模糊自适应滑模变结构控制及其在功率放大器中应用

Fuzzy adaptive sliding mode variable structure control and its application in power amplifier

针对目前使用的电力电子器件构成的功率放大器,提出一种新的基于模糊自适应的滑模变结构控制方法。该方法不仅充分体现了滑模控制的优势,克服了其他控制方法动态响应性能不好、总谐波畸变率较大、鲁棒性差等缺陷,而且因为增加了模糊自适应理论,改善了滑模变结构控制方法中的切换控制所产生的抖振。模糊自适应控制器由模糊化、规则库、模糊推理和反模糊化4部分组成。选择可解决学习算法收敛速度慢问题的模糊基函数作为模糊自适应控制函数,在非线性函数的基础上,对系统进行一系列基函数展开,通过参考值和反馈输出之间的误差不断修正基函数的权,从而达到学习的目的。仿真和试验结果表明该控制策略对系统参数和负载扰动具有很强的鲁棒性,系统动、静态性能良好。

A control strategy based on fuzzy adaptive SMVSC（Sliding Mode Variable Structure Control） is proposed for power amplifier composed of power electronics. It makes full use of advantages of SMVSC,such as excellent dynamic response,lower THD（Total Harmonic Distortion） and better robustness,and also effectively eliminates the chattering caused by SMVSC during switching by introducing the fuzzy adaptive theory. The fuzzy controller consists of fuzzy,rules, fuzzy reasoning and de-fuzzy. A series of fuzzy basis functions,being effective to improve the slow convergence speed of learning algorithms ,are adopted as the control functions and expanded based on nonlinear functions. The error between the reference and the feedback output is used to correct the weight of the basis function for learning. Simulation and experiment results show its good static and dynamic performance ,as well as robustness against system parameter variations and load disturbances.