基于新型滑模变结构策略的交流调速系统

AC Variable Speed Drive Based on a New Sliding-Mode Variable Structure Strategy

在交流传动系统设计中,通常采用电机的简化、降阶模型作为设计模型,因此,若采用经典线性控制设计,则实际系统中存在的电机参数不确定性、未建模动态及外扰必然对动、静态性能构成冲击。利用滑模控制在处理不确定性和外扰方面的优势,文章提出了一种基于新型滑模变结构策略的交流调速系统控制方案,采用滑模变结构控制环节与PI串联的结构,在瞬态过程中变结构为主导以提高鲁棒性,稳态过程中PI控制起主导作用以削弱振颤。仿真结果表明该方案在解决传统滑模控制振颤及等价控制设计困难等问题的同时,实现了优良的动、静态特性。

During design of AC drive system,simplified and/or reduced-order models of AC machines are usually used as design models,as the result,for control design based on classical linear controllers,the control performance,both in steady-state and transient-state,will be impacted by inevitable parameters uncertainties,un-modeled dynamic and external disturbance.Take advantages of sliding-mode control in dealing with uncertainties and perturbances,this paper proposes a control scheme of AC variable speed drive based on a new sliding-mode variable structure strategy,which combines sliding-mode variable structure control(SMVSC) with PI.SMVSC is dominant in transient to archive robustness,and PI control plays a leading role to suppress chattering during steady-state process.Simulation results indicate that the proposed strategies eliminate difficulty in chattering and equivalent control design of traditional SMVSC,perfect transient and steady-state characteristic are both achieved.