Speed Control of Variable-Speed Multiple-Phase Motors
AssigneeEmerson Electric Co.
InventorsPing Shan, Cai Bing Zhang
Life of this patent
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Abstract
Exemplary embodiments or implementations are disclosed of methods, apparatus, and systems for operating motors in variable speed situations. In an exemplary implementation, a method of controlling a variable-speed motor includes defining a control duration as a predetermined number of cycles of a multiple-phase power supply. Each speed in a range of speeds is defined by a corresponding number of the cycles of the control duration. Power is provided to the motor from the power supply at a selected one of the speeds, by enabling input from the power supply for the number of the cycles of the control duration corresponding to the selected speed.
Claims15
A method of controlling a variable-speed motor, the method comprising:
- defining a control duration as a predetermined number of cycles of a multiple-phase power supply;
- defining each speed in a range of speeds by a corresponding number of the cycles of the control duration;
- and
- providing power to a motor from the multiple-phase power supply at a selected one of the speeds, by enabling input from the multiple-phase power supply for the number of the cycles of the control duration corresponding to the selected speed.
A method of controlling a variable-speed motor, the method comprising:
- using a frequency of a multiple-phase power supply to define a control duration having a fixed number of cycles;
- defining each of a plurality of speeds as a corresponding number of the cycles of the control duration;
- and
- providing power to a motor from the multi-phase power supply at a selected one of the plurality of speeds, by driving a signal configured in accordance with the frequency to enable input from lines of the multi-phase power supply for the number of cycles of the control duration corresponding to the selected speed.
A system for controlling a variable-speed motor, the system comprising:
- a controller configured to provide a driver signal configured in accordance with a frequency of a multiple-line, multiple-phase power supply to a motor;
- and
- an interface circuit between an input and load of each line, each interface circuit configured to detect zero crossings in the corresponding line, and to enable or disable power through the corresponding line at the zero crossings based on the driver signal.
Dependencies are inferred from the claim text.