摘要 |
A control for an electric motor is utilized to avoid operation in or near the resonance frequencies for the electric motor and its associated system components. The resonance frequencies can be identified experimentally at the design stage, or during operation of a component and electric motor. During start-up, shutdown or frequency adjustment, the control drives the speed through the resonance frequency zones more rapidly, and also avoids operation in or near those resonance frequencies during steady state operation. In disclosed embodiments, the electric motors are associated with fans, pumps and compressors in a refrigerant system.
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