Precision electronic speed controller for an alternating-current

Patent · Fri Jan 01 00:00:00 EST 1988

OSTI ID:866532

Bolie, Victor W ^[1]

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1. Albuquerque, NM

A high precision controller for an alternating-current multi-phase electrical motor that is subject to a large inertial load. The controller was developed for and is particularly suitable for controlling, in a neutron chopper system, a heavy spinning rotor that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal having a meandering line frequency. The controller includes a shaft revolution sensor which provides a feedback pulse train representative of the actual speed of the motor. An internal digital timing signal generator provides a reference signal which is compared with the feedback signal in a computing unit to provide a motor control signal. In the preferred embodiment, the motor control signal is a weighted linear sum of a speed error voltage, a phase error voltage, and a drift error voltage, each of which is computed anew with each revolution of the motor shaft. The stator windings of the motor are driven by two amplifiers which are provided with input signals having the proper quadrature relationship by an exciter unit consisting of a voltage controlled oscillator, a binary counter, a pair of readonly memories, and a pair of digital-to-analog converters.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• Assignee: United States of America as represented by Department of Energy (Washington, DC)
• Patent Number(s): US 4731572
• OSTI ID: 866532
• Country of Publication: United States
• Language: English

Related Subjects

precision
electronic
speed
controller
alternating-current
multi-phase
electrical
motor
subject
inertial
load
developed
particularly
suitable
controlling
neutron
chopper
heavy
spinning
rotor
rotated
phase-locked
synchronism
reference
pulse
train
representative
power
supply
signal
meandering
line
frequency
shaft
revolution
sensor
provides
feedback
internal
digital
timing
generator
compared
computing
unit
provide
control
preferred
embodiment
weighted
linear
error
voltage
phase
drift
computed
anew
stator
windings
driven
amplifiers
provided
input
signals
proper
quadrature
relationship
exciter
consisting
controlled
oscillator
binary
counter
pair
readonly
memories
digital-to-analog
converters
speed control
stator windings
feedback signal
phase error
reference pulse
pulse train
stator winding
reference signal
particularly suitable
control signal
input signals
timing signal
preferred embodiment
power supply
input signal
signal generator
voltage controlled
motor control
spinning rotor
voltage control
digital-to-analog converter
generator provides
phase electric
unit consisting
speed controller
analog converter
precision control
electrical motor
controlled oscillator
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