Power quality enhancement in residential smart grids through power factor correction stages

The proliferation of non-linear loads and the increasing penetration of Distributed Energy Resources (DER) in Medium-Voltage (MV) and Low-Voltage (LV) distribution grids, make it more difficult to maintain the power quality levels in residential electrical grids, especially in the case of weak grids. Most household appliances contain a conventional Power Factor Corrector (PFC) rectifier, which maximizes the load Power Factor (PF) but does not contribute to the regulation of the voltage Total Harmonic Distortion (THDV) in residential electrical grids. This manuscript proposes a modification for PFC controllers by adapting the operation mode depending on the measured THDV. As a result, the PFCs operate either in a low current Total Harmonic Distortion (THDI) mode or in the conventional resistor emulator mode and contribute to the regulation of the THDV and the P F at the distribution feeders. To prove the concept, the modification is applied to a current sensorless Non-Linear Controller (NLC) applied to a single-phase Boost rectifier. Experimental results show its performance in a PFC front-end stage operating in Continuous Conduction Mode (CCM) connected to the grid with different THDV.This work is funded by the Spanish Ministry of Science and Innovation through the project TEC2014-52316-R ECOTREND Estimation and Optimal Control for Energy Conversion with Digital Devices