Method and apparatus for speed reversal control of motor drive
First Claim
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1. A method for speed reversal control in a motor drive with an inverter driving a motor through an output filter and a transformer to reverse rotation of the motor from a first direction to an opposite second direction, the method comprising:
- generating pulse width modulation control signals to operate the inverter to drive the motor according to a high or maximal drive current command using closed loop control while the motor is rotating in the first direction at a motor frequency having an absolute value greater than a predetermined threshold frequency; and
generating pulse width modulation control signals to operate the inverter to drive the motor using open loop control according to the high or maximal drive current command while the motor is rotating in the first direction at a motor frequency having an absolute value less than or equal to the predetermined threshold frequency to transition the motor speed through zero to reverse rotation of the motor from the first direction to the second direction.
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Abstract
Motor drive control apparatus and methods are presented for speed reversal control for drives used with output filters and transformers using a high or maximal drive current command to facilitate dissipation of regenerative energy seen in this system during speed reversal with open loop control to reverse the spin direction of a driven motor while quickly transitioning through zero speed.
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Citations
18 Claims
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1. A method for speed reversal control in a motor drive with an inverter driving a motor through an output filter and a transformer to reverse rotation of the motor from a first direction to an opposite second direction, the method comprising:
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generating pulse width modulation control signals to operate the inverter to drive the motor according to a high or maximal drive current command using closed loop control while the motor is rotating in the first direction at a motor frequency having an absolute value greater than a predetermined threshold frequency; and generating pulse width modulation control signals to operate the inverter to drive the motor using open loop control according to the high or maximal drive current command while the motor is rotating in the first direction at a motor frequency having an absolute value less than or equal to the predetermined threshold frequency to transition the motor speed through zero to reverse rotation of the motor from the first direction to the second direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A non-transitory computer readable medium with computer executable instructions for:
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generating pulse width modulation control signals to operate an inverter circuit to drive a motor according to a high or maximal drive current command using closed loop control while the motor is rotating in a first direction at a motor frequency having an absolute value greater than a predetermined threshold frequency; and generating pulse width modulation control signals to operate the inverter circuit to drive the motor using open loop control according to the high or maximal drive current command while the motor is rotating in the first direction at a motor frequency having an absolute value less than or equal to the predetermined threshold frequency to transition the motor speed through zero to reverse rotation of the motor from the first direction to an opposite second direction. - View Dependent Claims (11, 12, 13)
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14. A power conversion system, comprising:
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an inverter comprising a plurality of switching devices operative according to pulse width modulated inverter switching control signals to convert DC power to drive an AC motor load through an output filter and a transformer; and a controller (20) including at least one processor operatively coupled with an electronic memory, the at least one processor programmed to reverse rotation of the motor from a first direction to an opposite second direction by; generating the pulse width modulated inverter switching control signals to drive the motor at least partially according to a high or maximal drive current command using closed loop control while the motor is rotating in the first direction at a motor frequency having an absolute value greater than a predetermined threshold frequency; and generating the pulse width modulated inverter switching control signals to drive the motor using open loop control according to the high or maximal drive current command while the motor is rotating in the first direction at a motor frequency having an absolute value less than or equal to the predetermined threshold frequency to transition the motor speed through zero to reverse rotation of the motor from the first direction to the second direction. - View Dependent Claims (15, 16, 17, 18)
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Specification