Abstract

LARA, Jorge et al. Bidirectional EV charger with ancillary power quality capabilities. Ing. invest. y tecnol. [online]. 2022, vol.23, n.1, e1936.  Epub May 02, 2022. ISSN 2594-0732.  https://doi.org/10.22201/fi.25940732e.2022.23.1.008.

This paper presents a bidirectional electric vehicle (EV) charger with ancillary power quality (PQ) capabilities in grid-to-vehicle (G2V), vehicle-to-grid (V2G) and vehicle-to-home (V2H) applications. The proposed configuration consists of a five-level (5L) neutral point clamped (NPC) converter in cascade with a dual-active half-bridge (DAHB) DC-DC converter. The proposed cascaded control strategy used for regulating the common DC bus voltage as well as for compensating the grid current harmonics and the reactive power through the 5L-converter is based on a performant proportional-resonant (PR) compensator. By applying the single-phase-shift (SPS) technique to the DAHB converter, the battery power flow is accurately regulated. A detailed study with exhaustive tests and simulation results obtained in MATLAB-SimPowerSystems for a full-scale power system based on a Nissan Leaf´s battery validate the fairly good performance of the proposed configuration and control strategies. The main achievements of this work are: 1) the system’s stability is maintained even during fairly abrupt changing conditions, 2) in the steady-state of the G2V/V2G operation modes, the total harmonic distortion (THD) of the grid current remains below 3 % while the power factor (PF) is kept at unity, 3) the reactive power demanded from the grid is zero despite of feeding a highly nonlinear load, and 4) when a power outage occurs, the transition to the V2H mode is seamless and the home load is uninterruptedly supplied with a very low-distortion output voltage from the 5L-converter.

Keywords : Electric vehicle; EV charger; multilevel converter; G2V/V2G/V2H; active filter; power quality; resonant controller.