Abstract:
In a microgrid, two different control methods are often adopted for interfacing converters, the voltage control and current control method. For the former, it can be used in the connected or islanded mode, but it has slow power control dynamics. In contrast,the current control method has rapid power control dynamic response, but cannot be applied during standalone operation. To cope with these problems, the distributed generator( DG) is connected to the microgrid with two parallel converters. Different from conventional methods, one converter is controlled to regulate voltage while the other to regulate current. In this way, the advantages of both methods are made use of. At the same time, the application of power coupling loop enhances the dynamic characteristics of voltage-controlled converter and DG system. Simulation and experimental results from a single-phase prototype show the validity of the proposed structure and control strategy.