Grid integration of photovoltaic (PV) inverters has been increasing in the past decade. Due to the uncertainties introduced with this high penetration, better monitoring and control of the assets becomes crucial for the system stability. Multiple standards are available to enable interoperability in PV inverters. In this paper, an interoperable controller, enabled by DNP3 communications protocols, is developed for a grid-connected, three-phase PV inverter. Advanced inverter control function setpoints like VVAR curves, ride-through curves are sent from a data management system application to the PV inverter through DNP3. The DNP3 server for the PV inverter is programmed on the real-time layer of the inverter controller. A controller hardware-in-the-loop experimental setup is used to validate the developed communications capability of the PV inverter. This work will enable grid integration of smart PV inverters with advanced grid-support functions as well as allow better monitoring and control of assets for grid stability.

Learn the fundamentals of smart photovoltaic (PV) inverter technology with this insightful one-stop resource Smart Solar PV Inverters with Advanced Grid Support Functionalities presents a comprehensive coverage of smart PV inverter technologies in alleviating grid integration challenges of solar PV systems and for additionally enhancing grid reliability. Accomplished author Rajiv Varma systematically integrates information from the wealth of knowledge on smart inverters available from EPRI, NREL, NERC, SIWG, EU-PVSEC, CIGRE, IEEE publications; and utility experiences worldwide. The book further presents a novel, author-developed and patented smart inverter technology for utilizing solar PV plants both in the night and day as a Flexible AC Transmission System (FACTS) Controller STATCOM, named PV-STATCOM. Replete with case studies, this book includes over 600 references and 280 illustrations. Smart Solar PV Inverters with Advanced Grid Support Functionalities’ features include: Concepts of active and reactive power control; description of different smart inverter functions, and modeling of smart PV inverter systems Distribution system applications of PV-STATCOM for dynamic voltage control, enhancing connectivity of solar PV and wind farms, and stabilization of critical motors Transmission system applications of PV-STATCOM for improving power transfer capacity, power oscillation damping (POD), suppression of subsynchronous oscillations, mitigation of fault induced delayed voltage recovery (FIDVR), and fast frequency response (FFR) with POD Hosting capacity for solar PV systems, its enhancement through effective settings of different smart inverter functions; and control coordination of smart PV inverters Emerging smart inverter grid support functions and their pioneering field demonstrations worldwide, including Canada, USA, UK, Chile, China, and India. Perfect for system planners and system operators, utility engineers, inverter manufacturers and solar farm developers, this book will prove to be an important resource for academics and graduate students involved in electrical power and renewable energy systems.

Distributed energy resources (DER) such as photovoltaic (PV) systems, when deployed in a large scale, are capable of influencing significantly the operation of power systems. Looking to the future, stakeholders are working on standards to make it possible to manage the potentially complex interactions between DER and the power system. In 2009, the Electric Power Research Institute (EPRI), Sandia National Laboratories (SNL) with the U.S. Department of Energy (DOE), and the Solar Electric Power Association (SEPA) initiated a large industry collaborative to identify and standardize definitions for a set of DER grid support functions. While the initial effort concentrated on grid-tied PV inverters and energy storage systems, the concepts have applicability to all DER. A partial product of this on-going effort is a reference definitions document (IEC TR 61850-90-7, Object models for power converters in distributed energy resources (DER) systems) that has become a basis for expansion of related International Electrotechnical Commission (IEC) standards, and is supported by US National Institute of Standards and Technology (NIST) Smart Grid Interoperability Panel (SGIP). Some industry-led organizations advancing communications protocols have also embraced this work. As standards continue to evolve, it is necessary to develop test protocols to independently verify that the inverters are properly executing the advanced functions. Interoperability is assured by establishing common definitions for the functions and a method to test compliance with operational requirements. This document describes test protocols developed by SNL to evaluate the electrical performance and operational capabilities of PV inverters and energy storage, as described in IEC TR 61850-90-7. While many of these functions are not currently required by existing grid codes or may not be widely available commercially, the industry is rapidly moving in that direction. Interoperability issues are already apparent as some of these inverter capabilities are being incorporated in large demonstration and commercial projects. The test protocols are intended to be used to verify acceptable performance of inverters within the standard framework described in IEC TR 61850-90-7. These test protocols, as they are refined and validated over time, can become precursors for future certification test procedures for DER advanced grid support functions.

As more grid-connected photovoltaic (PV) inverters become compliant with evolving interconnections requirements, there is increased interest from utilities in understanding how to best deploy advanced grid-support functions (GSF) in the field. One efficient and cost-effective method to examine such deployment options is to leverage power hardware-in-the-loop (PHIL) testing methods. Two Hawaiian Electric feeder models were converted to real-time models in the OPAL-RT real-time digital testing platform, and integrated with models of GSF capable PV inverters that were modeled from characterization test data. The integrated model was subsequently used in PHIL testing to evaluate the effects of different fixed power factor and volt-watt control settings on voltage regulation of the selected feeders. The results of this study were provided as inputs for field deployment and technical interconnection requirements for grid-connected PV inverters on the Hawaiian Islands.

As revised interconnection standards for grid-tied photovoltaic (PV) inverters address new advanced grid support functions (GSFs), there is increasing interest in inverter performance in the case of abnormal grid conditions. The growth of GSF-enabled inverters has outpaced the industry standards that define their operation, although recently published updates to UL1741 with Supplement SA define test conditions for GSFs such as volt-var control, frequency-watt control, and volt-age/frequency ride-through, among others. A comparative experimental evaluation has been completed on four commercially available, three-phase PV inverters in the 24.0-39.8 kVA power range on their GSF capability and the effect on abnormal grid condition response. This study examines the impact particular GSF implementations have on run-on times during islanding conditions, peak voltages in load rejection overvoltage scenarios, and peak currents during single-phase and three-phase fault events for individual inverters. This report reviews comparative test data, which shows that GSFs have little impact on the metrics of interest in most tests cases.

In Hawai'i, the relatively high cost of electricity costs coupled with various incentives have made it cost-effective to install solar photovoltaics (PV) on residential homes and larger central-station PV plants. On some of the islands, PV has reached over 50% of the installed generation capacity base. To make sure these inverter-based PV plants can maintain stable and safe operations, new smart inverter functionality is being evaluated and demonstrated at significant scale across the islands This paper describes research conducted to validate high PV penetration scenarios with smart inverters and recent progress on the use of these advanced inverter grid support functions in actual power grids in Hawai'i.

This book addresses the need to understand the development, use, construction, and operation of smart microgrids (SMG). Covering selected major operations of SMG like dynamic energy management, demand response, and demand dispatch, it describes the design and operational challenges of different microgrids and provides feasible solutions for systems. Smart Micro Grid presents communication technologies and governing standards used in developing communication networks for realizing various smart services and applications in microgrids. An architecture facilitating bidirectional communication for smart distribution/microgrid is brought out covering aspects of its design, development and validation. The book is aimed at graduate, research students and professionals in power, power systems, and power electronics. Features: • Covers a broad overview of the benefits, the design and operation requirements, standards and communication requirements for deploying microgrids in distribution systems. • Explores issues related to planning, expansion, operation, type of microgrids, interaction among microgrid and distribution networks, demand response, and the technical requirements for the communication network. • Discusses current standards and common practices to develop and operate microgrids. • Describes technical issues and requirements for operating microgrids. • Illustrates smart communication architecture and protocols.