Technology advances including development of advanced distributed energy resources (DER) and grid-integrated operations and controls functionalities have surpassed the requirements in current standards and codes for DER interconnection with the distribution grid. The full revision of IEEE Standards 1547 (requirements for DER-grid interconnection and interoperability) and 1547.1 (test procedures for conformance to 1547) are establishing requirements and best practices for state-of-the-art DER including variable renewable energy sources. The revised standards will also address challenges associated with interoperability and transmission-level effects, in addition to strictly addressing the distribution grid needs. This paper provides the status and future direction of the ongoing development focus for the 1547 standards.

This paper presents a power hardware-in-the-loop (PHIL) framework for testing advanced inverter features such as voltage regulation and frequency response that interact dynamically with the electric grid. The PHIL model simulates grid voltage dynamics using a simplified Thevenin-based model and simulates grid frequency dynamics using a turbine-governor model including droop, inertia, and damping. Also presented are a statistical analysis of short-circuit impedances in the IEEE 8500-node test feeder, and analytical justification for approximating Thevenin impedances at inverter connection points as short-circuit impedances. Test results are presented for two inverters performing volt-VAr control, high-frequency power curtailment, voltage and frequency ride-through, and abnormal voltage disconnection while connected to the PHIL system. Results confirm advanced grid support functions have the desired effects when performing voltage regulation and high-frequency power curtailment while riding through large voltage and frequency transients. Some PHIL tests presented here replicate IEEE 1547.1-style conformance tests; no evidence is seen that grid dynamic response emulation affects the results of such conformance tests.

Ground faults and arc faults are the two most common reasons for fires in photovoltaic (PV) arrays and methods exist that can mitigate the hazards. This report provides field procedures for testing PV arrays for ground faults, and for implementing high resolution ground fault and arc fault detectors in existing and new PV system designs.

This paper presents a power hardware-in-the-loop (PHIL) framework for testing advanced inverter features such as voltage regulation and frequency response that interact dynamically with the electric grid. The PHIL model simulates grid voltage dynamics using a simplified Thevenin-based model and simulates grid frequency dynamics using a turbine- governor model including droop, inertia, and damping. Also presented are a statistical analysis of short-circuit impedances in the IEEE 8500-node test feeder, and analytical justification for approximating Thevenin impedances at inverter connection points as short-circuit impedances. Test results are presented for two inverters performing volt-VAr control, high-frequency power curtailment, voltage and frequency ride-through, and abnormal voltage disconnection while connected to the PHIL system. Results confirm advanced grid support functions have the desired effects when performing voltage regulation and high- frequency power curtailment while riding through large voltage and frequency transients. Some PHIL tests presented here replicate IEEE 1547.1-style conformance tests; no evidence is seen that grid dynamic response emulation affects the results of such conformance tests.

Public-private partnerships have been a mainstay of the U.S. Department of Energy and the National Renewable Energy Laboratory (DOE/NREL) approach to research and development. These partnerships also include technology development that enables grid modernization and distributed energy resources (DER) advancement, especially renewable energy systems integration with the grid. Through DOE/NREL and industry support of Institute of Electrical and Electronics Engineers (IEEE) standards development, the IEEE 1547 series of standards has helped shape the way utilities and other businesses have worked together to realize increasing amounts of DER interconnected with the distribution grid. And more recently, the IEEE 2030 series of standards is helping to further realize greater implementation of communications and information technologies that provide interoperability solutions for enhanced integration of DER and loads with the grid. For these standards development partnerships, for approximately $1 of federal funding, industry partnering has contributed $5. In this report, the status update is presented for the American National Standards IEEE 1547 and IEEE 2030 series of standards. A short synopsis of the history of the 1547 standards is first presented, then the current status and future direction of the ongoing standards development activities are discussed.

This paper introduces a new test plan and provides results for testing photovoltaic inverters with advanced grid support features including voltage regulation, wider voltage and frequency operating ranges, and voltage and frequency ride-through, as allowed by IEEE Standard 1547-Amendment 1. The test plan emphasizes testing for interactions between and among advanced inverter features and conventional features (e.g., unintentional islanding), and it includes testing of inverter dynamic response when regulating voltage. Results are included from testing of a single-phase inverter and a three-phase inverter.

This study considers potential system effects from the addition of Plug-in Electric Vehicle (PEV) load to individually metered residential customers together with a concurrent market adoption of Distributed Energy Resources (DER) and energy storage technologies to offset the associated load growth. To evaluate various renewable energy source conditions, a prototypical circuit is evaluated in Detroit, Los Angeles, and Orlando locations for both summer and winter loading conditions. Various load adoption scenarios are simulated by randomly assigning specified loading to target customer classes on the circuit.

High-penetration photovoltaic (PV) system deployment is becoming a reality in several regions of the United States and the trend toward high penetration levels will continue to rise due to decreasing PV system costs in concert with increasing electric utility rates and societal deliberations. New standards and codes for high-penetration PV deployment must be developed, while some existing standards and codes will need to be revised to accommodate increasing levels of PV deployment. According to a recent industry report, cumulative grid-tied PV capacity in the U.S. grew to 792 MW by the end of year 2008, with a growth rate of 81% for new grid-tied PV installations in 2008 over 2007 and 53% in 2007 over 2006. These rapid growth rates are expected to continue and will be further spurred by the President's energy plan to double renewable capacity in the next three years to help the U.S. concurrently meet its economic, energy security, and environmental challenges. On May 20, 2010, in Denver, Colorado, the National Renewable Energy Laboratory, in conjunction with the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), held a workshop to examine the key technical issues and barriers associated with high PV penetration levels. Addressing these standards and codes was a major finding of the High Penetration of PV Systems into the Distribution Grid Workshop held in Ontario, California, in February 2009.

While the number of PV systems interconnected to the electric grid has increased significantly over the last decade, only recently have PV systems been installed in major metropolitan areas and tied to electric distribution secondary network systems (networks). This paper examines six cases studies of photovoltaic (PV) systems integrated into secondary network systems. The six PV systems were chosen for evaluation because they are interconnected successfully to secondary network systems located in four major U.S. Cities.

This paper reports the interim status in identifying and reviewing photovoltaic (PV) codes and standards (C&S) and related electrical activities for grid-connected, high-penetration PV systems with a focus on U.S. electric utility distribution grid interconnection. That includes identifying topics and concerns not yet in the scope of existing C&S documents, identifying C&S-related ongoing work and approaches, and providing recommendations related to C&S needs. This paper also addresses certain technical concerns, e.g., monitoring, information exchange, and control pertaining to business models, tariffs, and economics governed by policy and regulatory mandates. However, the policy, regulatory, and business concerns are not this paper's direct focus. Rather, the primary focus is on systems engineering-based C&S technical concerns for high-penetration PV systems in U.S. utility distribution grids.

Microgrids are intentional islands formed at a facility or in an electrical distribution system that contain at least one distributed energy resource and associated loads. Microgrids that operate both electrical generation and loads in a coordinated manner can offer benefits to the customer and the local utility. The loads and energy sources in a microgrid can be disconnected from and reconnected to the utility system with minimal disruption, thereby improving reliability. Any time a microgrid is implemented in an electrical distribution system, it must be well planned to avoid problems. This paper discusses current microgrid technologies and standards that are being developed to address implementation of microgrids.

The IEEE American National Standards project P2030 TM addressing smart grid interoperability and the IEEE 1547 series of standards addressing distributed resources interconnection with the grid have been identified in priority action plans in the Report to NIST on the Smart Grid Interoperability Standards Roadmap. This paper presents the status of the IEEE P2030 development, the IEEE 1547 series of standards publications and drafts, and provides insight on systems integration and grid infrastructure. The P2030 and 1547 series of standards are sponsored by IEEE Standards Coordinating Committee 21 (SCC21). The title of the IEEE P2030 standard is Guide for Smart Grid Interoperability of Energy Technology and Information Technology Operation With the Electric Power System (EPS), and End-Use Applications and Loads. The guide will provide a knowledge base addressing terminology, characteristics, functional performance and evaluation criteria, and the application of engineering principles for smart grid interoperability. P2030 involves the integration of energy, information, and communications technologies, which are necessary to achieve seamless operation for electric generation, delivery, and end-use applications to permit two-way power flow with communication and control.

The California Energy Commission is cost-sharing research with the Department of Energy through the National Renewable Energy Laboratory to address distributed energy resources (DER) topics. These efforts include developing interconnection and power management technologies, modeling the impacts of interconnecting DER with an area electric power system, and evaluating possible modifications to rate policies and tariffs. As a result, a DER interconnection device has been developed and tested. A workshop reviewed the status and issues of advanced power electronic devices. Software simulations used validated models of distribution circuits that incorporated DER, and tests and measurements of actual circuits with and without DER systems are being conducted to validate these models. Current policies affecting DER were reviewed and ratemaking policies to support deployment of DER through public utility rates and policies were identified. These advancements are expected to support the continued and expanded use of DER systems.

This chapter contains sections titled: Introduction Interconnection Technologies Standards and Codes for Interconnection Interconnection Considerations Interconnection Examples for Alternative Energy Sources References