The grid-forming converter can provide inertia support to the AC grid,improving the system's frequency stability.However,the grid-forming converter also inherits the oscillatory characteristics,which make the converter participate in the oscillations triggered by grid disturbances and result in a broader oscillation range.grid inverter has inertia support capability,providing frequency support for low inertia power grids.A simplified state-space model of the grid-forming inverter station connected with the receiving power grid was constructed.Based on singular value decomposition,the effects of controller parameters,integration position,and inertia distribution on the oscillation characteristics of the AC/DC system were studied,and the optimal integration position was obtained.Then,utilizing the autonomous response of the grid-forming inverter to grid disturbances,a disturbance observer-based damping controller(DODC)based on extended state observation technology was designed.The key states of the AC/DC hybrid system were estimated in real time using the local measurements of the grid-forming inverter,and the quadratic optimal feedback control was used to dampen the critical oscillation modes.The effectiveness of the proposed control strategy is verified through the co-simulation of DIgSILENT/PowerFactory and MATLAB.
关键词
柔性直流输电系统/振荡阻尼/构网型控制/扰动观测器/二次型最优控制
Key words
VSC-HVDC systems/oscillation damping/grid-forming control/disturbance state observer/LQR
维普
万方数据