Transcript
Online Fall, 2013
A-frame MGs power Seattle-Tacoma Airport A trio of totally enclosed 400 kVA motor-generator (MG) sets housed in weatherproof enclosures will provide 400 Hz, ground power for the South Satellite at Seattle-Tacoma (Sea-Tac) International Airport. With a goal to better serve passengers, the MG sets are part of a $5 million electrical gate improvement project. Containers for the MGs have forklift and crane lift provisions. The special “A” frame is specifically designed to make lifting the entire piece of equipment from above possible. The MG set, panel, and
housing all together weigh 18,000 pounds (9 tons). With the weatherproof enclosures, they are designed to be outside. The new Sea-Tac MGs include the latest technology. Instead of analog metering and control, the controls are digitally based and include a touch-screen interface. The new, third-generation controls come with an updated user interface, data logging, trending and an easy system configuration. System updating is done using the MFC2000™, Kato Engineering’s new high-speed generator controller and protection relay. y The MFC2000™ controls
Three MGs 400 kVA 60-400 Hz Totally enclosed For Sea-Tac airport Purchased by Port of Seattle throug u h MCM Engineering Eng through
- ConƟnued on Page 4
Motor-generator set sales Motorengineer Danielle Liebhard Liebhar in front of one of the tthree Sea-Tac MGs.
Locomotive traction on fast track We recently visited with Kato Engineering sales engineer Louis Myers about growth in the locomotive traction alternator market. What is making the current market strong? It is a combination of Tier 4 emission requirements and engine accessibility. The market is looking to move to higher speed engines (1800 RPM) that allow pre-designed or factory Tier 4 solutions. Generally these solutions are found in the high speed engines offered by Cummins, Caterpillar and MTU. As an added feature, these high-speed engines tend to offer easier access to complete engines as well as service parts and service locations. This becomes even more important as these locomotives are used more globally or in more remote regions, where traditional service isn’t available. Finally, high-speed engines, combined with our alternators, generally represent a more cost effective solution than a slowspeed engine and alternator. Can you explain what the Tier 4 emission requirements mean? Over the last decade the U.S. government has enacted a number of rules designed to reduce smog and air pollution. Many of the Louis Myers regulations focus on two culprits: nitrogen oxide (NOx) and particulate matter, tiny chemical, metal, soil and dust particles. The most stringent of these rules, called Tier 4 emission standards, will kick in for locomotives on January 1, 2015. The upgraded standard will slash particulates for every new engine by 70 percent and NOx by 76 percent from the current (2005) Tier 3 emission levels. For what kinds of locomotives does Kato Engineering provide alternators? Currently we offer alternators for switchers (four and six-axle locomotives used for
Switcher locomoƟves are typically used for assembling trains or for making short hauls. Wikipedia image
short runs and assembling trains), small hauler locomotives and high-speed commuter locomotives. Is there more activity in any one of these locomotive types over the others? The growth in this industry looks to be in high-speed passenger locomotives for commuter locomotives (think Amtrak or Chicago Transit). These applications are very weight sensitive, and the high-speed engine packages are generally a better option. Kato has recently worked with several customers with prototype locomotive alternators to compete in this high-speed passenger market. How long has Kato Engineering been in the rail industry? We’ve been supplying alternators to this industry for around 30 years. This contains a variety of alternator combinations including; traction only, dual/companion and traction/companion combination units. What enhancements have been made to the Kato Engineering product in those three decades? We made great improvements in the sizes (cores) we offer, which have helped accommodate whole new group of projects. As engines got more powerful we had to have sizes to match. Also, the engineering group has done a great job with weight re2
duction. We are now using lighter weight frames while still maintaining structural integrity, as well as using aluminum or fiberglass covers, integral lifting provisions, etc. We are also implementing a Perfect Execution program with this line to maximize customer value and flexibility. These types of improvements are what gives us an advantage in this market. What makes the rail industry a challenging one for Kato Engineering? Each customer or application has unique characteristics that make fitting equipment a challenge. Even with a single customer it isn’t unusual to see several engine manufacturers represented as locomotive requirements change, customer preference is considered, or as projects come to realization. Also, there are a several types of locomotive builds/rebuilds where KATO™ traction alternators are used, including the re-powering of older locomotives and from-scratch new builds. Each one of these presents a unique challenge. How does Kato support the industry? To support the various customers, we work directly with them, engineer to engineer, technician to technician. The Kato Engineering team for locomotives has been together for a long time. I’m the “new guy,” and I have worked with our locomotive customers for 10 years.
Locomotive alternators are electrically unique While locomotive traction alternators have to be designed to fit in distinctive and tight locations, they are electrically a unique design as well. There are three major differences between a traction alternator and Kato’s typical synchronous ac generator. First off, a locomotive traction alternator is usually two units in one: a traction “main” alternator and a “companion” alternator. The two field (rotor) windings revolve on a common shaft, and the two stators are housed in a common frame. The main set of windings, rotor and stator, generates power for the traction motors, which are located on or near the locomotive’s wheel axels. The companion’s set of windings power the locomotives’ auxiliary equipment. The stator on the companion side commonly has two sets of windings. One set provides ac power for cooling fans, air compressors and other cab accessories. A tap on this set of windings also powers a static exciter. The other set of windings in the companion alternator powers a battery charger that charges a battery that in turn powers another static exciter.
AC rectified to DC in the outlet box
The second big difference is that the final output of the main traction alternator windings is dc instead of the standard three-phase ac. In the traction machine’s outlet box is a large rectifier, made up of six pairs of diodes, which transforms the three-phase alternating current to dc. This diode system or “bridge circuit” is similar to the rotating rectifier that excites the rotor on standard units, only much larger, and, of course, it doesn’t rotate. A third major differentiation between a locomotive traction alternator and the usual generator is that the two fields in the traction machine are excited with a brush-andslip-ring system and not the typical exciter with a rotating rectifier. Part of the reason for the brush-andslip-ring system is tradition, said engineer Al Windhorn. The rail industry is accustomed to using brushes. The other reason is that if an exciter were used, it would have to be very large to accommodate the different currents required. This is because
Traction armature
Inset: A locomoƟve tracƟon alternator Below: Basic locomoƟve tracƟon alternator electrical configuraƟon diagram
Companion armature
Field (rotor)
Slip rings
of the range of speeds the generator must handle. When the locomotive is going fast, current requirements are low, but more voltage is needed so the motors don’t become generators and start forcing voltage back in the other direction. When the locomotive is going slower, the voltage requirement is reduced, but the current needed is higher. The slip ring system that excites both rotating fields is typically on the same side of the shaft, opposite the drive end. Several brushes are used to reduce the current density. Too much current would cause excessive heat, voltage drop and increase the wear rate on the brushes. Power to the slip rings comes from the two static exciters. The companion’s static exciter is powered by the battery.
AC for auxiliary equipment
Field (rotor)
Brushes (+)
(-)
(+)
(-)
Static exciter Static exciter
Battery
Battery charger
Kato Current: The mission of the Kato Current is to enhance communication between Kato Engineering and its customers. Please forward comments to Richard Rohlfing, 507-345-2719;
[email protected]; Kato Engineering, PO Box 8447, Mankato, MN 56002. All content is copyright 2013 © Kato Engineering.
3
Sea-Tac MGs will have a two-part UL cert - ConƟnued from Page 1 the paralleling process as well as most of the generator protection including a patent-pending excitation fault detection system. The three motor-generators are in two-part process of being certified by UL. First, the UL inspector came to the Kato Engineering to conduct the spray test prior to the MG sets leaving the factory. The MGs were sprayed with water for one hour. The second half of the certification involves a site evaluation after installation is complete. This is considered an accepted approach to meeting the UL requirements (29 CFR 1910.303 and 1910.399). The field evaluation is an assessment of the MG set and related equipment conducted in an unbiased approach to verifying that UL safety standards are met. Aircraft use 400 Hz alternating current in order to employ lighter weight electromagnetic equipment in their power systems. While it may seem like 400 Hz would be an obvious advantage everywhere, 400 Hz power has significant line losses as compared with conventional 60 Hz power. However, the comparatively short power cabling runs on aircraft make 400 Hz power a practical alternative to 60 Hz power in order to save weight in aircraft construction.
Areal view of SeaƩle-Tacoma (Sea-Tac) airport near SeaƩle Washington. Wikipedia image by Harvey Henkelmann.
Simply put, a motor-generator set is an electric motor mechanically coupled to an electric generator. The motor runs on 60 Hz input current with the generator creating a 400 Hz output current. Thus, the motor-generator set is a electromechanical frequency converter. Power flows between the two halves of the machine as mechanical torque. The MGs were purchased by MCM Engineering. Located in Burlingame,
California, MCM is Kato Engineering’s partner in aircraft ground power. Sea-Tac is located about 10 miles south of Seattle and 20 miles north of Tacoma. It was constructed in 1944 by the Port of Seattle to serve civilians in the region after the military took over nearby Boeing Field for use in World War II. In 2012, Sea-Tac airport served over 33.2 million passengers. The South Satellite has 13 gates.
Martin, Daxner join Kato Engineering Sales & Marketing Kato Engineering has recently hired two off site employees to better serve OEM customers and end users. Luis Martin will lead the marketing effort in the oil and gas sector to help Kato better understand customer needs. Martin received a BS Degree in Mechanical Engineering at the National University in Colombia (1982). In 1985 he finished a specialization in Power Plants, Turbines and Compressors from Stuttgart University in Germany. He has worked in the energy sector for large oil and gas and power generation companies internationally, occupying increasing responsibilities as marketing and sales manager for the compression and power generation markets. Martin was born in Buffalo New York and was raised in Colombia. He and his wife currently live in Houston and have
a 16-year old son. In his spare time Martin enjoys fishing, golfing, reading and travelling. Julius Daxner brings over two decades of oil and natural gas industry experience to his new role as an Area Sales Manager Luis MarƟn in the Canadian region. His career has featured a strong focus on service, sales, business development and operations management. Before participating in the launch of Kato Engineering/Leroy Somer’s business growth strategy in Canada, Julius held various supervisory and senior management positions, both domestically and internationally, at a rotating equipment manufacturer. Prior to that, Julius worked 4
in the drilling industry servicing clients globally. Julius holds a Bachelor of Science degree in Mechanical Engineering and is a journeyman millwright (industrial mechanic). In addition to fulfillJulius Daxner ing his current role at Kato/Leroy Somer, Julius is studying to obtain his Masters degree in Environmental Engineering. Outside of work, Julius loves playing competitive hockey. When not playing and injuring himself, it is likely that Julius can still be found in an arena somewhere, watching and cheering on his daughter Nicole and wife Hana as they compete in horse shows.
