electric vehicle,the paper selects the step-down chopper circuit in the DC/DC part,and studies its control method.Finally,this paper verifies the characteristics of the VIENNA rectifier,including sag,inertia and damping characteristics,which shows that the virtual synchronous machine can participate in the primary frequency modulation of the system.It can support the stability of the system.Finally,this paper completes the model building and simulation experiment under the MATLAB/Simulink simulation environment,successfully builds the electric vehicle charging pile commutation system suitable for the high voltage,the high power application situation.The virtual synchronous machine technology of load side VIENNA rectifier is upgraded.