Performance estimation of voltage control with distributed generation

The growth of distributed generation in LV and MV networks promotes less dependence on large thermoelectric power plants and thus a significant reduction in the use of non-renewable energy sources, resulting in lower emissions. The proliferation of Distributed Energy Resources increases the probability that the produced energy will not be self-consumed on site, but will be fed into the grids, causing voltage problems and the reverse power flow phenomenon. To mitigate these problems, national and international grid codes have been updated requiring distributed generators to supply ancillary services, such as the voltage regulation with the aim of stabilizing voltages within the limits imposed by standards. The Italian Standards, and in particular the CEI 0-16, dictates that distributed generation units with a total installed capacity higher than 3 kW are required to participate in voltage control. Two voltage regulation modes for the local control are designed in CEI 0-16. In this paper, the presence of photovoltaic generators in MV grid is simulated using the PowerWorld Simulator, the two modalities of voltage regulation described in the CEI 0-16 standards are implemented to analyze the performance of these controls. The converter efficiency is also considered to study how their presence affects the network. Performance indices are used to compare the implemented control strategies.