Probabilistic evaluation of voltage control and reactive power techniques with photovoltaic distributed-generation

The high photovoltaic penetration at the distributed grid has been affecting the grid on various technical aspects, for instance: power loss, voltage profile and stability. Therefore, when voltage control and reactive power is used, the inclusion of photovoltaic distributed generation (GDFV) on power grid is an aspect the network's operators have to be aware of. One difficulty to be considered for this type of control is the GDFV's intermittence, due the stochastic nature of solar radiation. In addition, GDFV can operate in various control modes due to the use of inverters. This paper aims to evaluate the effects that GDFV control of voltage and reactive power has on the distribution network, this evaluation is performed using a robust probabilistic optimum power flow. The tests were made at a 33 bus network, and indicate that the inclusion of GDFV in the var / volt control significantly reduces the power losses and improve the voltage stability margin.