Improving power delivery through secondary voltage control

Traditionally, electric utilities have been maintaining their customer voltages within the desired limits by operating the primary devices, such as transformers with load tap changer (LTC), voltage regulators, and capacitor banks. In recent years, new advanced systems, such as conservation voltage reduction (CVR) have been implemented on the distribution systems with the main goal of reducing the demand and energy consumption by maintaining the customer voltages in the lower range of ANSI band, which resulted in challenges associated with tighter voltage control. In addition, the installation of the distributed generation (DG) on the distribution system primary and secondary also resulted in additional operational challenges, due to the intermittency of this type of energy source. In order to achieve better power delivery and voltage control, Duke Energy initiated exploratory pilot project that includes the new technology in form of low voltage power electronic devices called In-Line Power Regulators (IPR). The objective of the project is to increase the understanding of how these devices operate, test their ability to manage the grid at secondary level, and explore their agility and flexibility in controlling the voltage, power factor, the ability to reduce voltage and current harmonics on the system secondary and capability to provide the DC power from a 460V DC bus.