逆变式等离子切割电源变间距模糊-PI控制

Variable interval fuzzy-PI control for inverted plasma cutting power supply

针对切割过程的强非线性及不确定性,以逆变式等离子切割电源为研究对象,提出了一种在全论域范围内带有自调整因子的变间距模糊量化算法,并与PI控制结合构成模糊-PI双模控制器。控制算法避免了冗杂的非线性系统建模过程,且本身具有优化的特性,通过模糊-PI双模控制,有效解决了传统模糊算法在提高系统稳态精度和动态性能之间的矛盾。仿真结果表明,与PI控制或模糊控制相比,所设计的双模控制器在稳态性能和鲁棒性两方面都得到了改善。

Focusing on strong nonlinearity and cutting uncertainty of inverted plasma cutting power sup- ply, this paper proposes a fuzzy-PI double-mode controller. It consists of PI control and a new variable interval fuzzy quantification algorithm with self-adjusting factor in full domain introduced in this paper. This algorithm simplifies modeling of nonlinear system. And it has optimization property. Under fuzzy-PI control, this algorithm improves steady-state precision and dynamic performance of system, either of which the conventional algorithm can be realized simultaneously. The simulation result shows that compared with PI controller or fuzzy controller, the double-mode controller improves steady-state performance and robustness as well.