Analysis of the Impacts of V2G Chargers on LV Grid Harmonics

The current harmonics of a local low-voltage (LV) power network with two vehicle-to-grid (V2G) chargers connected are evaluated in this paper. Two indicators, the Total Harmonic Distortion (THD) and the Total Demand Distortion (TDD), are calculated based on the monitored data collected from the demonstration site. The system states are grouped into several scenarios according to different charger operational modes, including grid-to-vehicle (G2V), V2G, and off modes. The statistical analysis of the two indicators over a six-month period shows that, in terms of TDD, grid harmonics generally complied with the international standards under all scenarios. The experiments of this demonstration project prove that V2G chargers slightly improve the grid harmonics, which is useful information for charger manufacturers, site and utilities operators, and other power sector stakeholders.