Program 16

Project 3 - Best Practices to Mitigate Temporary Faults on Overhead Distribution

New feeder distribution technologies are being developed to help mitigate temporary faults. These technologies utilize automatic switching principles to detect and interrupt faults, while automatically determining if the fault is temporary or permanent. This allows for fewer customer interruptions, better temporary fault identification, and fewer manual reclosing operations needed to be performed by linemen crews (which can lead to higher outage times). This report summarizes current activities by DSTAR and non-DSTAR utility members across North America, highlighting best practices and lessons learned in mitigating temporary faults. Read More →

Tagged: Fusesaver, Temporary Faults, Tripsaver, fuse

Project 4 - SEDS Enhancements

This project adds both a min and max 3-phase transformer impedance field to allow for calculation of voltage drop using the maximum value and short circuit using the minimum value. This functionality does not apply to banked 1-phase transformers which is used for a small number of applications. Read More →

Tagged: secondary, flicker, design, SEDS, short circuit, voltage drop

Project 5 - Electronic Data Handbook (eHandbook)

The previous expansion of the ehandbook under Program 12 expanded the scope of the e-Handbook to include a variety of data tables, guidelines, discussions and calculations . This expansion includes tables with information on duplex and quadruplex conductors and additional calculators.

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Tagged: P16-5, System Protection, Engineering Guidelines, Engineering Analysis Software, Economic Analysis, Industry Perspectives / White Papers, System Reliability, Operational Efficiency, P16

Project 6 - Evaluation of Power Control Devices for Distribution Systems

High penetration of intermittent distributed generation such as photovoltaics (PV) generates a number of voltage and power quality issues including violation of voltage limits and excessive voltage variations. These issues inhibit the integration of PVs in the distribution systems and utility’s operational control over the voltage and loading conditions in their service territory. Recently introduced var compensation-based Smart Devices claim to mitigate these issues thereby improving PV integration and providing other benefits. The relatively low cost and autonomous operation of such devices make them potentially enticing options for long and weak distribution circuits. The objective of this project is to provide DSTAR utilities a quantitative third-party performance evaluation of commercially available three Smart Devices offered by three vendors: 1) Varentec’s Edge of Network Grid Optimizer (ENGO); 2) GridBridge’s Grid Energy Router (GER); and 3) American Superconductor’s (AMSC) Dynamic Var Volt-var Optimizer (DVAR VVO). Read More →

Tagged: Varentec, ENGO, AMSC, GridBridge, Volt-Var, PV impact, DVAR

Project 7 - Analysis of Distribution Capacitor Switching Transients

Capacitor bank switching is one of the most common switching events on electrical power systems. Capacitors are quite economical and are generally a convenient means of providing reactive power compensation to correct power factor and support voltage. This makes them prevalent in mots U.S. power systems. When energized, a capacitor bank can interact with the system inductance to yield oscillatory transients which can propagate into the local power system and pass through distribution transformers into customer loads and facilities. Under specific circumstances, these transients may cause misoperations or even damage equipment at customer facilities.

The primary objective of this project is to define and quantify, through use of detailed computer simulations, the key factors which affect capacitor switching transients, with respect to their magnitude and frequency, on distribution systems.

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Tagged: EMTP, capacitors, transients, cap switching

Project 8 - Distribution Series Capacitor Application Considerations and Recommendations

Before series capacitors were installed in transmission systems, they were first applied in distribution circuits in the first half of the 20th century. The typical distribution series capacitor application focused on solving voltage flicker and/or voltage regulation issues associated with variable loads usually combined with either weak systems and/or long distribution circuits.

Both the early distribution series capacitors as well as more modern installations have successfully mitigated voltage flicker issues. In some early applications, ferroresonance and subsynchronous resonance issues were encountered along with bypass gap issues. It is possible to mitigate these issues with proper application engineering and new gap technology. With this as background, the DSTAR membership proposes to re-visit this product as part of Project 16-8 starting with the history of this device, lessons learned from previous applications, identify the benefits/advantages of new equipment, provide some guidance on bank sizing and location, document previous motor experiences, and to the maximum extent possible, provide equipment prices.

The report from this project can serve as a reference for DTAR members considering this application. Read More →

Tagged: capacitor, subsynchronous, ferroresonance, transmission, series capacitor