POWER ELECTRONICS ABSTRACT 2016-2017 MATRIX CONVERTER BASED ACTIVE DISTRIBUTION TRANSFORMER ABSTRACT: This paper proposes a Matrix Converter Based Active Distribution Transformer (MC-ADT) with enhanced control functionalities to be used in Smart Grids (SG). The proposed MC-AD Tuses a Matrix Converter (MC) connected to a transformer inserted in series with the grid, and allows: a) real time voltage regulation of the LV side of the MC-ADT, based on an adjustable reference value defined by the Smart Grid requirements and bounded by the standard values; b) capability to regulate the LV grid voltage even in case of sags, voltage rises and over voltages in the transformer Medium Voltage (MV) side; c) contribution to Power Factor (PF) correction in the MV side. The MC-ADT grid voltage regulators are synthesized, establishing the MC reference currents. To guarantee the tracking of the MC input and output reference currents, space vector representation together with sliding mode direct control techniques are used. The obtained experimental and simulation results show the proposed system is able to regulate the LV grid voltages even for sags and over voltages up to 20% in the MV side, and contributes to power factor correction in MV, while presenting a fast dynamic response, without overshoot and almost zero steady-state error.