(Left) This 1800 rpm, four-pole, 3. 5 MW HIEC generator is ready for shipment for use with a gas turbine package for oilfield service. (Right) A view of
part of the large rotor assembly area in the HIEC plant, showing large generator rotors in manufacture for use in environmentally friendly hydro-
electric power plants. The vertically integrated Mansfield, Ohio, U.S.A., facility designs all motor, generator and system components and manufac-
tures everything required, with the exception of forgings and large rotor machining.
hubs use fabricated A36 steel. Large
motor rotor poles are stamped out of
16-gauge steel, stacked and riveted together. Four-pole designs use integral
pole laminations that are bolted together under pressure before being
shrunk-fit and keyed to the rotor
shaft. Typically, on 6-pole through 10-
pole machines, the synchronous poles
are dovetailed to the rotor hub.
Twelve-pole and above are bolted on
and connected to a cylindrical hub.
Poles are individually wound under
tension using wire with double-Dacron glass insulation with epoxy
applied between layers. Rotor bars,
connected using heavy copper for efficient current circulation, use a floating cage construction to allow for
thermal expansion and reduced mechanical stress during start-up. HIEC
offers heavy-duty sleeve bearings as
standard. Bearing designs can accommodate thrust, if required, and can be
oil-flood lubricated or self-lubricated
depending on the rating and application. Rigid frame construction and
pre-balancing of rotors are features
that help minimize vibration.
Special designs are available to
meet the requirements of all types of
driven equipment. Motors are also
designed to meet the demands of
variable frequency drive (VFD) appli-
cations. For example, when motors
are used to drive reciprocating com-
pressors, load pulsations can run as
high as 200%. HIEC can increase the
rotor hub size to raise the motor
WR2 so that current pulsations are
reduced without the need for a sepa-
rate flywheel.
A large vertical generator (left) is shown
ready for testing in
HIEC’s Mansfield
plant. When completed, it will be driven by a hydraulic
turbine in a hydropower plant. The
HIEC test facility includes two horizontal
and two vertical test
stands with computerized control
room and customer
witness lounge.
voltage ratings up to 15 kV; excellent
chemical, oil and moisture resistance;
high dielectric strength with low dielectric losses; high mechanical
strength; high thermal conductivity for
improved heat transfer; and the ability
to withstand starting and short circuit
stresses, voltage surges and thermal
cycling. HIEC said that the sealed insulation system is capable of passing
a stringent water spray test as defined
by NEMA MG- 1 industry standard.
HIEC manufactures motors and
generators to meet all current industry
standards, including IEEE, NEMA, API
and IEC. CSA labeling and ATEX/CEN-ELEC-approved designs are also available. HIEC routinely designs motors
for hazardous operation in Division 2,
Zone 2 environments.
Brush type or brushless excitation
systems can be provided. The brushless exciter is mounted outboard of the
bearings for easier maintenance. HIEC
indicated that an adjustable DC power
supply for the exciter field, pull-out
protection and incomplete sequence
protection make its system unique.
HIEC can supply induction motors
from 500 to 20,000 hp (373 to 14,914
kW) at speeds of 240 to 3600 rpm.
Ideal traditionally built both synchronous and induction motors at the
Mansfield facility, but since Hyundai
has a broad range of induction motors, Ideal’s focus is now entirely on
synchronous machines. Some induction motors are obtained from
Hyundai and packaged with auxiliaries in the Mansfield plant for the
U.S. market.
HIEC’s synchronous AC generators
range in size from 670 to 40,000 hp
(500 to 30,000 kW) in both horizontal
and vertical configurations. They can be
furnished at speeds of 100 to 1800 rpm,
