| 摘要 |
PROBLEM TO BE SOLVED: To reduce a switching loss while simplifying a control configuration in a motor driving device which controls an inverter according to a PWM switching system.SOLUTION: A motor driving circuit comprises an inverter bridge circuit and a motor control circuit which performs PWM control on a switching element of the inverter bridge circuit in such a manner that a three-phase current that flows in a three-phase motor becomes a sinusoidal three-phase current waveform. The motor control circuit performs the control by switching a three-phase control system and a two-phase control system at intervals of 60°. According to the three-phase control system, an on interval and an off interval are set to phases of upper and lower arms. According to the two-phase control system, an always-on interval is set to one of U, V and W phases in any one of the upper and lower arms and an always-off interval is set to the one phase in the other arm. When switching the three-phase control system and the two-phase control system, the on interval and the always-on interval are controlled to be continued and the off interval and the always-off interval are controlled to be continued. |
