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Industrial and Commercial Power Systems Technical Conference (I&CPS), 2011 IEEE

Date 1-5 May 2011

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Displaying Results 1 - 25 of 29
  • Load estimation in industrial power systems for expansion planning

    Page(s): 1 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (331 KB) |  | HTML iconHTML  

    To increase the competition in the future global shipbuilding markets, CSBC Corp., Taiwan (CSBC) has started to do an expansion plan to install more efficient facilities for valuing productivity and improving the overall efficiency of plant operations. The shipyard, however, has no power SCADA system due to old building ages and cost considerations and consequently real-time measurements for most load buses in the system are not available. For future expansion purposes, CSBC tries to develop a methodology for expansion planning of the shipyard power system. This paper presents the methodology and expansion planning results. A two-stage load estimation model that combines typical load characteristics and state estimation (SE) theory is developed to provide the daily load curves for all buses in the industrial distribution network at a sound accuracy with relatively few real-time measurements. It makes use of network information to check the validation of their estimates and even to eliminate errors in estimated load data so that the resulted estimates can match the available measurements and comply with power system operation relationships and constraints. The load estimation results that could reflect true system operation are then used as a base-case for expansion planning to determine proper system reinforcements to accommodate an increase in the site's electrical demand. The analysis model developed in this paper can be used for expansion planning, or possible performance measure of similar industrial power systems. View full abstract»

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  • Short-term wind power prediction based on wavelet transform-support vector machine and statistic characteristics analysis

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (514 KB) |  | HTML iconHTML  

    The prediction algorithm is an important key factor in wind power prediction. However, there are pros and cons on different forecasting algorithms. Based on the principles of wavelet transform (WT), support vector machine (SVM) as well as characteristics of wind turbine generation systems, two prediction methods are presented and compared in this paper. In method 1, the time series of model input are decomposed into different frequency composes and models are set up separately based on SVM. The results are combined together to obtain the final wind power output. In method 2, the wavelet kernel function is applied in place of RBF kernel function in SVM training. To supply more valuable suggestions, the means of evaluating prediction algorithm precision is proposed. The operation data from two wind farms both in North China and U.S.A are used to test the usability of the method. The mean relative error of WT-SVM model (method 1) is less than that of traditional SVM model. View full abstract»

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  • Design of phase identification system to support three-phase loading balance of distribution feeders

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1168 KB) |  | HTML iconHTML  

    In this paper, a phase identification system (PIS) is designed to incorporate a fuzzy microprocessor based controller for phase measurement of underground transformers. The proposed fuzzy calibration algorithm used in the controller aims to solve the offset and gain of frequency deviation of the real-time clock, which was generated by a voltage controlled crystal oscillator (VCXO) to maintain the timing lock with respect to the 1 Pulse per Second (1PPS) signal of the global positioning system (GPS) before phase measurement is executed. According to the field test of the PIS design, the phase deviation of the real time clock with embedded VCXO can be improved from 46.27° to 0.98° by applying the fuzzy calibration algorithm. The PIS has been applied for field measurement of underground distribution transformers to identify their phases and correct the corresponding attributes of the Automated Mapping Faulty Management (AM/FM) system in Taipower. By retrieving the information of the line segments and transformers from the AM/FM, the network modeling of distribution feeders is derived to analyze the three-phase unbalance. The rephasing strategy of laterals and distribution transformers has been derived and executed by Taipower engineers. By comparing the phase currents and neutral current of a test feeder before and after rephasing, the three-phase balance of the distribution system can be significantly enhanced with the PIS to identify the phasing of distribution transformers for deriving the rephasing strategy of the distribution feeders. View full abstract»

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  • Design of tie line tripping and load shedding scheme for distribution microgrid systems with wind power generation

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (287 KB) |  | HTML iconHTML  

    This paper is to study the enhancement of power system quality for distribution feeders with wind generator (WG) by applying the static synchronous compensator (STATCOM) to provide the voltage support during fault contingency. The critical clearing time for circuit breaker tripping to isolate the fault is derived by considering the low voltage ride through capability of WG and the reactive power compensation by STATCOM system. To restore the stable operation of the microgrid after the fault transient disturbance, an adaptive load shedding scheme is proposed to disconnect proper amount of nonessential loads according to the feeder loading and wind speed so that the tripping of WG due to under frequency constraint can be prevented. A Taipower distribution system has been selected for computer simulation to verify the effectiveness of the proposed strategy to determine the setting feeder CB tripping and load shedding to improve the power system stability of distribution feeder with wind generator. View full abstract»

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  • An AMI based measurement and control system in smart distribution grid

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (246 KB) |  | HTML iconHTML  

    To realize some of the smart grid goals, for the distribution system of the rural area, with GPRS communication network, a feeder automation based on AMI is proposed. The three parts of the system are introduced. Integrated with the advanced communication and measurement technology, the proposed system can monitor the operating situation and status of breakers, detect and locate the fault of the feeders. The information from the system will help realizing the advanced distribution operation, such as improve power quality, loss detection, state estimation and so on. The application case in Qingdao utilities in Shandong Province, PR China shows the effectiveness of the proposed system. View full abstract»

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  • Battery float charge technique using parallel-loaded resonant converter for discontinuous conduction operation

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (202 KB) |  | HTML iconHTML  

    This work presents a battery float charge technique based on a parallel-loaded resonant converter. The main purpose of the float charge is to ensure that the battery remains fully charged indefinitely. With a simple circuit configuration and few components, low switching loss and high efficiency are achieved. The proposed parallel-loaded resonant converter is operated in discontinuous current mode to achieve high efficiency at a fixed switching frequency. With carefully designed circuit parameters, the power switches can support zero voltage switching and zero current switching. The operating principles and equivalent circuit are analyzed in detail. Experimental results are obtained using a 12V-150Ah rechargeable battery to confirm the feasibility of the proposed scheme. The maximum charging efficiency of the proposed topology during the overall float charge period is 97.6%. The measurements yield satisfactory performance. View full abstract»

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  • Photovoltaic energy battery chargers with a series-parallel load resonant converter

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (257 KB) |  | HTML iconHTML  

    The price of raw materials for basic living requirements is increasing due to the quickly raising price of crude oil. The price of transportation, water and electricity and the fuel gas is being affected and getting higher as well. In this case, the green energy solar power becomes the best solution to solve this problem. In this paper, the series-parallel loaded resonant converter is used as the circuit of solar power battery charger. The parameters of the circuit are designed by using the equation derived from above circuit. The result of practical experiment can be used to verify the validity of the theory of the charger circuit. The average efficiency of charging achieved 89.6% in the experiment. View full abstract»

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  • Design of closed-loop buck-boost converter for LED driver circuit

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (537 KB) |  | HTML iconHTML  

    This paper develops a light emitting diode (LED) driver circuit with a buck-boost converter. The forward bias of the LED used was 3.1V~4.3V, and the forward current was 0.7A. Twelve 3W white-light LEDs were driven in series in the proposed circuit. Each LED was operated at 4V and 0.6A using ac 110V that was rectified by a bridge rectifier. It is operated in continuous buck-boost mode and the results are then simulated using IsSpice software. In an LED only 15% to 25% of electrical energy is converted into light; the rest is converted into heat, which increases its temperature. The resistance of an LED varies with temperature, making the circuit unstable. Therefore, a closed-loop voltage control system is used in this paper to increase output voltage stability. The circuit scheme and operation mode will first be explained. Then, the transfer function for calculating the shortest regulation time is derived using the state-space averaging method. MATLAB is applied to execute the whole circuit simulations. Finally, experimental results demonstrate that the power factor of the closed-loop buck-boost converter is 0.998 and the output voltage of the designed controller can be stably maintained at 48V. View full abstract»

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  • A novel method of measuring inherent power system charging current

    Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (686 KB) |  | HTML iconHTML  

    High-Resistance grounded (HRG) power systems have been used in many industries to minimize equipment damage, including, but not limited to mining, petrochemicals, shore-to-ship power supplies and many others. The system charging current value should be known for designing a HRG power system. One method of determining the system charging current is to perform engineering calculations involving the inherent capacitance to ground for each of the power system components. However, this method may not provide accurate data as the sneak capacitance to ground for power system components cannot be determined due to their installation configuration. Therefore, it is essential to have a reliable method of measuring the system charging current. Before describing the proposed method of measuring the system charging current, fundamental concepts of system charging currents and mathematical analysis are provided. In addition, power system arcing faults and the associated damage when a fault remains line-ground faulted, especially in case of a medium voltage power system, is included. Finally, a novel and suitable method of measuring the inherent power system charging current is proposed. View full abstract»

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  • Compatibility, sizing and design considerations for generators and UPSs in Tiers I, II, III & IV topologies

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (89 KB) |  | HTML iconHTML  

    Mission Critical Applications for Data Centers, Financial Institutions, Telecommunication and Government typically have Generators and UPS (Uninterruptible Power Supplies) providing backup power to keep their Critical IT (Information Technology) loads online. Tier I and Tier II topologies according to ANSI/TIA-942 are very simple and straightforward with no redundancy or single distribution path with redundant components. Tier III and Tier IV configurations are increasing complex with multiple distribution paths, concurrent maintainability and multiple active paths. This paper will explore the high level compatibility, sizing and design considerations for Generators and UPSs in Tiers I, II, III & IV topologies. View full abstract»

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  • IEC grounding terminology related to typical North American installations

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2747 KB) |  | HTML iconHTML  

    IEC grounding terminology provides concise descriptions of system configurations requiring a sentence or more using familiar North American verbiage. However, without relation to known systems, simple representations using only five letters of the alphabet join the list of meaningless acronyms that clutter our life. This paper begins with definitions of the five letters used to describe IEC grounding systems and follows with wiring diagrams that include North American terminology. Examples of global configuration applications are included. System variations are presented along with strengths and weaknesses to provide additional understanding of both grounding and grounded conductors. View full abstract»

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  • Influence of reactors on input harmonics of variable frequency drives

    Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (524 KB) |  | HTML iconHTML  

    AC line reactors and DC link reactors are widely used in variable frequency drives (VFDs) to improve the drive performance such as reducing input harmonics, improving the input power factor, and protecting the drives from surges etc. The effectiveness of both types of reactors in reducing input harmonics is affected by many factors, including the loading of the drives and the system source impedance. In this paper, a simulation is conducted to investigate the influence of such factors. An onshore and offshore power distribution systems with VFDs as the dominant loads are used as the case studies. The rules to evaluate needs for AC line or DC link reactors are proposed for practical applications. View full abstract»

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  • Power system optimization for industrial facilities using power studies

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (398 KB) |  | HTML iconHTML  

    Industrial facilities can experience continuous load modifications over time. If parameters and settings of system equipment are not adjusted accordingly, operational issues may result throughout the facility. In this paper, it is proposed that power system optimization for industrial facilities can be accomplished by conducting a combination of several power studies. This approach is verified to be effective in reality. A large 50-year old oil field facility is used as a case study to demonstrate this approach. View full abstract»

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  • Micro-Electromechanical-System (MEMS) based switches for power applications

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (326 KB) |  | HTML iconHTML  

    A new system for switching electrical power using Micro-Electromechanical-Systems (MEMS) is presented. The heart of the system utilizes custom designed MEMS switching device arrays that are able to conduct current more efficiently and can open orders of magnitude faster than traditional macroscopic mechanical relays. Up to now, MEMS switches have been recognized for their ability to switch very quickly due to their low mass, but have only been used to carry and switch very low currents at extremely low voltage. However, recent developments have enabled suppression of the arc that normally occurs when the MEMS switch is opened while current is flowing. The combination of the arc suppression with the MEMS switch arrays designed for this purpose enables a breakthrough increase in current and voltage handling capability. The resultant technology has been scaled to handle many Amps of current and switch 100's of volts. Such current and voltage handling capability delivers improved energy efficiency and the capacity to handle fault current levels that are encountered in typical AC or DC power systems. Fault current interruption takes place in less than 10 microseconds, almost regardless of the prospective fault current magnitude. The properties of the MEMS switch arrays allow the switching mechanism to operate at temperatures in excess of 200 deg. C. The switches also have a vibration tolerance in excess of 1000G. The combination of fast MEMS switching speed, optimized current and voltage handling capacity of the switch arrays, the arc suppression circuitry and optimized sensing and control enable a single sensing, control and switching system to operate in a small fraction of a millisecond. This paper will present the basic physics of the MEMS switches together with recent advances that enable the technology. Some illustrative examples of the ways the devices may be used to provide protection and control within electrical systems will also be presented. View full abstract»

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  • User specifications for operational and switching procedures, a working group report

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (76 KB)  

    In general, power software lacks lockout/tagout procedures and transfer/switching procedures - both critical shortcomings. In 2008 this Working Group was created to develop methodology for software programs addressing operational procedures, switching procedures including lockout/tagout, and transfer procedures. The “User Guideline Specification” provides this methodology. Software itself will be developed by software vendors. Related was a goal to present a clear, simple, mathematical and graphical language to promote rigorous analysis and virtual verification of the applicable software; a unified suite for an operational, mathematical and graphical language. Referenced papers provide a sound basis for work toward achieving this goal, a task which the WG commends to future authors and Working Groups. Although it is outside the defined scope, the WG notes that these basic concepts apply to other energy systems. The WG encourages interested parties to develop similar approaches for other energy systems. View full abstract»

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  • Grounding system in marinas: The micro-system approach

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB) |  | HTML iconHTML  

    The Micro-System design approach of electric systems has the purpose to improve their safety, maintenance, operation and reliability. The Micro-System design approach can be applied to the case of marinas, where pleasure craft may be moored. Marinas require a structured architecture for the shore electrical power distribution system, which supply power to distributed loads. In addition, the design must provide for solutions to electrical hazards, as possible stray currents circulating through the earth and the water. The Island-grounding system, which utilizes separation transformers grounded at the mid-point of their secondary sides, allows to supply loads divided into “islands” as independent electrical areas. This distribution system is an effective way to protect persons from shock hazards in installations with contained demand load, and to greatly limit electrical interferences among systems. According to these authors, the TN-Island-grounding system is the best option to supply shore power to pleasure craft in marinas. This paper substantiates that the TN-Island-grounding system allows the development of “hybrid” solutions that lend themselves to the application of either the NEC-USA or the IEC-UE codes and standards. This important achievement would contribute to eliminate technical obstacles and discourage market barriers still existing worldwide. View full abstract»

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  • Branch circuits ecodesign

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    The modeling of an industrial, commercial or residential electric power systems, pursuing goals on safety, energy and costs saving, operational performances, needs innovations and new approaches to be effective. In the aim of underlining parameters as guideline and indices of rules of thumb the paper approaches their definitions as much as possible in an easy manner for a suitable use by heart. Operational parameters like cable steady current S-density and transient current T-density, load current moment μ-density are introduced to support in a new way the selection and sizing of the cross sectional area S of circuit conductors and the understanding of their behavior. The introduced load current moments and joule moments are specific parameters that can assist the system design to guarantee energy saving, reduced voltage-drops and losses, a higher value of current densities, reduced volume of conductors and other related goals of efficiencies. The ecodesign needs a cultural change of classic approaches. View full abstract»

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  • A Darwinian evolution of electrical power systems design for preventing seismic risks in sensitive buildings

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (187 KB) |  | HTML iconHTML  

    Seismic events cause serious problems to the electrical supply continuity in sensitive structures. The design of electrical and mechanical power systems can apply a “Darwinian” approach in sizing the components and in drawing the layout for minimizing the seismic stresses during an earthquake. This kind of evolution has to aim in preventing more than protecting damages to systems operability. All the components should have adequate ratings and be installed in a proper manner to provide a reliable and safe electrical system after or during earthquake. The electrical engineer and mechanical engineer should work closely with the structural engineer. The paper suggests a comparison among different international approaches in simplified evaluation of the seismic forces to assist the design electrical engineers and highlights the need that the constructors of equipment essential to the service continuity, as transformers, switchboards, generator sets, uninterruptible power supplies, motors driving critical loads, have to promote certified tests of their seismic behavior and to make available their basic seismic parameters. View full abstract»

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  • Microsystem criteria in branch circuits design

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (133 KB) |  | HTML iconHTML  

    Microsystem criteria in branch circuits design consist in modeling their structure with components of smaller size, in grouping adequately the supplying loads, in adopting circuit with conductors/cables in bunch, in loop or in rope designs. The introduced operational parameters can assist the system design to guarantee, together to energy saving, reduced voltage-drops and losses, a higher value of current densities, reduced volume of conductors and other related goals of efficiencies. The microsystem ecodesign needs a cultural change of classic approaches and requires courage in innovating standardized series of components sizes and in revising parameters values. View full abstract»

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  • NFPA 780 standard for the installation of lightning protection systems 2011 edition

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (79 KB) |  | HTML iconHTML  

    This paper will briefly summarize the nature of lightning, provide a brief history of the document, the lead taken by the National Fire Protection Association to incorporate experience proven protections, and highlight topics of interest in the 2011 edition. View full abstract»

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  • Reliability engineering applied to Critical Operations Power Systems (COPS)

    Page(s): 1 - 8
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    At the request of the US Homeland Security Department in 2005 the National Fire Protection Association (NFPA) developed the first leading practice criterion for building premises wiring in emergency management facilities. These criteria first appeared in the 2008 National Electrical Code (NEC) as a new section - Article 708: Critical Operations Power Systems (COPS). Article 708 establishes minimum design, commissioning and maintenance requirements for facilities with engineering documentation that identifies them as designated critical operations areas (DCOAs). One of the key features of Article 708 is the application of quantitative methods for assessing risk and conveying the results into a power system design that is scaled according to hazards present in any given emergency management district. These methods employ classical lumped parameter modeling of power chain architectures and can be applied to any type of critical facility, whether it is a stand-alone structure, or a portion of stand-alone structure, such as a police station or government center. This article will provide a risk assessment roadmap for a typical COPS facility that is most common - a “911” Call Center (the facility that takes and routes the 911 calls to the police or fire departments). The existing methods of reliability engineering will be used in the risk assessment. View full abstract»

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  • Transformer failure due to circuit breaker induced switching transients

    Page(s): 1 - 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (989 KB) |  | HTML iconHTML  

    Switching transients associated with circuit breakers have been observed for many years. Recently this phenomenon has been attributed to a significant number of transformer failures involving primary circuit breaker switching. These transformer failures had common contributing factors such as 1) primary vacuum or SF-6 breaker, 2) short cable or bus connection to transformer, and 3) application involving dry-type or cast coil transformers and some liquid filled. This paper will review these recent transformer failures due to primary circuit breaker switching transients to show the severity of damage caused by the voltage surge and discuss the common contributing factors. Next, switching transient simulations in the electromagnetic transients program (EMTP) will give case studies which illustrate how breaker characteristics of current chopping and re-strike combine with critical circuit characteristics to cause transformer failure. Design and installation considerations will be addressed, especially the challenges of retrofitting a snubber to an existing facility with limited space. Finally, several techniques and equipment that have proven to successfully mitigate the breaker switching transients will be presented including surge arresters, surge capacitors, snubbers and these in combination. View full abstract»

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  • Unexpected changes to the protection of a 4160 V motor

    Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (186 KB) |  | HTML iconHTML  

    Careful consideration must be made when determining the proper specifications, application, starting method, and protection of a medium voltage motor-load combination. These considerations should include the type of load, the load duty cycle, the design of the overall facility electrical power system and information regarding the utility power system. This paper discusses a case at a newly constructed Midwestern industrial plant whereby these stated considerations were not properly followed which in turn lead to plant start-up electrical system design and protection changes in order to keep the plant startup on schedule. View full abstract»

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  • Improvements in protection and commissioning of digital transformer relays at medium voltage industrial facilities

    Page(s): 1 - 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1277 KB) |  | HTML iconHTML  

    The application of multifunction digital relays to protect medium voltage power transformers has become a common industrial practice. Industrial transformers, unlike utility transformers, frequently use neutral grounding resistors to limit ground current during faults to 200-400A range on medium voltage systems. This paper will discuss why these types of transformers require sensitive ground differential protection. The paper will also discuss the basics of transformer protection including: phasing standards, through-fault withstand capability, differential/fusing/overcurrent protection, slope, CT requirements, harmonic restraint, and communicating these requirements properly when programming and commissioning new digital relays. The rationale for providing transformer overexcitation protection on all major transformers within industrial facilities is also addressed. Advancements in digital technology have allowed relay manufacturers to include more and more relay functions within a single hardware platform as well as address more and more transformer winding configurations. This has resulted in digital transformer relays requiring an experienced protection engineer to set and an experienced relay testing technician to commission. Since there are fewer experienced professionals among us now, the next generation of transformer relays needs to concentrate on this complexity issue in addition to technical improvements. This paper addresses these issues that the author believes are the major shortcomings of existing digital transformer protective relays. View full abstract»

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  • Traditional Time Current Curves (TCC) are not enough, adding I2T considerations

    Page(s): 1 - 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (350 KB) |  | HTML iconHTML  

    Overcurrent device selectivity has always been desirable in power distribution systems. Recent changes in the US National Electrical Code (NFPA 70-2005 and subsequent) have increased the demand for near perfect selectivity. Simultaneously, heightened sensitivity to the effect of slow clearing times on Arc Flash Hazard has increased the need for fast and sensitive overcurrent protection, particularly at the larger upper tier overcurrent devices. When the selectivity solution is to oversize or slow down protection at mid-level feeders above the branch circuit breakers arc flash incident energy at higher levels in systems can reach unacceptable levels. Optimized protection and selectivity may be achieved by optimizing instantaneous settings and algorithms in upstream protectors. Such selectivity may be accomplished primarily by understanding the current limiting behavior of the downstream protective device and understanding the thermal capacitance needed to melt upstream fuse elements or intentional damping added to upstream circuit breaker trip units. When circuit breakers trip in sub-cycle times and clearing times are instantaneous, traditional Time Current Curves (TCC) are insufficient to correctly demonstrate device operation. The authors will describe a two graphical representations based on the I2t let-through of the downstream device and I2t requirement to trip the upstream device. The I2t representations more effectively describe protective device behavior in the instantaneous region below 0.010 seconds normally excluded in traditional TCCs. Furthermore, a technique, theoretical basis and proposed test protocol that suitable for a wide range of devices will be presented. View full abstract»

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