The power modules – this is transistor, thyristor, thyristor-diode and diode modules. The diode modules, depending on the type of used diodes, can be based on fast-recovery diodes, Schottky diodes or rectifying diodes; the last one is installed in pair with thyristors. The transistor diodes are also divided by type of the used transistor: either MOSFET-transistors, or IGBT-transistors. The first ones are intended to operate in rectifiers with peak voltage up to 200 V, the second ones – from 600 V to 6500 V.