Patent ID: 11929689
Assignee: TOSHIBA MITSUBISHI—ELECTRIC INDUSTRIAL SYSTEMS CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A power conversion device comprising:
a positive input terminal and a negative input terminal connected to an external DC power supply;
a positive arm and a negative arm connected in series between the positive input terminal and the negative input terminal, each of the positive arm and the negative arm including a semiconductor switching element and a diode connected in antiparallel to the semiconductor switching element;
an output terminal connected to a connection point between the positive arm and the negative arm;
a current detection circuitry to detect an output current outputted to the output terminal;
a drive circuitry to drive the semiconductor switching element of each of the positive arm and the negative arm by means of a gate signal; and
a control circuitry to control the gate signal, wherein
the control circuitry includes
a pulse signal generation circuitry to generate a pulse signal on the basis of a voltage command value and a carrier signal,
a dead time application circuitry to add a time width of a dead time to, or subtract the time width from, a pulse width in one pulse signal out of the pulse signal generated by the pulse signal generation circuitry and a pulse signal resulting from reversing the pulse signal, to apply the dead time to only the one pulse signal,
a current polarity detection circuitry to detect, on the basis of the output current detected by the current detection circuitry, a polarity of the output current, and
a gate signal selection circuitry to, if the polarity of the output current detected by the current polarity detection circuitry is positive, select the one pulse signal as a gate signal for the positive arm and select another one of the pulse signals as a gate signal for the negative arm, and, if the polarity of the output current detected by the current polarity detection circuitry is negative, select the one pulse signal as the gate signal for the negative arm and select the other pulse signal as the gate signal for the positive arm.