Characterizing Inductive and Capacitive Nonlinear RLC Circuits: A Passivity Test

Linear time-invariant RLC circuits are said to be inductive (capacitive) if the current waveform in sinusoidal steady-state has a negative (resp., positive) phase shift with respect to the voltage. Furthermore, it is known that the circuit is inductive (capacitive) if and only if the magnetic energy stored in the inductors dominates (resp., is dominated by) the electrical energy stored in the capacitors. In this paper we propose a framework, based on passivity theory, that allows to extend these intuitive notions to nonlinear RLC circuits.

Linear Dynamics and Control of a Kinematic Wobble–Yoke Stirling Engine

This paper presents a control systems approach for the modeling and control of a kinematic wobble–yoke Stirling engine. The linear dynamics of the Stirling engine are analyzed based on the dynamical model of the system, developed by these authors. We show that the Stirling engine can be viewed as a closed–loop system, where the feedback control law is given by the pressure variations in the pistons. Since the closed–loop system exhibits unstable dynamics, we design a pre–compensator to stabilize the displacements of the engine’s pistons, and an observer to estimate their piston velocities

Power factor compension of electrical circuits: a control theory wiewpoint

The purpose of this paper is to bring the attention of the control community some of the aspects of the practically important, and mathematically challenging, power factor compensation problem. Our main contribution is identifying the key role played by cyclo-dissipativity in the solution of the problem. Namely, we prove that a necessary condition for a (shunt) compensator to improve the power transfer is that the load satisfies a given cyclo-dissipativity property, which naturally leads to a formulation of the compensation problem as one of cyclo-dissipasivation. Cyclo-dissipativity systems exhibit a net absorption of (abstract) energy only along closed paths, while a dissipative system cannot create energy for all trajectories, henceforth, this concept generalizes the one of passivationPeer Reviewe