引入网侧电感电流修正量的LCL逆变控制器及其状态估计

LCL Inverter Controller With Grid-Side Inductor Current Correction and Its State Estimation

相较于单L滤波器,LCL滤波器可在有效滤除高次谐波的同时减小滤波器的体积、降低滤波器的功率损耗。为解决LCL滤波器的谐振以及网侧电感电流畸变等问题,提出了在单电感型并网电流控制策略的基础上引入网侧(或逆变器侧)电感电流修正量的控制策略。因在引入电流修正量时,须在非反馈侧安装电流传感器,为避免添加电流传感器带来的成本问题,利用二维状态观测器估计网侧电感电流,在不增加设备成本基础上有效观测网侧电感电流。仿真和实验结果验证了所提策略的可行性。

Compared with single L filter,LCL filter can reduce volume and power loss, meanwhile filtering out higher harmonics effectively. To solve problems with LCL filters such as resonance and grid-side current distortion, this paper proposes a strategy introducing grid-side（or inverter-side） current correction on basis of single inductor grid current control scheme. Since current sensor must be installed in non-feedback side when introducing current correction, in order to eliminate cost increase caused by additional sensor, a two-order state observer is used to effectively estimate grid-side current.Finally, feasibility of the new control strategy is verified with simulation and experiment.