Patent ID: 11863104
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  A | IPC A  H

Claim 0:
1. A motor drive device comprising
an inverter including a first arm and a second arm, the first arm being defined by a first upper-arm switching element and a first lower-arm switching element connected in series with the first upper-arm switching element, the second arm being defined by a second upper-arm switching element and a second lower-arm switching element connected in series with the second upper-arm switching element, the second arm being connected in parallel with the first arm, the inverter converting a direct-current voltage output from a direct-current power supply into an alternating-current voltage, and outputting the alternating-current voltage as a motor applied voltage to be applied to a single-phase motor, wherein
the motor applied voltage has a high level, low level, or zero level potential,
a set of the first upper-arm switching element and the first lower-arm switching element and a set of the second upper-arm switching element and the second lower-arm switching element generate the motor applied voltage by being alternately placed in off states for each half cycle of a power supply, and
in brake control to reduce a rotation speed of the single-phase motor, the first upper-arm switching element and the second upper-arm switching element are turned off, and the first lower-arm switching element and the second lower-arm switching element are turned on while the rotation speed of the single-phase motor is reduced in such a manner as to widen a section in which a potential of the motor applied voltage is zero level.