According to statistics, pomping unit in oilfields are working at empty situation withmotor running under light load, so make the motor efficiency and power factor toolower, cause a large amount of electric energy wasting. With Fuzzy control theory andadopting the working voltage of motor the line voltage of pump unit’s motor is a regulated byreal time phase–shift control. While meeting the usual running, the working efficiency andpower factor are improved, so as to save the electric energy. Moreover, the device willnot chang the rotational speed of the motor, during the whole work period of pumping theoil, and do not influent the petroleum production efficiency of the oil pumping machine.The device has the functions of starting softly, lacking phase, overload protection and so on.It is the ideal device of motor controling in the oil field, and has the extensive usingvalue. |