Motor drive device and electric equipment utilizing the same
AssigneePanasonic Corporation
InventorsYoshinori Takeoka, Hidehisa Tanaka
Life of this patent
Estimating the term…
Abstract
Brushless DC motor (4) is driven based on a first or second waveform signal output from switching determination unit (11), which switches outputting so that a first waveform signal by first waveform generation unit (6) is output when the speed of rotor (4a) is determined to be lower than a predetermined speed, and a second waveform signal by second waveform generation unit (10) is output when the speed of rotor (4a) is determined to be higher than the predetermined speed. Thereby, drive is stable even at high speed/under high load, and a driving range is extended.
Claims11
A motor drive device for driving a brushless DC motor comprising a rotor and a stator having three-phase windings, the motor drive device comprising:
- an inverter for supplying electric power to the three-phase windings;
- a terminal voltage obtaining unit for obtaining a terminal voltage of the brushless DC motor;
- a first waveform generation unit for outputting a first waveform signal that is a waveform having a conduction angle of 120° or more and 150° or less;
- a frequency setting unit for setting a frequency by changing only the frequency while keeping a duty constant;
- a second waveform generation unit for outputting a second waveform signal that is a waveform having a predetermined relation with respect to the terminal voltage obtained by the terminal voltage obtaining unit, the frequency set by the frequency setting unit, and a conduction angle of 120° or more and less than 180°;
- a switching determination unit for switching output so that the first waveform signal is output when a speed of the rotor is determined to be lower than a predetermined speed, and the second waveform signal is output when the speed of the rotor is determined to be higher than the predetermined speed;
- and
- a drive unit for outputting a drive signal to the inverter indicating a supplying timing of electric power supplied to the three-phase windings based on one of the first and the second waveform signals output from the switching determination unit.
Dependencies are inferred from the claim text.