Motor drive system and method
AssigneeFranklin Electric Co., Inc.
InventorsJason L. Coney, Jared E. Evans, Lyon van der Merwe
Life of this patent
Estimating the term…
Abstract
A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes powering the electric motor with a motor drive; driving a progressive cavity pump with the electric motor; monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor; and performing a protective action as a function of the speed difference.
Claims20
A method of operating an electric motor, the method comprising:
- powering the electric motor with a motor drive;
- driving a progressive cavity pump with the electric motor;
- monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor;
- and
- performing a protective action as a function of the speed difference,
- wherein performing the protective action as a function of the speed difference comprises performing the protective action responsive to the speed difference remaining:
- (A) below a speed difference corresponding to a minimum power boundary as a function of the observed speed, for a first time period, or
- (B) above a speed difference corresponding to a maximum torque boundary as a function of the observed speed, for a second time period.
A method of operating an electric motor, the method comprising:
- powering the electric motor with a motor drive;
- driving a progressive cavity pump with the electric motor;
- monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor;
- performing a protective action as a function of the speed difference, wherein performing the protective action as a function of the speed difference comprises:
- monitoring a maximum torque boundary between the observed speed and the speed difference;
- and
- performing the protective action responsive to the speed difference remaining above the maximum torque boundary at any corresponding observed speed for a second time period.
A method of operating an electric motor, the method comprising:
- powering the electric motor with a motor drive;
- driving a progressive cavity pump with the electric motor;
- monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor;
- and
- performing a protective action as a function of the speed difference,
- wherein performing the protective action as a function of the speed difference comprises:
- monitoring a safe operating zone defined by boundaries consisting of a minimum speed limit, a maximum speed limit, a maximum torque boundary, and a minimum power boundary;
- and
- if the speed difference is below the maximum speed difference, performing the protective action responsive to the speed difference and the observed speed indicating that one of the boundaries has been crossed for a time period corresponding to the one of the boundaries that has been crossed.
A motor drive configured to operate a progressive cavity pump in a water pumping system, the motor drive comprising a controller configured to perform a method comprising:
- powering an electric motor with the motor drive;
- driving the progressive cavity pump with the electric motor;
- monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor;
- and
- performing a protective action as a function of the speed difference,
- wherein performing a protective action as a function of the speed difference comprises:
- monitoring a safe operating zone defined by boundaries consisting of a minimum speed limit, a maximum speed limit, a maximum torque boundary, and a minimum power boundary;
- and
- if the speed difference is below the maximum speed difference, performing the protective action responsive to the speed difference and the observed speed indicating that one of the boundaries has been crossed for a time period corresponding to the one of the boundaries that has been crossed.
Dependencies are inferred from the claim text.