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US 4,653,285 AGranted
Self-calibrating control methods and systems for refrigeration systems
AssigneeGeneral Electric Company
InventorWalter J. Pohl
Life of this patent
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AssigneeGeneral Electric Company
InventorWalter J. Pohl
Estimating the term…
Disclosed are refrigeration system control systems and methods for compressor motor protection and defrost control. The disclosed systems and methods are generic in the sense that they are self-calibrating and so may be employed in a variety of different air conditioner or heat pump models of different sizes and capacities, without being specifically tailored for a particular model. The disclosed systems and methods sense loading on the compressor and evaporator fan motors, preferably by sensing the voltage across the capacitor-run winding of an AC induction motor and normalizing with respect to line voltage. The self-calibrating capability is implemented by taking advantage of the changing loads as a function of time on both the compressor and fan motors during both normal and abnormal operation of a refrigeration system. In overview, a reference value of motor loading is established for each motor at certain times during an ON cycle. At later times the then-prevailing motor loading is compared to the stored reference in order to provide a basis for control decisions. The ratio of capacitor-run winding voltage to line voltage is an advantageous indicator of motor loading. In one embodiment, a reference ratio of capacitor-run winding voltage to line voltage is established, and at later times is compared to the then-prevailing ratio of capacitor-run winding voltage to line voltage.
A self-calibrating method for protecting a motor driving a refrigerant compressor in a refrigeration system which is cycled ON and OFF during operation, said method comprising:
A self-calibrating method for protecting a single-phase induction motor supplied from an AC power line, of the type including a capacitor-run winding, and driving a refrigerant compressor in a refrigeration system which is cycled ON and OFF during operation, said method comprising:
A self-calibrating control system for a refrigeration system including a refrigerant compressor and a compressor motor for driving the compressor, said control system comprising:
A self-calibrating control system for a refrigeration system including a refrigerant compressor and a compressor motor for driving the compressor, the compressor motor being an AC induction motor of the type including a capacitor-run winding and supplied from an AC power line, said control system comprising:
Dependencies are inferred from the claim text.