Reliable Power Distribution Design for Water and Wastewater Facilities By Van Wagner, P.E., Schneider Electric Water Wastewater Competency Center
|
|
- Oliver Potter
- 5 years ago
- Views:
Transcription
1 Schneider Electric February, 2009 Reliable Power Distribution Design for Water and Wastewater Facilities By Van Wagner, P.E., Schneider Electric Water Wastewater Competency Center Introduction Reliable power distribution is critical to the safe operation of water and wastewater (WWW) treatment facilities. This loss of power to critical loads can result in raw sewage being dumped in streams, rivers and, lakes and forcing residents to boil water. The U.S. Environmental Protection Agency guidelines suggest two independent power sources be provided for wastewater facilities. This can either be two independent utility feeds, or one utility feed and one on-site generation. For on-site power distribution systems, there is still debate on whether to retain dual-source redundancy to the load. To determine the most failure-prone system components and whether or not they can be bypassed, an analysis of several types of common power system configurations needs to be completed. By analyzing configurations such as radial, looped, and main-tie-main for reliability and installed cost, the components that have the lowest reliabilities can be revealed. This provides not only insights on how to address the potential issues, but guidance on the most cost effective designs for given criteria. Background The purpose of a distribution system is to reliably deliver power to the loads. The system may use manual switches to select power sources, bypass malfunctioning equipment, or isolate equipment for maintenance. Upon loss of power, a system that must be manually switched to be reconfigured may be down for 20 to 30 minutes. In contrast, a system with automatic throw-over capability can switch automatically within 3 to 5 seconds. Since solid state transfer switches operate in a quarter cycle, each application needs to be analyzed so its requirements form the design specification for that particular power distribution system. Component Reliability When analyzing reliability, the failure rate is defined as the average failures per year from the data collected. Repair time is defined as the average time required to affect a repair of the failed component. Although a component may have a low failure rate, a long repair time can be just as disruptive as a high failure rate. To see this, it is helpful to compare the reliability of individual power system components in the context of overall configuration. Table 1 shows the data for several medium voltage power system components from one of the most extensive industrial reliability databases, the Institute of Electrical and Electronic Engineers (IEEE) Standard The components are ranked from least reliable to most reliable. The table shows that power sources have the poorest reliability, while distribution equipment has good reliability but can have very long repair times. 1
2 The utility circuit is assumed to consist of 15 kv to 35 kv single feed. Generally, higher voltage utility service has greater reliability but service voltage is largely determined by load. Depending on the total lengths, medium voltage conductors can be the next most likely component to fail. The remaining components have similar reliability values but time to repair varies widely. For instance, a rackable circuit breaker can be quickly replaced but a transformer would require days. Failure Rate (#/yr) Repair Time (Hours) Components Comments Utility Single feed Standby Gen Switchgear Bus MV Conductors per 1000 ft; Buried conduit MV Switch MV CB Replace CB (Drawout) Transformer Replace MV Termination Table 1: Reliability data of medium voltage equipment Utility Sources In the following section, it is assumed that where there are two utility sources, the reliability of those two sources is independent of one another. Realistically, though, there is always some coupling between utility sources. In order to increase independence, the two sources should be from separate utility substations or at least separate transformers within the same substation. For instance, in a regional blackout the circuits to the facility should be in separate rights-of-way. Whereas overhead conductors are subject to weather related disruptions, the most common cause of underground circuit disruption is dig-ins by excavators. Better independence can be gained with the second source as a standby generator. However, additional utility sources can be expensive,, and the cost of a second utility circuit is entirely born by the utility customer. Even in a dense metropolitan area where alternative circuits are more available, a second distribution circuit could cost $500,000 to $1 million with a two-year lead time. An alternative would be to use a standby generator for the second source. It s about twice as reliable as the utility, is fully independent and costs about $250,000 to install. However, the standby generator has greater operating and maintenance costs. So for capacities over 5 MW where multiple generators are required, the utility might actually be the least expensive. Switching Components The type of switching device employed in a design has significant impact on the down time and cost of the system. The following is a short review of the characteristics of fused switches and circuit breakers. Load Interrupting Fused Switch: This is the most inexpensive means of power system switching. At medium voltage this switch can average about $15,000, whereas a main circuit breaker section will be about $50,000. At low voltage, a fuseable switch board might be 25 percent less expensive 2
3 than switchgear using circuit breakers. Although fuses provide short circuit protection at each phase, they cannot open un-faulted phases. In addition, fuses cannot trip for sensitive ground fault, but can have greater interrupting capability than some breakers. The switch provides a manual means of reconfiguring the power system. It is appropriate where installation cost is a major factor and reliability is not critical. At medium voltage, there are two major issues:, the need for available trained personnel and the amount of time required to perform the switching. Repair time is not long for any of the devices discussed, although the switch has a much more limited number of rated operations. Circuit Breaker: A major advantage of the circuit breaker is its ability to operate automatically. This allows it to switch to a different source or reconfigure when necessary within a few seconds it could switch more quickly but must provide delay to allow residual motor voltages to decay. When a circuit breaker trips, all three phases are opened, preventing single-phase operation. Tripping is controlled by a separate protective relay that, in addition to simple over-current, can trip for low or high voltage, ground fault, phase sequence, differential, or other functions. Selective coordination can be more readily achieved with circuit breakers than fuses due to the large variety of protective functions and setting adjustability. Selective coordination selects the protective device setting that helps assure the nearest upstream device clears the fault. This prevents a situation where a fault causes several protective devices to operate. Circuit breakers are more durable than switches with a greater number of rated operations. If and when they need to be replaced, medium voltage circuit breakers are draw-out and can be quickly replaced with a spare. Low-voltage circuit breakers are available as draw-out or fixed while lower-rated breakers are only available as fixed. Approach In this section, the reliability analysis method used is one described by Billington and Allen in Reliability Evaluation of Power Systems 2. The analyses are for single contingency only, which means either a single failure or a planned shutdown, because the probabilities of independent multiple contingences are so small that it has little impact on the type of comparison performed here. Note: The derived reliabilities should only be used to compare design configurations. They are not absolute values that predict actual downtime in anything other than an approximate manner. Real reliabilities depend on equipment age, operating history, maintenance level, environmental conditions, etc. The reliability analysis is applied at two parts. The first includes the electric utility and the facility medium voltage (MV) distribution, while the second includes only the low voltage (LV) distribution system to the load. This approach helps clarify the contribution of each part and allows a greater number of configurations to be evaluated. Reliability is evaluated at a single point for each configuration. In the MV case, it is the load side of the feeder breaker or switch that supplies the load. For the LV case, it is the feed point of a load. The LV case includes the MV feeder conductor and the step down transformer. Although this does 3
4 not cleanly divide the equipment by voltage level, it does reveal the reliability of the MV and LV cases more distinctly. Installed costs include equipment and labor for the circuit breakers or switches shown in the figures. Engineered-to-order equipment costs are taken at current market prices. In addition, conductors are included and assumed to be installed in buried PVC for MV and overhead galvanized rigid conduit for LV. Wiring materials and labor costs are taken from RSMeans Electrical Cost Data. 3 Conductor lengths are assumed to be 300 feet unless otherwise noted. The reliability and cost determinations are sensitive to the number of feeders in the design. In the reliability analysis, adding more feeders decreases reliability because more equipment is added that can fail. To try to normalize the installed costs, they are determined on a per feeder basis. Obviously, more feeders spread the fixed cost of the scheme and reduce the per feeder cost. With the MV cases, three feeders are assumed fed off the bus while in the LV configurations, four feeders are assumed. Primary Distribution Radial The simplest power distribution system is a radial system, shown in Figure 1. A radial design provides power distribution with the minimum initial equipment cost and is typically configured with a load break switch. Loss of the utility, switch or conductors will make the system unavailable until repairs can be completed, as there are no alternate paths or sources. Figure 1: Example of single source radial power distribution system The reliability and cost data are shown in Table 2. The radial system forms the basis of comparison for all subsequent medium voltage designs. The failure rate is the probability of the loss of power to the load side of the transformer switch in a given year. To yield the average outage hours per year, the probability is multiplied by the mean time to repair. (For an example derivation of reliability indices see the Appendix.) From an operating standpoint, the average hours down from a forced outage (unavailability) is a more useful number than the failure rate. The utility is by far the most unreliable element in the configuration and dominates the reliability of the system. There is an estimated average of 3.30 hours of forced downtime per year due largely to the utility restoration time as the configuration does not allow any scheduled maintenance to be performed on the system without shutting the load down as well. The approximate cost for this 4
5 installation is $37,000 per feeder. This configuration could be appropriate where the loss of capability can be tolerated or offset by other methods, such as a small remote pumping station. Failure (#/yr) Unavail MTTR Cost (per Component (Hours/yr) (Hours) feeder) Radial $37k Primary Selective $71k Looped $57k Table 2: Reliability results and installation costs. Primary Selective Figure 2 shows a primary selective configuration. In this case a second utility feed is provided to a radial system at the transformer primary. It requires a second primary conductor and disconnect switch. A duplex switch can be provided at the transformer that utilizes a common fuse for a slightly lower switch cost. In this configuration, one source feeds the transformer; these installations normally do not parallel the sources. In this case and all subsequent configurations, it is assumed the manual switching takes 20 minutes to reconfigure the system. Figure 2: Example of primary selective feed The reliability numbers are shown in Table 2 at one of the load sides of one of the switches. The reliability is identical since the normal source is exactly the same as the radial case. There is substantial improvement in the unavailability compared to the radial arrangement because the load can be switched to the alternate source in 20 minutes. (It should be emphasized that the alternate source is assumed to always be available in this comparative analysis). The configuration allows work to be performed on the primary conductors to the transformer switch while the transformer is fed from the other conductor. Work can also be performed on one of the transformers while the others are energized. Note: the cost has doubled due largely to the additional switches needed. For the per feeder cost, it is assumed there are three feeders and the cost of the common components are shared. 5
6 Looped System The looped network is a variation on the primary selective configuration and is shown in Figure 3. In this case the loads are in series rather than parallel, as in the primary selective case. One of the switches will be open so that the utility sources are not paralleled. The number of switches required is equal to the equivalent primary selective scheme although duplex switches are shown here with one fuse per transformer. The advantage of the looped system is that less conductor length is required. Figure 3: Example of looped primary system A commercial version of the looped system can be applied as part of underground distribution at a campus-type setting where several separated buildings are fed from individual pad mounted outdoor transformers. Equipment cost can be further reduced by replacing the two disconnect switches with dead front elbow terminators in the transformer to switch source conductors. The overall failure rate of the looped system is slightly greater than the previous two schemes but its unavailability falls somewhere between them. After a fault occurs, all the transformers on the deenergized section will be down and all the equipment must be inspected to try to locate a visible fault. When a conductor fails, it can take eight hours to locate the faulted segment and the deenergized transformers cannot be restored until the faulted segment is isolated. If not for the fault locating time, the unavailability would be close to the primary selective time. The example looped system is 25 percent less expensive than the primary selective case and offers a second source. In this case, conductors were $7,000 less expensive than the primary selective case and the duplex switches were $7,000 less expensive than the full switches. From a scheduled maintenance standpoint, this configuration is identical to primary selective. It allows work to be performed on the primary conductors to the transformer switch while the transformer is fed from the other conductor. A transformer can be maintained while the other transformers are energized, although maintenance may require brief interruption of the other transformers to reconfigure the system. Main-Tie-Main A very common two-source selective configuration is the primary main-tie-main (MTM) shown in Figure 5. In this case, the primary source feeds an entire bus rather than a single load and a normally open tie between the two buses provides source selection. Where there are many nearby 6
7 medium voltage loads, a bus arrangement is a more effective means to distribute power than the previous configurations. With a MTM configuration, the buses must be rated for the load of both buses with the tie closed. A MTM typically employs circuit breakers rather than switches and the example shown uses circuit breakers as they can provide automatic switching within seconds of a loss of one of the utility feeds. Figure 5: Example of primary main-tie-main This analysis assumes a three-second automatic throwover by the circuit breakers to the other bus if the normal source is lost. The results are shown in Table 3. The three-second switching time reduces the unavailability almost 100 times for this configuration. However, there is no alternative source for the bus, feeder breakers or the feeder conductors. Component Failure (#/yr)r Unavail (Hours/yr) MTTR (Hours) Cost (per feeder) Radial $37k Primary Selective $71k Looped $57k MTM x x10-2 $77k Synch Bus x x10-2 $89k Ring Bus x x10-2 $110k Double Bus x x10-3 $122k Table 3: Reliability results and installation costs This analysis shows the reliability at the load feeder breaker. If the point of evaluation is moved to the transformer primary, the feeder conductor increases the unavailability to over 30 minutes per year. This is because there is no alternative feed to the transformer and it s assumed that it takes 97 hours to replace the conductor. In this case and the subsequent cases with MV buses, the analysis is to the feeder breaker. Feeder conductor failures can obscure the characteristics of the particular scheme. Medium voltage feeder conductor reliability will be included in the low voltage analysis. 7
8 Scheduled maintenance can be performed on the main beaker or upstream of it without disruption to the feeder loads. However, work on the bus, feeder breakers or tie would require shut down of the feeder loads. Synchronizing Bus Additional buses and ties can be added to the MTM arrangement if there are more than two sources. However, a more flexible scheme is to use the configuration shown in Figure 6. Here, a separate conductor, bus duct, or switchgear bus links all the buses through circuit breakers. It does use one more breaker than the MTM configuration, but it also provides the ability to tie any combination of buses together. This arrangement is called a synchronizing bus (or, less commonly, a star bus) even though none of the buses may be connected to a generator. Figure 6: Example of primary synchronizing bus Sometimes one of the buses will have a source but no load. For instance, a bus with several paralleled standby generators (hence the synchronizing bus designation), or a bus that is fed by a transformer, called a sparing bus. The availability and the reliability of the synchronizing bus decrease a small amount compared to the MTM arrangement. This decrease is due to the addition of the extra breaker. For the purposes of this analysis, the reliability of the two configurations should be considered identical. The cost of the synchronizing bus is about 15 percent greater than the MTM due to the extra breaker and cabling but that cost buys additional switching flexibility. As with the MTM scheme, scheduled maintenance can be performed on the main beaker or upstream of it without disruption to the feeder loads. However, work on the bus or feeder breakers would require shut down of the feeder loads. Ring Bus A configuration sometimes found in utilities but not often in industrials is the ring bus shown in Figure 7. A utility would normally operate with the sources paralleled but the industrial version 8
9 typically would not. This arrangement has the advantage of using a minimum number of breakers while having the ability to switch the loads between sources. The number of breakers required is equal to the number of sources and loads. More load buses can be added as the loads or sources are protected by a pair of breakers. Figure 7: Example of primary ring bus The availability of the ring bus in the figure is several times better than the best considered so far. This is because the design uses minimal hardware and can accommodate automatic throwover. The cost per feeder, however, is very high. Each feeder has two breakers sized as mains and the total number of breakers per feeder is high. Another disadvantage is the ring bus still does not address the loss of the bus or feeder conductor. The good availability of the ring bus is offset by the high per feeder cost. Nevertheless, it is not practical for industrial power distribution. An industrial version of the ring bus would need utility breakers and more feeders with individual breakers on the load or source buses, increasing cost even further. Double Bus The double bus arrangement can be considered a modification of the ring bus and is shown in Figure 8. There is no tie breaker between buses but each feeder can be fed from either bus. The switchgear lineups usually face each other across an isle and unlike the MTM, it allows throwover to the other source if the bus is lost. This configuration can be very flexible with multiple sources such as two utilities and a standby generator. In that case one of the buses would be split into a MTM for the other source. The double bus arrangement would be found in very large WWW facilities. 9
10 Figure 8: Example of a primary double bus Like the previous configurations, the reliability and cost of the double bus are based on three feeders. The time unavailable is reduced by about half compared to the MTM. The feeder cannot be restored after a bus or breaker fault with the MTM until the equipment is repaired, but with the double bus scheme, the feeder is switched to the other bus in three seconds for a source bus fault. However, a fault on the load bus or one of the load bus breakers does not provide an immediate alternate source. This configuration uses two breakers per feeder and increases per feeder cost 50 percent over that of the MTM. With the ability to feed loads from either bus, maintenance is possible at the MV bus while the other bus serves the loads. However, maintenance is not possible without a shutdown from the load bus to the load. Low Voltage Low voltage component reliability data from the Gold Book 1 is shown in Table 4. Overall, the failure rates are low but some of the repair times are quite long. Specifically, transformer and bus repair times can take days, which will reduce availability. Failure Rate (#/yr) Repair Time (Hours) Components Comments LV Switch Transformer Replace LV CB Replace CB (Drawout) Switchgear Bus
11 LV Conductors per 1000 ft; Table 4: Low voltage equipment reliability data Single Ended Radial This is the simplest low voltage radial configuration and is shown in Figure 9. It is the least expensive arrangement and provides no alternative feed to the loads if normal power is lost. The implementation would likely use fused switchboard rather than circuit breakers due to cost considerations. Figure 9: Example of single ended secondary substation Each of these examples assumes a 2000 kva transformer with a secondary main, four feeders, and 300 feet conductor lengths. The single ended radial configuration assumes a fused switchboard and the load evaluated for reliability is at the end of a 300 foot LV feeder conductor. The results are shown in Table 5. As can be seen, the failure rate is low compared to the MV examples primarily because no utility is included. However, the unavailability is similar, because of the long repair time for the transformer and, to a lesser extent, the MV conductors. This provides insight into what should be bypassed in subsequent configurations to improve reliability. Failure (#/yr) Unavail MTTR Cost (per Component (Hours/y) (Hour)s feeder) Radial 3.59x $66k MTM (LV) 2.29x x $76k Spot Network 1.25x $87k Table 5: Secondary reliability results and costs To determine the reliability of a single ended LV configuration together with one of the primary distribution systems, add the reliabilities and the unavailabilities. 11
12 The radial design serves as a reference for comparison of the other designs. Power must be shut down to the load for any maintenance that must be performed on the equipment. Secondary Selective One of the more common LV configurations is the secondary selective or MTM, as shown in Figure 10. For maximum reliability, drawout power circuit breakers with automatic transfer should be used in this configuration. The automatic transfer switches to the alternate source in three seconds rather than the 20 minutes it may take to manually transfer. Figure 10: Example of secondary Main-Tie-Main (MTM) The unavailability is reduced more than 10 times compared to the single-ended radial value. The transformer and MV conductor have long repair times and the MTM allows them to be automatically bypassed. Still, loss of the bus, one of the bus breakers, or the feeder conductor to the load, requires the load to be down until repairs are completed. Cost per feeder is 15 percent more compared to the radial configuration due to the transition from fused switches to breakers and the addition of the tie breaker. Secondary Spot Network Networks are implemented by utility companies to serve multiple loads in high density urban areas. A network typically covers several city blocks with service to individual loads connected to the network wherever convenient. The secondary spot network is shown in Figure 11. In this case, the secondaries of two or more transformers are paralleled through a special circuit breaker called a network protector. If there is a transformer or MV feeder fault, the secondary bus will back feed it through the network protector. 12
13 The network protector has instantaneous tripping for reverse flowing current to isolate the faulted equipment from the secondary bus. Typically, removable links are added to be able to isolate the buses. Figure 11: Example of secondary spot network. A spot network refers to two or more parallel sources to serve a specific load such as the main switchgear for a building. It is implemented in an industrial setting where loads are frequently moved by running a bus duct between the substations and adding loads where needed. The distribution is not likely used in WWW since loads tend to be permanent. An interruption will only occur when all the sources are lost or one of the secondary buses fault. However, the loads will see all the voltage sags on the sources or as a result of a fault within the facility. With the voltage sag threshold of some electronic equipment at 85 percent of nominal voltage, a voltage sag may be as disruptive as an interruption. This evaluation assumes a power circuit breaker main and 300 feet of 3000 A aluminum bus duct with eight 600 A bus duct plugs. In this case, the bus duct drops are assumed to be 150 feet since the bus duct should be closer to the loads than a substation. Interestingly, the reliability results don t demonstrate a remarkable performance for this design. While the spot network is immune to interruptions originating upstream of the network protector (barring loss of all sources), it is vulnerable to loss of the bus duct, network protectors and the load conductors. The bus duct failure rate and repair time are high and dominate the results, therefore this design has an availability that is comparable to the single ended radial configuration. The cost of the spot network is higher than any of the other configurations. The largest cost item is the long length of high ampacity bus duct. The transformers and bus must be oversized and circuit breakers must have a high interrupting rating due to the increased fault current available with the paralleled sources. 13
14 Conclusions This paper presents the relative reliability of several power distribution configurations with approximate installation costs. These will help determine both the value of downtime and which components have the greatest effect on reliability. Actual systems are a composite of those evaluated and may have variations on the configurations presented. The key concept is that the reliability of the design should be reviewed and balanced against the cost. For a complex system or one where reliability is extremely important, a formal reliability analysis should be performed. References 1 IEEE Standard , IEEE Recommended Practice for Design of Reliable Industrial and Commercial Power Systems (The Gold Book). 2 Billington, Roy & Allen, Ronald N, Reliability Evaluation of Power Systems, Plenum Press, RSMeans Electrical Cost Data, 30 th Edition, Beeman, Donald, (editor), Industrial Power System Handbook, McGraw-Hill,
15 Appendix Example Reliability Calculation for MV Radial Configuration The reliability will be determined at the load side of the left transformer switch. The elements that can cause loss of power to the left transformer when failed are: Utility Main Switch Each cable segment 300 feet each) Three transformer switches The table below shows how the reliability indices are derived. Failure (#/yr) Unavail MTTR Component (Hours/y) (Hour)s Utility Switch (X4) 2.44x x Cable (X0.9) 5.52x x Terminations (X12) 4.00x Result The components are in series, which means failure of any one of them will result in loss of power at the point of evaluation. For a series arrangement, the expected failure rate, λ, of the system is the sum of the individual failure rates. λ s = λi The unavailability, U, of each component is the product of the failure rate and the mean time to repair, r, of the component. U i = λ i r i The unavailability of the system is the sum of the component unavailability s. U s = U i 15
16 The mean time to repair of the system is the system unavailability divided by the system failure rate. r s = U s λ s In this analysis, it is assumed that an alternative source or path is always available. That is not the case in actual systems, but including failure of an alternate source or path changes the indices very little. This is a comparative analysis and the small change does not alter the relative effectiveness of the configurations. If the load can be switched to restore power, the mean repair time can be replaced with the mean switching time for all the components upstream of the switching point. For a simple analysis, this method suffices to represent the interruption time. About the Author Van Wagner is a staff power systems engineer for Schneider Electric. He is responsible for power studies, design, investigations and training in the Midwest region and for strategic accounts. He has 33 years of experience in power systems, 10 of which are with Schneider Electric. Wagner received a Bachelor of Science degree ( 74) and Master of Science degree in electrical engineering ( 93) from the University of Michigan and Michigan State University, respectively. He is a former chair of IEEE 1346 and is the current chair of the new industrial chapter of the IEEE 1100 "Emerald Book. Wagner is a registered professional engineer in the state of Michigan. 16
A comparison of metal-enclosed load interrupter (ME) switchgear and metal-clad (MC) switchgear
Robert J. Gustin Eaton Fellow Application Engineer, P. E. Southfield, Michigan Definitions Metal-enclosed load interrupter switchgear type ME Metal-enclosed switchgear is defined in ANSI C37.20.3-1987,
More informationGuideline for Parallel Grid Exit Point Connection 28/10/2010
Guideline for Parallel Grid Exit Point Connection 28/10/2010 Guideline for Parallel Grid Exit Point Connection Page 2 of 11 TABLE OF CONTENTS 1 PURPOSE... 3 1.1 Pupose of the document... 3 2 BACKGROUND
More information400/230 Volt 60Hz UPS Power
olt 60Hz Power Using ual Voltage standby generation and in one Nothing protects quite like Piller www.piller.com Contents 1 Abstract...3 2 Introduction...4 3 Alternative Power istribution...6 4 Integrating
More information3.0 Radial Distribution Systems
3.0 Radial Distribution Systems Radial distribution systems (RDS) are the most common design used by electric utilities, and are the least expensive to plan, construct, and maintain. They generally consist
More informationDesign Considerations to Enhance Safety and Reliability for Service Entrance Switchboards
Design Considerations to Enhance Safety and Reliability for Service Entrance Switchboards Robert P. Hansen, P.E., PhD GE Specification Engineer Introduction Switchboards are a widely used type of equipment
More informationRex Healthcare Medium Voltage System Presentation APEC 2015 March 15-19, 2015
Rex Healthcare Medium Voltage System Presentation APEC 2015 March 15-19, 2015 Maximizing the Efficiency of Hospital Distribution Systems Through the Use of Advancing Technology and Design Creativity MISSION:
More information9/16/2010. Chapter , The McGraw-Hill Companies, Inc. TRANSMISSION SYSTEMS. 2010, The McGraw-Hill Companies, Inc.
Chapter 3 TRANSMISSION SYSTEMS 1 Transmitting large amounts of electric energy over long distances is accomplished most efficiently by using high-voltages. Without transformers the widespread distribution
More informationStandby Power Systems
Source: Power Quality in Electrical Systems Chapter 13 Standby Power Systems The term standby power systems describes the equipment interposed between the utility power source and the electrical load to
More informationShippensburg University
Shippensburg University 1871 Old Main Drive Shippensburg, PA 17257 SUPPLEMENT 1 Electrical Coordination Study Professional: Entech Engineering, Inc. 4 South Fourth Street P.O. Box 32 Reading, PA 19603
More informationService Entrance Methods
Service Section Typical switchboards consist of a service section, also referred to as the main section, and one or more distribution sections. The service section can be fed directly from the utility
More informationUNIVERSITY OF WASHINGTON Facilities Services Design Guide. Electrical. Switchboards. Basis of Design. Design Evaluation
Basis of Design This section applies to the design relating to low voltage switchboards. Design Criteria UW Class N1 facilities main switchboards shall be rear accessible. The main, tie and feeder breakers
More informationB-03 ELECTRICIAN TRAINING SKILL DEVELOPMENT GUIDE
B-03 ELECTRICIAN TRAINING SKILL DEVELOPMENT GUIDE Duty B: Power Distribution (600V and below) B-03: Troubleshoot 480V System Issued 06/01/98 Task Preview Troubleshoot 480V System The 480V distribution
More informationDesign considerations for generator set mounted paralleling breakers
Our energy working for you. Design considerations for generator set mounted paralleling breakers White Paper Hassan Obeid, Application Group Cummins Power Generation Cummins Power Systems has been delivering
More informationEH2741 Communication and Control in Electric Power Systems Lecture 3. Lars Nordström Course map
EH2741 Communication and Control in Electric Power Systems Lecture 3 Lars Nordström larsn@ics.kth.se 1 Course map 2 1 Outline 1. Repeating Power System Control 2. Power System Topologies Transmission Grids
More informationA Cost Benefit Analysis of Faster Transmission System Protection Schemes and Ground Grid Design
A Cost Benefit Analysis of Faster Transmission System Protection Schemes and Ground Grid Design Presented at the 2018 Transmission and Substation Design and Operation Symposium Revision presented at the
More informationTransformer Protection
Transformer Protection Course No: E01-006 Credit: 1 PDH Andre LeBleu, P.E. Continuing Education and Development, Inc. 9 Greyridge Farm Court Stony Point, NY 10980 P: (877) 322-5800 F: (877) 322-4774 info@cedengineering.com
More informationTRANSMISSION SYSTEMS
TRANSMISSION SYSTEMS Transmitting large amounts of electric energy over long distances is accomplished most efficiently by using high-voltages. Without transformers the widespread distribution of electric
More informationGuide. Services Document No: GD-1401 v1.0. Issue Date: Title: WIND ISLANDING. Previous Date: N/A. Author: Heather Andrew.
Guide Department: Interconnection Services Document No: GD-1401 v1.0 Title: WIND ISLANDING Issue Date: 11-24-2014 Previous Date: N/A Contents 1 PURPOSE... 2 2 SCOPE AND APPLICABILITY... 2 3 ROLES AND RESPONSIBILITIES...
More informationCost Benefit Analysis of Faster Transmission System Protection Systems
Cost Benefit Analysis of Faster Transmission System Protection Systems Presented at the 71st Annual Conference for Protective Engineers Brian Ehsani, Black & Veatch Jason Hulme, Black & Veatch Abstract
More informationSTATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS ENERGY FACILITY SITING BOARD
STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS ENERGY FACILITY SITING BOARD In re : : Docket No. SB-00-0 () : Testimony of David M. Campilii, P.E. June, 00 PROV-- 0 0 TESTIMONY OF DAVID M. CAMPILII,
More informationETAP Implementation of Mersen s Medium Voltage Controllable Fuse to Mitigate Arc Flash Incident Energy
ETAP Implementation of Mersen s Medium Voltage Controllable Fuse to Mitigate Arc Flash Incident Energy ETAP 17 Goodyear, Suite 100 Irvine, CA 92618 White Paper No.001.14-2016 Albert Marroquin, PE Member
More informationGrounding Of Standby & Emergency Power Systems
July / August 2007 ELECTRICAL LINE 53 Grounding Of Standby & Emergency Power Systems By Andrew Cochran Power continuity is essential in many industrial and commercial installations where a trip out due
More informationSwitchgear and Distribution Systems for Engineers and Technicians
Switchgear and Distribution Systems for Engineers and Technicians WHAT YOU WILL LEARN: How to identify typical characteristics of an industrial distribution system Become familiar with the main components
More informationWhen power interruptions happen.
When power interruptions happen. We know it s never a good time to have your power go out, so we work all year pruning trees and investing in our system to cut down on problems before they start. Outage
More informationA system fault contribution of 750 mva shall be used when determining the required interrupting rating for unit substation equipment.
General Unit substations shall be 500 kva minimum, 1500 kva maximum unless approved otherwise by the University. For the required configuration of University substations see Standard Electrical Detail
More informationGuidelines for Modernizing Existing Electrical Switchgear in LV and MV Networks
Guidelines for Modernizing Existing Electrical Switchgear in LV and MV Networks by Georges Barbarin Executive summary Aging electrical switchgear infrastructure is a threat to the reliability of power
More informationSelective Coordination
Circuit Breaker Curves The following curve illustrates a typical thermal magnetic molded case circuit breaker curve with an overload region and an instantaneous trip region (two instantaneous trip settings
More informationMar H: SUPPLEMENTAL PARALLELING GEAR (16315-H)
2101 Commonwealth Blvd, Suite B Ann Arbor, MI 48105-5759 www.med.umich.edu/facilities/plan/ 263010-H: SUPPLEMENTAL PARALLELING GEAR (16315-H) Related Sections Basis Guideline: N/A For an explanation of
More informationChapter 6 Generator-Voltage System
Chapter 6 Generator-Voltage System 6-1. General The generator-voltage system described in this chapter includes the leads and associated equipment between the generator terminals and the low-voltage terminals
More informationRecommended Procedures
Selective Coordination Study Recommended Procedures The following steps are recommended when conducting a selective coordination study.. One-Line Diagram Obtain the electrical system one-line diagram that
More informationLoad Side PV Connections
Perspectives on PV Load Side PV Connections 705.12(D) in the 2014 NEC by John Wiles Through the exceptional efforts of the members of NFPA NEC Code-Making Panel 4 working with the proposals and comments
More informationINTERCONNECTION STANDARDS FOR PARALLEL OPERATION OF SMALL-SIZE GENERATING FACILITIES KILOWATTS IN THE STATE OF NEW JERSEY
INTERCONNECTION STANDARDS FOR PARALLEL OPERATION OF SMALL-SIZE GENERATING FACILITIES 10-100 KILOWATTS IN THE STATE OF NEW JERSEY January 1, 2005 Rockland Electric Company 390 West Route 59 Spring Valley,
More informationElbert County 500 MW Generation Addition Interconnection Feasibility Study Report OASIS POSTING # GI
Executive Summary Elbert County 500 MW Generation Addition Interconnection Feasibility Study Report OASIS POSTING # GI-2003-2 Xcel Energy Transmission Planning January 2004 This Interconnection Feasibility
More informationSelective Coordination Requirements
Selective Coordination Requirements Background Selective coordination of all upstream overcurrent protective devices in the supplying circuit paths is required by the NEC for a limited number of specific
More informationSource-Side Fuse/Load-Side Recloser Coordination
How to Coordinate ransformer Primary-Side Fuses with Feeder Reclosers Using Coordinaide M he S&C Protection and Coordination Assistant Part I: Conservative Method his is the first in a series of articles
More informationIII. Substation Bus Configurations & Substation Design Recommendations
III. Substation Bus Configurations & Substation Design Recommendations 1.0 Introduction Pre-existing conditions, electrical arrangements or the criticality of the existing facility may limit this flexibility,
More informationMechanical, Electrical, Technology Engineering Firm
Mechanical, Electrical, Technology Engineering Firm Established 1995 Current staff of forty-five Twenty engineers (12 registered P.E. s) Three Registered Communications Distribution Designers - RCDD s
More informationPower & High Voltage Joslyn Hi-Voltage Overhead Reclosers & Switches H-220. Series HVI Hi-Velocity Interrupter Attachment
Use load interrupter attachments to enable loop sectionalizing, line dropping, load breaking and transformer-magnetizing current interruption. Increase the capability of your disconnect switches by adding
More informationMichigan State University Construction Standards SECONDARY UNIT SUBSTATIONS PAGE
PAGE 261116-1 SECTION 261116 PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections,
More informationJoslyn Clark Controls, Inc. Simple, Safe, Retrofit Programs to Significantly Extend Life of Existing Circuit Breakers
Joslyn Clark Controls, Inc. Simple, Safe, Retrofit Programs to Significantly Extend Life of Existing Circuit Breakers 2 Introduction This discussion describes in detail retrofitting medium voltage circuit
More informationFuture Proof Your Arc Flash Assessment
Future Proof Your Arc Flash Assessment 2017 ENERGY CONNECTIONS CONFERENCE TRADE SHOW Presented by: Keith Mullen, P.E. November 9, 2017 Agenda > Utility requirements > Study objectives > Applicable standards
More informationABB POWER SYSTEMS CONSULTING
ABB POWER SYSTEMS CONSULTING DOMINION VIRGINIA POWER Offshore Wind Interconnection Study 2011-E7406-1 R1 Summary Report Prepared for: DOMINION VIRGINIA POWER Report No.: 2011-E7406-1 R1 Date: 29 February
More informationSmall Generator Interconnection Program Interconnection Technical Requirements
General Program Information What is the purpose of the PGE Small Generator Interconnection Program? How do I initiate a distribution interconnection request for my project? The purpose of our Small Generator
More informationZone Selective Interlock Module. For GE Circuit Breakers
GE Zone Selective Interlock Module For GE Circuit Breakers Table of Contents 1. Introduction... 4 What is Zone-Selective Interlocking (ZSI)?...4 What is a Zone-Selective Interlock Module?...4 2. Description...
More informationWhite Paper. Ground Fault Application Guide. WL Low Voltage Power Circuit Breakers
White Paper Ground Fault Application Guide WL Low Voltage Power Circuit Breakers Table of Contents Introduction 3 Need for ground fault tripping 3 Requirements from industry standards 3 National Electrical
More informationArc-Flash Mitigation Technologies. Dennis Balickie
Arc-Flash Mitigation Technologies Dennis Balickie The purpose of the session is to provide an overall understanding of the strategic impact of arc-flash. Special focus is on the tactical means to minimize
More informationDual Power. Protection. Protection
54 Fault Clearing Systems by Damien Tholomier., AREVA T&D Automation, Canada Dual Power Single Battery What if it? Short circuits and other abnormal power system conditions are very rear, but may result
More informationCircuit breaker interlocking and operation requirements SIEMENS
Circuit breaker interlocking and operation requirements SIEMENS When manufacturers and specifiers discuss circuit breaker operational and interlocking requirements, several terms are used repeatedly. Despite
More informationModular Standardized Electrical and Control Solutions for Fast Track Projects
Modular Standardized Electrical and Control Solutions for Supporting fast track projects ABB is the leading supplier of electrical and control equipment for power plants. The company offers a comprehensive
More informationCRITICAL ISSUES DOWNTOWN CONTINGENCY PORTFOLIO
EB-0-0 Tab Schedule Page of CRITICAL ISSUES DOWNTOWN CONTINGENCY PORTFOLIO THESL s DOWNTOWN CONTINGENCY WORK PROGRAM The purpose of this portfolio is to provide distribution load transfer capability from
More information7. SERVICES OVER 600 VOLTS
7. SERVICES OVER 600 VOLTS 7.1 GENERAL The Company shall always be consulted to obtain required design criteria where service is contemplated.preliminary plans of the Customer shall be submitted for review
More informationData Bulletin. Ground-Censor Ground-Fault Protection System Type GC Class 931
Data Bulletin 0931DB0101 July 2001 Cedar Rapids, IA, USA Ground-Censor Ground-Fault Protection System Type GC Class 931 09313063 GT Sensor Shunt Trip of Circuit Interrupter Window Area for Conductors GC
More informationELECTRIC SERVICE RULES DISTRIBUTED GENERATION Issued Jan 2016
DISTRIBUTED GENERATION CHAPTER 5 500. SCOPE This chapter includes distributed or customer-owned generation connected in parallel and operating with Alliant Energy s electric distribution system. For all
More informationIEEE Guide for the Design of Low Voltage AC and DC Auxiliary Systems for Substations
1 IEEE1818-2017 Guide for the Design of Low Voltage AC and DC Auxiliary Systems for Substations Sponsored by the IEEE Substations Committee Presented By Joe Gravelle Organization of the Guide 1. Scope
More information9. Non-Residential Services (Commercial, Industrial, and Agricultural)
Section 9 2016 Electric Service Requirements, 3rd Edition Section 9 Non-Residential Services Directory Page 9.1 General Requirements 68 9.2 Direct-Connect Metering, Single Installations 69 9.3 Direct-Connect
More informationThe University of New South Wales. School of Electrical Engineering and Telecommunications. Industrial and Commercial Power Systems Topic 6
The University of New South Wales School of Electrical Engineering and Telecommunications Industrial and Commercial Power Systems Topic 6 PROTECTIONS 1 FUNCTION OF ELECTRICAL PROTECTION SYSTEMS Problems:
More information3.2. Current Limiting Fuses. Contents
.2 Contents Description Current Limiting Applications................. Voltage Rating.......................... Interrupting Rating....................... Continuous Current Rating................ Fuse
More informationGuidelines for connection of generators:
Guidelines for connection of generators: Greater than 30 kva, and not greater than 10 MW, to the Western Power distribution network January, 2017. EDM 32419002 / DM 13529244 Page 1 of 14 Contents 1 INTRODUCTION...
More information4-Day Power System Analysis, Coordination, System Studies
4-Day Power System Analysis, Coordination, System Studies Contact us Today for a FREE quotation to deliver this course at your company?s location. https://www.electricityforum.com/onsite-training-rfq Our
More informationSelective Coordination Enforcement:
Selective Coordination Enforcement: Overcurrent Protective Device Basics by Tim Crnko The Basics of Selective Coordination Merely having a higher ampere overcurrent protective device (OCPD) feeding a lower
More informationAppendix C. Safety Analysis Electrical System. C.1 Electrical System Architecture. C.2 Fault Tree Analysis
Appendix C Safety Analysis Electrical System This example analyses the total loss of aircraft electrical AC power on board an aircraft. The safety objective quantitative requirement established by FAR/JAR
More informationDER Commissioning Guidelines Community Scale PV Generation Interconnected Using Xcel Energy s Minnesota Section 10 Tariff Version 1.
Community Scale PV Generation Interconnected Using Xcel Energy s Minnesota Section 10 Tariff Version 1.3, 5/16/18 1.0 Scope This document is currently limited in scope to inverter interfaced PV installations
More informationELECTRICAL POWER DISTRIBUTION FOR INFORMATION TRANSPORT SYSTEMS
ELECTRICAL POWER DISTRIBUTION FOR INFORMATION TRANSPORT SYSTEMS Bob Hertling Senior Communications Engineer / RCDD, OSP PARSONS Your ITS equipment requires AC power Do you know what is on the other side
More informationHigh Effective Availability Decentralized UPS HEAD-UPS (c) 3.0 High Effective Availability Decentralized UPS-HEAD-UPS(c)
High Effective Availability Decentralized UPS HEAD-UPS (c) Contents: Executive Summary 1.0 Introduction 2.0 UPS and Batteries 3.0 High Effective Availability Decentralized UPS-HEAD-UPS(c) 4.0 Availability
More informationCHAPTER 3. Basic Considerations and Distribution System Layout
CHAPTER 3 Basic Considerations and Distribution System Layout Utility Load Classifications The electrical power distribution system is that portion of the electrical system that connects the individual
More informationShunt Capacitor Bank Protection in UHV Pilot Project. Qing Tian
Shunt Capacitor Bank Protection in UHV Pilot Project Qing Tian 2012-5 INTRODUCTION State Grid Corp. of China, the largest electric power provider in the country, has first build a 1000 kv transmission
More informationTRI-SERVICE ELECTRICAL WORKING GROUP (TSEWG) 03/05/09 TSEWG TP-11: UFC N BEST PRACTICES
TSEWG TP-11: UFC 3-500-10N BEST PRACTICES UFC 3-500-10N was developed by NAVFAC and was used as the starting point for the tri-services development of UFC 3-500-10, Design: Electrical Engineering. UFC
More informationModel ESV Uninterruptible Power System 1.5 KVA/KW KVA/KW Single Phase
Model ESV Uninterruptible Power System 1.5 KVA/KW - 14.0 KVA/KW Single Phase 1.0 General General Specification This specification describes the features and design of an on-line, dual conversion, uninterruptible
More information10 Commercial, Industrial, Agricultural Services
10 Commercial, Industrial, Agricultural Services This section describes the Power Company requirements for commercial, industrial, and agricultural services. This section covers single phase and three
More informationMichigan/Grand River Avenue Transportation Study TECHNICAL MEMORANDUM #18 PROJECTED CARBON DIOXIDE (CO 2 ) EMISSIONS
TECHNICAL MEMORANDUM #18 PROJECTED CARBON DIOXIDE (CO 2 ) EMISSIONS Michigan / Grand River Avenue TECHNICAL MEMORANDUM #18 From: URS Consultant Team To: CATA Project Staff and Technical Committee Topic:
More informationTHE CURVE FOR DOUBLE PROTECTION TRANSFORMER & SYSTEM PROTECTION WITH CHANCE SLOFAST FUSE LINKS
THE CURVE FOR DOUBLE PROTECTION TRANSFORMER & SYSTEM PROTECTION WITH CHANCE SLOFAST FUSE LINKS CHANCE SLOFAST FUSE LINKS ARE DESIGNED FOR BOTH TRANSFORMER AND SYSTEM PROTECTION. For many years in the electric
More informationReasonableness Test RT 015 /11 Salisbury Substation 11kV Feeders
Reasonableness Test RT 015 /11 Salisbury Substation 11kV Feeders Reasonableness Test: Salisbury Substation 11kV Feeders DISCLAIMER The purpose of this document is to inform customers, Interested Parties,
More informationUniversity of California, San Diego Cal (IT) 2 Technical Assignment #2. Brian Smith
University of California, San Diego Cal (IT) 2 Technical Assignment #2 Brian Smith Advisor: Dr. Moeck 31 October 2005 Brian Smith Lighting/Electrical Option University of California, San Diego Cal (IT)
More information.3 Section Waste Management and Disposal.
Issued 2005/06/01 Section 16261 Uninterruptible Power Systems Static Page 1 of 10 PART 1 GENERAL 1.1 RELATED SECTIONS.1 Section 01330 Submittal Procedures..2 Section 01780 Closeout Submittals..3 Section
More informationSolar Power Switchgear & Energy Storage Renewable Energy Systems
7 Solar Power Switchgear & Energy Storage Renewable Energy Systems - Solution Brochure www.apt-power.com 433 N. 36 th Street PROVIDING A COMPREHENSIVE Lafayette, IN 47905 www.apt-power.com 433 APPROACH
More informationA Practical Guide to Free Energy Devices
A Practical Guide to Free Energy Devices Part PatD20: Last updated: 26th September 2006 Author: Patrick J. Kelly This patent covers a device which is claimed to have a greater output power than the input
More informationDocument Requirements for Engineering Review- PV Systems v1.1 12/6/2018
Document Requirements for Engineering Review- PV Systems v1.1 12/6/2018 Outlined below are the engineering documents and their associated minimum detail requirements for a Distributed Energy Resource (DER)
More informationJoseph Lookup Senior Thesis 2005 Wegmans Fairfax. Section 2.0. Electrical Depth
Section 2.0 Electrical Depth 2.0 Electrical Depth 2.1 Introduction The electrical distribution system was analyzed to determine if any improvements could be made, to analyze its capabilities, to verify
More informationModular integrated transportable substation (MITS)
Technical Data TD027002EN transportable substation (MITS) Contents Description Page Voltage regulation with bypassing........................................................ 2 Mobile MITS application...............................................................
More informationElectrical Safety. Introduction
Electrical Safety Introduction Electrical hazards 300 electrocutions every year in the U.S. Leading cause is insufficient training ALL were preventable What is Electricity? How Electricity Works Created
More informationTitle: YALE OFFICE OF FACILITIES PROCEDURE MANUAL Chapter: 01 - Yale Design Standard Division: Electrical Standards
Change History Date Description of Change Pages / Sections Modified 8/1/17 Updated section for System Design and Performance Requirements and Manufacturers 5>6 C. 4.c..&d.; m; remove p. 8 F. Change Approver
More informationERDF EXPERIENCE IN REDUCING NETWORK LOSSES
ERDF EXPERIENCE IN REDUCING NETWORK LOSSES Michel ODDI Frédéric GORGETTE Guillaume ROUPIOZ EDF R&D France ERDF France EDF R&D - France michel.oddi@edf.fr frederic.georgette@erdfdistribution.fr guillaume.roupioz@edf.fr
More informationDESIGN GUIDELINES LOW VOLTAGE SWITCHGEAR PAGE 1 of 5
DESIGN GUIDELINES LOW VOLTAGE SWITCHGEAR PAGE 1 of 5 1.1. APPLICABLE PUBLICATIONS 1.1.1. Publications listed below (including amendments, addenda, revisions, supplements, and errata), form a part of this
More informationElectrical Depth. Mark W. Miller Sibley memorial Hospital Grand Oaks Washington, DC CURRENT SYSTEM
CURRENT SYSTEM The current electrical system can best be described as star; one main switchboard that feeds to the main distribution panel, which then feeds the other panels. The normal power is provided
More informationSecondaries. arc flash note Introduction. By Mike Lang, engineer and. Services Supervisor
Reducing Arc Flash Energies on Transformer Secondaries arc flash note 6 By Mike Lang, principal field engineer and Dave Komm, Technical Services Supervisor 1. Introduction Arc flash incident energy calculations
More informationSectionalizing. Rick Seeling. Pete Malamen. Introduction Philosophy. Three Phase Reclosers High-Side Protection Specific Applications
Sectionalizing Rick Seeling Introduction Philosophy Pete Malamen Three Phase Reclosers High-Side Protection Specific Applications History Early 1970 s Small Substation Transformers
More informationEmergency Back-up Power Generation for Water & Wastewater Facilities
Emergency Back-up Power Generation for Water & Wastewater Facilities Emergency Back-up power sources Multiple utility feeds On site emergency power sources Diesel powered generator sets Natural Gas generator
More informationWheeler Ridge Junction Substation Project Description and Functional Specifications for Competitive Solicitation
Wheeler Ridge Junction Substation Project Description and Functional Specifications for Competitive Solicitation 1. Description In the 2013-2014 Transmission Planning Cycle, the ISO approved the construction
More informationFundamentals of Modern Electrical Substations Part 3: Electrical Substation Engineering Aspects
Fundamentals of Modern Electrical Substations Part 3: Electrical Substation Engineering Aspects Course No: E03-014 Credit: 3 PDH Boris Shvartsberg, Ph.D., P.E., P.M.P. Continuing Education and Development,
More informationApplication Note: Protection of Medium-Power Motors With SIPROTEC Compact 7SK80
Application Note: Protection of Medium-Power Motors With SIPROTEC Compact 7SK80 Motor settings using the SIPROTEC Compact motor protection relay 7SK80 is explained below. Information is given on how to
More informationA member-consumer with a QF facility shall not participate in the Cooperative s electric heat rate program.
Electric Tariff _2nd Revised Sheet No. 72 Filed with Iowa Utilities Board Cancels _1st Sheet No. _72 Cooperative is a member of Central Iowa Power Cooperative (CIPCO), a generation and transmission cooperative
More informationTIME REQUIREMENT GUIDE (TRG)
CAT SWITCHGEAR TIME REQUIREMENT GUIDE (TRG) This warranty repair time requirement guide is designed to: Provide detailed guidance on troubleshooting Determine possible solutions Guide the technician to
More informationTECHNICAL SPECIFICATION FOR INDEPENDENT POWER PRODUCERS. NB Power Customer Service and Distribution. June 2008
NB Power Customer Service and Distribution June 2008 Prepared by: Steven Wilcox Revised by: Steven Wilcox TABLE OF CONTENTS 1.0 Introduction 4 2.0 NB Power Policy on Independent Power Production 4 3.0
More informationVOLTAGE SAGS; A LITTLE STORAGE CAN GO A LONG WAY
WHITE PAPER VOLTAGE SAGS; A LITTLE STORAGE CAN GO A LONG WAY I. Utility power in the U.S. is very reliable; we count on it to be there, expect it to be there, and it usually is. Barring natural disasters
More informationTransmission Competitive Solicitation Questions Log Question / Answer Matrix Harry Allen to Eldorado 2015
No. Comment Submitted ISO Response Date Q&A Posted 1 Will the ISO consider proposals that are not within the impedance range specified? Yes. However, the benefits estimated and studies performed by the
More informationThe Case for Hybrid Generator Grounding
I-Gard Hybrid Generator Whitepaper 1 The Case for Hybrid Generator Sergio Panetta March 10, 2014 VP of Engineering, I-Gard Medium Voltage Generators are not designed to withstand full fault current during
More informationWisconsin Public Utility Institute. June 28, Minimum Distribution Charges. Larry Vogt. Director, Rates Mississippi Power
Wisconsin Public Utility Institute June 28, 2017 Minimum Distribution Charges Larry Vogt Director, Rates Mississippi Power 1 Costs of Service vs. Cost Recovery Residential Service Example Assuming that
More informationBackfeed, Safety, and Work Practices
Backfeed, Safety, and Work Practices Michael T. Sheehan, P.E. March, 2015 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the
More informationThe Narragansett Electric Company. d/b/a National Grid (Interstate Reliability Project) RIPUC Dkt. No Testimony of. David M. Campilii, P.E.
(Interstate Reliability Project) RIPUC Dkt. No. 0 Testimony of David M. Campilii, P.E. November, 0 -v RIPUC Dkt. No. 0 PREFILED TESTIMONY OF DAVID M. CAMPILII 0 0 INTRODUCTION Q. Please state your name
More informationMedium Voltage. Power Factor Correction Reactive Compensation Harmonic Filters. Electrical Power Quality Management at its best.
Medium Voltage Power Factor Correction Reactive Compensation Harmonic Filters POWER QUALITY Electrical Power Quality Management at its best. From electricity generation, transmission, thru its distribution
More information