DSM-Based Methodology Development for Addressing Problems of High PV Penetrated Distribution Syste

Rooftop photovoltaic (PV) systems supply customer loads without the need of transporting electricity through long distance, making them an efficient distributed generation resource for supplying residential and small commercial loads. With the declination of the PV panel price and the installation cost, many areas such as Hawaii and California start to see large-scale deployment of residential and commercial roof-top PV systems [1].;However, because solar is a variable generation resource with intermittency and uncertainty in its power outputs, both the end users and the utilities would suffer some problems with the implementation of the PV panel. For end users, because there is a high possibility that the user consumption profile is not consistent with the PV power profile, the generated solar power cannot be efficiently utilized if no further measures such as installing appropriate energy storage (ES) or applying energy management programs could be implemented. For utilities, the intermittence of PV outputs may cause no or little operational issues as long as the solar penetration level is lower than 10% because power distribution systems are designed to handle large load variations. However, in areas where solar resources are abundant, policies support investment made towards PV installations, and environmental consciousness of residents are high, solar penetration levels are quickly reaching 20% or higher on some residential feeders. As a result, distribution grid operators start to observe overvoltage and reverse power flow at the point of connection and neighboring distribution networks [2- 5].;In this dissertation, proper methodologies and approaches have been derived to solve or mitigate the problems and fulfil the requirements and expectations of both the end users and utilities from various aspects. In the first part of the dissertation, I focused my effort on developing residential PV and energy storage sizing methods considering demand-side management (DSM). Then, I studied the aggregated impact of high penetration of residential PV systems on distribution feeders operations. In the second part of the dissertation, I focused my effort on solving the voltage problems caused by PV integration. I developed a two-stage hierarchical control strategy for deploying demand response on distribution system, with the control objective of implementing demand response requirement from transmission system while regulating the voltage profiles at distribution system. This control strategy enables the co-optimization of demand response operation between the transmission and distribution systems. The Voltage-Load Sensitivity Matrix (VLSM) and the price functions for different demand response resources we developed have enabled us to consider the coordination among different demand response resources including both customer-owned and utility-owned devices.