Abstract:
In order to alleviate the power oscillation problem caused by the integration of renewable energy into the grid, an improved method for the control circuit of the virtual synchronous generator(VSG) was proposed. An analysis was conducted on the existing models, and detailed explanations were provided for the active and reactive power control loops. The synergetic control theory was introduced based on the traditional droop control, and a synergetic controller for the active and reactive parts was designed. The corresponding controller outputs were added to the two control loops in the form of negative feedback, completing the improvement of the original model. This method established parameter connections between active and reactive control loops through state variables in macro-variables, achieving synergetic control of the two loops. Compared with the control results of the original model, the results show that adding a feedback loop can reduce the output power and frequency oscillation of the virtual synchronous generator, proving the effectiveness of this strategy. Compared with single synergetic feedback control, the dual synergetic feedback control form can further reduce the output overshoot of the system in the case of a three-phase short-circuit fault, and the state variables can achieve stable control within 0.5 s. The analysis of the impact of synergetic control parameters provides a reference for the selection of later parameters.