Control using new passivity property with differentiation at both ports

Abstract

Port Hamiltonian systems are usually passive with respect to port variables that are power conjugate (eg: voltage and current, force and velocity) and this lead to energy shaping control methods. But systems with `dissipation obstacle' cannot be controlled using these port variables and therefore we need to search for alternative passive maps. One option is within the Brayton Moser framework, where passivity is obtained by differentiating one of the port variables. This has led to power shaping methods for control, but the solutions (if exists) obtained impose constraints on the physical parameters of the system. In this paper, starting from the Brayton Moser framework we present a new passivity property with differentiation at both the port variables. Further using this new passive map, a PI like controller is proposed and presented using parallel RLC circuit and transmission line system with non zero boundary conditions as examples.