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Distributed Energy Resources (DER) Projects
These projects are described below: Integration of Distributed Energy Resources in Electric Utility SystemsOverviewDistributed Resources (DR) will have increased impacts on distribution utilities, due not only to improvements in DR device technology, cost, and efficiency, but also to the rapid growth of the deregulated electricity marketplace. These deregulation forces have spurred interest in non-standard and dispersed sources of generation to meet increasingly competitive requirements for energy, ancillary services, and other energy services. Distribution utilities will be a major player in deregulation as retail marketing becomes more widespread. DR devices will present not only technological headaches for incorporating these devices in the distribution system, but the operation and ownership of DR devices will also provide significant opportunities to distribution utilities, particularly if they can manage these resources effectively. This management requires communications between the distribution operations centers and the DR devices in the field, and entails the development of monitoring and control capabilities. In particular, the flow of information among all of the different stakeholders in the DR marketplace is crucial to the effective use of DR technology. No single communications and control technology or strategy will be the best for all distribution utilities. Rather, a proliferation of choices exist which utilities will need to assess individually, based on their business goals, the mix and range of customers within their territory, the types of DR devices being installed, their power system characteristics and equipment, the availability of different public and private communications infrastructures, and their existing distribution automation capabilities. EPRI StudyXanthus staff performed the EPRI study on “Integration of Distributed Resources in Electric Utility Systems Functional Definition for Communication and Control Requirements” EPRI TR-111491, November 1998. The EPRI report discusses the probable future of DR within the deregulated utility industry as a source of energy and ancillary services, assesses the range of benefits and opportunities of DR for distribution utilities in the electricity marketplace, evaluates in detail the capabilities of different telecommunications media for providing the communications infrastructure to utilities for monitoring and control DR devices, and describes possible scenarios and examples to interest distribution utilities to explore the alternatives which match their business goals and technical environment. Open Architecture for Distributed Energy Resources (DER) in Distribution Automation (DA)Xanthus staff worked on an EPRI project to pursue the key issues raised in the some of the previous work with EPRI on DR or Distributed Energy Resources (DER). The overall project objectives include: 1. Improve the strategic value of DER in electric utility system operations through contributions to the development of the needed utility communication infrastructure. 2. Create the ability to use DER as a valuable resource in distribution automation. 3. Develop DER device communication object models that enable strategic use of DER in distribution automation for functions such as routine energy supply, voltage regulation, power factor control, emergency power supply, disaster recovery operations, and harmonic suppression. 4. Enable flexible reconfiguration of distribution systems into islands or “microgrids” to aid in strategic and emergency system operations. 5. Enable the complementary interactive strategic use of new technologies being deployed in distribution system environments, such as DER, Custom Power™ and other power quality devices, and load management capabilities. 6. Determine other activities that are needed to integrate DER into the evolving communication infrastructure of future distribution systems, to aid in further development of the CEIDS program. The project encompasses the following tasks: 1. Refine the DER Communications Architecture Work Plan, based on EPRI’s updated DER work plan: 2. Organize a DER Architecture Consortium to help fund and support the DER Communications Architecture Project. The steps to organize this Consortium include: 3. Determine what additional efforts are needed for integrating DER into distribution automation, including additional studies, automation tools, and trials. These efforts include initial studies to analyze the issues, development of tools to assist utilities, and possible pilot projects to validate the studies and tools. The areas for study include: 4. Sponsor DER Object Modeling Workshops to develop device object models, focusing on reciprocating engines and gas turbines first, but addressing common issues for all DER. DER device object models need to be developed and validated through the consensus process, primarily by modeling experts and vendors who will need to implement the object models. The straw-man DER device object model will be used as the first draft. Vendors and other interested parties will review and update the DER object models iteratively after the first Device Object Modeling Workshop, using teleconferences and email exchanges, until consensus is achieved for DER Object Models, draft 1. This initial draft will be used and updated during the subsequent steps of the project. The final DER device object models will be ready for submittal to the IEEE and/or the IEC for standardization. 5. Refine the DER object models through coordination with other object modeling efforts, including IEC efforts, the Common Information Model (CIM), and pilot implementations. 6. Verify the DER object models through individual and integrated testing in a laboratory and/or factory environment. This effort entails development efforts by vendors and participation by utilities and other interested parties. Some of the activities include: 7. Validate the DER object models integrated in actual DER equipment in the field, through pilot programs with participating Consortium members. 8. Promulgate the DER object models through the standards processes of the IEEE and/or the IEC, by appropriate formatting of the DER object model documents, and subsequent editing of the documents to reflect IEC/IEEE comments. 9. Implement a program to encourage vendor adoption of the DER object models. 10. Develop Certification procedures and tools for validating vendor implementations of the DER object models. International Data Object Models for Distributed Energy Resources (DER) (IEC 61850-7-420)Data object models are data with standardized names and standardized formats for exchanging data between different equipment or systems. Standard object models, combined with standard service models (methods for sending the data, e.g. report-by-exception, periodic, control commands) and standard protocols (the bits and bytes actually send over the communication channel), permit different systems to interact with minimal customization and greater interoperability. The combination of object model, service model, and protocol profiles can be termed the “information model”. These DER information models are based on open-system language, semantics, services, protocols, and architecture, which have been standardized by IEC 61850, but they include some extensions to IEC 61850. The DER object models will eventually be provided to the IEC as a draft set of object models for international standardization. In order to ensure the standardization process is simplified, these DER information models are compatible with IEC 61850, IEC61970 (CIM), IEC60870-5 (telecontrol protocol, which also formed the base for DNP), and IEC60870-6 (ICCP/TASE.2) standards. The object models in this draft document are ready for trial use by vendors in order to provide feedback and updates. However, it must be understood that these are still draft object models and are subject to change. Communications for DER plants involve not only local communications between DER units and the plant management system, but also between the DER plant and the operators who manage both the plant and the individual DER units. This is illustrated in Figure 1‑1.
Figure 1‑1: Example of a Communications Configuration for a DER Plant There is a growing interest in implementing DER devices throughout the world. As the DER technology evolves, nations recognize the economic, social, and environmental benefits of integrating DER technology within their electric infrastructure. The manufacturers of DER devices are facing the age-old issues of what communication standards and protocols to provide to their customers for monitoring and controlling DER devices, in particular when they are interconnected with the electric utility system. In the past, DER manufacturers developed their own proprietary communication technology. However, as utilities and other energy service providers start to manage DER devices which are interconnected with the utility power system, they are finding that coping with these different communication technologies present major technical difficulties, implementation costs, and maintenance costs. Therefore, utilities, DER manufacturers, and the customers they serve are increasingly interested in having one international standard that would define the communication and control interfaces for all DER devices. Such standards, along with associated guidelines and uniform procedures would simplify implementation, reduce installation costs, reduce maintenance costs, and improve reliability of power system operations. At the same time, the object modeling technology has developed within the last few years to become well-established as the most effective method for managing information exchanges. In particular, the IEC 61850 object models for the exchange of information within substations have moved through the standardization process, and are now formally designated as the IEC 61850 International Standard. Many of the components of this standard can be reused for object models of other types of devices. Some new components are also needed, but these can follow the rules for creating these new components, thus making them compatible with the existing IEC 61850 standards. The interrelationship between IEC TC57 modeling standards is illustrated in Figure 1‑2.This illustration shows as horizontal layers the three components to an information exchange model for retrieving data from the field, namely, the communication protocol profiles, the service models, and the object models. Above these layers is the information model of utility-specific data, termed the Common Information Model (CIM), as well as all the applications and databases needed in utility operations. Vertically, different areas are shown: substation automation, DER, distribution automation, customer services, generation (including large hydro plants), etc. Although this document addresses only the IEC 61850 object models, additional modeling efforts will be needed for DER (and other domain areas) in the CIM/CFL areas.
Figure 1‑2: IEC 61850 Modeling and Connections with Other IEC TC57 Models
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