Dynamic Control of Volt-VAr Control Devices: an Effective Approach to Overcome Associated Issues with High Penetration of Solar Photovoltaic Resources

With high penetration of solar Photovoltaic (PV) resources, controlling voltage of distribution systems with conventional control strategies such as fixed set-point operation mode of Load Tap Changers (LTCs) or even in some cases with Line-Drop Compensation (LDC) operation mode is not possible anymore. In case of LDC operation mode, optimizing the R & X settings is time-consuming and is required with every change in PV penetration level. Hence, a robust and dynamic control strategy is required to handle the challenges induced by high penetration levels of solar PV resources. In this work, dynamic control of LTC and Line Voltage Regulators (LVRs) of a Hawaii substation with multiple voltage control zones is implemented in OpenDSS and controlled by Python through COM interface. Then its performance in terms of reducing voltage volatility, Operation and Maintenance (O&M) costs and ramp-rate, facilitating LDC R&X settings optimization and energy saving is evaluated. Furthermore, the impact of Dynamic Var Controllers (DVCs) in accomplishing the aforementioned objectives is illustrated through comprehensive time-series simulations. Simulation results show that by using dynamic control of voltage regulators and DVCs, PV penetration increases by 45% due to reducing voltage volatility. Moreover, generation ramp-rate reduces by 8%. Furthermore, energy savings are tripled compared to energy savings achieved by existing controls. Finally, the utilization of DVCs reduces the O&M costs by 14%.