基于VVVF调压的人造金刚石压机压力控制系统设计

Precise Pressure Control System Design for Man-made Diamond Synthetic Machine Based on VVVF Pressure Regulation

深入分析基于变频器调压的人造金刚石压力控制系统的特性,建立了该系统的数学模型和仿真模型。由于系统参数存在大时变,传统PID控制由于缺乏适应性,控制效果差。为解决这一问题,提出了一种依据压力变化率以一定规则在线调整参数的变参数PI控制方法。该方法简单实用、易于在工控PLC上实现。仿真结果和理论实践表明,该方法控制精度高、自适应性强,在系统参数大幅度变化时仍能保持良好控制效果。因此,该方法提供了一种有效途径,完满解决目前人造金刚石装备中普遍存在的压力控制粗糙导致金刚石合成质量不稳定问题。

The pressure control system of the man-made diamond synthetic machine using VVVF motor as pressure regulation was studied in depth and its mathematical model and simulation model were established, Due to the large time-variable of the system parameters, the bad adaptability of the conventional PID control results in poor controlling effects, To handle these problems, a parameter-variable PI controller was proposed, in which the Pl parameters were on-line adjusted according to the derivative of the system pressure in a specific way. The simulation results show that this controller has characteristics of high control precision and well adaptability; it works well even when the system parameters change greatly. Furthermore, this controller has a simple structure and is easy to realize in industrial Programmable Logic Controller （PLC）, hence it gives an effective ways to solve the present problem of unstable quality of the synthetic diamond caused by imprecise pressure control of the synthetic machine.