Long-term Reliability Evaluation of Power Semiconductor Devices used in Power Station Rectifiers and Substation Rectifiers

Abstract

In power stations and substations of electric power companies, power semiconductor devices such as diodes and thyristors have been used in control power supplies and emergency power supplies since the 1970s. Such equipments designed on the assumption that power semiconductor devices are semipermanent, since their service life is much longer than those of capacitors and resistors. Therefore, it is hard to find studies that systematically examine the long-term reliability of semiconductor devices.
Such studies are very important from the viewpoint of assuring reliability and of improving the renewal period by proper equipment maintenance. This paper presents the long-term reliability of power semiconductor devices used in power station rectifiers and substation rectifiers.