Modeling of Utility Distribution Feeder in OpenDSS and Steady State Impact analysis of Distributed Generation

Modeling of Utility Distribution Feeder in OpenDSS and Steady State Impact analysis of Distributed Generation Vaidyanath Ramachandran, Master of Science in Electrical Engineering, West Virginia University Dr. Sarika Khushalani Solanki, Ph.D., Chair With the deregulation of the electric power industry and the advancement of new technologies, the attention of the utilities has been drawn towards adopting Distributed Generation (DG) into their existing infrastructure. The deployment of DG brings ample technological and environmental benefits to the traditional distribution networks. The appropriate sizing and placement of DGs which generate power locally to fulfill consumer demands, helps to reduce power losses and avoid transmission and distribution system expansion. The primary objective of this thesis is to model a utility distribution feeder in OpenDSS. Studies are conducted on the data obtained from American Electric Power utility. This thesis develops models for 12.47 kV (medium voltage) distribution feeders in OpenDSS by utilizing the existing models in CYMDIST. The model conversion is achieved by a detailed one-to-one component matching approach for multi phased lines, conductors, underground cables, loads, regulators and capacitor banks. The power flow results of OpenDSS and CYMDIST are compared to derive important conclusions. The second major objective is to analyze the impacts of DG on distribution systems and two focus areas are chosen, namely: effect on voltage profiles and losses of the system and the effects on power market operation. To analyze the impacts of DG on the distribution systems, Photovoltaic (PV) system with varying penetration levels are integrated at different locations along the developed feeder model. PV systems are one of the fastest growing DG technologies, with a lot of utilities in North America expressing interest in its implementation. Many utilities either receive incentives or are mandated by green-generation portfolio regulations to install solar PV systems on their feeders. The large number of PV interconnection requests to the utilities has led to typical studies in the areas of power quality, protection and operation of distribution feeders. The high penetration of PV into the system throws up some interesting implications for the utilities. Bidirectional power flow into a distribution system, (which is designed for one way power flow) may impact system voltage profiles and losses. In this thesis, the effects of voltage unbalance and the losses of the feeder are analyzed for different PV location and penetration scenarios. Following this, this thesis tries to assess the impact of DG on power market operations. In a deregulated competitive market, Generation companies (Genco) sell electricity to the Power exchange (PX) from which large customers such as distribution companies (Disco) and aggregators may purchase electricity to meet their needs through a double sided bidding system. The reliable and efficient operation of this new market structure is ensured by an independent body known as the Independent System Operator (ISO). Under such a market structure, a particular type of unit commitment, called the Price Based Unit Commitment (PBUC) is used by the Genco to determine optimal bids in order to maximize its profit. However, the inclusion of intermittent DG resources such as wind farms by the Gencos causes uncertainty in PBUC schedules. In this research, the effects of intermittency in the DG resource availability on the PBUC schedule of a Genco owning a distribution side wind farm are analyzed.