Optimization of photovoltaic penetration with DSTATCOM in distribution systems

The penetration level of a PV system is often limited due to the violation of voltage variation introduced by the large intermittent power generation. This paper discusses the use of distribution static compensator (DSTATCOM) to compensate reactive power during peak solar irradiation to prevent voltage violation so that the PV penetration level of a distribution feeder can be increased to fully utilize solar energy. The PV power generation is simulated according to the hourly solar irradiation and temperature data provided by the weather bureau. The voltage variation at the point of common coupling (PCC) is also derived by executing the 3-φ load flow analysis to investigate the maximum PV power injection without causing a voltage violation problem. When using the proposed voltage control scheme of the DSTATCOM during high solar irradiation periods, the total power generation and total energy delivered by the PV system over a 1-year period are determined according to the annual duration of solar irradiation. The annual cash flow from sales of PV power, the DSTATCOM installation cost, the O&M cost over the system life cycle, and the capital investment in the PV system are then used to calculate the net present value (NPV) of the PV project. With the proposed voltage control to perform reactive power compensation of the DSTATCOM, the optimal installation capacity of PV systems can be determined by maximizing the net present value of the system so that better cost effectiveness of the PV project and better utilization of solar energy can be obtained.