【摘要】 建立永磁直驱风力发电系统并网逆变器在电网电压不平衡故障下的数学模型。在两相α-β静止坐标系下,设计全阶滑模变结构电流内环控制器,证明控制器的稳定性,达到了非奇异、去抖振的控制效果。电压外环在传统PI调节器的基础上增加了机侧功率前馈,以提高直流母线电压的稳定性。控制器设计无需旋转变换,省去繁琐的锁相、电流正负序分离以及解耦控制,并能根据要求实现不同的控制目标。控制系统具有原理简单、运算量小、易于实现的特点。仿真结果可验证所提方法的正确性、有效性。更多还原

【Abstract】 A mathematical model of the grid connected inverter under unbalanced grid voltages is built. Control strategy of the DC voltage was designed,and the motor side power was feed-forward in this strategy:a novel full-order sliding-mode controller was presented in αβ stationary frame,which allows both chattering and singularity problems to be resolved:the different current references to achieve different targets are calculated. In the proposed method,all targets can be obtained without the need of grid voltage phase detecting,separation of positive and negative sequence of the current,decoupling control or rotating transformation,which offers a simple and easy control method for grid connected inverter compared with the traditional method. The correctness and effectiveness of the proposed control strategy is validated by simulation results.更多还原