초록 ▼

Motor control apparatus for controlling the speed of a motor as a function of a variable frequency square wave and chopping pulses. The chopping pulses are cut off at some value greater than zero pulse width which causes motor voltage to increase in a step manner thus causing a feed forward voltage

Motor control apparatus for controlling the speed of a motor as a function of a variable frequency square wave and chopping pulses. The chopping pulses are cut off at some value greater than zero pulse width which causes motor voltage to increase in a step manner thus causing a feed forward voltage signal which is related to a DC rectified voltage which cooperates with the square wave production system to increase accordingly. A hysteresis circuit is provided within the pulse generating means to guarantee that once the pulse generation has stopped it will not increase again as a result of the aforementioned motor voltage rise.

대표청구항 ▼

Apparatus for controlling the speed of a motor, comprising: a source of direct electrical current (PWB) having a nominal DC source voltage (VS) which may vary within limits; inverter means (INV) interconnected with said source and the motor (M) for providing controlled power to the motor in the form

Apparatus for controlling the speed of a motor, comprising: a source of direct electrical current (PWB) having a nominal DC source voltage (VS) which may vary within limits; inverter means (INV) interconnected with said source and the motor (M) for providing controlled power to the motor in the form of controlled variable frequency square waves (VAB), said square waves being chopped in accordance with controlled width-modulated chopping pulses in a predetermined square wave frequency range (CONSTANT TORQUE) for providing speed control and complementary motor winding voltage control in said frequency range, said inverter means being unreliable for producing width-modulated chopping pulses which are narrower than a predetermined minimum pulse width; control means (PWM) interconnected with said source and said inverter means for providing controlled signals to said inverter means indicative of the frequency of said square waves and for providing said chopping pulses to said inverter means in accordance with a speed signal (VCOM) and a DC source voltage feed forward signal (VLINK), said control means, comprising: pulse generator means (PG) interconnected to receive VCOM and VLINK as inputs for producing said chopping pulses the width of which is proportional to (VLINK-VCOM) for only those values of VCOM less than VLINK, for values of VCOM equal to or greater than VLINK no pulses being produced; hysteresis switching means (HS) interconnected to receive VCOM and VLINK as inputs and interconnected with said pulse generator means to selectively provide as an additional input for said pulse generator means a bias signal (DDDD