| 摘要 |
A fuzzy logic control circuit is employed to vary the rate of refrigerant liquid injection for cooling the motor (20) of an air conditioning compressor (10). Control is based on the temperature of the motor and another measurable operating condition. The temperature deviations are grouped, rather than treated proportionately or gradually. The controller response to a given temperature deviation depends on the other operating condition. In a preferred mode, the other operating condition is the rate that the motor is heating up or cooling down. In a preferred embodiment, the control circuit determines the duty cycle for the solenoid valve (44) according to a matrix of five columns by five rows. This control scheme maintains the motor temperature within about 25 DEG F of setpoint over a wide range of load conditions. <IMAGE> |
