Transient control strategy of virtual synchronous generator with adaptive regulation of active power deviation
The virtual synchronous generator ( VSG ) controlled grid-connected inverter exhibits transient instability and overcurrent phenomena during grid voltage drops.Therefore,a transient control strategy for VSG was proposed.According to the active power angle characteristics of VSG,the relationship be-tween active power and transient angle stability was derived.Based on the transient current characteristics of VSG,the relationship between the dynamic response characteristics of VSG reactive power and the change of transient power angle was analyzed.On this basis,taking the positive and negative of angular frequency deviation,active power deviation and change rate of active power deviation as the interval divi-sion basis of the power angle characteristic curve,a piecewise adaptive adjustment strategy for the active power deviation coefficient was designed.By controlling the active power deviation,the increase of power angle is suppressed,and the output overcurrent of VSG is suppressed.The transient stability of VSG is proved based on the equal area criterion.Simulation results indicate that the proposed control strategy ef-fectively eliminates the transient instability and overcurrent phenomena of the grid-connected inverter con-trolled by VSG.Furthermore,regardless of the presence of a stable operating equilibrium point during the transient period,the proposed strategy ensures stability of the VSG power angle.
grid-connected invertervirtual synchronous generatortransient stabilitygrid voltage sagovercurrent suppressionadaptive regulation
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