基于满意优化的三电平PWM整流器瞬时开关频率抑制方法
发布时间：2018-09-08 07:01
【摘要】：提出一种新型的基于满意优化的三电平脉冲宽度调制(pulse width modulation,PWM)整流器有限控制集模型预测控制(finite control set model predictive control,FCS-MPC)方法,将满意优化思想引入模型预测控制的在线规划中,代替传统方法中的权值函数,避免了复杂的加权系数整定过程。然而受到电力电子系统结构的限制,三电平PWM整流器仅可输出27种可行电压矢量,过多的控制约束被引入后,极易造成系统优化无解。该文采用几何分析法揭示了优化无解现象的产生原理,并论证了其与瞬时开关频率过高问题之间的内在联系。通过约束松弛的方式弱化满意和失控的界限,使低优先级指标可以参与在线规划。仿真和实验结果表明,该方法在保证系统功率、中点电位等多项指标达到期望满意度的前提下,最大限度的降低了开关动作频率,避免了高采样频率造成器件局部过热损坏。与经典矢量控制的对比结果可知,在较低的开关频率下(fs≈300 Hz)所提方法可获得更优异的动、稳态性能。
[Abstract]:A new method of finite control set predictive control (finite control set model predictive control,FCS-MPC) for three-level pulse width modulation (pulse width modulation,PWM) rectifier based on satisfactory optimization is proposed. The idea of satisfactory optimization is introduced into the on-line planning of model predictive control. Instead of the weight function in the traditional method, the complex weighting coefficient tuning process is avoided. However, due to the limitation of the power electronic system structure, the three-level PWM rectifier can only output 27 feasible voltage vectors. When too many control constraints are introduced, it is easy to cause the system optimization without solution. In this paper, the geometric analysis method is used to reveal the principle of the problem of optimization without solution, and the internal relationship between the problem and the problem of excessive instantaneous switching frequency is demonstrated. The limits of satisfaction and runaway are weakened in the way of constraint relaxation, so that the low priority index can participate in online planning. The simulation and experimental results show that the method can reduce the switching frequency and avoid the local overheating damage caused by high sampling frequency on the premise that the system power and midpoint potential can reach the desired satisfaction. Compared with classical vector control, the proposed method can obtain better dynamic and steady performance at lower switching frequency (fs 鈮，
本文编号：2229724
[Abstract]:A new method of finite control set predictive control (finite control set model predictive control,FCS-MPC) for three-level pulse width modulation (pulse width modulation,PWM) rectifier based on satisfactory optimization is proposed. The idea of satisfactory optimization is introduced into the on-line planning of model predictive control. Instead of the weight function in the traditional method, the complex weighting coefficient tuning process is avoided. However, due to the limitation of the power electronic system structure, the three-level PWM rectifier can only output 27 feasible voltage vectors. When too many control constraints are introduced, it is easy to cause the system optimization without solution. In this paper, the geometric analysis method is used to reveal the principle of the problem of optimization without solution, and the internal relationship between the problem and the problem of excessive instantaneous switching frequency is demonstrated. The limits of satisfaction and runaway are weakened in the way of constraint relaxation, so that the low priority index can participate in online planning. The simulation and experimental results show that the method can reduce the switching frequency and avoid the local overheating damage caused by high sampling frequency on the premise that the system power and midpoint potential can reach the desired satisfaction. Compared with classical vector control, the proposed method can obtain better dynamic and steady performance at lower switching frequency (fs 鈮，
本文编号：2229724
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