2013 66th Annual Conference for Protective Relay Engineers最新文献

{"title":"Effect of transformer connection and construction on single phasing detection","authors":"G. Johnson, R. Hamilton, S. Thakur","doi":"10.1109/CPRE.2013.6822036","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822036","url":null,"abstract":"On January 30, 2012, Unit 2 at Exelon Corporation's Byron Generating Station experienced an event that resulted in a unit trip and a loss of offsite power to the unit. The root cause of the event was determined to be the failure of an under hung insulator on the phase C feed to the Unit 2 Station Auxiliary Transformers (SAT). An insulator on a bus support broke and grounded the high voltage bushing of the SAT, causing a short section of 345 kV bus to become disconnected. The section on the SAT side also fell to ground. See Figure 1. This bus section was associated with the phase C offsite source to the SATs. This event caused an open circuit on phase C; however, neither the protective relay system in the switchyard nor the plant relaying detected the loss of phase C. This paper will provide an outline of the event, failure analysis and follow-up actions as a result of the event, including a microprocessor based relay solution, as well as transformer theory relevant to single phasing issue.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115602215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Open phase conditions in transformers analysis and protection algorithm","authors":"Amir Norouzi","doi":"10.1109/CPRE.2013.6822031","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822031","url":null,"abstract":"This paper first provides an in-depth analysis of open phase conditions in three phase power transformers. It describes why and how, upon loss of a single phase on the high or primary side of a transformer, voltages and currents on the low or secondary side greatly depend not only on the windings configuration but also sometimes on transformer's core construction as well. Some particular cases are discussed in which detecting a high side open phase is very difficult with current transformers (CT) only on the low side. Then after examination of the secondary voltages and currents practical and reliable algorithms are presented for identification and protection of high side open phase conditions from the low side of a power transformer. Digital simulation is used for verification of the analysis results and the protection algorithms.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123756452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges and solutions of protecting variable speed drive motors","authors":"Angelo D'Aversa, B. Hughes, Subhas Patel","doi":"10.1109/CPRE.2013.6822040","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822040","url":null,"abstract":"Variable frequency drives (VFDs), also known as variable speed drives, provide significant advantages for the operation of induction motors. These advantages include reduced starting currents, adjustable speed control, and improved energy efficiency. However, VFDs create additional challenges for motor operation and protection that are not present in line-connected motors. The protection challenges are solved by new protection elements available in an electronic motor protection relay. Traditional motor protection elements use fundamental frequency measurements for operating current. VFD-operated motors have a fundamental frequency that changes rapidly in response to speed adjustments. Additionally, the synthesized sine waves produced by the VFD contain significant harmonic content. The new protection elements use true rms (fundamental plus harmonics) operating current. True rms measurements are not dependent on having a fixed fundamental frequency. True rms measurements properly account for the motor heating caused by harmonic currents. Conventional single-speed motor protection uses a fixed value for the full-load amperes (FLA) of the motor. This single FLA assumes that a fixed cooling rate is available to the motor. Commonly used low-voltage motors have shaft-coupled cooling fans that spin at the same speed as the motor. At reduced operating speeds, the cooling air provided by the fan is significantly reduced. In order to prevent overheating of the motor, the protection elements should compensate for the reduced cooling. The new protection elements dynamically compensate for the reduced cooling available at reduced speed operation. VFDs are typically installed in motor control centers (MCCs). Because of the large available fault current, MCCs can have significant arc-flash hazard potential. The safety of VFD-operated motors can be improved using arc-flash protection elements. VFDs are often installed in large numbers at industrial facilities. This makes it impractical to manually monitor and control each motor as a standalone device. A centralized motor management system solves this problem. This paper describes novel protection elements that accommodate the unique protection, monitoring, and control challenges of VFD-operated motors.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125338519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of protection scheme dependencies on communications","authors":"G. Antonova, Eduardo Colmenares, I. Jankovic","doi":"10.1109/CPRE.2013.6822043","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822043","url":null,"abstract":"Many protection and control schemes highly depend on the quality of the underlying communications. Communications availability and reliability have a direct impact on security and dependability of the protection systems. Classical use cases include but are not limited to line differential protection, teleprotection schemes, etc. This paper analyzes how the quality of the underlying communications affects various protection schemes security and dependability. A number of protection and control applications will be discussed with a focus on the requirements that they impose on communications. An overview of current communications technologies and their characteristics will be given. Practical uses cases will be discussed and suggestions will be made on appropriated use of certain communication technologies for particular protection and control schemes.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133240027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of application of ground distance protection","authors":"Terrence Smith, Zhiying Zhang, Maria Elena Lacedonia, Steve Pitts","doi":"10.1109/CPRE.2013.6822026","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822026","url":null,"abstract":"Ground distance protection philosophies will affect how ground distance is applied to protect transmission lines. This paper will explore some of the common philosophies and demonstrate under which conditions each philosophy should be used. Some of the philosophies to be explored are resistive ground fault coverage, the use of Quadrilateral verses Mho characteristics, supervision and polarization techniques for weak in-feed lines, and utilization of directional ground overcurrent protection verses ground distance over-reaching element protection.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127509402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Practical EHV reactor protection","authors":"Faridul Katha Basha, M. Thompson","doi":"10.1109/CPRE.2013.6822055","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822055","url":null,"abstract":"Shunt reactors are applied to long, high-voltage transmission lines to offset the impact of line charging capacitance to prevent high voltage during lightly loaded conditions. Shunt reactors are becoming more prevalent associated with the construction of long transmission lines to connect remote wind energy sources to load centers. During conditions when wind generation is at a minimum, the system is more likely to need reactive compensation to control high voltage on the transmission system. It can be difficult to design a protection system that provides adequate sensitivity to the extremely low levels of fault current for in-zone reactor faults, especially turn-to-turn faults, while remaining dependable for high-level terminal faults that are not limited by the impedance of the reactor. Current transformer (CT) selection criteria must balance sensitivity with performance during switching and internal faults. Often, standard equipment ratings put further restrictions on CT sizing selection. This paper discusses the different reactor types currently used, their characteristics, CT selection and performance issues, and different types of reactor faults. The paper also provides guidelines to practicing engineers to evaluate reactor protection design and determine protection elements and relay settings for a high-voltage transmission line shunt reactor. The discussion of various factors that affect the sensitivity and dependability of the protection elements helps in understanding the challenges encountered while determining relay settings. Detailed examples of CT performance calculations and guidelines are provided for protection element settings calculations.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"47 68","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120942151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creating a sustainable protective relay asset strategy","authors":"J. Sykes, A. Feathers, E. Udren, B. Gwyn","doi":"10.1109/CPRE.2013.6822037","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822037","url":null,"abstract":"Microprocessor based relays with their rapid pace of technology change and high integration of functions will be at the center of protective relaying implementation for the foreseeable future. The industry has more than 20 years of experience with these devices, and is still learning about how to deal most effectively with their characteristics. Notably, generations of protection must be updated far more often in the future. It is the responsibility of the relay practitioner and the owner to implement a sustainable relay asset strategy. As discussed in this paper there are many factors to consider; there are also market variables that will play a role in how utilities approach this task. Each owner will need to examine its particular systems and choose the course to take - no one plan will suit all users.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132562293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upgrading relay protection? — Be prepared","authors":"D. Ransom","doi":"10.1109/CPRE.2013.6822032","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822032","url":null,"abstract":"There are many advantages to upgrading old electromechanical, solid-state, and first-generation numeric relays with modern numeric relays. Reliability increases because there is less direct wiring and interconnection wiring. Reliability and security of multifunction logic and settings are improved with next-generation user interface software. Remote I/O modules, remote analog/digital inputs, and thermal measurement capabilities have expanded protection, control, and monitoring. New protection and monitoring features improve power system equipment life and increase personnel safety. Maintenance costs are reduced, while internal watchdogs alert the user if the relay has a problem. Settings groups can be changed instantaneously to adapt to varying power system requirements. Modern, second-generation numeric relays offer a variety of secure communications capabilities for interfacing with Smart Grid controls, SCADA systems, and business networks. Event memory is larger for more on-board, standardized oscillographs and event reporting. Relay security is in accord with the latest NERC standards. Initially, every relay upgrade seems simple and straight forward; then come the details. Operating personnel have expectations for reading targets, resetting trips, ease of interface for settings and events, motor restarting, synch closing, etc. Regulator requirements (NERC-CIP, for example) must be implemented while maintaining smooth operations. Relay engineers must assure that operational ease is maintained with the new upgrade relay. Accurate one-line drawings and connection drawings, as well as good wiring documentation, are essential. Escutcheon plates might be necessary, or perhaps switchgear will need modification (panel cutting, new doors, relocation, etc). Also, this is an opportunity to reevaluate arc-flash hazards and possibly reduce the risks. These and other considerations are taken from actual relay replacement projects. This paper provides guidance for your next replacement or upgrade project, resulting in reducing cost, saving time, and minimizing unexpected or unplanned complications.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134105412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the challenges and application of auto reclosing in high voltage multi breaker line terminals","authors":"Alejandro Schnakofsky","doi":"10.1109/CPRE.2013.6822027","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822027","url":null,"abstract":"This presentation is a tutorial on the application of auto reclosing in overhead lines where at least one of the terminals is multi breaker. Design considerations will be presented for breaker and a half, ring bus, and double bus - double breaker line terminals. The mentioned bay arrangements will be described in detail including the position of current and voltage instrument transformers. Finally, the utilization of communication technologies to aid in the deployment of such schemes will be discussed.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116906560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Rogowski coils inside protective relays","authors":"V. Skendzic, B. Hughes","doi":"10.1109/CPRE.2013.6822022","DOIUrl":"https://doi.org/10.1109/CPRE.2013.6822022","url":null,"abstract":"Traditionally, microprocessor-based relays incorporate a secondary current transformer to convert the 5 A or 1 A input current to a lower level for input to an analog-to-digital (A/D) converter as part of the input processing. The limits of this input circuit are well known, and relay designers take them into account when determining operating characteristics. A Rogowski coil produces an output based on the rate of change of the current input, so passing the output of the coil through an integrator produces a signal that is proportional to the current. There are additional characteristics of a Rogowski coil that give it particular advantages for use in a microprocessor-based relay, including the following: An air core. This leads to no saturation, even at very high currents; A flexible shape. With no iron core, the coil can be shaped and sized to fit the application; Immunity to electromagnetic interference. This makes the coil suitable for electrically noisy environments. These advantages, and others, make a Rogowski coil something to consider for the input of microprocessor-based relays, where the integration required to obtain the input current is a relatively easy operation. This paper discusses the practical considerations of using this coil in a relay. Complicating and mitigating factors are discussed, along with the performance impact on the relay and practical experiences in the field. Application impacts of Rogowski coil use are presented, including which types of relays are most benefited by this technology. Future implications of this technology are also presented.","PeriodicalId":221348,"journal":{"name":"2013 66th Annual Conference for Protective Relay Engineers","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127726062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}