Design, modeling, control and simulation of a two-stage grid-connected power load emulator

In this paper, a study of a two-stage regenerative grid-connected AC-DC power module for load emulation is presented. It consists of an active rectifier connected with a dual active bridge. Both conversion stages are designed and controlled in order to ensure power factor correction at the AC side and a regulated voltage at the DC side. The development of the control system is based on the small-signal transfer functions of the converter, which are computed the average modeling technique. A 5 kW module is used as a base to design and simulate such system. The steady-state and dynamic behavior of the converter is tested under varying operating conditions, and the stability of the interconnection between the two conversion stages is discussed.