PROJECT TITLE :

A Unified Control for the DC-AC Interlinking Converters in hybrid AC-DC micro grids - 2017

ABSTRACT:

A completely unique unified control of the dc-ac interlinking converters (ICs) for autonomous operation of hybrid ac/dc microgrids (MGs) has been proposed during this paper. When the slack terminals in the ac and dc MGs are out there, the ICs can operate in autonomous control of interlinking power between the ac and dc subgrids, with the entire load demand proportionally shared among the prevailing ac and dc slack terminals. With a flexible control variable added in power management loop, style of the interlinking power control and droop options of ac and dc MGs will be decoupled. Moreover, this management variable can be tuned flexibly in line with completely different power control objectives, like proportional power sharing in terms of capacity (which is considered in this work), interlinking power dispatch, and different optimal power dispatch algorithms, guaranteeing a well-designed flexibility and compatibility. Furthermore, if the dc MG or the ac MG loses dc voltage management or ac voltage and frequency control capability because of failures of operation of its slack terminals, the ICs can automatically and seamlessly transfer to dc MG support or ac MG support management modes without operation mode detection, communication, management scheme switching and control saturation. In order to reinforce the stability of the proposed unified control in several modes with totally different control plants, a phase compensation transfer operate has been added in the power control loop. After thorough theoretical analysis and discussions, detailed simulation verifications primarily based on PSCAD/EMTDC and experimental results based on a hardware experimental MG platform have been presented.