Ja. Carrasco et al., A conductance-controlled variable transformer turns ratio regulator for a zero-voltage-zero-current power switching converter, IEEE POW E, 14(6), 1999, pp. 1070-1077
This paper describes the application of the conductance control to a very h
igh-efficiency parallel-regulated converter, Conductance control is one of
the best ways of providing simplicity of design while preserving fast dynam
ic response and high reliability in power converters, The parallel regulato
r was conceived for space applications, to regulate a zero-voltage and zero
-current power switching topology that works at constant frequency and cons
tant duty cycle, but its range of applicability can be extended to any kind
of power converter or inverter that utilizes a transformer to produce an i
solated output, By using the concept of addition or subtraction of ac volta
ges, a fully regulated output voltage is achieved, The resultant effect of
this regulation scheme is that the main transformer of the converter or inv
erter appears to have a variable turns ratio, This turns constant can be ch
anged dynamically by means of a conductance control scheme and in almost a
lossless way to maintain the converter (or inverter) outputs.