一种非线性微分PID控制器及应用研究

针对常规PID控制器中的微分作用虽可加快系统响应但很容易引起执行机构过度动作而加快磨损这一问题,提出一种由速率限制环节代替实际微分中的惯性环节而构成新型非线性微分的方法.该微分具有实际微分的微分特性,且其微分作用不仅与输入变化速率有关还与输入幅度有关.利用该非线性微分获得一种非线性微分PID控制器,将其应用于串级主汽温控制系统中,在Simulink环境中进行给定值扰动和输出扰动实验仿真.结果表明,给定值扰动时非线性微分P1D控制器在系统响应方面和控制器输出方面均优于常规PID控制器；输出扰动时,小扰动时非线性微分PID控制器相当于PI控制器,避免执行机构磨损；大扰动时非线性微分PID不仅可以更快消除扰动,保证设备安全运行,而且控制器输出曲线明显优于PID,避免执行机构磨损.

One Nonlinear Differential PID Controller and Its Application Research

The differential effect of the conventional PID controller can speed up system response,but it is easy to cause wear for actuators excessive movement.In order to solve this problem,this paper presents a new method that a new nonlinear differential is structured by rate limiter instead of the inertial link in actual differential.It is of the differential properties,and the differential effect is relavent with not only the change rate of input but also the amplitude of input.A nonlinear differential PID controller maked by the nonlinear differential is applied to cascade control system of main steam temperature.In Simulink environment,a given value disturbance and output disturbance simulation experiment have been done.The results show that,with a given value disturbance nonlinear differential PID controller in the system response and the controller outputs are better than those of PID controller.With little output disturbance,nonlinear differential PID controller is equal to a PI controller which can avoid actuators wear.When output disturbance is large,not only it can eliminate disturbance quickly to ensure the safe running of the equipment,but also its controller outputs is better than PID controller output,which can protect actuators from being worn.