This work deals with the controllability analysis in timed continuous Petri nets (TCPNs) under infinite server semantics, a class of linear hybrid systems. In the literature, this problem has been addressed by analyzing each configuration (that defines a linear mode) of the system. However, the number of configurations may grow exponentially. Here, by using a global structural approach, we study the net rank-controllability (NRC), a structural property of the TCPN. Under the assumption of liveness, it is shown that NRC is a sufficient condition for controllability; nevertheless, if liveness is not fulfilled then controllability is not guaranteed by NRC The advantage of this approach is that NRC is characterized in terms of global structural objects of the net, thus, avoiding the analysis by configurations. In this sense, some new structural sufficient conditions for NRC are introduced for general TCPNs. Finally, polynomial-time algorithms for the verification of NRC are provided.