约束分段仿射系统的鲁棒一步预测控制

针对一类具有附加有界扰动的离散时间约束分段仿射系统，提出了一种鲁棒低复杂性的模型预测控制方法，即鲁棒一步控制。首先，基于最大鲁棒正不变集，计算系统的最大鲁棒可稳定集并作为第一步预测状态的约束集，使得产生的滚动时域控制器可以在较小的预测时域内控制最大鲁棒可稳定集。然后，在最大鲁棒正不变集外，通过构建线性矩阵不等式来寻找而二次李雅普诺夫函数以证明其鲁棒稳定性。两个步骤分别确保控制器的可行性和闭环系统的鲁棒稳定性。大量的仿真例子表明，和已有的控制方法相比，所得的鲁棒一步控制器具有更低的复杂性。

Fault Diagnosis Technology Based on S Transform in Power Electronics Circuit

A method based on S transform and support vector machines was presented for fault diagnosis of power electronics circuit, in which the S transform time-frequency analysis of fault signal is used to extract the features corresponding to various fault, then fault types are identified through the pattern recognition classifier based on SVM. The simulation result of fault diagnosis of thyristor in three-phase full-bridge controlled rectifier shows that the proposed method can accurately diagnose fault and locate fault element for power electronics circuit, and it has excellent performance on noise robust and training ability, thus it has very good practical value and applicable prospect in the solution to fault question for power electronics circuit.