Some Typical Application Research Of Advanced Control Method

With the development of science and technology,control systems need to possess much high performance in industrial processes,the traditional PID control method is hard to obtain a higher performances,thus,it is necessary to do some practical design and research of the advanced control method for improving industrial system perfor-mance.This dissertation investigates design and application for some advanced control algorithms with many control issues in traditional industry systems.The main results and contribution are as below:1.For induction motor system,the two basic control strategies such as field orient control method and direct torque control are introduced and analyzed in details.In addition,considering the voltage source inverter only can produce finite output voltage without pulse wide modulator,motivated by this idea,the so-called finite control set model predictive control(FCS-MPC)is proposed,such as predictive torque control and predictive current control.The comparison and experimental analysis for these four control methods are also given and summarized.In addition,considering influence of system load torque disturbances and parameter uncertainties.The disturbance observer technique is adopted to suppress such disturbances and uncertainties.Simulation and experimental results show the effectiveness of the proposed method.2.Considering the fact that the speed loop control period and the current loop con-trol period are becoming smaller or even vanishing for permanent magnet synchronous motor(PMSM)system.In this case,neglecting the current dynamics will degrade the closed loop performance.Thus a second-order model of speed loop which is built for describing the relationship between the reference q-axis current and speed.A finite time integral sliding mode(FTISM)controller is designed based on such a model.Moreover,considering the nature chattering problem of sliding mode control method,for reducing chattering of PMSM system,a feed-forward compensation term based on disturbance observation(DOB)for estimating the lumped disturbances is combined with the FTISM feedback term.This feed-forward compensation design helps to select a smaller switch-ing gain which can reduce chattering.Comparative studies are also carried out by experiments.3.Aiming to improve the performance of the controlled DC-DC buck converter system with mismatched/matched disturbances which act not the sa^me channel with control input,an extended state observer(ESO)based sliding-mode control method is developed to completely counteract the mismatched/matched disturbances for DC-DC system.By fully taking into account the estimation value of disturbances,a dynamic sliding mode surface is firstly designed which is insensitive to not only matched dis-turbances but also mismatched ones.As a result,the DC-DC buck converter system output voltage can be driven to the reference signal asymptotically by sliding motion along the sliding mode surface.Note that the sliding mode surface here is specific since an estimate of the mismatched disturbances based on ESO is introduced.Moreover,a better convergence performance and a stronger disturbance rejection ability against mismatched resistance load disturbances are achieved with the proposed control scheme,which has been shown by simulation and experimental results.In addition,Considering that the finite time control has better convergence character and robustness,finite time disturbance observer based nonsingular terminal sliding mode controller is also designed for DC-DC converter system.Simulation and experimental comparison are also given to show the effectiveness.4.The above research focus on the state feedback control,finite-time output feed-back control for DC-DC buck switched power converters in current sensor-less mode is proposed,it can reduce the hardware cost.A finite-time state feedback controller is first built by utilizing a recursive design method,then a novel reduced-order observer,rather than conventional full-order observer,is derived to estimate the unmeasurable state of the DC-DC buck system with a finite-time convergence rate.The output feedback con-trol law built by combining the state-feedback control law and the estimated system state from the observer is proved to be effective with a stability analysis.Different from non-singular terminal sliding mode control,the proposed method is continuous.Sim-ulations and experimental comparison results verify the effectiveness of the proposed control method with different power.