Output Feedback Compensator Design Research Articles

Observer‐based output feedback compensator design for linear parabolic PDEs with local piecewise control and pointwise observation in space

This study presents an observer-based output feedback compensator design for a linear parabolic partial differential equation (PDE), where a finite number of actuators and sensors are active over partial areas and at specified points in the spatial domain, respectively. In the proposed design method, a Luenberger-type PDE observer is first constructed by using the non-collocated pointwise observation to exponentially track the PDE state. Based on the estimated state, a collocated local piecewise state feedback controller is then proposed. By employing a Lyapunov direct method, integration by parts, Wirtinger's inequality and first mean value theorem for definite integrals, sufficient conditions on the exponential stability of the resulting closed-loop coupled PDEs are presented in terms of standard linear matrix inequalities. Furthermore, both open-loop and closed-loop well-posedness analysis results are also established by the C 0 -semigroup method. Numerical simulation results are presented to show the effectiveness of the proposed design method.

Transition between grid-connected mode and islanded mode in VSI-fed microgrids

This paper investigates the behaviour of a microgrid system during transition between grid-connected mode and islanded mode of operation. During the grid-connected mode the microgrid sources will be controlled to provide constant real and reactive power injection. During the islanded mode the sources will be controlled to provide constant voltage and frequency operation. Special control schemes are needed to ensure proper transition from constant P–Q mode to constant f–V mode and vice versa. Transition from one mode to other will introduce severe transients in the system. Two kinds of transition schemes based on the status of the off-line controller are discussed and a comparative study is presented for various step changes in the load. An additional-pole-placement-based output feedback controller augmentation during transition between the modes is proposed to reduce the transients. A static output feedback compensator design is proposed for the grid connected to island mode transition and a dynamic output feedback compensator design is proposed for resynchronisation. The performance of the output feedback controllers is tested under various operating conditions and found to be satisfactory for the tested conditions.

Design of Output Feedback Compensator for Discrete Time System via Reduced Order Model

A method to design an output feedback compensator for a higher order discrete time system with distinct complex eigenvalues via its reduced order model is presented. Its application is shown for vibration control of a smart cantilever beam. As the states are not needed for feedback, the method is simple and can be easily implemented.

A new dynamic output feedback compensator design for pole assignment

This paper proposes a new approach which is applicable for any open loop system either with more outputs than inputs or with at least one stable transmission zero, for the design of dynamic output feedback compensator (DOFC) and for pole assignment. Although this DOFC cannot always guarantee arbitrary pole placement of the feedback system, it has three unique advantages: (1) the DOFC poles are part of the feedback system poles and thus the DOFC stability is guaranteed; (2) this new DOFC can implement state feedback control which is most powerful and whose design is well developed; (3) the design is decoupled into two pole assignment problems of orders r and n, respectively, instead of the existing design of order n + r, where n and r are the orders of open loop system and DOFC, respectively.

Eigenstructure assignment for descriptor systems by output feedback compensation

A method for output feedback compensator design that assigns the eigenstructure of a descriptor system is presented. The adopted approach is based on transforming the problem into that of eigenstructure assignment for a linear state space system using output feedback.