POWER CONVERSION DEVICE

摘要

An electric power conversion device comprises a conversion circuit having bi-directionally switchable plural pairs of switching elements connected to respective phases and converting an inputted AC power into an AC electric power. A first switching time is calculated using detected voltages detected by voltage sensors and an output command value. A second switching time is calculated using a carrier and the calculated first switching time. The second switching time is such that, in one period of the alternating current electric power outputted from the conversion circuit, the second switching time included in a first half period of the one period is equal to the second switching time included in a second half period of the one period.

主权项

1. An electric power conversion device, comprising:
a conversion circuit having plural pairs of bi-directionally switchable switching elements connected to respective phases, the conversion circuit being configured to convert an inputted alternating current electric power into an alternating current electric power; voltage detecting means for detecting input voltages to the conversion circuit; and control means for switching on and off of the switching elements to control the conversion circuit,wherein the control means comprises:
a switching time calculating section configured to calculate a first switching time during which one of the switching elements of an upper arm circuit of the plural pairs of switching elements included in one phase from among the respective phases is turned on, the other switching elements of the upper arm circuit of the plural pairs of switching elements included in the other phases are turned off, at least one switching element of a lower arm circuit of the plural pairs of switching elements included in the other phases is turned on, and the other switching elements of the lower arm circuit of the plural pairs of switching elements included in the one phase are turned off using the detected voltages detected by the voltage detecting means and an output command value and to calculate a second switching time during which the plural pairs of switching elements included in the one phase from among the respective phases are turned on and the plural pairs of switching elements included in the other phases from among the respective phases are turned off using the carrier and the first switching time; and a control signal generating section configured to generate control signals to switch on and off of the switching elements using the first switching time and the second switching time, and wherein the second switching time is such that, in one period of the alternating current electric power outputted from the conversion circuit, the second switching time included in a first half period of the one period is equal to the second switching time included in a second half period of the one period.