Disturbance Observer-based Damping Controller of Grid-forming VSC-HVDC Systems
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.
VSC-HVDC systemsoscillation dampinggrid-forming controldisturbance state observerLQR
万方数据
维普
