scholarly journals Advanced exponential sliding mode control for microgrid at autonomous and grid-connected modes

2021 ◽  
Vol 10 (1) ◽  
pp. 474-486
Author(s):  
A. Elnady ◽  
Mohammad AlShabi

This paper introduces a novel control scheme for the operation of multilevel inverters forming a microgrid. The core of the suggested control scheme is an advanced (power-rate) exponential sliding mode controller. This developed controller is robust toward any variation of the system’s parameters and loads in addition to its fast and accurate performance. The presented control scheme provides advantageous characteristics to the microgrid operation in an autonomous mode (microgrid mode) and grid-connected mode. In the microgrid mode, the voltages and frequency are stable at any variable balanced and unbalanced load. In the grid-connected mode, an effective procedure for connecting the microgrid to the main grid is proposed to guarantee a seamless and fast transition to the grid-connected mode. The performance of the presented control scheme along with its proposed controller is validated by comparing its results to another linear and non-linear controllers for the same microgrid loading conditions.

2009 ◽  
Vol 23 (16) ◽  
pp. 2021-2034 ◽  
Author(s):  
XINGYUAN WANG ◽  
DA LIN ◽  
ZHANJIE WANG

In this paper, control of the uncertain multi-scroll critical chaotic system is studied. According to variable structure control theory, we design the sliding mode controller of the uncertain multi-scroll critical chaotic system, which contains sector nonlinearity and dead zone inputs. For an arbitrarily given equilibrium point of the uncertain multi-scroll chaotic system, we achieve global stabilization for the equilibrium points. Particularly, a class of proportional integral (PI) switching surface is introduced for determining the convergence rate. Furthermore, the proposed control scheme can be extended to complex multi-scroll networks. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.


Author(s):  
Jun Zhou ◽  
Jing Chang ◽  
Zongyi Guo

The paper describes the design of a fault-tolerant control scheme for an uncertain model of a hypersonic reentry vehicle subject to actuator faults. In order to improve superior transient performances for state tracking, the proposed method relies on a back-stepping sliding mode controller combined with an adaptive disturbance observer and a reference vector generator. This structure allows for a faster response and reduces the overshoots compared to linear conventional disturbance observers based sliding mode controller. Robust stability and performance guarantees of the overall closed-loop system are obtained using Lyapunov theory. Finally, numerical simulations results illustrate the effectiveness of the proposed technique.


Author(s):  
Swati Sucharita Pradhan ◽  
Raseswari Pradhan ◽  
Bidyadhar Subudhi

Purpose The dynamics of the PV microgrid (PVMG) system are highly nonlinear and uncertain in nature. It is encountered with parametric uncertainties and disturbances. This system cannot be controlled properly by conventional linear controllers. H− controller and sliding mode controller (SMC) may capable of controlling it with ease. Due to its inherent dynamics, SMC introduces unwanted chattering into the system output waveforms. This paper aims to propose a controller to reduce this chattering. Design/methodology/approach This paper presents redesign of the SMC by modifying its sliding surface and tuning its parameters by employing water-evaporation-optimization (WEO) based metaheuristic algorithm. Findings By using this proposed water-evaporation-optimization algorithm-double integral sliding mode controller (WEOA-DISMC), the chattering magnitude is diminished greatly. Further, to examine which controller between H8 controller and proposed WEOA-DISMC performs better in both normal and uncertain situations, a comparative analysis has been made in this paper. The considered comparison parameters are reference tracking, disturbance rejection and robust stability. Originality/value WEO tuned DISMC for PVMG system is the contribution.


2013 ◽  
Vol 427-429 ◽  
pp. 1179-1182
Author(s):  
Sheng Bin Hu ◽  
Jin Yuan Xu ◽  
Xuan Wu ◽  
Chi Zhang ◽  
Yi Hao He

A fast terminal fuzzy sliding mode control scheme for the attitude of flapping wing micro aerial vehicle is proposed in this paper. Based on the feedback linearization technique, a fast terminal sliding mode controller is designed. To diminish the chattering in the control input, a fuzzy controller is designed to adjust the generalized gain of fast terminal fuzzy sliding mode controller according to fast terminal sliding mode surface. The stability of the control algorithm is verified by using Lyapunov theory. Simulation results show that the proposed control scheme is effective.


Author(s):  
Mehmet Akar

This paper presents a multiple model/controller scheme for robust tracking of a class of nonlinear systems in the presence of large plant uncertainties and disturbance. Each model is associated with a sliding mode controller, and a switching logic is designed to pick the model that best approximates the plant at each instant. Theoretically, it is shown that the proposed control scheme achieves perfect tracking despite the existence of disturbance, whereas simulation results verify the improvement in the transient performance.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
P. Ahmadi ◽  
M. Golestani ◽  
S. Nasrollahi ◽  
A. R. Vali

A combination of two nonlinear control techniques, fractional order sliding mode and feedback linearization control methods, is applied to 3-DOF helicopter model. Increasing of the convergence rate is obtained by using proposed controller without increasing control effort. Because the proposed control law is robust against disturbance, so we only use the upper bound information of disturbance and estimation or measurement of the disturbance is not required. The performance of the proposed control scheme is compared with integer order sliding mode controller and results are justified by the simulation.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hao Sheng ◽  
Xia Liu

This paper studies the problems of external disturbance and various actuator faults in a nonlinear robotic system. A composite compensation control scheme consisting of adaptive sliding mode controller and observer-based fault-tolerant controller is proposed. First, a sliding mode controller is designed to suppress the external disturbance, and an adaptive law is employed to estimate the bound of the disturbance. Next, a nonlinear observer is designed to estimate the actuator faults, and a fault-tolerant controller is obtained based on the observer. Finally, the composite compensation control scheme is obtained to simultaneously compensate the external disturbance and various actuator faults. It is proved by Lyapunov function that the disturbance compensation error and fault compensation error can converge to zero in finite time. The theoretical results are verified by simulations. Compared to the conventional fault reconstruction scheme, the proposed control scheme can compensate the disturbance while dealing with various actuator faults. The fault compensation accuracy is higher, and the fault error convergence rate is faster. Moreover, the robot can track the desired position trajectory more accurately and quickly.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Salahuddin Abdul Rahman ◽  
Mohamed Zribi ◽  
Nejib Smaoui

This paper deals with the projective synchronization (PS) of two identical discrete-time generalized four-dimensional (4D) hyperchaotic Henon maps using a master-slave configuration. A discrete sliding mode controller (DSMC) scheme is proposed to synchronize the master and the slave systems. The performance of the controlled systems is simulated; the simulation results indicate that the proposed controller works well. In addition, a secure communication scheme is proposed based on the developed control scheme. The validity of the proposed scheme is tested by transmitting an image and simulating the results. The simulation results clearly indicate the effectiveness of the proposed secure communication scheme.


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