Port-controlled Hamiltonian Research Articles

Adaptive Fuzzy Control of Switched Port-Controlled Hamiltonian Systems with Input Saturation

Adaptive Fuzzy Control of Switched Port-Controlled Hamiltonian Systems with Input Saturation

Fixed-time stabilization and [formula omitted] control of time-delay port-controlled Hamiltonian systems

In this paper, we investigate the fixed-time stability (FxTS) and fixed-time H∞ control design of time-delay port-controlled Hamiltonian (PCH) systems. Firstly, we establish an improved FxTS criterion. Secondly, by utilizing this criterion and interconnection and damping assignment passivity-based (IDA-PBC) technique, two new FxTS results are given for PCH systems with the assumption about Hamiltonian functions. Then, a fixed-time H∞ control design procedure is presented by using a new Lyapunov–Krasovskii (L-K) functional. Finally, the forced mathematical pendulum model with a constant time-delay shows the effectiveness of our results.

Research on strategy of load-side resonant soft-switching inverter based on interconnection and damping assignment-passivity based control

Soft-switching technologies can effectively solve the problem of switching losses caused by increasing switching frequency of grid-connected inverters. As a branch of soft-switching technologies, load-side resonant soft-switching is a hotspot for applications of high-frequency inverters, because it has the advantage of achieving soft-switching without using additional components. However, the traditional PI control strategy based on the linear model is prone to destabilization and non-robust dynamic performance when large signal perturbation occurs. In this paper, a novel Passivity-Based Control (PBC) method is proposed to improve the dynamic performance of load-side resonant soft-switching grid-connected inverter. Besides, the model based on the Port Controlled Hamiltonian (PCH) model of the soft switching inverter is carried out, and the passivity-based controller is designed based on the established model using the way of interconnection and damping assignmentpassivity based control (IDA-PBC). Both stable performance and dynamic performance of the load-side resonant soft-switching inverter can be improved over the whole operating range. Finally, a 750 W load-side resonant soft-switching inverter simulation model is built and the output performance is compared with the traditional PI control strategy under stable and dynamic conditions. The simulation results show that the proposed control strategy reduces the harmonic distortion rate and improves the quality of the output waveforms.

Cooperative control of NN super twisting sliding mode and EPH methods for uncertain nonlinear systems

A cooperative control strategy is proposed based on radial basis function neural network (NN) super twisting sliding mode and error port-controlled Hamiltonian (EPH) methods to enhance dynamic performance and steady state performance of the system. First, a NN super twisting sliding mode control method is developed for system with unknown external disturbances and uncertain parameters, where NN is adopted to approximate unknown control gain, the disturbance observer (DOB) is employed to estimate the unknown lumped disturbance. The dynamic performance of the control system is enhanced. Second, the EPH control method based on DOB is developed to increase the accuracy of the control system. Lastly, NN super twisting sliding mode and EPH methods-based cooperative control strategy is developed, the superiority of the proposed method is verified through the simulation and experiments.

Energy-Based Control for Switched Uncertain Port-Controlled Hamiltonian Systems With Its Application to RLC Circuit Systems

Energy-Based Control for Switched Uncertain Port-Controlled Hamiltonian Systems With Its Application to RLC Circuit Systems

Adaptive NN state error PCH trajectory tracking control for unmanned surface vessel with uncertainties and input saturation

AbstractA novel robust state error port controlled Hamiltonian (PCH) trajectory tracking controller of an unmanned surface vessel (USV) subject to time‐varying disturbances, dynamic uncertainties and control input saturation is presented. The proposed control scheme combines the advantages of the high robustness and energy minimization of the state error PCH approach and the approximation capability of adaptive radial basis function neural networks (RBFNNs). Adaptive RBFNNs are used to the time‐varying disturbances of the environment and unknown dynamics uncertainties of the USV model. The state error PCH control approach is designed such that the system can optimize energy consumption, and the state error PCH technique makes the designed trajectory tracking controller be easy to implement in practice. To handle the effect of the control input saturation, a Gaussian error function model is employed. It has been demonstrated that the proposed approach can maintain the USV's trajectory at the desired trajectory, while the closed‐loop control system can guarantee the uniformly ultimate boundedness. The energy consumption model of the USV is constructed to reveal to the energy consumption. Simulation results demonstrate the effectiveness of the proposed controller.

Optimized Cooperative Control of Error Port-Controlled Hamiltonian and Adaptive Backstepping Sliding Mode for a Multi-Joint Industrial Robot

Robot joints driven by permanent magnet synchronous motors (PMSM) often cannot have both superior accuracy and rapidity when they track target signals. The robot joints have fine dynamic characteristics and poor steady-state characteristics when the signal controller is used, or they have fine steady-state characteristics and poor dynamic characteristics when the energy controller is used. It is hard to make robot joints that have both superior dynamic and steady-state characteristics at once using a single control method. In order to solve this problem, the strategy of optimized cooperative control is proposed. First, an error port-controlled Hamiltonian (EPCH) energy controller and an adaptive backstepping sliding mode (ABSM) signal controller are designed. Second, an optimized cooperative control coefficient based on the position error of a robot joint is designed; this enables the system to switch smoothly between the EPCH energy controller and ABSM signal controller. Next, the strategy of optimized cooperative control is designed. In this way, robot systems can combine the advantages of the EPCH energy controller and the ABSM signal controller. Finally, simulation results demonstrate that using the strategy of optimized cooperative control gives robot joints outstanding control performance in terms of tracking accuracy and response rapidity.

FPGA Based Integrated Control of Brushless DC Motor for Renewable Energy Storage System

To reduce air pollution and global warming, renewable energy technologies may generate power. Wind, solar PV, and fuel cell energy are the primary sources. Solar PV system-powered brushless direct current motor (BLDC) drives are used in the automobile industry due to their importance. In this study, Sheppard–Taylor (S-T) converter and Pulse Width Modulated (PWM) Inverter-fed BLDC provide steady voltage across the BLDC motor drive independent of solar PV system power output. When renewable energy is scarce, the proposed battery-supercapacitor hybrid energy storage system (BS-HESS) provides electricity. S-T converters may be used for load matching and power processing to create energy-efficient systems and stabilize PV panel output voltage. The variable step size open circuit voltage-Maximum Power Point Tracking (VSSOCV-MPPT) technique in S-T converter switching pulses extracts maximum power from the solar PV system. This study considers the PVSWPS control function as a Port-Controlled Hamiltonian (PCH) system to continue rural growth and reduce the greatest demand and load. MATLAB/Simulink software simulates the system’s performance, and FPGA controllers validate the controller’s real-time performance.

Finite-time adaptive control for uncertain switched port-controlled Hamiltonian systems

In this paper, the finite-time boundedness (FTB) and H∞ control are discussed for a class of uncertain switched port-controlled Hamiltonian (PCH) systems via adaptive control strategies. In view of the mode-dependent matching principle, the energy-based multiple Lyapunov functions method and the mode-dependent average dwell time (MDADT) approach, sufficient conditions on the FTB are obtained for uncertain switched PCH systems by employing a set of adaptive mode-dependent state feedback controllers. Furthermore, to solve the finite-time H∞ control for the system under consideration, a new set of mode-dependent state feedback controllers are designed to restrain both the structured uncertainties and disturbances, and sufficient conditions on the H∞ control problem are derived for the system under a new MDADT scheme. Finally, the numerical simulations are presented to illustrate the effectiveness of the proposed finite-time adaptive control methods.

An EPCH Control Strategy for Complex Nonlinear Systems with Actuator Saturation and Disturbances

This paper presents a novel error port-controlled Hamiltonian (EPCH) strategy with adaptive gains for a class of complex nonlinear systems subject to actuator saturation and disturbances. Considering the actuator saturation phenomenon in real complex systems, a new smooth saturation function with hyperbolic tangent is adopted to deal with the limitations between the actuator and the control signal. A nonlinear disturbance observer (NDOB) is utilized to compensate the influence of model parameter uncertain, noise, measurement error, external disturbance and other factors in real complex systems. To enhance the accuracy of position control and tracking control for the target, we propose a novel EPCH strategy, which adopts adaptive gain and variable damping technology in the damping injection link. Finally, the permanent magnet synchronous motor (PMSM) servo system is applied to verify the proposed method. The strategy proposed compared with port-controlled Hamiltonian based on disturbance observer, port-controlled Hamiltonian based on load torque estimator and other methods has better control performances by simulation results.

Anti-Saturation Coordination Control of Permanent Magnet Synchronous Wind Power System

This paper is concerned with the anti-saturation control problem of a permanent magnet synchronous wind power system. By virtue of adaptive sliding mode control method and port-controlled Hamiltonian (PCH) control method, a new coordination controller is designed, which removes the input saturation effects and compensates the uncertainties of system model parameters. The controller takes the exponential function with parameters as the coordination function. By adjusting the parameters of coordination function, the designed coordination controller can respond to input saturation more quickly and improve the system’s dynamic performance. The effectiveness of the proposed strategy is demonstrated through simulations. The comparison results with the traditional control approach are also presented. It is shown that the proposed strategy can realize the speed tracking control of the generator and improve the maximum wind energy capture of wind turbine, so as to further improve the utilization efficiency of wind energy.

Comparative Performance Analysis of the DC-AC Converter Control System Based on Linear Robust or Nonlinear PCH Controllers and Reinforcement Learning Agent

Starting from the general topology and the main elements that connect a microgrid represented by a DC power source to the main grid, this article presents the performance of the control system of a DC-AC converter. The main elements of this topology are the voltage source inverter represented by a DC-AC converter and the network filters. The active Insulated Gate Bipolar Transistor (IGBT) or Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) elements of the DC-AC converter are controlled by robust linear or nonlinear Port Controlled Hamiltonian (PCH) controllers. The outputs of these controllers are modulation indices which are inputs to a Pulse-Width Modulation (PWM) system that provides the switching signals for the active elements of the DC-AC converter. The purpose of the DC-AC converter control system is to maintain ud and uq voltages to the prescribed reference values where there is a variation of the three-phase load, which may be of balanced/unbalanced or nonlinear type. The controllers are classic PI, robust or nonlinear PCH, and their performance is improved by the use of a properly trained Reinforcement Learning-Twin Delayed Deep Deterministic Policy Gradient (RL-TD3) agent. The performance of the DC-AC converter control systems is compared using performance indices such as steady-state error, error ripple and Total Harmonic Distortion (THD) current value. Numerical simulations are performed in Matlab/Simulink and conclude the superior performance of the nonlinear PCH controller and the improvement of the performance of each controller presented by using an RL-TD3 agent, which provides correction signals to improve the performance of the DC-AC converter control systems when it is properly trained.

Sensorless passivity based control of doubly-fed induction generators in variable-speed wind turbine systems based on high gain observer

The current study presents a robust sensorless control using passivity based control (PBC) combined with high gain observer (HGO). The proposed controller is applied to control the generated doubly-fed induction generator (DFIG) active and reactive power installed on a variable speed wind energy conversion system. The control objective is used to regulate independently the DFIG stator active and reactive power, which are decoupled by using the field oriented control technique. Additionally, this process leads to reduce the cost of control scheme by eliminating the speed sensor. Firstly, the DFIG is modeled under the port controlled Hamiltonian (PCH) model, as well as the method of simultaneous injection damping. Then, the DFIG is further modeled by assignment passivity based on the simultaneous injection damping and assignment (SIDA-PBC) control of the obtained model under such conditions and a comparison with the fuzzy sliding mode controller is carried out. Furthermore, the HGO is selected in order to estimate the rotor position and the speed from the measurement of the DFIG currents and voltages, and compared with fuzzy sliding mode observer. For testing the proposed control scheme performance, a 1.5 MW DFIG system is developed and simulated using MATLAB/Simulink. The obtained results demonstrate the effectiveness of the proposed control scheme in the presence of various DFIG parameters variation. Additionally, the control objective is achieved without speed sensor.

Finite‐time adaptive control for port‐controlled Hamiltonian systems with parametric perturbations

SummaryIn this article, finite‐time boundedness (FTB) and control are addressed for a class of port‐controlled Hamiltonian (PCH) systems with parametric perturbations. Based on adaptive state feedback control strategies, sufficient conditions are obtained for FTB of the PCH systems with parametric perturbation and external disturbances. Furthermore, another adaptive state feedback controller is applied to compensate the parameter perturbation and attenuate the external disturbances, and finite‐time control conditions are acquired for the PCH systems with parametric perturbation and external disturbances. In addition, the FTB and finite‐time control conditions are also given for uncertain nonlinear systems via the Hamiltonian realization method. Finally, the numerical simulations are presented to verify the feasibility of the proposed results.

Learning Data-Driven PCHD Models for Control Engineering Applications*

The design of control engineering applications usually requires a model that accurately represents the dynamics of the real system. In addition to classical physical modeling, powerful data-driven approaches are increasingly used. However, the resulting models are not necessarily in a form that is advantageous for controller design. In the control engineering domain, it is highly beneficial if the system dynamics is given in PCHD form (Port-Controlled Hamiltonian Systems with Dissipation) because globally stable control laws can be easily realized while physical interpretability is guaranteed. In this work, we exploit the advantages of both strategies and present a new framework to obtain nonlinear high accurate system models in a data-driven way that are directly in PCHD form. We demonstrate the success of our method by model-based application on an academic example, as well as experimentally on a test bed.

Interconnection and damping assignment passivity-based non-linear observer control for efficiency maximization of permanent magnet synchronous motor

The permanent magnet synchronous motor (PMSM) has several advantages over the DC motor and is gradually replacing it in the industry. The dynamics of the PMSM are described by non-linear equations; it is sensitive to unknown external disturbances (load), and its characteristics vary over time. All of these restrictions complicate the control task. Non-linear controls are required to adjust for non-linearities and the drawbacks mentioned above. This paper investigates an interconnection and damping assignment (IDA) passivity-based control (PBC) combined with a non-linear observer approach for the PMSM using the model represented in the dq-frame. The IDA-PBC approach has the inherent benefit of not canceling non-linear features but compensating them in a damped manner. The suggested PBC is in charge of creating the intended dynamic of the system, while the non-linear observer is in charge of reconstructing the recorded signals in order to compel the PMSM to track speed. The primary objective of this study is to synthesize the controller while accounting for the whole dynamic of the PMSM and making the system passive. It is performed by restructuring the energy of the proposed strategy and introducing a damping component that addresses the non-linear elements in a damped instead of deleted way, so providing a duality concept between both the IDA-PBC and the observer There are three methods for computing IDA-PBC: parametric, nonparametric, and algebraic. The parameterized IDA-PBC method is used to control the speed of the PMSM. This method uses the energy function in parameterized closed-loop in terms of some functions depending on the system’s state vector, such that the energy formation step is satisfied. Then, the original port-controlled Hamiltonian (PCH) dynamics in open-loop (OL) are equalized with the desired one in closed-loop (CL). The equalization process allows obtaining a set of solutions of the partial differential equations. The latter must be solved in terms of the parameters of the energy function of the closed-loop. Finally, the stability properties are studied using the Lyapunov theory. Generally, the proposed candidate offers high robustness, fast speed convergence, and high efficiency over the conventional benchmark strategies. The effectiveness of the proposed strategy is performed under extensive numerical investigation with MATLAB/Simulink software.

Simultaneous exponential stabilization for stochastic port-controlled Hamiltonian systems with actuator saturations, fading channels and delays

This paper is concerned with the simultaneous exponential stabilization problem for a set of stochastic port-controlled Hamiltonian (PCH) systems. Due to the limited bandwidth of the channels, the phenomena of fading channels and transmission delays which are described by a time-varying stochastic model always occur in the communication channels from the controller to the actuator. Meanwhile, actuator saturation constraint is taken into account. On the basis of dissipative Hamiltonian structural and saturating actuator properties, those stochastic PCH systems are combined to generate an augmented system. By utilizing the stochastic analysis theory, sufficient criterions are given for the simultaneous stabilization controller design ensuring that the closed-loop system is simultaneously exponentially mean-square stable (SEMSS). For the case that there exist external disturbances in the systems, some results on stability analysis and controller design are given. The developed controller design scheme is proved by a three-helicopter model simulation example.

Sensorless Adaptive Voltage Control for Classical DC-DC Converters Feeding Unknown Loads: A Generalized PI Passivity-Based Approach.

The problem of voltage regulation in unknown constant resistive loads is addressed in this paper from the nonlinear control point of view for second-order DC-DC converters. The converters’ topologies analyzed are: (i) buck converter, (ii) boost converter, (iii) buck-boost converter, and (iv) non-inverting buck-boost converter. The averaging modeling method is used to model these converters, representing all these converter topologies with a generalized port-Controlled Hamiltonian (PCH) representation. The PCH representation shows that the second-order DC-DC converters exhibit a general bilinear structure which permits to design of a passivity-based controller with PI actions that ensures the asymptotic stability in the sense of Lyapunov. A linear estimator based on an integral estimator that allows reducing the number of current sensors required in the control implementation stage is used to determine the value of the unknown resistive load. The main advantage of this load estimator is that it ensures exponential convergence to the estimated variable. Numerical simulations and experimental validations show that the PI passivity-based control allows voltage regulation with first-order behavior, while the classical PI controller produces oscillations in the controlled variable, significantly when the load varies.

Finite-time stabilization and H∞ control of Port-controlled Hamiltonian systems with disturbances and saturation.

The finite-time stabilization and finite-time H∞ control problems of Port-controlled Hamiltonian (PCH) systems with disturbances and input saturation (IS) are studied in this paper. First, by designing an appropriate output feedback, a strictly dissipative PCH system is obtained and finite-time stabilization result for nominal system is given. Second, with the help of the Hamilton function method and truncation inequality technique, a novel output feedback controller is developed to make the PCH system finite-time stable when IS occurs. Further, a finite-time H∞ controller is designed to attenuate disturbances for PCH systems with IS, and sufficient conditions are presented. Finally, a numerical example and a circuit example are given to reveal the feasibility of the obtained theoretical results.

PASSIVITY-BASED CONTROL SYSTEM FOR STAND-ALONE HYBRID ELECTROGENERATING COMPLEX

The desire for energy independence presupposes the use of various types of elements for energy generation from renewable sources, for the stand-alone operation of which energy storage devices are required. Apower generation complex created in this way must perform a number of tasks that are formed by the energy management system. The control system performs these tasks and ensures proper static and dynamic characteristics of this complex with many inputs and outputs. The results of recent world researches, as well as the authors experience of this work, show that,for creating such control systems, it is advisable to use Passive-Based Control (PBC), presenting the control object as a Port-Controlled Hamiltonian (PCH) system. Thanks to the developed method of additional interconnections and damping injection (Interconnection & Damping Assignment -IDA) passive control provides ample opportunities to adjust the control effects, while ensuring the asymptotic stability of the system as a whole. This is particularly useful in the complex system considered in this paper that includes both a hybrid power plant for electricity generation from the sun and windanda hybrid energystorage unit consisting of the battery and supercapacitor module. This article shows the procedure of PBCsystem synthesis, according to which three structures of control influence formers (CIF) were designed and investigated. These structures have different combinations of additional interconnections and damping, which allows forming the desired energy flows inside the closed-loop systemand therefore provide desired control results.Among them, there are tasks of maintaining voltages on the DC bus and the supercapacitor module at referencelevels, and the smoothness of the battery current transients.A comparative simulation studies were performed on a computer model of the power generation complex with synthesized control systems, whichwas created in the MATLAB/Simulink environment. It showed the efficiency of their work and the advantages of different CIF structures.