  We study a type of port-Hamiltonian system, in which the controller or
disturbance is not applied to the flow variables, but to the systems power, a
scenario that appears in many practical applications. A suitable framework is
provided to model these systems and to investigate their shifted passivity
properties, based on which, a stability analysis is carried out. The
applicability of the results is illustrated with the important problem of
stability analysis of electrical circuits with constant power loads.
