A superposition principle of waveform based on conceptions of waveform continuity and flexible regulation of voltage proposes three concepts, respectively being flexible AC transformation, flexible power transmission and transformation and flexible voltage regulation; proposes three new technologies, respectively being a transient impedance technology, a flexible stepless voltage regulation technology and a flexible stepped voltage regulation technology; proposes three new products, being an AC voltage regulating electronic switch, a transient impedance transformer and a high-speed voltage regulating transformer; proposes six high-voltage power grid connection methods, being a power grid connection method type of a transient impedance transformer, a power grid connection method of a transient impedance step up auto transformer and the like; and proposes a new reactive compensation connection method for a reactive compensation device to be in series or parallel connections at a terminal of a secondary outgoing
