带参数辨识功能的三电平变换器高效模型预测控制方法
An Efficient Model Predictive Control for Three-Level Converters With the Function of Parameter Identification
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摘要: 三电平PWM变换器在工业领域尤其是中高压大功率场合得到了广泛应用。在实际运行中,受现场环境及温度等因素的影响,系统的参数可能会发生改变,从而影响控制效果。模型预测控制具有优秀的多目标优化控制能力以及灵活的约束处理能力,在三电平变换器控制领域得到了广泛重视和研究。现有的三电平PWM变换器模型预测控制方法在获得最优电压矢量时需要大量的计算并且依赖于精确的电感参数,存在计算量大和鲁棒性差等问题。针对以上问题,本文首先提出了一种改进的模型预测控制方法,极大地减小了系统选取最优电压矢量时的计算量,进一步通过引入基于递推最小二乘法的电感在线辨识算法,提高了系统的参数鲁棒性。仿真和实验结果表明,本文提出的简化模型预测控制算法具有良好的动静态性能以及参数鲁棒性。Abstract: Three-level PWM converters have been widely used in the industrial field especially in the high voltage and high power applications. In practical applications, the parameters of the system may change due to the variation of working environment and temperature, which will deteriorate the control performance. Model predictive control (MPC) has the merits of multivariable control and flexibility to handle various constraints, which receives wide study and attention in the area of three-level converter control. The existing MPC for three-level PWM converters requires many calculations and accurate inductance value to select the optimal voltage vector, which has the problems of huge computation and poor robustness. To solve these problems, an efficient MPC method is proposed in the paper, which greatly reduces the computational burden when selecting the optimal voltage vector. By further introducing the online inductance identification technique, the system robustness is improved. Both simulation and experimental results confirm the effectiveness of the proposed methods in terms of steady-state performance, dynamic response and robustness against parameter variation.