Showing 15 results for Sliding Mode Control
J. Ghazanfari, M. Maghfoori Farsangi,
Volume 9, Issue 3 (9-2013)
Abstract
In this paper, a robust Maximum Power Point Tracking (MPPT) for PV array has been proposed using sliding mode control by defining a new formulation for sliding surface which is based on increment conductance (INC) method. The stability and robustness of the proposed controller are investigated to load variations and environment changes. Three different types of DC-DC converter are used in Maximum Power Point (MPP) system and the results obtained are given. The simulation results confirm the effectiveness of the proposed method in the presence of load variations and environment changes for different types of DC-DC converter topologies.
M. Azadegan, S. Ozgoli, H. Taghirad,
Volume 10, Issue 3 (9-2014)
Abstract
This paper proposes a new bilateral control scheme to ensure both transparency and robust stability under unknown constant time delay in stiff environment. Furthermore, this method guaranties suitable performance and robust stability when transition occurs between soft and stiff environments. This framework is composed of an adaptive sliding mode controller and an adaptive impedance controller, where online estimation of the environment impedance is performed, and then used as the desired impedance at the master side. Numerical simulations are provided to verify the theoretical results under different conditions, such as constant and time-varying delay, obstructed environment and transitioning between soft and stiff environment. Afterwards, comparison with a recent work is addressed.
V. Behnamgol, A. R. Vali,
Volume 11, Issue 2 (6-2015)
Abstract
In this paper, we extend the sliding mode idea to a class of unmatched uncertain variable structure systems. This method is achieved with introducing a new terminal sliding variable and the finite time stability of proposed method is proved using a new particular finite time condition in both reaching and sliding phases. In reaching phase new sliding mode controller is derived to guarantee the finite time stability of sliding surface with considering matched uncertainty. Also in sliding phase, because of introducing a new terminal sliding variable, the finite time stability of state variables with considering unmatched uncertainty has been guarantee. Therefore in proposed algorithm we are able to adjust reaching and sliding times in the presences of both matched and unmatched uncertainty. This algorithm is applied to designing control law for a moving cart system with bounded matched and unmatched uncertainties. Simulation results show the effectiveness and robustness of the proposed algorithm.
H Moradi, V Johari Majd,
Volume 11, Issue 4 (12-2015)
Abstract
This paper develops a new method of integral sliding mode control redesign for a class of perturbed nonlinear dissipative switched systems by modifying the dissipativity-based control law that was designed for the unperturbed systems. The nominal model is considered affine with matched and unmatched perturbations. The redesigned control law includes an integral sliding-based control signal such that the system always operates on the sliding mode and the dissipativity of the perturbed switched system is maintained from the initial time of the system operation for the norm bounded perturbations. The proposed techniques eliminates the restrictive design conditions on the derivative of storage functions offered in a recent work. In addition, the global dissipativity of the perturbed system is always maintained if the original unperturbed system is globally dissipative. Depending on the type of stability of the unperturbed system, the designed control law for the perturbed system guarantees robust exponential or asymptotic stability of the closed-loop system. The theoretical results are applied to nonlinear switched systems, and the convergence of the state vectors to the origin is verified by simulation in presence of nonlinear perturbations.
A. Safari, H. Ardi,
Volume 14, Issue 1 (3-2018)
Abstract
In this paper, sliding mode control (SMC) for a bidirectional buck/boost DC-DC converter (BDC) with constant frequency in continuous conduction mode (CCM) is discussed. Since the converter is a high-order converter, the reduced-order sliding manifold is exploited. Because of right-half-plan zero (RHPZ) in the converter’s duty ratio to output voltage transfer function, sliding mode current controller is used. This controller benefits from various advantages such as fast dynamic response, robustness, stable and small variation of the settling time over a wide range of operation conditions. Because the converter operates in both step-down and step-up modes, two sliding manifold is derived for each mode. The existence and stability conditions are analyzed for both SMC in step-down and step-up modes. Finally, Simulation results are also provided to justify the feasibility of the controller using MATLAB/Simulink.
H. Benbouhenni, Z. Boudjema, A. Belaidi,
Volume 14, Issue 4 (12-2018)
Abstract
This paper applied second order sliding mode control (SOSMC) strategy using artificial neural network (ANN) on the rotor side converter of a 1.5 MW doubly fed induction generator (DFIG) integrated in a wind turbine system. In this work, the converter is controlled by a neural space vector modulation (NSVM) technique in order to reduce powers ripples and total harmonic distortion (THD) of stator current. The validity of the proposed control technique applied on the DFIG is verified by Matlab/Simulink. The active power, reactive power, torque and stator current are determined and compared with conventional control method. Simulation results presented in this paper shown that the proposed control scheme reduces the THD value and powers ripples compared to traditional control under various operating conditions.
S. Haghighatnia, H. Toossian Shandiz,
Volume 15, Issue 2 (6-2019)
Abstract
A novel nonlinear fractional order sliding mode controller is proposed to control the chaotic atomic force microscope system in presence of uncertainties and disturbances. In the design of the suggested fractional order controller, conformable fractional order derivative is applied. The stability of the scheme is proved by means of the Lyapunov theory based on conformable fractional order derivative. The simulation results show the advantages of the designed controller such as fast convergence speed, high accuracy and robustness against uncertainties and disturbances.
R. Babaie, A. F. Ehyaei,
Volume 15, Issue 2 (6-2019)
Abstract
In this paper, using the State Dependent Riccati Equation (SDRE) method, we propose a Robust Optimal Integral Sliding Mode Controller (ROISMC) to guarantee an optimal control law for a quadrotor which has become increasingly important by virtue of its high degrees of manoeuvres ability in presence of unknown time-varying external disturbances and actuator fault. The robustness of the controller is ensured by an Integral Sliding Mode Controller (ISMC). Subsequently, based on Luenberger linear state estimator, the control algorithm is reformed and the actuator’s faults are detected. Moreover, design of the controller is based on Lyapunov method which can provide the stability of all system states during the tracking of the desired trajectory. The stability of suggested algorithm is verified via the execution of sudden maneuvers subjected to forcible wind disturbance and actuator faults while performing accurate attitude and position tracking by running an extensive numerical simulation. It is comprehended that the proposed optimal robust method can achieve much better tracking capability compared with conventional sliding mode controller.
H. Benbouhenni,
Volume 15, Issue 3 (9-2019)
Abstract
This article presents a sliding mode control (SMC) with artificial neural network (ANN) regulator for the doubly fed induction generator (DFIG) using two-level neural pulse width modulation (NPWM) technique. The proposed control scheme of the DFIG-based wind turbine system (WTS) combines the advantages of SMC control and ANN regulator. The reaching conditions, robustness and stability of the system with the proposed control are guaranteed. The SMC method which is insensitive to uncertainties, including parameter variations and external disturbances in the whole control process. Finally, the SMC control with neural network regulator (NSMC) is used to control the stator reactive and a stator active power of a DFIG supplied by the NPWM strategy and confirms the validity of the proposed approach. Results of simulations containing tests of robustness and tracking tests are presented.
S. M. Hoseini, N. Vasegh, A. Zangeneh,
Volume 16, Issue 2 (6-2020)
Abstract
In this paper, a robust local controller has been designed to balance the power for distributed energy resources (DERs) in an islanded microgrid. Three different DER types are considered in this study; photovoltaic systems, battery energy storage systems, and synchronous generators. Since DER dynamics are nonlinear and uncertain, which may destabilize the power system or decrease the performance, distributed robust nonlinear controllers are designed for the DERs. They are based on the Lyapunov stabilization theory and super-twisting integral sliding mode control which guarantees system stability and optimality simultaneously. The reference signals for each DER are generated by a supervisory controller as a power management system. The controllers proposed in this work are robust, have fast response times, and most importantly, the control signals satisfy physical system constraints. The designed controller stability and effectiveness are also verified using numerical simulations.
A. Zakipour, K. Aminzare, M. Salimi,
Volume 18, Issue 3 (9-2022)
Abstract
Considering the presence of different model parameters and controlling variables, as well as the nonlinear nature of DC to AC inverters; stabilizing the closed-loop system for grid current balancing is a challenging task. To cope with these issues, a novel sliding mode controller is proposed for the current balancing of local loads using grid-connected inverters in this paper. The closed-loop system includes two different controlling loops: a current controller which regulates the output current of grid-connected inverter and a voltage controller which is responsible for DC link voltage regulation. The main features of the proposed nonlinear controller are reactive power compensation, harmonic filtering and three-phase balancing of local nonlinear loads. The developed controller is designed based on the state-space averaged modelling its stability and robustness are proved analytically using the Lyapunov stability theorem. The accuracy and effectiveness of proposed controlled approach are investigated through the PC-based simulations in MATLAB/Simulink.
M. Ehsani, A. Oraee, B. Abdi, V. Behnamgol, S. M. Hakimi,
Volume 19, Issue 1 (3-2023)
Abstract
A novel nonlinear controller is proposed to track active and reactive power for a Brushless Doubly-Fed Induction Generator (BDFIG) wind turbine. Due to nonlinear dynamics and the presence of parametric uncertainties and perturbations in this system, sliding mode control is employed. To generate a smooth control signal, dynamic sliding mode method is used. Uncertainties bound is not required in the suggested algorithm, since the adaptive gain in the controller relation is used in this study. Convergence of the sliding variable to zero and adaptive gain to the uncertainty bound are verified using Lyapunov stability theorem. The proposed controller is evaluated in a comprehensive simulation on the BDFIG model. Moreover, output performance of the proposed control algorithm is compared to the conventional and second-order sliding mode and proportional-integral-derivative (PID) controllers.
G. Hamza, M. Sofiane, H. Benbouhenni, N. Bizon,
Volume 19, Issue 2 (6-2023)
Abstract
In this paper, a wind power system based on a doubly-fed induction generator (DFIG) is modeled and simulated. To guarantee high-performance control of the powers injected into the grid by the wind turbine, five intelligent super-twisting sliding mode controllers (STSMC) are used to eliminate the active power and current ripples of the DFIG. The STSMC controller is a high-order sliding mode controller which offers high robustness compared to the traditional sliding mode controller. In addition, it reduces the phenomenon of chattering due to the discontinuous component of the SMC technique. However, the simplicity, ease of execution, durability, and ease of adjusting response are among the most important features of this control compared to some other types. To increase the robustness and improve the response of STSMC, particle swarm optimization method is used for this purpose, where this algorithm is used for parameter calculation. The simulation results obtained using MATLAB software confirm the characteristics of the designed strategy in reducing chattering and ensuring good power control of the DFIG-based wind power.
Somayeh Rajabi, Hadi Chahkandi Nejad, Majid Reza Naseh,
Volume 20, Issue 0 (12-2024)
Abstract
In this paper, a Lyapunov-based adaptive 2nd order sliding mode controller is proposed to control the current in an active power filter (APF). The penetration of the APFs has been exponentially increased because of their high flexibility and less resonance problems. Moreover, they can compensate high range of current harmonics and reactive power. The voltage and current control loops have always been an interesting area for researchers since the satisfactory performance of the APF is highly dependent to these control loops. Sliding mode controller (SMC) is a mighty controller when uncertain conditions are considered. However, in order to reduce the chattering- high-frequency switching- and improve the steady state operation, stability, and robustness of the controller, it is usually decided to adaptively tune the gains of the controller. In this paper, a simple-structure adaptive SMC (ASMC) is proposed which can be implemented easily. This ASMC is showed to be stable using the Lyapunov theorem and proved with SIMULINK simulation that has less steady state error, less chattering, and faster dynamic response compared to the conventional SMC.
Abolfazl Masnabadi, Mehdi Asadi,
Volume 20, Issue 1 (3-2024)
Abstract
This paper proposed a control system for the battery charger of a solar vehicle. The battery charger has two parts, boost converter and isolated DC/AC/DC converter. The boost converter is controlled by a proposed control system based on sliding mode. In this controller, the MPPT is implemented by an extreme point of the solar cell P-V curve. Also, the control system of the DC/AC/DC converter is based on sliding mode with consideration of uncertainties of the output filter. A fast charging algorithm based on variable frequencies was carried out by the presented control system and charging of a Lithium-ion battery was done during 20 min from SOC 20% to SOC 80%. The simulation results show control system effectiveness.
