Control system for controlling revolution speed of electric motor
Patent 5155797 Issued on October 13, 1992. Estimated Expiration Date: 
October 13, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 13, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesPower control of a stalling motor Method and apparatus for controlling the energization of an electric motor Motor speed control system Microprocessor-based control apparatus for a direct current machine drive system Motor speed controller Tire curing press Patent #: 4698003 InventorsAssigneeApplicationNo. 322250 filed on 03/10/1989US Classes:388/815, By voltage or current modification318/799, Responsive to speed or rotation phase angle318/801, Including inverter388/902CompensationExaminersPrimary: Shoop, William M. Jr.Assistant: Martin, David Attorney, Agent or FirmForeign Patent References
International ClassH02P 005/00Foreign Application Priority Data1987-09-08 JPAbstractA motor speed control system takes one approach to establish dummy load models having characteristics equivalent to an electric motor to be controlled. One of the dummy load models is established for feedback controlling the electric motor on the basis of the speed of the dummy model. The dummy model is divided into first and second models. The first model is designed to have equivalent characteristics to output a first motor speed representative data. The current to supply to the first model is so adjusted as to reduce a difference between the motor speed representative data and a desired motor speed data to zero. A frequency signal is added to the current applied to the first model and supplied to the electric motor to drive the latter. The second model receives the frequency signal to output a frequency signal dependent second motor speed representative value. Sum of the first and second motor speed representative value is compared with a measured motor speed indicative value to derive a speed difference compensation value based on the error therebetween. Based on the speed difference between the sum value and the measured motor speed and the frequency signal, inertia condition on the motor is assumed for controlling transfer characteristics so that the inertia condition in the first model becomes coincident with that of the motor.Other References
Field of SearchLoad or torqueBy voltage or current modification By phase or frequency modification Compensation INDUCTION MOTOR SYSTEMS Power-factor control With commutated winding Slipping and/or racing control for electric motors Responsive to motor condition Responsive to speed or rotation phase angle With controlled power conversion Including inverter Responsive to an additional condition With controlled a.c. to d.c. circuit in inverter supply With controlled magnetic reactance Responsive to motor voltage | |
