基于单一旋转角虚拟功率的虚拟同步发电机功率解耦策略

Virtual Synchronous Generator Power Decoupling Strategy Based on Virtual Power of Single Rotion Angle

虚拟同步发电机(VSG)技术模仿了同步发电机的运行机制,使分布式发电为电网提供惯性,改善了系统的稳定性。针对在线路传输过程中VSG的输出功率存在耦合而引起功率振荡甚至控制失效的问题,将虚拟功率解耦策略与VSG相结合,以降低输出功率之间的耦合效应。建立了改进VSG控制策略的小信号模型,并进行了分析,确定了虚拟功率的最佳旋转角度,以消除线路阻抗比对策略产生的影响。最后,通过MATLAB/Simulink仿真,验证了所提方案抑制功率振荡的有效性,提高了VSG的动静态性能。

The virtual synchronous generator(VSG)technology imitates the operating mechanism of the synchronous generator,enabling the distributed generation to provide inertia to the grid and improve system stability.In order to deal with the problem of power oscillation or even control failure due to the coupling of the output power of the VSG in the process of line transmission,the virtual power decoupling strategy is combined with the VSG to reducing the coupling between the active power and the reactive power.On this basis,a small-signal model is established,and a small rotation angle of the virtual power is analyzed according to its small-signal model to eliminate the influence of the line impedance ratio.Finally,the MATLAB/Simulink simulation is used to verify that the proposed scheme suppresses power oscillations caused by coupling between VSG power loops,and the dynamic and static performance of the VSG is improved.