Title:
CONTROL OF INVERTER
Document Type and Number:
Japanese Patent JPS5558782
Kind Code:
A
Abstract:
PURPOSE:To apply an inverse-polarity voltage to thyristors and improve efficiency to a higher frequency region by turning on one of two pairs of electric valves provided on positive and negative dc bus lines at the time of commutation of the thyristors which supply ac to a load. CONSTITUTION:Electric valves 2 and 3 are connected to a dc power supply so that they are turned off when a thyristor bridge 4 is commutated, and electric valves 11 and 12 are provided to discharge a capacitor 9. When thyristors S1-S3 are on and S2 and S4 are going to be turned on after commutation, a current level sensor 16 operates, the electric valve 2 is turned off, and the electric valve 3 is turned on by a logic circuit; and when electric valves 11 and 12 are turned on, the capacitor 9 is discharged, an inverse voltage is applied to S1, S3, and S5, and blocking ability is quickly restored. When S2 and S4 are on and S3 and S5 are going to be turned on after commutation, the same function is performed. In this constitution the period for restoring the thyristors are greatly shortened and efficiency is improved even in a higher frequency region.
Inventors:
UKAI ISAMU
Application Number:
JP13041678A
Publication Date:
May 01, 1980
Filing Date:
October 25, 1978
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H02M7/515; (IPC1-7): H02M7/515