Comprehensive and Asymptotic Stable Controller for SST-based Micro-Grids

Abstract

Solid-State Transformers are one of the most complicated power electronic devices that are sought to be an alternative for conventional low frequency distribution transformers (LFDTs) with embedded functionalities. Active power injection at MVDC and LVDC ports of the SST can affect the stability of the controller, drastically. In this paper, a control method based on the Lyapunov Direct Theory (LDT) is presented for the SST-based MGs. Simulations are performed using MATLAB/Simulink for constant and variable power injection at MVDC and LVDC ports of the SST as well LVAC side. Simulation results show that the proposed controller guarantees the global and asymptotic stability features of the SST-based MGs subject to internal stability of the connected subsystems.