Efficient Time Series Simulation of Distribution Systems with Voltage Regulation and PV Penetration

This paper presents an approach for solving the time-series simulation (TSS) for three-phase unbalanced distribution systems with voltage regulator control and photovoltaic (PV) generation. Efficient time-series simulation approach based on Lagrange polynomial approximation is developed to decrease the execution time and enhance the convergence characteristics. The formulation is developed to find efficient initial values for voltage magnitudes and phase angles corresponding to load variations during the day. These initial values of voltage magnitudes and phase angles are calculated from the variations of reactive and active powers, respectively. The predicted values are updated using forward/backward sweep power-flow engine. A line drop compensator (LDC) is used to regulate the voltage by modelling the drop of transmission line from the transformer to the load center. In addition, the effect of PV penetration on tap setting, to regulate the voltage magnitude, is investigated. The developed TSS technique with voltage regulator and PV generation are validated using the standard three-phase unbalanced IEEE 123-node. The developed technique is compared with the traditional method that uses the previous voltage magnitudes and phase angles as initial values. The obtained results prove the effectiveness of the developed TSS in reducing both of the number of iterations and execution time compared to the traditional method.