中压并网变流器的模型预测直接电流控制

Model Predictive Direct Current Control of Medium Voltage Grid-connected Converter

为了提高三电平中点钳位型中压并网变流器的控制性能,设计了一种新颖的模型预测直接电流控制(MPDCC)策略。新型MPDCC控制器基于虚拟电阻较好地处理了LCL滤波器谐振问题。同时,MPDCC控制器具有较长的预测范围,故基于虚拟电阻的参考项在每个步长内与状态轨迹一起被预测,从而使得控制器做出更准确的决策,获取更高的控制精度。利用仿真平台和实验设备进行了仿真研究和实验验证,结果表明,所提出的方法在电网电压扰动下能表现出较好的稳态特性,同时动态性能也较优。

In order to improve the control performance of the three-level neutral-point-clamped medium voltage grid-connected converter,a novel model predictive direct current control(MPDCC)strategy was designed.The new MPDCC controller better handled the LCL filter resonance problem based on virtual resistors.At the same time,the MPDCC controller has the long prediction horizons,so the reference terms based on the virtual resistance were predicted together with the state trajectories in each step,so that the controller got more accurate decisions and obtained higher control precision.The simulation research and experimental verification were carried out by the simulation platform and experimental equipment.The results show that the proposed method has better steady-state characteristics under the grid voltage distortion,and the dynamic performances are also excellent at the same time.