Voltage and Reactive Power Combined Control of Utility Devices and Smart Inverters on a Distribution Grid with Solar PV

With adoption of distributed energy resources (DERs) expected in future grids, voltage regulation methods need to be reevaluated and improved to ensure their effectiveness under the high volatility of renewable generation. A multi-timescale cluster-based method is proposed to optimize and disperse operation of voltage controlling utility devices including capacitor banks (CBs) and load tap changers (LTCs) while allowing faster response time with customer-owned smart inverters (SIs) in-between switching operations. The proposed method is tested on a digital twin (DT) of a very large utility distribution grid with 2,018 nodes and 8.65MW peak load to evaluate its effectiveness in future grid conditions with high DER penetration. The proposed method reduced the total energy by 1.66%, in the projected range of conservation voltage reduction (CVR), while limiting CB and LTC switching operations to 35 and 7 total adjustments respectively over a 24-hour period.