초록 ▼

An AC Motor Speed Controller used to control the Speed, Torque and Horsepower of an AC motor. It allows the speed of the motor to be adjusted to the desired level and is calibrated to develop the desired torque, either automatically through load feedback or through a predetermined or preset level. I

An AC Motor Speed Controller used to control the Speed, Torque and Horsepower of an AC motor. It allows the speed of the motor to be adjusted to the desired level and is calibrated to develop the desired torque, either automatically through load feedback or through a predetermined or preset level. It also allows for excessive torque to be developed under starting and acceleration conditions while providing for controlled deceleration with proportional braking of the inertia load.

대표청구항 ▼

In a speed and torque controller for an AC motor having at least one winding and wherein power from a source of high DC voltage power is applied to the winding through power switches whose conduction intervals are controlled by pulse duratoin variable pulses with the power switches coupled to the wi

In a speed and torque controller for an AC motor having at least one winding and wherein power from a source of high DC voltage power is applied to the winding through power switches whose conduction intervals are controlled by pulse duratoin variable pulses with the power switches coupled to the winding and with the enabling of the power switches being controlled by a square wave whose frequency is representative of a desired speed of the AC motor and with the duration of the variable pulses, during which current is supplied to the winding by the power switches, being representative of a desired output voltage to the winding of the AC motor, the improvement comprising: means which is DC coupled to said AC motor winding for producing a feedback signal representative of the output voltage to said AC motor winding: means for producing and storing a plurality of values representative of output voltages as a function of said feedback voltage and producing a feedback signal that is linearized with respect to frequency in response to said feedback voltage; means responsive to the linearized feedback signal for establishing a desired duration of the duration variable pulses, commensurate with the frequency of the square wave signals and a desired voltage per hertz relationship at the AC motor winding; means for determining whether the AC motor speed is within a low speed boost region and producing a low speed signal indicative thereof; and means responsive to the low speed signal for generating a boost signal representative of a desired output voltage to the AC motor winding, said boost signal generating means including means for producing a plurality of look-up tables composed of values for the boost signal at predetermined speed ranges of the AC motor.