| With the rapid development of renewable energy generation technology,high-power grid-connected inverters are widely used.However,to realize high the efficiency of high-power grid-connected inverter system,the switching frequency of the inverter is generally 1～3kHz,resulting in the high ripple component of the output current.One topic of current research is to suppress the output current ripple of high-power grid-connected inverters.This paper focuses on the series active ripple rejection and damping system of high-power grid-connected inverters.The main contents are as follows:Firstly,a series type active ripple rejection and damping system is proposed to reduce the high frequency ripple of the output current of the high-power grid-connected inverter.The working principle of the system is clarified and the mathematical model is set up.This is the theoretical basis of the following series active ripple rejection and damping system control strategy.Secondly,this paper analyzes the working principle of the grid-connected inverter.Using direct ripple voltage compensation and virtual inductance technology,the paper studies the ripple control strategy of series active ripple and damping system.At the same time,this paper uses the virtual resistance control method to reduce the power loss caused by the damping resistor in the grid-connected inverter.Then,this paper establishes the mathematical model of the power conversion of the series system.The power relationship between the main circuit of the grid-connected inverter and the series system is analyzed.Based on this relationship,a DC side bus voltage control method of the active ripple suppressor is designed.At the same time,this paper also studies the coupling relationship between the main circuit grid-connected inverter and the active ripple suppressor control process.Finally,the simulation model of the series active ripple rejection and damping system of the grid-connected inverter is built with Matlab/Simulink,and the simulation analysis is carried out.At the same time,the experimental platform of series active ripple rejection and damping system of grid-connected inverter is set up,and the system and control strategy proposed in this paper are studied experimentally. |
