CATEGORY: LARGE MOTORS
Petroleum and Chemical Industry Technical
Conference (PCIC), 2013, Digital Object Identifier:
10.1109/PCICon.2013.6666034, Page(s): 1 - 7
Applying
permanent magnet motors in an ex environment
McElveen, R. ; Martin, B. ; Massey, E. ; Stelzner, D.
Abstract
Ceretain
characteristics of permanent magnet (PM) motors create new challenges in
certifying for oil and gas environments. Currently, certifications of permanent
magnet motors are handled on a case by case basis. Authors identify areas in
the standards that require additional clarification or assumptions when
applying PM motors.
Many of the differences between PM motors and traditional induction
motors revolve around the working voltage of a PM motor. Often the working
voltage is not the input voltage, but rather the voltage generated by the
machine as the rotor spins at a given RPM. This generated voltage can reach or
exceed the nameplate voltage of the machine. The generated voltage increases
linearly with speed. Accordingly, the operational speed of the motor plays a
large part in determining whether or not the motor meets a certain Ex
definition.
Motor manufacturer must be engaged early in the certification process. As
discussed for a cageless PM motor, it may be desirable to design the stator
windings for 90% of the nameplate voltage to avoid any heating problems when
caused by being forced to lower the drive input voltage to 90% of rated
voltage.
There are differences between certifying a cageless PM motor and a line start
PM motor. Many of the standards contain specific requirements for motors with
cage windings in the rotor. All of these requirements are also applicable to
line start PM machines. The standards typically do not specifically address
cageless designs. Standard revisions are underway to better address this type
of PM motor. Until standards are revised, the users and motor manufacturers
must work closely with certifying agencies to properly interpret the intent of
each protection concept.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6666034&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel7%2F6657459%2F6666008%2F06666034.pdf%3Farnumber%3D6666034
Showing posts with label LARGE MOTORS. Show all posts
Showing posts with label LARGE MOTORS. Show all posts
Monday, January 27, 2014
Starting large synchronous motors in weak power systems
CATEGORY: LARGE MOTORS
Petroleum and Chemical Industry Technical Conference (PCIC), 2013, Page(s): 1 - 8
Starting large synchronous motors in weak power systems
LeDoux, K. ; Visser, P. ; Hulin, D. ; Nguyen, H.
Abstract
Utility company standards for power quality make it difficult for industrial users to start large induction and synchronous motors due to high inrush current. Authors describe a large oil company’s challenges starting large motors driven by the utility company in a relatively weak power system in East Texas while not violating the Utility company’s standards.
A workable solution is an air cooled pulse width modulated (PWM) voltage source variable frequency drive (VFD) system designed to start multiple large horsepower, medium voltage synchronous motors without any measurable voltage flicker. Authors review a variety of motor design and starting methods. They report challenges encountered during the design and provide start-up solutions with final performance details.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6666022&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6666022
Petroleum and Chemical Industry Technical Conference (PCIC), 2013, Page(s): 1 - 8
Starting large synchronous motors in weak power systems
LeDoux, K. ; Visser, P. ; Hulin, D. ; Nguyen, H.
Abstract
Utility company standards for power quality make it difficult for industrial users to start large induction and synchronous motors due to high inrush current. Authors describe a large oil company’s challenges starting large motors driven by the utility company in a relatively weak power system in East Texas while not violating the Utility company’s standards.
A workable solution is an air cooled pulse width modulated (PWM) voltage source variable frequency drive (VFD) system designed to start multiple large horsepower, medium voltage synchronous motors without any measurable voltage flicker. Authors review a variety of motor design and starting methods. They report challenges encountered during the design and provide start-up solutions with final performance details.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6666022&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6666022
Thermal issues in operating large motors outside their rated power and speed range
CATEGORY: LARGE MOTORS
Petroleum and Chemical Industry Technical Conference (PCIC), 2013, Page(s): 1 - 10
Thermal issues in operating large motors outside their rated power and speed range
Lockley, B. ; Noonan, M. ; Lyle, B. ; Paes, R. ; MacDonald, W.
Abstract
Because of anticipated occasional hydraulic issues in an oil sands slurry pumping application, it was expected that the existing Adjustable Speed Drive (ASD) driven 2500 HP motors would be overloaded at up to 3333 HP at a slightly reduced speed from time to time. Using factory test data, researchers estimated losses and temperature rises at the expected load points. They validated the temperature rises by testing a motor on an ASD using a “Back to Back” ASD/Motor arrangement in a specially set up off site arrangement, with the available base power being an 800 kVA alternator.
In the particular application, the temperature rises were not excessive and the predicted loss of insulation life due to the higher insulation temperatures for brief times involved would not be excessive. Authors describe the expected losses and temperature rises, the test setup and operation, as well as the achieved temperatures and the method of predicting loss of insulation life.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6666045&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6666045
Petroleum and Chemical Industry Technical Conference (PCIC), 2013, Page(s): 1 - 10
Thermal issues in operating large motors outside their rated power and speed range
Lockley, B. ; Noonan, M. ; Lyle, B. ; Paes, R. ; MacDonald, W.
Abstract
Because of anticipated occasional hydraulic issues in an oil sands slurry pumping application, it was expected that the existing Adjustable Speed Drive (ASD) driven 2500 HP motors would be overloaded at up to 3333 HP at a slightly reduced speed from time to time. Using factory test data, researchers estimated losses and temperature rises at the expected load points. They validated the temperature rises by testing a motor on an ASD using a “Back to Back” ASD/Motor arrangement in a specially set up off site arrangement, with the available base power being an 800 kVA alternator.
In the particular application, the temperature rises were not excessive and the predicted loss of insulation life due to the higher insulation temperatures for brief times involved would not be excessive. Authors describe the expected losses and temperature rises, the test setup and operation, as well as the achieved temperatures and the method of predicting loss of insulation life.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6666045&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6666045
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