三相并网逆变器微分平坦控制策略

对并网逆变器的控制传统方式通常将非线性系统线性化后设计控制器,根据微分平坦理论直接对并网逆变器设计非线性控制器。首先建立了并网逆变器的数学模型,根据微分平坦理论基本定义证明了并网逆变器具有平坦性,并设计相应的控制器。控制器主要分为两部分:参考轨迹生成和轨迹实现,轨迹生成是指在选取合适系统平坦输出量在空间规划状态变量的参考轨迹,轨迹实现部分则利用前馈参考轨迹和反馈误差补偿量根据系统状态方程生成并网逆变器的输入控制量,同时前馈量处于控制系统的主导地位使得整个系统的动态性能得到提高。最后通过搭建仿真模型验证了文中提出的控制策略的有效性。

Control Strategy of Three-phase Gird-Connected Inverter Based on Differential Flatness

Traditional controller of grid-connected inverter usually was designed after linearization of the nonlinear system, a nonlinear controller of inverter was designed directly based on differential flatness theory. Firstly, a mathematical model of grid-connected inverter was established, according to the basic definition of differential flatness theory proved that grid-connected inverter was flatness, and then the corresponding controller was designed. The controller was consist of two part: expected trajectory generation and trajectory implementation. Trajectory generation part is to plan the trajectory of state variables based the suitable flatness output of the system, and the implementation part was utilized the feedforward reference trajectory and feedback error compensation according the state equations to generate the input control variables, the dynamic performance of system was improved because of the feedforward in dominant position. Finally, a simulation model was constructed to verify the proposed control strategy.