초록 ▼

A motor driver includes an inverter having at least one arm including two series-connected switching elements and converting a direct current to an alternating current to supply the alternating current to an electric motor, a booster circuit connected between the inverter and a DC power supply and i

A motor driver includes an inverter having at least one arm including two series-connected switching elements and converting a direct current to an alternating current to supply the alternating current to an electric motor, a booster circuit connected between the inverter and a DC power supply and including a reactor, a switching element and a reverse-flow preventing diode, the booster circuit supplying the direct current from the DC power supply to the inverter, a current detector for detecting current flowing into the booster circuit, a speed detector for detecting a rotational speed of the motor, and a controller for comparing a speed value detected by the speed detector with a set speed value, thereby determining a command value. The controller controls the inverter on the basis of the command value by pulse width modulation and further controls the booster circuit pulse width modulation so that the booster circuit executes a voltage boosting operation and the current detector so that the detected current value does not exceed an upper limit value.

대표청구항 ▼

[ We claim:] [1.] A driver for an electric motor comprising:an inverter having at least one arm including two switching elements connected in series, the inverter converting a direct current to an alternating current to supply the alternating current to the motor;a booster circuit connected between

[ We claim:] [1.] A driver for an electric motor comprising:an inverter having at least one arm including two switching elements connected in series, the inverter converting a direct current to an alternating current to supply the alternating current to the motor;a booster circuit connected between the inverter and a DC power supply and including a reactor, a switching element and a diode to prevent a reverse current, the booster circuit supplying the direct current from the DC power supply to the inverter;a current detecting element which detects current flowing into the booster circuit;a speed detecting element which detects a rotational speed of the motor; anda controller comparing a speed value detected by the speed detecting element with a set speed value to determine a command value, the controller controlling the inverter on the basis of the command value by pulse width modulation and further controlling the booster circuit by pulse width modulation, wherein the booster circuit carries out a voltage boosting operating to prevent the current value from exceeding an upper limit value in the booster circuit.