考虑负荷变化的VSG并网模型预测有功补偿控制方法

Predictive Active Power Compensation Control Method for VSG Grid-connected Model Considering Load Variation

随着负荷类型复杂多变,传统虚拟同步发电机难以应对不确定性环境带来的诸多挑战。为此,本文提出一种模型预测控制方法来设计补偿环节,旨在优化负荷大幅度变化情况下虚拟同步发电机并网控制的鲁棒性。首先,根据虚拟同步发电机基本原理建立系统离散形式的状态方程;其次,考虑负荷变化引起的并网点电压和频率波动,将多种输入绝对误差值的二次型形式作为模型预测控制的代价函数,并将其赋予权重,预测输出值补偿至有功功率输入环节中,进而减少负荷波动对中低压配电网的影响;最后,通过Matlab/Simulink平台验证该方法在单节点和IEEE33节点网络上具有可行性。实验结果表明,相比于传统控制方法,该方法具有很强的暂态鲁棒性,响应时间降低82%以上,同时有效改善了多组虚拟同步发电机产生的欠阻尼现象。

Along with the complexity and variability of load types,traditional virtual synchronous generators(VSGs)are struggling to cope with the challenges posed by uncertain environments.Under this background,a model predictive control(MPC)method is proposed in this paper to design a compensation link for optimizing the robustness of VSG grid-connected control under large load variations.First,the state equations of the system in discrete form are established based on the basic principles of VSG.Second,the voltage and frequency fluctuations at the grid-connected point caused by load variations are considered,the quadratic form of multiple input absolute error values is used as the cost function of MPC,and the corresponding weights are assigned.The predicted output values are compensated into the active power input link,which in turn reduces the impact of load fluctuations on low-and medium-voltage distribution networks.Finally,the Matlab/Simulink platform is used to verify the feasibility of the proposed method on single-node and IEEE 33-node networks.Experimental results show that it has strong transient robustness compared with the traditional control method,and the response time is reduced by more than 82%.Meanwhile,the underdamping phenomenon caused by multiple VSGs is effectively improved.