Port Controlled Hamiltonian With Dissipation Research Articles

L2 Disturbance Suppression Controller Design for Multiple Time Delays Offshore Wind Turbines

With the large-scale development of offshore wind power and the rapid development of smart grid, more and more attention has been paid to the stable operation of wind turbines under various conditions. In the actual operation process of wind turbines, there are inevitably many kinds of uncertain time delays, and also external or parameter disturbances, which affect the stable operation of wind turbines and make the system deviate from the original stable state. Based on Hamiltonian energy theory, the disturbance rejection of doubly fed wind turbines with multiple time delays is studied in this paper. Firstly, the doubly fed wind turbine is Hamiltonian realized to obtain its port controlled Hamiltonian with dissipation(PCH-D) model. Then, aiming at the PCH-D model, a multiple time delays controller is designed based on Casimir function, which can make wind turbines run stably under multiple time delays. Furthermore, based on the passive control theory, L2 gain disturbance rejection control technology is introduced to eliminate the steady-state error caused by external disturbance and improve the stability of wind turbines. Finally, the simulation results show that the proposed controller can effectively solve the multiple time delays and disturbance problems in the system, and improve the stability and anti-interference of wind turbines.

Research on Ratio Consensus of Flywheel Energy Storage System Based on Hamiltonian Theory

A control strategy based on Hamiltonian energy theory is proposed for the wind farm with flywheel energy storage system (FESS). The control of the ratio consensus of the flywheel energy storage system is realized by adjusting the speed of the flywheel energy storage unit. First, the port-controlled Hamilton (PCH) model of the flywheel energy storage unit is established, and the port-controlled Hamiltonian with dissipation (PCH-D) model is obtained by using the feedback stabilization principle of the PCH system. Then, the problem of the ratio consensus control of the flywheel energy storage system is investigated. In order to realize that all flywheel energy storage units can store and release energy at the same rate, the control strategy of Hamilton energy shaping is applied to adjust the speed of flywheel energy storage units. Finally, the effectiveness of the proposed control strategy is verified by simulations.

IDA-PB control design for VSC-HVDC transmission based on PCHD model

SUMMARY An interconnection and damping assignment passivity-based (IDA-PB) control design is proposed to improve the dynamic performance of voltage source converter high-voltage direct current (VSC-HVDC) system. The port-controlled Hamiltonian with dissipation (PCHD) model for voltage source converter (VSC) is developed according to the PCHD equation, and the strict passivity of the PCHD model is proved. On the basis of the PCHD model, a desired energy function is constructed by assigning interconnection and damping matrix and used as Lyapunov function. Then the IDA-PB control is designed according to desired equilibrium point, state variables, and IDA-PB control principle. By using this type of controller, the influence of the equivalent resistance of the VSC direct current side on the VSC-HVDC system is eliminated. The effectiveness of the proposed IDA-PB control is demonstrated through simulation studies on a two-terminal VSC-HVDC system by PSCAD/EMTDC software. The simulation results show that the controller has significant contribution to improve the dynamic behavior of the VSC-HVDC system under a variety of operation conditions. Copyright © 2014 John Wiley & Sons, Ltd.

A New Control Strategy of Three Phase Voltage Source PWM Rectifiers

In order to improve the properties of three phase voltage source PWM rectifiers, this paper proposes a new control strategy based on port-controlled Hamiltonian with dissipation (PCHD) model and Interconnection and Damping Assignment Passivity Based Control (IDA-PBC). Compared with other strategies, the rectifier has more dynamic and static performances by using the new strategy. Because of utilizing IDA-PBC to design passivity based controller, the stable state performance and robustness against the load's disturbance of PWM rectifiers are both improved. The results of simulation show feasibility of this new strategy.

Passivity Based Controller Design Based on EL and PCHD Model

In this paper, the method of passivity based controller design, is introduced according to passivity, EL (Euler-Lagrange) and PCHD(Port Controlled Hamiltonian with Dissipation) model of nonlinear system. In order to improve the property of system, energy shaping and damping injection are adopted in passivity based controller design. Passivity based controller is used in PWM rectifier, the properties of PWM rectifier is improved. The paper points out deficiencies of passivity based controller design based on EL and PCHD model, and further research.

Performance improvement of PI controller with nonlinear error shaping function: IDA-PBC approach

The general dilemma faced in a conventional linear proportional–integral (PI) controller is to achieve the best transient performance (i.e. fast rise time and low overshoot level) at the same time. However, fast response is usually accompanied by high overshoot level. On the other hand, very stable control without overshoot is usually achieved at the expense of a more sluggish response to set point changes and load disturbances. Therefore, compromise between fast response and low overshoot level should be made. In this paper, to overcome these contradictions and limitations, nonlinear error shaping function (ESF) is introduced to amplify gain at low error level but reduce gain at high error level. Firstly, interconnection and damping structure for the closed-loop system composed of PI controller and first-order plant is revealed based on the port-controlled hamiltonian with dissipation (PCHD) formation. Secondly, passivity analysis is performed by the interconnection and damping assignment (IDA) passivity-based control (PBC) algorithm. In simulation studies, several nonlinear error shaping functions are examined and compared to verify performance improvements.

DAMPING INJECTION CONTROL OF WINDING SYSTEMS BASED ON PORT CONTROLLED HAMILTONIAN SYSTEMS

In web and metal sheet processing systems and winders, flexibility of the web is a source of vibrations and resonance amongst motor drives. Port-Controlled Hamiltonian with Dissipation (PCHD) modelling is considered to develop stabilization strategies with a physical interpretation and motivation of the control action. A web transport system is modelled as a PCHD system and the control action is defined to obtain asymptotically stable operating points for the controlled system by a passivity argument. The controller negative output feedback gain matrix is interpreted as the realization of virtual dampers added to the system.

Hamiltonian modelling and nonlinear disturbance attenuation control of TCSC for improving power system stability

To tackle the obstacle of applying passivity-based control (PBC) into power systems, an affine non-linear system widely existing in power systems is formulated as a standard Hamiltonian system using a pre-feedback method. The port controlled Hamiltonian with dissipation (PCHD) model of TCSC is then established corresponding with a revised Hamiltonian function. Furthermore, employing the modified Hamiltonian function directly as the storage function, a non-linear adaptive L2 gain control method is proposed to solve the problem of L2 gain disturbance attenuation for this Hamiltonian system with parametric perturbations. Finally, simulation results are presented to verify the validity of the proposed controller.