| 主权项 |
1. A power conversion apparatus comprising:
an inverter unit having a plurality of high-potential-side switching elements disposed on a high-potential side and a plurality of low-potential-side switching elements disposed on a low-potential side, each of the high-potential-side switching elements and the low-potential-side switching elements corresponding to one of a plurality of phases of a winding of a rotating electrical machine; a current detecting unit connected between the inverter unit and a positive side or a negative side of a DC power supply; and a control unit controlling an on-operation and an off-operation of the high-potential-side switching elements and the low-potential-side switching elements based on a PWM reference signal and a duty instruction value, wherein the control unit includes:
a phase current computing device computing a phase current of each phase, which flows through one of phases of the winding, based on a current detection value detected by the current detecting unit; anda voltage instruction value computing device computing a voltage instruction value, which relates to a voltage applied to the winding, based on the phase current of each phase, wherein the control unit computes an active voltage vector interval in both a first-half period and a second half period of predetermined one cycle or multiple cycles of the PWM reference signal to be longer or equal to a predetermined period required to obtain the current detection value, wherein the control unit computes a first-half duty instruction value and a second-half duty instruction value as a duty instruction value based on the voltage instruction value in such a manner that a first voltage vector interval and a second voltage vector interval are equal to or longer than minimum time, and the first voltage vector interval and the second voltage vector interval are included in at least one of the first-half period and the second-half period, wherein, in the first voltage vector interval, the low-potential-side switching elements of all of the phases turn on, wherein, in the second voltage vector interval, the high-potential-side switching elements of all of the phases turn on, wherein the minimum time is equal to or longer than a dead time period, and wherein, in the dead time period, both one high-potential-side switching element and one low-potential-side switching element corresponding to a same phase of the winding are turned off. |
