Contents I. Introduction
In the past, single-phase to three-phase conversion systems were made possible by the connection of passive elements (capacitors and reactors) with autotransformer converters [1]–[3]. Such kind of system presents well-known disadvantages and limitations [3]. In those days, power electronics with silicon power diodes and thyristors was just emerging. As described in [4], the so-called power electronics, with gas tube and glass-bulb electronics, was known as industrial electronics, and the power electronics with silicon-controlled rectifiers began emerging in the market from the early 1960s.
