ABSTRACT
This chapter presents the major power electronic devices. It examines their operating regimes and modes of operation. The chapter provides their ratings, losses and heat transfer properties. It also examines means of protection. The principal semiconductor material used for power electronic devices is silicon, a member of Group IV of the periodic table elements which means it has four electrons in its outer orbit. The operation of all power semiconductors is limited by a series of ratings which define the operating boundaries of the device. These ratings include limits on the peak, average and RMS currents, the peak forward and reverse voltages for the devices, maximum rates of change of device current and voltage, device junction temperature and, in the case of the thyristor, the gate current limits. For operation at low frequencies a series resistance is usually included in the gate circuit to limit any spurious high frequency currents.
