Improved VSG Pre-synchronization Model Based on Virtual Impedance
In order to eliminate the large impact current generated at the moment of closing when VSG controlled new energy systems are switched off or connected to the grid,and to solve the problem of multiple PI modules in traditional pre-synchronization methods,an improved pre-synchronization control method based on virtual impedance was proposed.Firstly,by calculating the virtual power flow,the angular velocity and voltage amplitude of the new energy system were compensated to meet the grid connection requirements;then,through the subsequent grid connection judgment module,the safe operation of the grid connection process was ensured;after that,the virtual impedance model using MATLAB/Simulink was simulated and verified;finally,dSPACE was used to conduct semi physical simulation of the construction system to verify the effectiveness of the method.The simulation and experimental results show that the pre-synchronization control strategy using the improved virtual impedance method effectively reduces the number of PI modules while reducing voltage and current fluctuations during grid connection,thus demonstrating good stability performance.
万方数据
维普
