DISTRIBUTION SYSTEM ANALYSIS CONSIDERING PHOTOVOLTAIC GENERATION WITH OPTIMAL CONTROL OF INVERTER POWER FACTOR
Distributed Generation Systems (DG) are very convenient because they can delay or even avoid reinforcing investments in the distribution networks. However, the impacts of the increase of the DG must be taken into account by the operators of the power system and regulators agencies both in operation and in system planning. In particular, we can mention the Photovoltaic Generation (PV), which is currently growing quickly and the sun, its primary source, is available all over the planet. With this large increase, it is necessary to worry about the control of technical losses in the network and the voltage levels at each bus, that means an economical and safe operation. The solar inverters can operate within a power factor (pf) range, injecting or absorbing reactive power which can contribute to the network performance. The optimal adjustment of the power factor at solar inverters´s buses/nodes contributes to an economical and safe operation. The distribution network was modeled as a multiperiod Optimal Power Flow (OPF) problem aiming to minimize active losses and considering the network constraints, hourly variations of the load and power availability on the photovoltaic inverters. The problem solution will point to the optimal adjustment of the pf on the inverters. The modeling was developed in AMPL and the Knitro solver was used. The algorithm was tested on 10 and 34 bus systems operating with different configurations of photovoltaic generation. With this technique and comparing with the system operating with unity pf, the results show a reduction of up to 15.97% in technical losses and a voltage profile improvement.