Control Strategy Study Of A Two-stage Bidirectional DC/AC Converter Based On V2G

With the shortage of resources and the view of carbon neutrality,the concept of sustainable development is gradually deepening.The study of electric vehicles as a product of new energy development and its derivatives is gradually becoming a hot spot.The electric vehicle V2G(Vehicle to Grid)system has a strong development potential as a structure for the interaction between electric vehicles and the grid.The bidirectional DC/AC part of the two-stage V2 G,as the key structure directly connected to the grid,control strategy is important for a high performance and efficiency.The totem pole PFC(Power Factor Correction)has a good application on the DC/AC side due to its low common mode noise and the simple topology.In this paper,the mathematical model of the totem pole PFC is first derived and the relationship between switching state and voltage and current is summarized.Starting from the classical PID(Proportion Integration Differentiation)algorithm,establish a PI controller.A quasi-PR(Proportion Resonant)controller for specific frequency is established to filter the harmonics;and a notch filter is introduced in the voltage loop to reduce the output voltage harmonics in the voltage loop.Based on the mathematical model of the totem pole PFC,the predictive control algorithm is derived and the cost function is numerically optimized based on the relationship between the predicted actual current and the predicted reference current.In addition,an Extend State Observer is modelled for the disturbances present in the system,which is estimated and fed back into the system,and the control effect is verified by simulation.In addition to the algorithmic optimization,the introduction of a parallel topology achieves an increase in power level.It also reduces the ripple of the input current and alleviate the stress on the device in hardware.And study the relationship with totem pole PFC through mathematical models and working principles.Bring the control strategy of PFC and verify it by simulation.