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US 8,134,316 B2Granted
Method for braking an AC motor
AssigneeSiemens Industry, Inc.
InventorsRichard H. Osman, Mukul Rastogi
Life of this patent
Estimating the term…
Abstract
A system for braking a motor. The system includes at least one resistor and a contactor connected to the at least one resistor and a motor. The system further includes a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises a controller operably connected to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to a command from the controller. The variable frequency drive is configured such that motor flux levels may be maintained at a relatively high level as motor torque current is reduced, resulting in a consistently high motor flux level as the motor speed decreases.
Claims16
A system for braking a motor, comprising:
- at least one resistor;
- a contactor connected to the at least one resistor and a motor;
- and
- a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises:
- a motor model configured to receive one or more inputs and produce a plurality of first outputs,
- a speed regulator operably connected to the motor module and configured to process at least a portion of the plurality of first outputs to produce a second output,
- a flux regulator operably connected to the motor model and configured to process at least a portion of the plurality of first outputs to produce a third output,
- a torque current regulator operably connected to the motor model and configured to process at least a portion of the plurality of first outputs and the second output to produce a first reference voltage, and
- a magnetizing current regulator operably connected to the motor model and configured to process at least a portion of the plurality of first outputs and the third output to produce a second reference voltage;
- and
- a controller operably connected to the contactor and the variable frequency drive and configured to:
- load instructions for braking the motor based upon at least the first reference voltage and the second reference voltage, and
- bases upon the loaded instruction, issue a braking command to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to the braking command from the controller.
10 more elements
A method for braking a motor, the method comprising:
- detecting, by a variable frequency drive, a reduction in speed demand, wherein the reduction initiates deceleration of an motor and wherein the detecting comprises:
- producing, by a motor model, a plurality of first outputs based upon one or more received inputs,
- producing, by a speed regulator operably connected to the motor model, a second output based upon at least a portion of the plurality of first outputs,
- producing, by a flux regulator operably connected to the motor model, a third output based upon at least a portion of the plurality of first outputs,
- producing, by a torque current regulator operably connected to the motor model, a first reference voltage based processing at least a portion of the plurality of first outputs and the second output,
- producing, by a magnetizing current regulator operably connected to the motor model, a second reference voltage based processing at least a portion of the plurality of first outputs and the third output, and
- loading, at a controller operably connected to the variable frequency drive, instructions for braking a motor based upon at least the first reference voltage and the second reference voltage;
- issuing a command by the variable frequency drive to close at least one contactor, wherein the closed contactor connects a resistor bank to the motor;
- and
- absorbing, by the resistor bank, deceleration current generated by the motor.
7 more elements
A system for braking a motor, the system comprising:
- a resistor bank having a plurality of phases;
- a contactor connected to the resistor bank and a motor, the contactor having a plurality of phases, wherein each phase of the contactor is connected to one phase of the resistor bank;
- and
- a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises:
- a motor model configured to receive one or more inputs and produce a plurality of first outputs,
- a speed regulator operably connected to the motor module and configured to process at least a portion of the plurality of first outputs to produce a second output,
- a flux regulator operably connected to the motor model and configured to process at least a portion of the plurality of first outputs to produce a third output,
- a torque current regulator operably connected to the motor model and configured to process at least a portion of the plurality of first outputs and the second output to produce a first reference voltage, and
- a magnetizing current regulator operably connected to the motor model and configured to process at least a portion of the plurality of first outputs and the third output to produce a second reference voltage;
- and
- a controller operably connected to the contactor and the variable frequency drive and configured to:
- load instructions for braking the motor based upon at least the first reference voltage and the second reference voltage, and
- bases upon the loaded instruction, issue a braking command to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to the braking command from the controller.
10 more elements
Dependencies are inferred from the claim text.