Program 13 projects focus on the following technical areas: Distributed Generation Impact, Economic Analysis, Engineering Analysis Software, Engineering Guidelines, Industry Perspectives / White Papers, Operational Efficiency, Power Quality, Smart Grid, System Protection, System Reliability
Commercial estimating requires correct handling of a broad range of issues. The input data requirements are more complex, as well as, the logic to process that data. Southern Company has invested a significant amount of effort into this process resulting in the iCLEAR™ (Industrial & Commercial Load Estimating and Referencing) system. This system is available for licensing to the DSTAR members. This project will develop and validate regional models, based on a proprietray method developed by Z Solutions, and using DSTAR member facility data. The models will be implemented in iCLEAR to estimate commercial loads in different regions of the country.
The goal of this project is to understand how distribution utilities inspect their systems and how often they do maintenance on reclosers, regulators, and other critical assets, and what are the best practices for using thermal imaging devices. The scope will include a survey of how often inspection is performed, what gets inspected, and observed failure rates for various assets. This will be used as a starting point to dig into what type of inspection is actually being done, and what are the results and lessons learned. For example, there is a lot of interest in understanding how to successfully use infrared heat guns to determine when connections are running too hot and what decisions to take based on the readings.
The Secondary Electrical Design Software (SEDS), developed during Program 7 and enhanced during Programs 9, 10, 11 and 12, has been successfully used by the DSTAR membership to perform electrical calculations, such as voltage drop and flicker, for multi-tiered, single-phase and three-phase secondary systems. SEDS employs a drag and drop-style user interface that is very simple to use and affords users tremendous flexibility. As users have grown accustomed to SEDS, they have continued to ask for increased functionality. In this project, the DSTAR membership has requested some improvements to the three-phase load database, some GUI enhancements, bulk editing importing of data, and the handling of seasonal coincidence factors.
DSTAR Project 12-6 was initiated to investigate the changing nature of loads on electric distribution systems. The project confirmed that the utility load is becoming more active and non-linear, and as a result the loading due to harmonics created by these loads is increasing and changing. With more phase-to-neutral connected electronic loads, distribution utilities are finding that in many cases the dominant harmonic is the 3rd, which causes high neutral currents and neutral-to-ground voltages in addition to substantial increase in voltage distortion. This project will study and report on 3rd harmonic producing loads, (as well as other harmonics) and
- Analyze their impact on distribution systems, with regard to thermal loading, distortion and neutral voltage elevation
- Identify what mitigating measures are currently available or in development, including system design, equipment application, filters, etc.
- Assess (as far as possible) their effectiveness in mitigating impacts
This project will investigate and compare centralized and distributed feeder automation schemes that are currently adopted by utilities or will be likely implemented in future. A thorough literature review and interviews among utilities/vendors will be carried out to determine performance and economic benefits of each. As far as possible, centralized, substation-based and peer-to-peer offerings commonly available will be compared on a normalized basis to determine the key elements of differentiation. The report will discuss how each FA arrangement enables distribution system operations such as sensing and monitoring, feeder switching, fault location, isolation and restoration, and volt/var control. In addition, their ability to impact performance metrics such as reliability indices, as well as asset utilization, life extension, and operational efficiency will be compared.
Specifically, this project is expected to accomplish the following:
- Investigate the structure of centralized and distributed FA schemes that are currently in use or will likely be in use in future
- Evaluate major applications of centralized and distributed FA schemes and their operational benefits
- Compare challenges, concerns, advantages, and disadvantages of centralized vs. distributed FA
- Discuss the performance and economics of centralized vs. decentralized automation schemes
With the emergence of Smart Grid technologies and eco-friendly initiatives, utilities are interested in more fully utilizing CVR strategies to reduce peak demand, energy delivered during high-cost periods, overall energy demand, and generation emissions (where applicable). Several of the DSTAR members have adopted CVR strategies either as pilot programs or as part of their long-term strategy. In most cases, DSTAR members are engaged in evaluating the effectiveness, benefits and tradeoffs of CVR implementation. It is expected that the methodologies used among DSTAR member utilities and the benefits gained will vary widely due to differences in feeder topology, connected equipment, load characteristics, voltage profile, and other factors. In addition, the effectiveness of CVR is impacted by how it is implemented and operated over of the year. As the popularity of CVR increases, it is desirable to develop guidelines to enable DSTAR members to evaluate the effectiveness of CVR and maximize the potential benefits.
To achieve the desired objectives, this project will rely on a combination of literature search, pilot CVR projects, DSTAR member CVR data and circuit simulations. Some of the questions that the three tasks will try to address are:
- How to develop guidelines to select feeders best suited for CVR implementation?
- How to identify loads or load mix that best respond best to CVR?
- How to evaluate CVR effectiveness (CVR factor) from data accounting for weather and other variables?
- What are the pros and cons of different CVR evaluation and operation modes? (hour/day/week on-off cycles, control groups, etc.)
- What is the impact of various Volt/VAr control strategies including CVVC and IVVC?
- How to quantify CVR benefits and tradeoffs in terms of losses, energy, peak load, revenue impact, emissions, etc.?
This is a SEDS-based tool that is focused exclusively on lighting applications. SEDS Light will be a simplified version of the existing application with the same underlying calculation engine. The scope of the development includes:
- Strip unused functionality from current SEDS Version 3-phase
- Reduced load choices
- Simplified load selection
- Update voltage drop calculations for lighting
- Allow applications of up to 4 lights/pole
- Allow connections from “load”-to-”load” without the need for a node in between
- Clean up reporting to be consistent with lighting needs
- Update messaging and documentation
Due to strong incentives, there has been increasing interest in photovoltaic (PV) systems interconnected to distribution systems as a form of distributed generation. Of all the various types of distributed generation (DG), it appears that PV has the greatest potential for widespread application. It is also one of the types of DG that are most suited for small-scale application, which makes the distribution system the gateway for solar PV. This form of DG can have impacts on the distribution system that are significantly different from most other types of DG, such as engine-driven generators.
This project will produce a white paper evaluating the impacts of PV on distribution systems. Inputs to the paper will be based on available literature, experience gained by GE Energy Consulting in performing PV integration studies, and illustrative simulations and calculations to demonstrate the potential impact. These inputs will be combined with critical analysis, in the same spirit as the analysis performed in the Project 8-8 review of general DG impacts. Some of the issues of specific focus in this report will be:
- Correlation of PV output variations and the importance of geographic diversity.
- Voltage regulation, and specifically rapid voltage variation, will be examined in detail. Approaches that can be used to mitigate these variations will also be discussed and demonstrated in simulations.
- Protection impacts of PV; under what circumstances will these impacts be significant.
- The impact of present standards and potential future standards on PV integration.
- Evaluation of harmonic issues, in perspective with other harmonic sources commonly connected to distribution systems, and potential mitigation options.
- Evaluation of steady-state imbalance
One of the promises of the “smart grid” is that it will improve the operation of the aging power delivery infrastructure by providing increased visibility and control of distributed assets. Technologies such as advanced metering infrastructure (AMI), fault detection, isolation and restoration (FDIR), integrated volt/var control (IVVC), and others have the potential to impact grid operations by offering near real time sense and respond capabilities to changing conditions. While there is an overload of information about smart gird and its impact on energy efficiency, there is not a lot of discussion about specific impacts on distribution reliability. This project will directly address this question and discuss the inherent benefit/cost tradeoffs in the applications.
DSTAR has produced a wide range of software products over the last six (6) programs, and during this time, execution environments and operating systems have undergone several migrations. In DSTAR Program 11, all Excel-based software tools were updated to be compatible with Office 2007 (and Office 2010 by extension). Many DSTAR members are seeing their operating systems upgraded to Windows 7, and there are concerns that some of the most commonly used DSTAR tools are being affected by the change. Some members have reported potential problems with SEDS, CPA, and GTA, but there might be others as well. DSTAR members would like to understand (1) which DSTAR software tools are commonly used by the membership, (2) how these tools are affected by Windows 7 upgrade, (3) how to update the software tools to maintain usability and compatibility.
- Software Survey: A survey of DSTAR members will be conducted to determine which software tools are commonly used, and what Windows 7 issues are present or are likely to occur.
- Software Updates: From the survey, the 3-4 most commonly used Windows 7 tools will be selected for extensive testing and verification in the Windows 7 environment.