Abstract
Analysis of voltage stability of transmission network with high photovoltaic (PV) integration is a challenging problem because of the stochastic generation of a solar system. Stabilization of the output power is an important criterion for determining the degree of penetration of PV in active distribution networks, considering loading capability. This article describes the effective voltage regulation strategy for the transmission system using the STATCOM module to resolve the drop and the effect aspects on the voltage stability in the transmission network. This paper analyzes also the influence of the STATCOM control system on preventing the combination of injection voltage STATCOM with harmonics from achieving pure voltage compensation. The proposed test system under analysis is the 53-Bus Tunisian distribution power network integrating 12 MW solar PV plant. Simulation results are added to demonstrate the efficiency of the proposed control technique for enhancing the power system quality based on the Tunisian grid code. Investigation of voltage stability shows that the dynamic behavior of the voltage depends strongly on the short circuit capacity of the power network at the point of PVs integration.
1. Introduction
Currently, Distribution grids are solely designed for radial service, with large centralized power stations providing power to the delivery of networks over long distances. However, as decentralized and distributed generators with smaller capacities are added gradually to the electricity distribution system, it undergoes dramatic changes. Renewable sources of energy have appropriated a large share in the recently proliferating distributed mode of generation during the past few years, and especially in the 2000 s. A major chunk of this recent distributed mode of generation are contributed by renewable sources of energy. In such generation systems, renewable sources like biomass, fuel cells, hydroelectric, solar and wind have demonstrated promising potential and viability [2].
5. Conclusion
This paper investigated the influence of photovoltaic integration on the voltage stability of the 53-Bus distribution grid. Efficiency and quality of voltage in PV system degrades due to instability in voltage in Grid connected system. To overcome this problem, the STATCOM is implemented for improving the power quality and the power system voltage stability under various scenarios based on the Tunisian grid code. STATCOM contributes better alternatives to increases static voltage stability margin and power transfer capability. STATCOM is also implemented to regulate the injected P-Q power to the power transmission network. In this paper, we also presented some appropriate models for the STATCOM in the steady-state analysis and with a rigorous discussion. Thus, we have derived a technique for identifying optimal placement of FACTS devices. The related equations are also derived. Simulation results show that there is a significant improvement of these parameters and steady-state stability of the system with insertion of STATCOM.
