Method and apparatus for monitoring the rotating frequency of de-energized induction motors

Patent · Thu Jan 01 00:00:00 EST 1998

OSTI ID:871354

Mikesell, Harvey E ^[1]; Lucy, Eric ^[2]

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1. McMurray, PA
2. Murrysville, PA

The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.

• Assignee: United States of America as represented by Department of Energy (Washington, DC)
• Patent Number(s): US 5714862
• OSTI ID: 871354
• Country of Publication: United States
• Language: English

Related Subjects

method
apparatus
monitoring
rotating
frequency
de-energized
induction
motors
rotational
speed
coasting
motor
measured
sensing
residual
electrical
voltages
power
terminals
eliminating
conventional
tachometer
equipment
additional
mechanical
components
modifications
terminal
voltage
signal
detected
transformed
dc
proportional
input
control
variable
controller
regulate
output
characteristics
relative
motor controller
power terminal
induction motor
rotational speed
voltage signal
variable frequency
dc voltage
motor control
mechanical components
power terminals
voltage proportional
electrical voltages
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