  In this paper we introduce a new notion of passivity which we call
Krasovskii's passivity and provide a sufficient condition for a system to be
Krasovskii's passive. Based on this condition, we investigate classes of
port-Hamiltonian and gradient systems which are Krasovskii's passive. Moreover,
we provide a new interconnection based control technique based on Krasovskii's
passivity. Our proposed control technique can be used even in the case when it
is not clear how to construct the standard passivity based controller, which is
demonstrated by examples of a Boost converter and a parallel RLC circuit.
