The state of energy (SoE) is a critical metric for battery management systems, complementing the state of charge (SoC) in providing comprehensive battery management insights. This paper addresses SoE estimation for lithium-ion batteries by designing a sliding mode observer that utilizes sliding mode control technology to enhance the robustness of the SoE estimation algorithm. Leveraging the correlation between SoC and SoE, this study develops a method to accurately estimate SoC and determine SoE. Additionally, we introduce a sliding mode observer based on the Super-twisting algorithm, which stabilizes the observer by carefully selecting parameters. The effectiveness of the proposed SoE estimation algorithm is validated using Dynamic Stress Test (DST) data, confirming its practical utility.

This paper proposes a novel terminal sliding mode control (TSMC) method for grid-connected voltage source inverters (VSIs) in balanced three-phase three-wire grids. First, the mathematical model of the VSI is built. Then a double-loop TSMC controllers are presented for the DC-link voltage and the grid current respectively. The TSMC approach ensures stable and efficient VSI operation, effectively handling uncertainties and disturbances, and incorporates an LCL filter to enhance harmonic performance and overall power quality. Theoretical analysis and simulation studies validate the effectiveness and superiority of the proposed TSMC method.

This paper presents a study on the control of the neutral point of DC/AC converters connected to an unbalanced 3-phase 4-wire grid. The mathematical models of the converters, including an LCL filter, and the neutral line circuit in both balanced and unbalanced 3-phase 4-wire grids are developed. An active balancing method is employed to maintain the DC bus voltage's zero DC offset voltage. A virtual control technique is implemented in the controller design. Furthermore, a sliding mode control strategy is proposed to regulate the neutral point of DC/AC converters. The efficacy of the proposed approach is demonstrated through simulation results.

In this paper, the research object of the three-phase LCL inverter under the AC microgrid is studied. Transforming the LCL inverter model to the Euler Lagrange (EL) equation and judging the passive characters of the EL model. Based on the theory of passive based control (PBC), a double closed-loop control with PBC control as the inner current loop and PI control as the outer voltage loop is proposed. The superiority of the PBC- PI controller in stabilizing the DC bus voltage and grid-connected current is verified under the conditions of sudden changes in DC side input and sudden changes in grid voltage. The comparative simulation results verified the the proposed strategy has better stability and rapidity.

In recent years, the development and utilization of Lithium-ion batteries have further promoted the development of electric vehicle and related battery management systems. Estimating the battery state of charge (SoC) is essential for battery management systems. Most studies on SoC estimation have focused on model-based observer designing. The sliding mode control strategy is suitable for estimating the battery SoC due to its strong robustness, insensitivity to parameter perturbation and external disturbance, and high estimation accuracy. This paper aims to design a battery SoC estimator using the proposed fuzzy sliding mode control strategy. The fuzzy control logic is introduced to suppress chattering by regulating the switching gain in the sliding mode control law. Firstly, the second-order Thevenin equivalent circuit model of the battery is established. Then a fuzzy sliding mode observer is designed based on the equivalent circuit model to estimate the battery’s SoC. Finally, the designed observer is simulated and verified.

Most of the microgrid inverters are based on PI-based voltage and current double-loop control structure to achieve control target, but the controller parameter setting is complicated and the dynamic response speed is slow. The paper adopt Predictive Models Control (MPC) replace traditional voltage and current double-loop and modulation to improve the dynamic response speed and parameters tuning. In order to maintain the damping character of microgrid and overcome droop control frequency change rate, this paper adopts the strategy of Virtual Synchronous Generator (VSG) in the power loop to make the system have inertia and enhance stability. The simulation comparison verifies the proposed control strategy is effective and the faster response speed.

This article proposes a continuous adaptive integral-type sliding-mode control approach for a class of mechatronic systems by taking into consideration matched and unmatched uncertainties, and uncertainty in the control gain. Four different sliding-mode controllers are designed to enable: 1) the avoidance of the singularity by preventing differentiating the system states with fractional power; and 2) the attenuation of the chattering by utilizing full-order sliding manifolds. The control gain adaptation in the full-order sliding-mode controller is presented to avoid the overestimation of the gain. With the continuous control in place, the mechatronic systems have a fast response with high precision. The soften action from carefully designed controllers with the gain adaptation guarantees the trajectories of the mechatronic systems to move smoothly and prevents damage to the mechanical components of the systems. Both the simulation and experimental results demonstrate the effectiveness and feasibility of the proposed control approach.

This paper proposes a neural network based nonsingular terminal sliding-mode control for the position servo system of induction motors. A systematic design of the position and flux controllers is developed to implement the robust control of induction motors. The proposed method is presented by combining the neural network and the nonsingular terminal sliding-mode control. The method can compensate the uncertainties and enhance the stability of induction motor systems. The controllers can attenuate the chattering phenomenon and can be directly applied in the position servo system of induction motors. The simulations validate the proposed method.

An online estimation algorithm of State-of-Charge (SoC) of Lithium-ion (Li-ion) batteries based on terminal sliding mode (TSM) observer technique is proposed. A first-order RC equivalent circuit model is utilized to describe the dynamical behaviors of Li-ion batteries. A sliding mode observer is developed to track the states of the Li-ion batteries and the control signal of the observer is used to estimate the SoC of a Li-ion battery accurately. The proposed observer is robust to internal parameter uncertainties of the battery model, and the environment changes. Compared with the traditional sliding mode observers, the proposed sliding mode observer has the continuous control signal, which can be used for the SoC estimation algorithm directly. The proposed method has been verified by the estimation results and the effectiveness has benn demonstrated.

A novel active-switched-capacitor-Γ-source inverter (ASCΓSI) is proposed in this paper. Compared to other topologies, the proposed inverter uses a Γ-shape coupled inductor and active-switched-capacitor cell to realize the higher voltage-boost ability, suppress the startup current and realize the continuous input current. The voltage gain can be adjusted by varying the turns ratio nrof Γ-shape coupled inductor within the narrow range of 1r≤ 2, and increase as the turn ratios decreases, which is beneficial to lower the turn ratios in the higher gain. The corresponding topologies and steady operation principles are analyzed. The simulation and experiment results have verified the validity of the theoretical analysis.

The paper firstly establishes a passivity-based control (PBC) of a double-fed inductor generator (DFIG). A new control method of the DFIG is proposed with the outer speed loop controlled by a full-order terminal sliding mode (TSM) controller to undertake maximum wind power point tracking (MPPT), while the inner current control loop is a PBC designed to manage the three-phase PWM rectifier. Simulation results show that the controller design is effective and that the system exhibits satisfactory performance.

Recently, the state estimation issue of a TCP/IP network has attracted much attention from different communities. In this paper, a terminal sliding-mode observer (TSMO) is proposed based on a fluid-flow model of a TCP/IP network to estimate traffic flow states. A novel control strategy is proposed to fasten the convergence of the estimation error for average congestion window (ACwnd). Furthermore, a continuous control strategy is directly used to estimates the flooding rate of additional traffic flow (ATF). The efficacy of the proposed TSMO is verified by a numerical simulation implementations via the networking simulator NS-2.

This paper proposes a full-order terminal sliding-mode based energy saving control for the grid-connected converter of induction motor systems. DC-link voltage and currents controllers of the converter are designed respectively using the full-order terminal sliding manifold and the related control strategies. The chattering in the sliding-mode control is attenuated, and continuous control signals are obtained. The energy-saving operation of the induction motor systems is achieved because the regenerative energy of the induction motor is fed back to the power grid with unity power factor. The simulation results validate the proposed method.

This paper proposes a gain margin technique based continuous sliding-mode control method for position servo systems of induction motors. A systematic design method for position and current controllers is developed to implement the robust control of induction motors in the field orientation control system. In the proposed controllers design, the boundaries of disturbances and parameter perturbations in the control system can be determined in advance based on the upper-bounds of uncertainties in the induction motor model. The gain margin technique is utilized to regulate the gain of the switching control. The chattering phenomenon are attenuated by using a continuous sliding-mode control method, so continuous control signals can be generated and directly applied in servo systems of induction motors. The simulation results show that the proposed method can implement high-performance position control of induction motors with improvement of steady-state and dynamic performances, control precision and robustness.

This manuscript discusses a new algorithm for finite time convergence of the states for a higher order system. To this end, a set of fast terminal sliding mode surfaces are constructed. The fractional powers of the switching surfaces are selected such that singularity is avoided during sliding. A control signal is developed with necessary and sufficient conditions for the finite time convergence is obtained, under which the system states reach the fast terminal sliding surfaces in a finite time and stay in the sliding modes thereafter. A condition on external disturbance is obtained to guarantee the finite time convergence. Numerical simulations are provided to validate the theoretical results and examine the robustness of control against external disturbances.

For the actuator uncertain nonlinear system, the paper proposed a nonsingular terminal sliding-mode (NTSM) control. The proposed strategy not only can eliminate the singularity problem but also can converge to the equilibrium point in finite time. The paper designed the controller for the two-order system and the higher-order uncertain actuator systems, respectively. The simulation results validate the proposed method.

This paper proposes an adaptive full-order Sliding Mode Observer (SMO) for the rotor speed and position estimation in the Permanent Magnet Synchronous Generator (PMSG). A full-order terminal SMO is designed to make the estimated stator current track the actual stator current, and eliminate the chattering. Furthermore, A back Electro Motive Force (EMF) observer adopts adaptive control to estimate the back EMF. Thus the rotor speed can be estimated from the adaptive law, and the rotor position can be calculated by the back EMF. The design of the adaptive back EMF observer further reduced the chattering. Compared simulation results are presented to validate the proposed method.

The standard application of nonsingular terminal sliding mode (NTSM) control is strictly limited to n-order (n≥2) systems and suffers from chattering problem. This paper proposes a continuous NTSM control for extended first order systems to obtain the global finite-time convergence and free-chattering simultaneously. Firstly, utilizing the concept of relative degree, a power-fractional NTSM manifold is designed. Then, based on Lyapunov stability theorem, a switching control law is designed to act on the derivative of NTSM variable, so that the real control is smoothed by integral action. Meanwhile, since the integral term is incompatible with input saturation in real systems, anti-windup compensation should be made accordingly. Taking permanent magnet synchronous motor as an example, simulation results are presented to validate the proposed method.

This paper investigates the robust control of two-link flexible manipulator systems subject to parameter perturbations, and a hybrid control scheme consisting of a continuous nonsingular terminal sliding mode (NTSM) controller and an observer-based LQR controller is proposed. In order to solve the non-minimum phase problem of flexible manipulator, singular perturbation method is utilized to decompose the system into a slow and fast subsystem in two-time scale, and joint angles and corrected flexible modes are modeled as the slow and fast variables, respectively. For the slow subsystem, a novel continuous NTSM control based on the concept of relative degree is proposed for robustness, finite-time convergence and free-chattering. For the fast subsystem, a reduced-order observer is designed to estimate corrected flexible modes and then a LQR controller is proposed for its optimal stability. Simulation results are presented to validate the control scheme.

This paper proposes a high-order terminal sliding-mode control strategy for the grid-side PWM converter of Doubly-Fed Induction Generators (DFIG) - based Wind Power System. The objective is to keep the DC-link voltage in a desirable value and the input or output power factors staying unitary. The high-order terminal sliding-mode voltage and current regulators are designed respectively to control the DC-link voltage and the current rapidly and exactly. The simulation results validate the proposed method.

This paper proposes high-order terminal sliding mode control strategies for wind energy conversion systems. Nonsingular terminal sliding mode manifolds and related second-order sliding mode control strategies are designed respectively for the speed controller and the current controllers of the induction generator in a wind energy conversion system. The second-order sliding mode technique is utilized to soften the non-smooth control signal, which can guarantee the actual control signal is continuous and smooth. The simulations are presented to validate the proposed method.

In order to avoid the flaw while keeping all the merits of image encryption scheme based on line maps, an improved image encryption scheme is proposed, which extended the original 2D scheme to 3D. An image with size NtimesM is firstly depicted by a 3D bit matrix, and then it is supposed as composed of 8timesM vectors with size N. Line maps are used to stretch the vectors to an array, while the fold map is used to transform the array to a same sized 3D matrix. Simulation results show that the improved image encryption scheme complete pixel permutation and confusion simultaneously, it enhance the security of the original cipher.

The robotic system of a two-link flexible manipulator is decomposed into an input-output subsystem and a zero dynamics subsystem using the input-output linearization technique. A novel inverse dynamics nonsingular terminal sliding mode controller is designed to make the input-output subsystem converge to its equilibrium point in finite time. The parameters of the zero dynamic subsystem are optimized by a genetic algorithm so that the zero dynamics subsystem is asymptotically stable at equilibrium point and finally the whole original flexible manipulator system is guaranteed to be asymptotically stable. Additionally, in order to overcome the chattering, this paper adapts a fuzzy logic controller to realize the nonlinear switching function. Simulation results are presented to validate the design.