초록 ▼

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 differ

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.

대표청구항 ▼

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: determining a compressor motor reference loading at a relatively early time during a compressor ON cycle by allowing a stab

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: determining a compressor motor reference loading at a relatively early time during a compressor ON cycle by allowing a stabilization interval to elapse during which the refrigeration system stabilizes and the compressor motor is still lightly loaded, and then sensing and storing at least a representation of compressor motor loading as the reference loading; and thereafter, during each ON cycle, at least periodically sensing at least a representation of prevailing compressor motor loading, comparing the prevailing loading to the reference loading, and de-energizing the compressor motor if the prevailing loading exceeds a high load threshold loading established as a predetermined function of the reference loading.