scholarly journals Current PIλ Control of the Single-Phase Grid Inverter

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xueqin Yang ◽  
Xingyu Liu ◽  
Jichao Li ◽  
Binbin Zhang
Keyword(s):  
Control System ◽  
Steady State ◽  
Fractional Order ◽  
Single Phase ◽  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Pi Controller ◽  
Fractional Order Pi Controller ◽  
Control System Model ◽  
Steady State Performance

In a grid-connected power generation system, the grid-connected current of the inverter is sensitive to nonlinear factors such as periodic disturbance of grid voltage, which results in grid-connected current waveform distortion. By establishing a single-phase photovoltaic grid-connected inverter control system model, designing an inverse current fractional-order PI (PIλ or FO-PI) controller and the dynamic and steady-state performance, antidisturbance and grid connection inversion characteristics of the system are simulated and compared under the action of the integer-order PI controller and fractional-order PI controller. The quality of the inverter grid-connected current is analyzed by using the fast Fourier transform (FFT). The simulation results show that the fractional-order control system can reduce the total harmonic distortion (THD) of the grid-connected current and dynamic performance and antidisturbance ability of the improving system while satisfying the steady-state performance indexes.

scholarly journals Robust control strategy for improving the performance of a soft robotic link

2021 ◽  
pp. 499-506
Author(s):  
Luis Nagua ◽  
Jorge Muñoz ◽  
Lisbeth Mena ◽  
Concepcion A. Monje ◽  
Carlos Balaguer
Keyword(s):  
Control System ◽  
Robust Control ◽  
Fractional Order ◽  
Control Strategy ◽  
Parallel Mechanism ◽  
Pi Controller ◽  
Main Element ◽  
Flexion Extension ◽  
Robust Control System ◽  
Fractional Order Pi Controller

The robotic neck mechanism considered in this paper has as main element a soft link that emulates a human neck with two DOF (flexion, extension and lateral bending). The mechanism is based on a Cable-Driven Parallel Mechanism (CDPM) with components easy to manufacture in a 3D printer.Due to the soft link properties and the platform mechanics, it is important to provide a robust control system. Two designs, a robust PID controller and a Fractional Order PI controller (FOPI) are proposed and compared, the fractional order control showing an enhanced performance. Both control approaches are tested in the real prototype, validating the soft neck feasibility and showing the robustness of the platform to mass changes at the neck tip.

scholarly journals Evaluation of SIPIC01 and SIPIC02 on Motor Speed Control

2018 ◽  
Vol 152 ◽  
pp. 02010
Author(s):  
Kah Kit Wong ◽  
Choon Lih Hoo ◽  
Mohd Hardie Hidayat Mohyi
Keyword(s):  
Control System ◽  
Steady State ◽  
Dynamic Performance ◽  
Pi Controller ◽  
Settling Time ◽  
Motor Speed ◽  
Proportional Integral ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Decoupling Effect

Due to its simplicity, Proportional-Integral (PI) controller still remains as the widely used controller for motor speed control system. However, PI controller exhibits windup phenomenon when the motor operates in a saturated state, which may cause degradation to the control system. In order to overcome the windup phenomenon, many researches have introduced various types of anti-windup methods such as the Conditioning Technique (CI), Tracking Back Calculation (TBC), Integral State Prediction (ISP), Steady-state Integral Proportional Integral Controller-01 (SIPIC01) and Steady-state Integral Proportional Integral Controller-02 (SIPIC02). These are anti-windup techniques with integral control switching mechanism, coupling of proportional gain, kp, and integral gain, ki. Due to the coupled kp and ki, tuning motor performance is a difficult task with short settling time without experiencing overshoot. SIPIC01 and SIPIC02 are robust anti-windup methods without a switching mechanism and exhibit decoupling feature. SIPIC01 and SIPIC02 have shown better dynamic performance compared to CI, TBC and ISP. However, SIPIC01 has not been compared to SIPIC02 in terms of their decoupling effect flexibility and dynamic performance. The decoupling effect was verified using MATLAB simulation, while the performance analysis was verified through hardware simulation and testing by using Scilab. The results obtained from the simulation showed that both SIPIC01 and SIPIC02 consist of decoupling features that allow a performance with coexistence of zero or minimum overshoot with short settling time. However, SIPIC02 consists of longer rise and settling time as compared to SIPIC01. Therefore, it can be concluded that SIPIC01 is better than SIPIC02 in term of dynamic performance.

Fuzzy Fractional Order Proportional Integral Controllers for UAV Lateral Attitude Control System

2014 ◽  
Vol 716-717 ◽  
pp. 1609-1613 ◽  
Author(s):  
Yi Duo Liu ◽  
Chun Yang Wang ◽  
Ming Qiu Li ◽  
Cheng Jun Tian ◽  
Duan Yuan Bai
Keyword(s):  
Control System ◽  
Fractional Order ◽  
Flight Control ◽  
Attitude Control ◽  
Pi Controller ◽  
System Stability ◽  
Step Response ◽  
Attitude Control System ◽  
Unit Step ◽  
Fractional Order Pi Controller

This article is based on the theory of fractional calculus control, and put forward a kind of fractional order PI controller design method for lateral attitude control system of unmanned aerial vehicle (UAV) model. And the unit step response of the control system is analyzed in the simulation to improve the UAV flight control system stability and robustness. Use the controller parameter tuning method and combined with fuzzy reasoning to design IOPID controller, FOPI controller and fuzzy fractional order PI controller. Then, by exploiting Matlab, the frequency domain response and unit step response characteristics of the different control systems can be plotted. The results verified that the designed fuzzy fractional order controller for the attitude control system is effective.

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